Professor, Director of the Laboratory
Courses
- Digital DesignHY1101st semester · Core
- Graph TheoryMA1504th semester · Elective
- Social Network AnalysisME1406th semester · Elective, DTDA track
Publications
Journal Articles
Stavropoulou, G., Tsitseklis, K., Mavraidi, L., Chang, K. I., Zafeiropoulos, A., Karyotis, V., & Papavassiliou, S. (2024). Digital Twin Meets Knowledge Graph for Intelligent Manufacturing Processes. Sensors, 24(8). https://doi.org/10.3390/s24082618
@article{Stavropoulou2024,
title = {Digital Twin Meets Knowledge Graph for Intelligent Manufacturing Processes},
author = {G. Stavropoulou and K. Tsitseklis and L. Mavraidi and K. -I. Chang and A. Zafeiropoulos and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85191412428&doi=10.3390%2fs24082618&partnerID=40&md5=cf5b51c8b7dcd4b785279973b67a7847},
doi = {10.3390/s24082618},
issn = {14248220},
year = {2024},
date = {2024-01-01},
urldate = {2024-01-01},
journal = {Sensors},
volume = {24},
number = {8},
publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},
abstract = {In the highly competitive field of material manufacturing, stakeholders strive for the increased quality of the end products, reduced cost of operation, and the timely completion of their business processes. Digital twin (DT) technologies are considered major enablers that can be deployed to assist the development and effective provision of manufacturing processes. Additionally, knowledge graphs (KG) have emerged as efficient tools in the industrial domain and are able to efficiently represent data from various disciplines in a structured manner while also supporting advanced analytics. This paper proposes a solution that integrates a KG and DTs. Through this synergy, we aimed to develop highly autonomous and flexible DTs that utilize the semantic knowledge stored in the KG to better support advanced functionalities. The developed KG stores information about materials and their properties and details about the processes in which they are involved, following a flexible schema that is not domain specific. The DT comprises smaller Virtual Objects (VOs), each one acting as an abstraction of a single step of the Industrial Business Process (IBP), providing the necessary functionalities that simulate the corresponding real-world process. By executing appropriate queries to the KG, the DT can orchestrate the operation of the VOs and their physical counterparts and configure their parameters accordingly, in this way increasing its self-awareness. In this article, the architecture of such a solution is presented and its application in a real laser glass bending process is showcased. © 2024 by the authors.},
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pubstate = {published},
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In the highly competitive field of material manufacturing, stakeholders strive for the increased quality of the end products, reduced cost of operation, and the timely completion of their business processes. Digital twin (DT) technologies are considered major enablers that can be deployed to assist the development and effective provision of manufacturing processes. Additionally, knowledge graphs (KG) have emerged as efficient tools in the industrial domain and are able to efficiently represent data from various disciplines in a structured manner while also supporting advanced analytics. This paper proposes a solution that integrates a KG and DTs. Through this synergy, we aimed to develop highly autonomous and flexible DTs that utilize the semantic knowledge stored in the KG to better support advanced functionalities. The developed KG stores information about materials and their properties and details about the processes in which they are involved, following a flexible schema that is not domain specific. The DT comprises smaller Virtual Objects (VOs), each one acting as an abstraction of a single step of the Industrial Business Process (IBP), providing the necessary functionalities that simulate the corresponding real-world process. By executing appropriate queries to the KG, the DT can orchestrate the operation of the VOs and their physical counterparts and configure their parameters accordingly, in this way increasing its self-awareness. In this article, the architecture of such a solution is presented and its application in a real laser glass bending process is showcased. © 2024 by the authors.
Dimitriou, P., & Karyotis, V. (2024). Empowering Random Walk Link Prediction Algorithms in Complex Networks by Adapted Structural Information. IEEE Access, 12, 45044-45059. https://doi.org/10.1109/ACCESS.2024.3381510
@article{Dimitriou202445044,
title = {Empowering Random Walk Link Prediction Algorithms in Complex Networks by Adapted Structural Information},
author = {P. Dimitriou and V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85189142829&doi=10.1109%2fACCESS.2024.3381510&partnerID=40&md5=87890e22714752dd52338e7a791b1f94},
doi = {10.1109/ACCESS.2024.3381510},
issn = {21693536},
year = {2024},
date = {2024-01-01},
journal = {IEEE Access},
volume = {12},
pages = {45044-45059},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In the link prediction problem a relevant algorithm running over a network attempts to determine whether a link between two nodes will exist in the future, given that it is not present at the moment. Most link prediction algorithms take into account the structure of the network on which they are applied and based on this, they attempt to predict the existence or not of future new edges in the network. However, many of them are quite standardized, applying the same concept and parametrization to all networks, thus not always achieving good results in every different network structure. Algorithms based on Graph Neural Networks (GNNs) are more adaptive to any network structure but they do not give appreciable results when the only information available is the network structure. In this paper, we propose a new approach to this problem that approximates the structure of a complex network by allowing adjusted weight to this network structure to create additional information, which we can embed into effective algorithms such as local and superposed random walk link prediction. To achieve this goal, we use well-known kernel functions such as Sigmoids, in which we fit their parameters appropriately by a genetic algorithm to achieve the best possible approximation. To demonstrate the effectiveness of our proposed method we have compared our prediction method results based on precision, AUC and AUPR on eleven selected networks of different structures and properties with seven well-known link prediction algorithms and one more utilizing GNNs. In every case, we have improved the results of random walk algorithms and in most cases we achieved better results from all employed benchmark algorithms. © 2013 IEEE.},
note = {cited By 0},
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pubstate = {published},
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In the link prediction problem a relevant algorithm running over a network attempts to determine whether a link between two nodes will exist in the future, given that it is not present at the moment. Most link prediction algorithms take into account the structure of the network on which they are applied and based on this, they attempt to predict the existence or not of future new edges in the network. However, many of them are quite standardized, applying the same concept and parametrization to all networks, thus not always achieving good results in every different network structure. Algorithms based on Graph Neural Networks (GNNs) are more adaptive to any network structure but they do not give appreciable results when the only information available is the network structure. In this paper, we propose a new approach to this problem that approximates the structure of a complex network by allowing adjusted weight to this network structure to create additional information, which we can embed into effective algorithms such as local and superposed random walk link prediction. To achieve this goal, we use well-known kernel functions such as Sigmoids, in which we fit their parameters appropriately by a genetic algorithm to achieve the best possible approximation. To demonstrate the effectiveness of our proposed method we have compared our prediction method results based on precision, AUC and AUPR on eleven selected networks of different structures and properties with seven well-known link prediction algorithms and one more utilizing GNNs. In every case, we have improved the results of random walk algorithms and in most cases we achieved better results from all employed benchmark algorithms. © 2013 IEEE.
Kakkavas, G., Fryganiotis, N., Karyotis, V., & Papavassiliou, S. (2024). Generative Deep Learning Techniques for Traffic Matrix Estimation from Link Load Measurements. IEEE Open Journal of the Communications Society, 5, 1029-1046. https://doi.org/10.1109/OJCOMS.2024.3358740
@article{Kakkavas20241029,
title = {Generative Deep Learning Techniques for Traffic Matrix Estimation from Link Load Measurements},
author = {G. Kakkavas and N. Fryganiotis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85183941616&doi=10.1109%2fOJCOMS.2024.3358740&partnerID=40&md5=bbc1e767cb9b5d8bf30cadd9973dd81a},
doi = {10.1109/OJCOMS.2024.3358740},
issn = {2644125X},
year = {2024},
date = {2024-01-01},
journal = {IEEE Open Journal of the Communications Society},
volume = {5},
pages = {1029-1046},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Traffic matrices (TMs) contain crucial information for managing networks, optimizing traffic flow, and detecting anomalies. However, directly measuring traffic to construct a TM is resource-intensive and computationally expensive. A more practical approach involves estimating the TM from readily available link load measurements, which falls under the category of inferential network monitoring based on indirect measurements known as network tomography. This paper focuses on solving the problem of estimating the traffic matrix from link loads by utilizing deep generative models. The proposed models are trained using historical data - specifically, previously observed TMs - and are then leveraged to transform traffic matrix estimation (TME) into a simpler minimization problem in a lower-dimensional latent space. This transformed problem can be efficiently solved using a gradient-based optimizer. Our work aims to examine and test different model architectures and optimization approaches. The performance of the proposed methods is comparatively evaluated over a comprehensive set of suitable metrics on two publicly available datasets comprising actual traffic matrices obtained from real backbone networks. In addition, we compare our approach with a state-of-the-art method previously published in the literature. © 2020 IEEE.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Traffic matrices (TMs) contain crucial information for managing networks, optimizing traffic flow, and detecting anomalies. However, directly measuring traffic to construct a TM is resource-intensive and computationally expensive. A more practical approach involves estimating the TM from readily available link load measurements, which falls under the category of inferential network monitoring based on indirect measurements known as network tomography. This paper focuses on solving the problem of estimating the traffic matrix from link loads by utilizing deep generative models. The proposed models are trained using historical data - specifically, previously observed TMs - and are then leveraged to transform traffic matrix estimation (TME) into a simpler minimization problem in a lower-dimensional latent space. This transformed problem can be efficiently solved using a gradient-based optimizer. Our work aims to examine and test different model architectures and optimization approaches. The performance of the proposed methods is comparatively evaluated over a comprehensive set of suitable metrics on two publicly available datasets comprising actual traffic matrices obtained from real backbone networks. In addition, we compare our approach with a state-of-the-art method previously published in the literature. © 2020 IEEE.
Dimitriou, P., & Karyotis, V. (2023). On the computation of Delaunay triangulations via genetic algorithms. Evolutionary Intelligence, 13(17). https://doi.org/10.1007/s12065-023-00893-5
@article{Dimitriou2023,
title = {On the computation of Delaunay triangulations via genetic algorithms},
author = {P. Dimitriou and V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85180719695&doi=10.1007%2fs12065-023-00893-5&partnerID=40&md5=ce28c67dcb7bd7bbfa3417161b1fa975},
doi = {10.1007/s12065-023-00893-5},
issn = {18645909},
year = {2023},
date = {2023-01-01},
journal = {Evolutionary Intelligence},
volume = {13},
number = {17},
publisher = {Springer Science and Business Media Deutschland GmbH},
abstract = {In this work, we introduce a new approach for computing Delaunay triangulations. Delaunay triangulations have numerous applications in geolocation, communications and other ICT systems or practical applications. Having available various types of approaches for computing such structures is rather desired from an implementation and computational point of view. We adopt Genetic Algorithms for computing Delaunay triangulations and present the design and evaluation of our novel approach. We consider a set of points in the plane as vertices and connect them with edges, creating the point graph. We have developed in C++ an application framework based on genetic algorithms, called Delaunay_Genetic, which produces the Delaunay triangulation structure of a given set of points in the plane. Delaunay_Genetic considers a novel graph-based chromosome representation of desired solutions, creates an initial population of individuals (chromosomes), an initial generation, and produces from the original population (generation) new generations of individuals in each repetition of the genetic process of Reproduction. Each new generation emerges more robust than the previous one. Our evaluations have revealed that the Delaunay triangulation yielded by Delaunay_Genetic, achieves an accuracy of 98–100% of the optimal Delaunay triangulation, while maintaining good convergence speed. Despite its limitations in computational time and space, the proposed novel approach exhibits several complementary benefits to computational geometry based approaches, such as allowing the insertion of new points in the triangulation dynamically, leading to seamless adaptation to new conditions, parallelization of the computational process and tolerance to noise regarding the coordinates of the points. Therefore, this work provides a useful alternative approach for computing Delaunay triangulations. © 2023, The Author(s).},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
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In this work, we introduce a new approach for computing Delaunay triangulations. Delaunay triangulations have numerous applications in geolocation, communications and other ICT systems or practical applications. Having available various types of approaches for computing such structures is rather desired from an implementation and computational point of view. We adopt Genetic Algorithms for computing Delaunay triangulations and present the design and evaluation of our novel approach. We consider a set of points in the plane as vertices and connect them with edges, creating the point graph. We have developed in C++ an application framework based on genetic algorithms, called Delaunay_Genetic, which produces the Delaunay triangulation structure of a given set of points in the plane. Delaunay_Genetic considers a novel graph-based chromosome representation of desired solutions, creates an initial population of individuals (chromosomes), an initial generation, and produces from the original population (generation) new generations of individuals in each repetition of the genetic process of Reproduction. Each new generation emerges more robust than the previous one. Our evaluations have revealed that the Delaunay triangulation yielded by Delaunay_Genetic, achieves an accuracy of 98–100% of the optimal Delaunay triangulation, while maintaining good convergence speed. Despite its limitations in computational time and space, the proposed novel approach exhibits several complementary benefits to computational geometry based approaches, such as allowing the insertion of new points in the triangulation dynamically, leading to seamless adaptation to new conditions, parallelization of the computational process and tolerance to noise regarding the coordinates of the points. Therefore, this work provides a useful alternative approach for computing Delaunay triangulations. © 2023, The Author(s).
Kakkavas, G., Diamanti, M., Stamou, A., Karyotis, V., Bouali, F., Pinola, J., Apilo, O., Papavassiliou, S., & Moessner, K. (2022). Design, Development, and Evaluation of 5G-Enabled Vehicular Services: The 5G-HEART Perspective. Sensors, 22(2), 426.
@article{kakkavas2022design,
title = {Design, Development, and Evaluation of 5G-Enabled Vehicular Services: The 5G-HEART Perspective},
author = {Grigorios Kakkavas and Maria Diamanti and Adamantia Stamou and Vasileios Karyotis and Faouzi Bouali and Jarno Pinola and Olli Apilo and Symeon Papavassiliou and Klaus Moessner},
year = {2022},
date = {2022-01-01},
journal = {Sensors},
volume = {22},
number = {2},
pages = {426},
publisher = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Avgeris, M., Spatharakis, D., Dechouniotis, D., Leivadeas, A., Karyotis, V., & Papavassiliou, S. (2022). ENERDGE: Distributed energy-aware resource allocation at the edge. Sensors, 22(2), 660.
@article{avgeris2022enerdge,
title = {ENERDGE: Distributed energy-aware resource allocation at the edge},
author = {Marios Avgeris and Dimitrios Spatharakis and Dimitrios Dechouniotis and Aris Leivadeas and Vasileios Karyotis and Symeon Papavassiliou},
year = {2022},
date = {2022-01-01},
journal = {Sensors},
volume = {22},
number = {2},
pages = {660},
publisher = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kakkavas, G., Karyotis, V., & Papavassiliou, S. (2022). Topology Inference and Link Parameter Estimation Based on End-to-End Measurements. Future Internet, 14(2), 45.
@article{kakkavas2022topology,
title = {Topology Inference and Link Parameter Estimation Based on End-to-End Measurements},
author = {Grigorios Kakkavas and Vasileios Karyotis and Symeon Papavassiliou},
year = {2022},
date = {2022-01-01},
journal = {Future Internet},
volume = {14},
number = {2},
pages = {45},
publisher = {MDPI},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Kallitsis, G., Karyotis, V., & Papavassiliou, S. (2022). On the Potential of Enhancing Delay-Tolerant Routing Protocols via Age of Information. Future Internet, 14(8), 242.
@article{kallitsis2022potential,
title = {On the Potential of Enhancing Delay-Tolerant Routing Protocols via Age of Information},
author = {Georgios Kallitsis and Vasileios Karyotis and Symeon Papavassiliou},
year = {2022},
date = {2022-01-01},
journal = {Future Internet},
volume = {14},
number = {8},
pages = {242},
publisher = {Multidisciplinary Digital Publishing Institute},
keywords = {},
pubstate = {published},
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Karageorgiou, S., & Karyotis, V. (2022). Markov-Based Malware Propagation Modeling and Analysis in Multi-Layer Networks. Network, 2(3), 456–478.
@article{karageorgiou2022markov,
title = {Markov-Based Malware Propagation Modeling and Analysis in Multi-Layer Networks},
author = {Stavros Karageorgiou and Vasileios Karyotis},
year = {2022},
date = {2022-01-01},
journal = {Network},
volume = {2},
number = {3},
pages = {456--478},
publisher = {Multidisciplinary Digital Publishing Institute},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Karageorgiou, S., & Karyotis, V. (2022). Markov-Based Malware Propagation Modeling and Analysis in Multi-Layer Networks. Network, 2(3), 456-478. https://doi.org/10.3390/network2030028
@article{Karageorgiou2022456,
title = {Markov-Based Malware Propagation Modeling and Analysis in Multi-Layer Networks},
author = {S. Karageorgiou and V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85147550817&doi=10.3390%2fnetwork2030028&partnerID=40&md5=7ea772731efd89baef0e3a0dde1c8236},
doi = {10.3390/network2030028},
issn = {26738732},
year = {2022},
date = {2022-01-01},
journal = {Network},
volume = {2},
number = {3},
pages = {456-478},
publisher = {Multidisciplinary Digital Publishing Institute (MDPI)},
abstract = {In this paper, we focus on the dynamics of the spread of malicious software (malware) in multi-layer networks of various types, e.g., cyber-physical systems. Recurring malware has been one of the major challenges in modern networks, and significant research and development has been dedicated to mitigating it. The majority of relevant works has focused on networks characterized by “flat” topologies, namely topologies in which all nodes consist of a single layer, studying the dynamics of propagation of a specific threat or various types of malware over a homogeneous topology. As cyber-physical systems and multi-layer networks in general are gaining in popularity and penetration, more targeted studies are needed. In this work, we focus on the propagation dynamics of recurring malware, namely Susceptible–Infected–Susceptible (SIS type) in multi-layer topologies consisting of combinations of two different types of networks, e.g., a small-world overlaying a random geometric, or other such combinations. We utilize a stochastic modeling framework based on Markov Random Fields for analyzing the propagation dynamics of malware over such networks. Through analysis and simulation, we discover the most vulnerable and the most robust topology among the six considered combinations, as well as a result of rather practical use, namely that the denser the network, the more flexibility it provides for malware mitigation eventually. © 2022 by the authors.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we focus on the dynamics of the spread of malicious software (malware) in multi-layer networks of various types, e.g., cyber-physical systems. Recurring malware has been one of the major challenges in modern networks, and significant research and development has been dedicated to mitigating it. The majority of relevant works has focused on networks characterized by “flat” topologies, namely topologies in which all nodes consist of a single layer, studying the dynamics of propagation of a specific threat or various types of malware over a homogeneous topology. As cyber-physical systems and multi-layer networks in general are gaining in popularity and penetration, more targeted studies are needed. In this work, we focus on the propagation dynamics of recurring malware, namely Susceptible–Infected–Susceptible (SIS type) in multi-layer topologies consisting of combinations of two different types of networks, e.g., a small-world overlaying a random geometric, or other such combinations. We utilize a stochastic modeling framework based on Markov Random Fields for analyzing the propagation dynamics of malware over such networks. Through analysis and simulation, we discover the most vulnerable and the most robust topology among the six considered combinations, as well as a result of rather practical use, namely that the denser the network, the more flexibility it provides for malware mitigation eventually. © 2022 by the authors.
Kallitsis, G., Karyotis, V., & Papavassiliou, S. (2022). On the Potential of Enhancing Delay-Tolerant Routing Protocols via Age of Information. Future Internet, 14(8). https://doi.org/10.3390/fi14080242
@article{Kallitsis2022,
title = {On the Potential of Enhancing Delay-Tolerant Routing Protocols via Age of Information},
author = {G. Kallitsis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136674256&doi=10.3390%2ffi14080242&partnerID=40&md5=88202815a5ca02b44073f8b85926fabd},
doi = {10.3390/fi14080242},
issn = {19995903},
year = {2022},
date = {2022-01-01},
journal = {Future Internet},
volume = {14},
number = {8},
publisher = {MDPI},
abstract = {In this paper, we study the potential of using the metric of Age of Information (AoI) for enhancing delay-tolerant routing protocols. The latter have been proposed for alleviating the impact of long roundtrip time in networks operating in harsh environments, e.g., in distributed applications deployed in a desert/sparsely populated area without infrastructure, a space network, etc. Delay-tolerant routing protocols can prevent excessive packet timer expiration, but do not provide any packet delivery time guarantee. Thus, they are unsuitable for time-sensitive applications that are more intensely desired nowadays in the next generation networking applications. By incorporating AoI into the operation of delay-tolerant routing protocols, we aim at devising routing protocols that can cope with both long propagation times and challenges related to time-sensitivity in packet delivery. More specifically, in this work, we modify the operation of a well-known delay-tolerant routing protocol, namely FRESH, to make AoI-based packet forwarding decisions, aiming at achieving specific delay guarantees regarding the end-to-end delivery time. We investigate the advantages and disadvantages of such an approach compared to the traditional FRESH protocol. This work serves as a cornerstone for successfully demonstrating the potential of exploiting AoI in delay-tolerant routing and its applications. © 2022 by the authors.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we study the potential of using the metric of Age of Information (AoI) for enhancing delay-tolerant routing protocols. The latter have been proposed for alleviating the impact of long roundtrip time in networks operating in harsh environments, e.g., in distributed applications deployed in a desert/sparsely populated area without infrastructure, a space network, etc. Delay-tolerant routing protocols can prevent excessive packet timer expiration, but do not provide any packet delivery time guarantee. Thus, they are unsuitable for time-sensitive applications that are more intensely desired nowadays in the next generation networking applications. By incorporating AoI into the operation of delay-tolerant routing protocols, we aim at devising routing protocols that can cope with both long propagation times and challenges related to time-sensitivity in packet delivery. More specifically, in this work, we modify the operation of a well-known delay-tolerant routing protocol, namely FRESH, to make AoI-based packet forwarding decisions, aiming at achieving specific delay guarantees regarding the end-to-end delivery time. We investigate the advantages and disadvantages of such an approach compared to the traditional FRESH protocol. This work serves as a cornerstone for successfully demonstrating the potential of exploiting AoI in delay-tolerant routing and its applications. © 2022 by the authors.
Kakkavas, G., Diamanti, M., Stamou, A., Karyotis, V., Bouali, F., Pinola, J., Apilo, O., Papavassiliou, S., & Moessner, K. (2022). Design, Development, and Evaluation of 5G-Enabled Vehicular Services: The 5G-HEART Perspective. Sensors, 22(2). https://doi.org/10.3390/s22020426
@article{Kakkavas2022,
title = {Design, Development, and Evaluation of 5G-Enabled Vehicular Services: The 5G-HEART Perspective},
author = {G. Kakkavas and M. Diamanti and A. Stamou and V. Karyotis and F. Bouali and J. Pinola and O. Apilo and S. Papavassiliou and K. Moessner},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85122184044&doi=10.3390%2fs22020426&partnerID=40&md5=94c4a7adfcadc3d81cda5f51e00ce6d7},
doi = {10.3390/s22020426},
issn = {14248220},
year = {2022},
date = {2022-01-01},
journal = {Sensors},
volume = {22},
number = {2},
publisher = {MDPI},
abstract = {The ongoing transition towards 5G technology expedites the emergence of a variety of mobile applications that pertain to different vertical industries. Delivering on the key commitment of 5G, these diverse service streams, along with their distinct requirements, should be facilitated under the same unified network infrastructure. Consequently, in order to unleash the benefits brought by 5G technology, a holistic approach towards the requirement analysis and the design, development, and evaluation of multiple concurrent vertical services should be followed. In this paper, we focus on the Transport vertical industry, and we study four novel vehicular service categories, each one consisting of one or more related specific scenarios, within the framework of the “5G Health, Aquaculture and Transport (5G-HEART)” 5G PPP ICT-19 (Phase 3) project. In contrast to the majority of the literature, we provide a holistic overview of the overall life-cycle management required for the realization of the examined vehicular use cases. This comprises the definition and analysis of the network Key Performance Indicators (KPIs) resulting from high-level user requirements and their interpretation in terms of the underlying network infrastructure tasked with meeting their conflicting or converging needs. Our approach is complemented by the experimental investigation of the real unified 5G pilot’s characteristics that enable the delivery of the considered vehicular services and the initial trialling results that verify the effectiveness and feasibility of the presented theoretical analysis. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.},
note = {cited By 16},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
The ongoing transition towards 5G technology expedites the emergence of a variety of mobile applications that pertain to different vertical industries. Delivering on the key commitment of 5G, these diverse service streams, along with their distinct requirements, should be facilitated under the same unified network infrastructure. Consequently, in order to unleash the benefits brought by 5G technology, a holistic approach towards the requirement analysis and the design, development, and evaluation of multiple concurrent vertical services should be followed. In this paper, we focus on the Transport vertical industry, and we study four novel vehicular service categories, each one consisting of one or more related specific scenarios, within the framework of the “5G Health, Aquaculture and Transport (5G-HEART)” 5G PPP ICT-19 (Phase 3) project. In contrast to the majority of the literature, we provide a holistic overview of the overall life-cycle management required for the realization of the examined vehicular use cases. This comprises the definition and analysis of the network Key Performance Indicators (KPIs) resulting from high-level user requirements and their interpretation in terms of the underlying network infrastructure tasked with meeting their conflicting or converging needs. Our approach is complemented by the experimental investigation of the real unified 5G pilot’s characteristics that enable the delivery of the considered vehicular services and the initial trialling results that verify the effectiveness and feasibility of the presented theoretical analysis. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Avgeris, M., Spatharakis, D., Dechouniotis, D., Leivadeas, A., Karyotis, V., & Papavassiliou, S. (2022). ENERDGE: Distributed Energy-Aware Resource Allocation at the Edge. Sensors, 22(2). https://doi.org/10.3390/s22020660
@article{Avgeris2022,
title = {ENERDGE: Distributed Energy-Aware Resource Allocation at the Edge},
author = {M. Avgeris and D. Spatharakis and D. Dechouniotis and A. Leivadeas and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123731074&doi=10.3390%2fs22020660&partnerID=40&md5=3f622c6a52a9e5935515a33023f22b4b},
doi = {10.3390/s22020660},
issn = {14248220},
year = {2022},
date = {2022-01-01},
journal = {Sensors},
volume = {22},
number = {2},
publisher = {MDPI},
abstract = {Mobile applications are progressively becoming more sophisticated and complex, increasing their computational requirements. Traditional offloading approaches that use exclusively the Cloud infrastructure are now deemed unsuitable due to the inherent associated delay. Edge Computing can address most of the Cloud limitations at the cost of limited available resources. This bottleneck necessitates an efficient allocation of offloaded tasks from the mobile devices to the Edge. In this paper, we consider a task offloading setting with applications of different characteristics and requirements, and propose an optimal resource allocation framework leveraging the amalgamation of the edge resources. To balance the trade-off between retaining low total energy consumption, respecting end-to-end delay requirements and load balancing at the Edge, we additionally introduce a Markov Random Field based mechanism for the distribution of the excess workload. The proposed approach investigates a realistic scenario, including different categories of mobile applications, edge devices with different computational capabilities, and dynamic wireless conditions modeled by the dynamic behavior and mobility of the users. The framework is complemented with a prediction mechanism that facilitates the orchestration of the physical resources. The efficiency of the proposed scheme is evaluated via modeling and simulation and is shown to outperform a well-known task offloading solution, as well as a more recent one. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.},
note = {cited By 17},
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Mobile applications are progressively becoming more sophisticated and complex, increasing their computational requirements. Traditional offloading approaches that use exclusively the Cloud infrastructure are now deemed unsuitable due to the inherent associated delay. Edge Computing can address most of the Cloud limitations at the cost of limited available resources. This bottleneck necessitates an efficient allocation of offloaded tasks from the mobile devices to the Edge. In this paper, we consider a task offloading setting with applications of different characteristics and requirements, and propose an optimal resource allocation framework leveraging the amalgamation of the edge resources. To balance the trade-off between retaining low total energy consumption, respecting end-to-end delay requirements and load balancing at the Edge, we additionally introduce a Markov Random Field based mechanism for the distribution of the excess workload. The proposed approach investigates a realistic scenario, including different categories of mobile applications, edge devices with different computational capabilities, and dynamic wireless conditions modeled by the dynamic behavior and mobility of the users. The framework is complemented with a prediction mechanism that facilitates the orchestration of the physical resources. The efficiency of the proposed scheme is evaluated via modeling and simulation and is shown to outperform a well-known task offloading solution, as well as a more recent one. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
Vlachakis, D., Papakonstantinou, E., Sagar, R., Bacopoulou, F., Exarchos, T., Kourouthanassis, P., Karyotis, V., Vlamos, P., Lyketsos, C., Avramopoulos, D., & others (2021). Improving the Utility of Polygenic Risk Scores as a Biomarker for Alzheimer’s Disease. Cells, 10(7), 1627.
@article{vlachakis2021improvingb,
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author = {Dimitrios Vlachakis and Eleni Papakonstantinou and Ram Sagar and Flora Bacopoulou and Themis Exarchos and Panos Kourouthanassis and Vasileios Karyotis and Panayiotis Vlamos and Constantine Lyketsos and Dimitrios Avramopoulos and others},
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Tsitseklis, K., Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2021). Socio-Aware Recommendations Under Complex User Constraints. IEEE Transactions on Computational Social Systems, 8(2), 377–387.
@article{tsitseklis2021socio,
title = {Socio-Aware Recommendations Under Complex User Constraints},
author = {Konstantinos Tsitseklis and Margarita Vitoropoulou and Vasileios Karyotis and Symeon Papavassiliou},
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Vitoropoulou, M., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2021). CoveR: An Information Diffusion Aware Approach for Efficient Recommendations Under User Coverage Constraints. IEEE Transactions on Computational Social Systems, 8(4), 894–905.
@article{vitoropoulou2021cover,
title = {CoveR: An Information Diffusion Aware Approach for Efficient Recommendations Under User Coverage Constraints},
author = {Margarita Vitoropoulou and Konstantinos Tsitseklis and Vasileios Karyotis and Symeon Papavassiliou},
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Bouali, F., Pinola, J., Karyotis, V., Wissingh, B., Mitrou, M., Krishnan, P., & Moessner, K. (2021). 5G for Vehicular Use Cases: Analysis of Technical Requirements, Value Propositions and Outlook. IEEE Open Journal of Intelligent Transportation Systems, 2, 73–96.
@article{bouali20215g,
title = {5G for Vehicular Use Cases: Analysis of Technical Requirements, Value Propositions and Outlook},
author = {Faouzi Bouali and Jarno Pinola and Vasileios Karyotis and Bastiaan Wissingh and Michalis Mitrou and Prageeth Krishnan and Klaus Moessner},
year = {2021},
date = {2021-01-01},
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Kakkavas, G., Stamou, A., Karyotis, V., & Papavassiliou, S. (2021). Network tomography for efficient monitoring in SDN-enabled 5G networks and beyond: Challenges and opportunities. IEEE Communications Magazine, 59(3), 70–76.
@article{kakkavas2021network,
title = {Network tomography for efficient monitoring in SDN-enabled 5G networks and beyond: Challenges and opportunities},
author = {Grigorios Kakkavas and Adamantia Stamou and Vasileios Karyotis and Symeon Papavassiliou},
year = {2021},
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Vlachakis, D., Papakonstantinou, E., Sagar, R., Bacopoulou, F., Exarchos, T., Kourouthanassis, P., Karyotis, V., Vlamos, P., Lyketsos, C., Avramopoulos, D., & others (2021). Improving the Utility of Polygenic Risk Scores as a Biomarker for Alzheimer’s Disease. Cells, 10(7), 1627.
@article{vlachakis2021improving,
title = {Improving the Utility of Polygenic Risk Scores as a Biomarker for Alzheimer’s Disease},
author = {Dimitrios Vlachakis and Eleni Papakonstantinou and Ram Sagar and Flora Bacopoulou and Themis Exarchos and Panos Kourouthanassis and Vasileios Karyotis and Panayiotis Vlamos and Constantine Lyketsos and Dimitrios Avramopoulos and others},
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Tsitseklis, K., Krommyda, M., Karyotis, V., Kantere, V., & Papavassiliou, S. (2021). Behavioral Information Diffusion for Opinion Maximization in Online Social Networks. IEEE TRANSACTIONS ON NETWORK SCIENCE AND ENGINEERING, 8(2), 1269–1282.
@article{tsitseklis2021behavioral,
title = {Behavioral Information Diffusion for Opinion Maximization in Online Social Networks},
author = {Konstantinos Tsitseklis and Maria Krommyda and Vasileios Karyotis and Verena Kantere and Symeon Papavassiliou},
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Vitoropoulou, M., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2021). CoveR: An Information Diffusion Aware Approach for Efficient Recommendations under User Coverage Constraints. IEEE Transactions on Computational Social Systems, 8(4), 894-905. https://doi.org/10.1109/TCSS.2021.3067711
@article{Vitoropoulou2021894,
title = {CoveR: An Information Diffusion Aware Approach for Efficient Recommendations under User Coverage Constraints},
author = {M. Vitoropoulou and K. Tsitseklis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85103753269&doi=10.1109%2fTCSS.2021.3067711&partnerID=40&md5=24ae5598764569c3f5f8bd69b762c4fb},
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date = {2021-01-01},
journal = {IEEE Transactions on Computational Social Systems},
volume = {8},
number = {4},
pages = {894-905},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this article, we consider the problem of recommendations to the users of an online social network (OSN), through an information diffusion aware recommender system (IDARS). We map the assignment of recommendations in influence networks to a problem of selecting an $ell $ -cover of the minimum total cost, which is defined to be a set of assignments such that each user in the OSN is recommended of at least $ell $ different items at the minimum defined cost. This corresponds to a special case of the minimum weighted partition set cover problem, which is a generalization of the minimum weighted set cover problem, both of which are proven to be NP-hard. We formulate a corresponding integer programming problem and we apply a linear programming (LP)-based branch and bound (BnB) methodology for its solution. We also propose a greedy algorithm, denoted as CoveR, which we show to be an $O((Delta /delta )cdot H(Delta))$ -approximation for the $ell $ -coverage problem, where $Delta $ and $delta $ are the maximum and minimum degree of an influence network, respectively, and $H(Delta)$ is the $Delta text th$ harmonic number. We investigate CoveR's performance through extensive simulations on both synthetic and real networks, which indicate that the quality of its solution is comparable to the one obtained by the BnB method, while at the same time outperforms other information diffusion-aware recommendation heuristics. © 2014 IEEE.},
note = {cited By 2},
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In this article, we consider the problem of recommendations to the users of an online social network (OSN), through an information diffusion aware recommender system (IDARS). We map the assignment of recommendations in influence networks to a problem of selecting an $ell $ -cover of the minimum total cost, which is defined to be a set of assignments such that each user in the OSN is recommended of at least $ell $ different items at the minimum defined cost. This corresponds to a special case of the minimum weighted partition set cover problem, which is a generalization of the minimum weighted set cover problem, both of which are proven to be NP-hard. We formulate a corresponding integer programming problem and we apply a linear programming (LP)-based branch and bound (BnB) methodology for its solution. We also propose a greedy algorithm, denoted as CoveR, which we show to be an $O((Delta /delta )cdot H(Delta))$ -approximation for the $ell $ -coverage problem, where $Delta $ and $delta $ are the maximum and minimum degree of an influence network, respectively, and $H(Delta)$ is the $Delta text th$ harmonic number. We investigate CoveR's performance through extensive simulations on both synthetic and real networks, which indicate that the quality of its solution is comparable to the one obtained by the BnB method, while at the same time outperforms other information diffusion-aware recommendation heuristics. © 2014 IEEE.
Vlachakis, D., Papakonstantinou, E., Sagar, R., Bacopoulou, F., Exarchos, T., Kourouthanassis, P., Karyotis, V., Vlamos, P., Lyketsos, C., Avramopoulos, D., & Mahairaki, V. (2021). Improving the utility of polygenic risk scores as a biomarker for alzheimer’s disease. Cells, 10(7). https://doi.org/10.3390/cells10071627
@article{Vlachakis2021,
title = {Improving the utility of polygenic risk scores as a biomarker for alzheimer’s disease},
author = {D. Vlachakis and E. Papakonstantinou and R. Sagar and F. Bacopoulou and T. Exarchos and P. Kourouthanassis and V. Karyotis and P. Vlamos and C. Lyketsos and D. Avramopoulos and V. Mahairaki},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85110284259&doi=10.3390%2fcells10071627&partnerID=40&md5=c4fc2228d5300c29c3dad75f7d553f2d},
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issn = {20734409},
year = {2021},
date = {2021-01-01},
journal = {Cells},
volume = {10},
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abstract = {The treatment of complex and multifactorial diseases constitutes a big challenge in day-to-day clinical practice. As many parameters influence clinical phenotypes, accurate diagnosis and prompt therapeutic management is often difficult. Significant research and investment focuses on state-of-the-art genomic and metagenomic analyses in the burgeoning field of Precision (or Personalized) Medicine with genome-wide-association-studies (GWAS) helping in this direction by linking patient genotypes at specific polymorphic sites (single-nucleotide polymorphisms, SNPs) to the specific phenotype. The generation of polygenic risk scores (PRSs) is a relatively novel statistical method that associates the collective genotypes at many of a person’s SNPs to a trait or disease. As GWAS sample sizes increase, PRSs may become a powerful tool for prevention, early diagnosis and treatment. However, the complexity and multidimensionality of genetic and environmental contributions to phenotypes continue to pose significant challenges for the clinical, broad-scale use of PRSs. To improve the value of PRS measures, we propose a novel pipeline which might better utilize GWAS results and improve the utility of PRS when applied to Alzheimer’s Disease (AD), as a paradigm of multifactorial disease with existing large GWAS datasets that have not yet achieved significant clinical impact. We propose a refined approach for the construction of AD PRS improved by (1), taking into consideration the genetic loci where the SNPs are located, (2) evaluating the post-translational impact of SNPs on coding and non-coding regions by focusing on overlap with open chromatin data and SNPs that are expression quantitative trait loci (QTLs), and (3) scoring and annotating the severity of the associated clinical phenotype into the PRS. Open chromatin and eQTL data need to be carefully selected based on tissue/cell type of origin (e.g., brain, excitatory neurons). Applying such filters to traditional PRS on GWAS studies of complex diseases like AD, can produce a set of SNPs weighted according to our algorithm and a more useful PRS. Our proposed methodology may pave the way for new applications of genomic machine and deep learning pipelines to GWAS datasets in an effort to identify novel clinically useful genetic biomarkers for complex diseases like AD. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.},
note = {cited By 8},
keywords = {},
pubstate = {published},
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The treatment of complex and multifactorial diseases constitutes a big challenge in day-to-day clinical practice. As many parameters influence clinical phenotypes, accurate diagnosis and prompt therapeutic management is often difficult. Significant research and investment focuses on state-of-the-art genomic and metagenomic analyses in the burgeoning field of Precision (or Personalized) Medicine with genome-wide-association-studies (GWAS) helping in this direction by linking patient genotypes at specific polymorphic sites (single-nucleotide polymorphisms, SNPs) to the specific phenotype. The generation of polygenic risk scores (PRSs) is a relatively novel statistical method that associates the collective genotypes at many of a person’s SNPs to a trait or disease. As GWAS sample sizes increase, PRSs may become a powerful tool for prevention, early diagnosis and treatment. However, the complexity and multidimensionality of genetic and environmental contributions to phenotypes continue to pose significant challenges for the clinical, broad-scale use of PRSs. To improve the value of PRS measures, we propose a novel pipeline which might better utilize GWAS results and improve the utility of PRS when applied to Alzheimer’s Disease (AD), as a paradigm of multifactorial disease with existing large GWAS datasets that have not yet achieved significant clinical impact. We propose a refined approach for the construction of AD PRS improved by (1), taking into consideration the genetic loci where the SNPs are located, (2) evaluating the post-translational impact of SNPs on coding and non-coding regions by focusing on overlap with open chromatin data and SNPs that are expression quantitative trait loci (QTLs), and (3) scoring and annotating the severity of the associated clinical phenotype into the PRS. Open chromatin and eQTL data need to be carefully selected based on tissue/cell type of origin (e.g., brain, excitatory neurons). Applying such filters to traditional PRS on GWAS studies of complex diseases like AD, can produce a set of SNPs weighted according to our algorithm and a more useful PRS. Our proposed methodology may pave the way for new applications of genomic machine and deep learning pipelines to GWAS datasets in an effort to identify novel clinically useful genetic biomarkers for complex diseases like AD. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.
Tsitseklis, K., Krommyda, M., Karyotis, V., Kantere, V., & Papavassiliou, S. (2021). Scalable Community Detection for Complex Data Graphs via Hyperbolic Network Embedding and Graph Databases. IEEE Transactions on Network Science and Engineering, 8(2), 1269-1282. https://doi.org/10.1109/TNSE.2020.3022248
@article{Tsitseklis20211269,
title = {Scalable Community Detection for Complex Data Graphs via Hyperbolic Network Embedding and Graph Databases},
author = {K. Tsitseklis and M. Krommyda and V. Karyotis and V. Kantere and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85112343198&doi=10.1109%2fTNSE.2020.3022248&partnerID=40&md5=29b1774f2e931454978b20d2dd8d9592},
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volume = {8},
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publisher = {IEEE Computer Society},
abstract = {Community detection and its variations is one of the typically employed approaches for analyzing graph data originating from various diverse fields. In this paper, we focus on a particular approach for community detection capitalizing on hyperbolic network embedding, which is aimed at analyzing large data graphs. In order to enable its scaling to arbitrary sized data sets and respective data graphs, we extend it by incorporating a graph database approach. This allows for handling a larger number of nodes and edges in the data graph. Also, we turn our focus on the discovery and visualization of communities in Resource Description Framework (RDF) data, namely over linked datasets from diverse areas, explaining how our approach can accommodate relevant analysis. We demonstrate the applicability of the new approach over both real-world and artificially generated datasets showing its feasibility in producing correct results, while being able to scale seamlessly in large datasets. The approach can be used for multi-lateral analysis of feature-rich graph data, originating from diverse sources, enabling the discovery of hidden correlations through the hyperbolic network embedding. © 2013 IEEE.},
note = {cited By 3},
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Community detection and its variations is one of the typically employed approaches for analyzing graph data originating from various diverse fields. In this paper, we focus on a particular approach for community detection capitalizing on hyperbolic network embedding, which is aimed at analyzing large data graphs. In order to enable its scaling to arbitrary sized data sets and respective data graphs, we extend it by incorporating a graph database approach. This allows for handling a larger number of nodes and edges in the data graph. Also, we turn our focus on the discovery and visualization of communities in Resource Description Framework (RDF) data, namely over linked datasets from diverse areas, explaining how our approach can accommodate relevant analysis. We demonstrate the applicability of the new approach over both real-world and artificially generated datasets showing its feasibility in producing correct results, while being able to scale seamlessly in large datasets. The approach can be used for multi-lateral analysis of feature-rich graph data, originating from diverse sources, enabling the discovery of hidden correlations through the hyperbolic network embedding. © 2013 IEEE.
Tsitseklis, K., Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2021). Socio-Aware Recommendations under Complex User Constraints. IEEE Transactions on Computational Social Systems, 8(2), 377-387. https://doi.org/10.1109/TCSS.2020.3046686
@article{Tsitseklis2021377,
title = {Socio-Aware Recommendations under Complex User Constraints},
author = {K. Tsitseklis and M. Vitoropoulou and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099574885&doi=10.1109%2fTCSS.2020.3046686&partnerID=40&md5=dd9c5d680b886d8e4fcaf5abba0c7d4e},
doi = {10.1109/TCSS.2020.3046686},
issn = {2329924X},
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date = {2021-01-01},
journal = {IEEE Transactions on Computational Social Systems},
volume = {8},
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pages = {377-387},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this work, we consider the joint behavior of an information diffusion process integrated with a recommender system (RecSys) over an online social network (OSN), where the typical users' resilience to information varies, leading to potential information overloads. We assume that each user has a threshold over the information that she can process in a meaningful way, and exceeding it could lead to user dissatisfaction or the user remaining idle. In order to efficiently tackle this issue, while considering complex user constraints, we consider two types of users' capacity to information, that is, capacity for distinct items and capacity for duplicate items. In this setting, we aim to allocate the items in the OSN in order to maximize users' total relevance to the former while ensuring that no user exceeds any type of capacity. We show that this problem is NP-complete and present various heuristic methods to address it. A novel framework, called socially constrained recommendations (SCoRe), is developed for the final assignment of items to users, consisting of a two-step procedure. We present and evaluate two different approaches for each step and discuss the usability of SCoRe for the efficient diffusion of items in the network while respecting the users' constraints. © 2014 IEEE.},
note = {cited By 1},
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In this work, we consider the joint behavior of an information diffusion process integrated with a recommender system (RecSys) over an online social network (OSN), where the typical users' resilience to information varies, leading to potential information overloads. We assume that each user has a threshold over the information that she can process in a meaningful way, and exceeding it could lead to user dissatisfaction or the user remaining idle. In order to efficiently tackle this issue, while considering complex user constraints, we consider two types of users' capacity to information, that is, capacity for distinct items and capacity for duplicate items. In this setting, we aim to allocate the items in the OSN in order to maximize users' total relevance to the former while ensuring that no user exceeds any type of capacity. We show that this problem is NP-complete and present various heuristic methods to address it. A novel framework, called socially constrained recommendations (SCoRe), is developed for the final assignment of items to users, consisting of a two-step procedure. We present and evaluate two different approaches for each step and discuss the usability of SCoRe for the efficient diffusion of items in the network while respecting the users' constraints. © 2014 IEEE.
Kakkavas, G., Stamou, A., Karyotis, V., & Papavassiliou, S. (2021). Network Tomography for Efficient Monitoring in SDN-Enabled 5G Networks and Beyond: Challenges and Opportunities. IEEE Communications Magazine, 59(3), 70-76. https://doi.org/10.1109/MCOM.001.2000458
@article{Kakkavas202170,
title = {Network Tomography for Efficient Monitoring in SDN-Enabled 5G Networks and Beyond: Challenges and Opportunities},
author = {G. Kakkavas and A. Stamou and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85105611912&doi=10.1109%2fMCOM.001.2000458&partnerID=40&md5=16953d3d2cba346d5c5b36d400f023c4},
doi = {10.1109/MCOM.001.2000458},
issn = {01636804},
year = {2021},
date = {2021-01-01},
journal = {IEEE Communications Magazine},
volume = {59},
number = {3},
pages = {70-76},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Efficient monitoring plays a vital role in software-defined networking (SDN)-enabled 5G networks, involving the monitoring of performance metrics for both physical and virtual networks and considering the requirements of a variety of traffic types originating from different applications. However, conventional network monitoring tools based on traditional IP-based mechanisms may not be able to keep up with the dynamic nature of 5G networks. Network tomography (NT) is an emerging monitoring approach that estimates network performance based on measurements realized at a limited subset of network elements, presenting benefits over traditional monitoring techniques, but susceptible to identifiability issues. In this article, we demonstrate how NT can respond to current monitoring challenges, complementing and working together with SDN, yielding accurate estimations with low overhead, while exploiting SDN capabilities such as the centralized view of the entire network, direct flow-level measurements, and controllable routing. Furthermore, we present the spectrum of applications of NT-based solutions in 5G networks and beyond, ranging from virtual to vehicular networks. © 1979-2012 IEEE.},
note = {cited By 29},
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Efficient monitoring plays a vital role in software-defined networking (SDN)-enabled 5G networks, involving the monitoring of performance metrics for both physical and virtual networks and considering the requirements of a variety of traffic types originating from different applications. However, conventional network monitoring tools based on traditional IP-based mechanisms may not be able to keep up with the dynamic nature of 5G networks. Network tomography (NT) is an emerging monitoring approach that estimates network performance based on measurements realized at a limited subset of network elements, presenting benefits over traditional monitoring techniques, but susceptible to identifiability issues. In this article, we demonstrate how NT can respond to current monitoring challenges, complementing and working together with SDN, yielding accurate estimations with low overhead, while exploiting SDN capabilities such as the centralized view of the entire network, direct flow-level measurements, and controllable routing. Furthermore, we present the spectrum of applications of NT-based solutions in 5G networks and beyond, ranging from virtual to vehicular networks. © 1979-2012 IEEE.
Bouali, F., Pinola, J., Karyotis, V., Wissingh, B., Mitrou, M., Krishnan, P., & Moessner, K. (2021). 5G for Vehicular Use Cases: Analysis of Technical Requirements, Value Propositions and Outlook. IEEE Open Journal of Intelligent Transportation Systems, 2, 73-96. https://doi.org/10.1109/OJITS.2021.3072220
@article{Bouali202173,
title = {5G for Vehicular Use Cases: Analysis of Technical Requirements, Value Propositions and Outlook},
author = {F. Bouali and J. Pinola and V. Karyotis and B. Wissingh and M. Mitrou and P. Krishnan and K. Moessner},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85115699611&doi=10.1109%2fOJITS.2021.3072220&partnerID=40&md5=064d6c7ee6054b96672f977e53cabcf6},
doi = {10.1109/OJITS.2021.3072220},
issn = {26877813},
year = {2021},
date = {2021-01-01},
journal = {IEEE Open Journal of Intelligent Transportation Systems},
volume = {2},
pages = {73-96},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {The fifth generation (5G) of wireless networks promises to meet the stringent requirements of vehicular use cases that cannot be supported by previous technologies. However, the stakeholders of the automotive industry (e.g., car manufacturers and road operators) are still skeptical about the capability of the telecom industry to take the lead in a market that has been dominated by dedicated intelligent transport systems (ITS) deployments. In this context, this paper constructs a framework where the potential of 5G to support different vehicular use cases is thoroughly examined under a common format from both the technical and business perspectives. From the technical standpoint, a storyboard description is developed to explain when and how different use case scenarios may come into play (i.e., pre-conditions, service flows and post-conditions). Then, a methodology to trial each scenario is developed including a functional architecture, an analysis of the technical requirements and a set of target test cases. From the business viewpoint, an initial analysis of the qualitative value perspectives is conducted considering the stakeholders, identifying the pain points of the existing solutions, and highlighting the added value of 5G in overcoming them. The future evolution of the considered use cases is finally discussed. © 2020 IEEE.},
note = {cited By 11},
keywords = {},
pubstate = {published},
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The fifth generation (5G) of wireless networks promises to meet the stringent requirements of vehicular use cases that cannot be supported by previous technologies. However, the stakeholders of the automotive industry (e.g., car manufacturers and road operators) are still skeptical about the capability of the telecom industry to take the lead in a market that has been dominated by dedicated intelligent transport systems (ITS) deployments. In this context, this paper constructs a framework where the potential of 5G to support different vehicular use cases is thoroughly examined under a common format from both the technical and business perspectives. From the technical standpoint, a storyboard description is developed to explain when and how different use case scenarios may come into play (i.e., pre-conditions, service flows and post-conditions). Then, a methodology to trial each scenario is developed including a functional architecture, an analysis of the technical requirements and a set of target test cases. From the business viewpoint, an initial analysis of the qualitative value perspectives is conducted considering the stakeholders, identifying the pain points of the existing solutions, and highlighting the added value of 5G in overcoming them. The future evolution of the considered use cases is finally discussed. © 2020 IEEE.
Kakkavas, G., Gkatzioura, D., Karyotis, V., & Papavassiliou, S. (2020). A review of advanced algebraic approaches enabling network tomography for future network infrastructures. Future Internet, 12(2), 20.
@article{kakkavas2020review,
title = {A review of advanced algebraic approaches enabling network tomography for future network infrastructures},
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Kakkavas, G., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2020). A software defined radio cross-layer resource allocation approach for cognitive radio networks: From theory to practice. IEEE Transactions on Cognitive Communications and Networking, 6(2), 740–755.
@article{kakkavas2020software,
title = {A software defined radio cross-layer resource allocation approach for cognitive radio networks: From theory to practice},
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Tsitseklis, K., Krommyda, M., Karyotis, V., Kantere, V., & Papavassiliou, S. (2020). Scalable Community Detection for Complex Data Graphs via Hyperbolic Network Embedding and Graph Databases. IEEE Transactions on Network Science and Engineering, 8(2), 1269–1282.
@article{tsitseklis2020scalable,
title = {Scalable Community Detection for Complex Data Graphs via Hyperbolic Network Embedding and Graph Databases},
author = {Konstantinos Tsitseklis and Maria Krommyda and Vasileios Karyotis and Verena Kantere and Symeon Papavassiliou},
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Stai, E., & Karyotis, V. (2020). Optimal resource allocation in multihop wireless networks relying on energy harvesting. IEEE Communications Letters, 25(1), 224–228.
@article{stai2020optimal,
title = {Optimal resource allocation in multihop wireless networks relying on energy harvesting},
author = {Eleni Stai and Vasileios Karyotis},
year = {2020},
date = {2020-01-01},
journal = {IEEE Communications Letters},
volume = {25},
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Kakkavas, G., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2020). A Software Defined Radio Cross-Layer Resource Allocation Approach for Cognitive Radio Networks: From Theory to Practice. IEEE Transactions on Cognitive Communications and Networking, 6(2), 740-755. https://doi.org/10.1109/TCCN.2019.2963869
@article{Kakkavas2020740,
title = {A Software Defined Radio Cross-Layer Resource Allocation Approach for Cognitive Radio Networks: From Theory to Practice},
author = {G. Kakkavas and K. Tsitseklis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85091103528&doi=10.1109%2fTCCN.2019.2963869&partnerID=40&md5=f3ef66fa9a91cbcdb443849280fc72ab},
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abstract = {Software Defined Radio (SDR)-enabled cognitive radio network architectures are expected to play an important role in the future 5G networks. Despite the increased research interest, the current implementations are of small-scale and provide limited functionality. In this paper, we contribute towards the alleviation of the limitations in SDR deployments by developing and evaluating a resource allocation approach for cognitive radios implemented with SDR technology over two testbeds of the ORCA federation. Resource allocation is based on a Markov Random Field (MRF) framework realizing a distributed cross-layer computation for the secondary nodes of the cognitive radio network. The proposed framework implementation consists of self-contained modules developed in GNU Radio realizing cognitive functionalities, such as spectrum sensing, collision detection, etc. We demonstrate the feasibility of the MRF based resource allocation approach and provide extensive results and performance analysis that highlight its key features. The latter provide useful insights about the advantages of our framework, while allowing to pinpoint current technological barriers of broader interest. © 2015 IEEE.},
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Software Defined Radio (SDR)-enabled cognitive radio network architectures are expected to play an important role in the future 5G networks. Despite the increased research interest, the current implementations are of small-scale and provide limited functionality. In this paper, we contribute towards the alleviation of the limitations in SDR deployments by developing and evaluating a resource allocation approach for cognitive radios implemented with SDR technology over two testbeds of the ORCA federation. Resource allocation is based on a Markov Random Field (MRF) framework realizing a distributed cross-layer computation for the secondary nodes of the cognitive radio network. The proposed framework implementation consists of self-contained modules developed in GNU Radio realizing cognitive functionalities, such as spectrum sensing, collision detection, etc. We demonstrate the feasibility of the MRF based resource allocation approach and provide extensive results and performance analysis that highlight its key features. The latter provide useful insights about the advantages of our framework, while allowing to pinpoint current technological barriers of broader interest. © 2015 IEEE.
Kakkavas, G., Gkatzioura, D., Karyotis, V., & Papavassiliou, S. (2020). A review of advanced algebraic approaches enabling network tomography for future network infrastructures. Future Internet, 12(2). https://doi.org/10.3390/fi12020020
@article{Kakkavas2020,
title = {A review of advanced algebraic approaches enabling network tomography for future network infrastructures},
author = {G. Kakkavas and D. Gkatzioura and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85081124193&doi=10.3390%2ffi12020020&partnerID=40&md5=7ee335c31d13b5708e2b5265f6547fee},
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year = {2020},
date = {2020-01-01},
journal = {Future Internet},
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abstract = {Network tomography has emerged as one of the lean approaches for efficient network monitoring, especially aiming at addressing the ever-increasing requirements for scaling and efficiency in modern network architectures and infrastructures. In this paper, we explore network coding and compressed sensing as enabling technologies in the context of network tomography. Both approaches capitalize on algebraic tools for achieving accuracy while allowing scaling of operation as the size of the monitored network increases. Initially, a brief overview of the tomographic problems and the related classification of methods is provided to better comprehend the problems encountered and solutions provided to date. Subsequently, we present representative approaches that employ either one of the aforementioned technologies and we comparatively describe their fundamental operation. Eventually, we provide a qualitative comparison of features and approaches that can be used for further research and technology development for network monitoring in future Internet infrastructures. © 2020 by the authors.},
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Network tomography has emerged as one of the lean approaches for efficient network monitoring, especially aiming at addressing the ever-increasing requirements for scaling and efficiency in modern network architectures and infrastructures. In this paper, we explore network coding and compressed sensing as enabling technologies in the context of network tomography. Both approaches capitalize on algebraic tools for achieving accuracy while allowing scaling of operation as the size of the monitored network increases. Initially, a brief overview of the tomographic problems and the related classification of methods is provided to better comprehend the problems encountered and solutions provided to date. Subsequently, we present representative approaches that employ either one of the aforementioned technologies and we comparatively describe their fundamental operation. Eventually, we provide a qualitative comparison of features and approaches that can be used for further research and technology development for network monitoring in future Internet infrastructures. © 2020 by the authors.
Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2019). Sensing and monitoring of information diffusion in complex online social networks. Peer-to-Peer Networking and Applications, 12(3), 604–619.
@article{vitoropoulou2019sensing,
title = {Sensing and monitoring of information diffusion in complex online social networks},
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Stamou, A., Kakkavas, G., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2019). Autonomic network management and cross-layer optimization in software defined radio environments. Future Internet, 11(2), 37.
@article{stamou2019autonomic,
title = {Autonomic network management and cross-layer optimization in software defined radio environments},
author = {Adamantia Stamou and Grigorios Kakkavas and Konstantinos Tsitseklis and Vasileios Karyotis and Symeon Papavassiliou},
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Karyotis, V., Vitoropoulou, M., Kalatzis, N., Roussaki, I., Papavassiliou, S., Khalid, O., Khan, S., & Zomaya, A. (2019). Efficient and socio-aware recommendation approaches for big data networked systems. Big Data Recommender Systems, 1(4), 58–87.
@article{karyotis2019efficient,
title = {Efficient and socio-aware recommendation approaches for big data networked systems},
author = {Vasileios Karyotis and Margarita Vitoropoulou and Nikos Kalatzis and Ioanna Roussaki and Symeon Papavassiliou and O Khalid and S Khan and A Zomaya},
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Lessi, C., Doukoglou, T., Gezerlis, V., Verrios, P., Georgiou, A., Tzalas, K., Diamanti, M., Kakkavas, G., Stamou, A., Karyotis, V., & others (2019). Christina Lessi (Editor),“D2. 1 Use Case Description and Scenario Analysis,” 5G-HEART Project, Deliverable D2. 1.. .
@article{lessi2019christina,
title = {Christina Lessi (Editor),“D2. 1 Use Case Description and Scenario Analysis,” 5G-HEART Project, Deliverable D2. 1.},
author = {Christina Lessi and Tilemachos Doukoglou and Velissarios Gezerlis and Panayiotis Verrios and Andonis Georgiou and Konstantinos Tzalas and Maria Diamanti and Grigoris Kakkavas and Adamantia Stamou and Vasileios Karyotis and others},
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Karyotis, V. (2019). A Markov Random Field Framework for Modeling Malware Propagation in Complex Communications Networks. IEEE Transactions on Dependable and Secure Computing, 16(4), 551-564. https://doi.org/10.1109/TDSC.2017.2703622
@article{Karyotis2019551,
title = {A Markov Random Field Framework for Modeling Malware Propagation in Complex Communications Networks},
author = {V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85068941002&doi=10.1109%2fTDSC.2017.2703622&partnerID=40&md5=2eaddbe72ca542b6f71f846ca8250533},
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journal = {IEEE Transactions on Dependable and Secure Computing},
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abstract = {The proliferation of complex communication networks (CCNs) and their importance for maintaining social coherency nowadays have urgently elevated the need for protecting networking infrastructures from malicious software attacks. In this paper, we propose a Markov Random Field (MRF) based spatio-stochastic framework for modeling the macroscopic behavior of a CCN under random attack, where malicious threats propagate through direct interactions and follow the Susceptible-Infected-Susceptible infection paradigm. We exploit the MRF framework for analytically studying the propagation dynamics in various types of CCNs, i.e., lattice, random, scale-free, small-world and multihop graphs, in a holistic manner. By combining Gibbs sampling with simulated annealing, we study the behavior of the above systems for various topological and malware related parameters with respect to the general random attacks considered. We demonstrate the effectiveness of the MRF framework in capturing the evolution of SIS malware propagation and use it to assess the robustness of synthetic and real CCNs with respect to the involved parameters. It is found that random networks are more robust, followed by scale-free, regular and small-world, while multihop emerge as the most vulnerable of all. © 2004-2012 IEEE.},
note = {cited By 10},
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The proliferation of complex communication networks (CCNs) and their importance for maintaining social coherency nowadays have urgently elevated the need for protecting networking infrastructures from malicious software attacks. In this paper, we propose a Markov Random Field (MRF) based spatio-stochastic framework for modeling the macroscopic behavior of a CCN under random attack, where malicious threats propagate through direct interactions and follow the Susceptible-Infected-Susceptible infection paradigm. We exploit the MRF framework for analytically studying the propagation dynamics in various types of CCNs, i.e., lattice, random, scale-free, small-world and multihop graphs, in a holistic manner. By combining Gibbs sampling with simulated annealing, we study the behavior of the above systems for various topological and malware related parameters with respect to the general random attacks considered. We demonstrate the effectiveness of the MRF framework in capturing the evolution of SIS malware propagation and use it to assess the robustness of synthetic and real CCNs with respect to the involved parameters. It is found that random networks are more robust, followed by scale-free, regular and small-world, while multihop emerge as the most vulnerable of all. © 2004-2012 IEEE.
Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2019). Sensing and monitoring of information diffusion in complex online social networks. Peer-to-Peer Networking and Applications, 12(3), 604-619. https://doi.org/10.1007/s12083-018-0684-7
@article{Vitoropoulou2019604,
title = {Sensing and monitoring of information diffusion in complex online social networks},
author = {M. Vitoropoulou and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054326149&doi=10.1007%2fs12083-018-0684-7&partnerID=40&md5=390e817a3dd9238e84b5acc810114175},
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abstract = {Sensing and monitoring information diffusion in online social networks is a complex problem of prominent importance, typically requiring significant sensing resources to address it properly. In this paper, we propose an inference approach for an information diffusion process where information is considered to belong to different classes, characterized by different spreading dynamics and possibly different topical content. Our framework utilizes social network analysis metrics in order to reduce the sensing resources that would be required in an otherwise exhaustive approach, while employing statistical learning and probabilistic inference for maintaining the accuracy of information tracking, whenever needed. The proposed framework defines an edge coloring scheme, based on which it is possible to keep track of information diffusion. We assume that the latter spreads according to various biased random walks that represent the dynamics of the considered classes of information. We have employed learning for the inference of those cases where backtracking leads to multiple potential choices for information paths. We demonstrate the operation and efficacy of our approach in characteristic online social networks, such as distributed wireless (spatial) and scale-free (relational) topologies, and draw conclusions on the impact of topology on information spreading. Finally, we discuss the emerging trends applicable for each topology and provide broader guidelines on the suitability of the proposed information diffusion inference scheme for each network. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.},
note = {cited By 6},
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Sensing and monitoring information diffusion in online social networks is a complex problem of prominent importance, typically requiring significant sensing resources to address it properly. In this paper, we propose an inference approach for an information diffusion process where information is considered to belong to different classes, characterized by different spreading dynamics and possibly different topical content. Our framework utilizes social network analysis metrics in order to reduce the sensing resources that would be required in an otherwise exhaustive approach, while employing statistical learning and probabilistic inference for maintaining the accuracy of information tracking, whenever needed. The proposed framework defines an edge coloring scheme, based on which it is possible to keep track of information diffusion. We assume that the latter spreads according to various biased random walks that represent the dynamics of the considered classes of information. We have employed learning for the inference of those cases where backtracking leads to multiple potential choices for information paths. We demonstrate the operation and efficacy of our approach in characteristic online social networks, such as distributed wireless (spatial) and scale-free (relational) topologies, and draw conclusions on the impact of topology on information spreading. Finally, we discuss the emerging trends applicable for each topology and provide broader guidelines on the suitability of the proposed information diffusion inference scheme for each network. © 2018, Springer Science+Business Media, LLC, part of Springer Nature.
Stamou, A., Kakkavas, G., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2019). Autonomic Network Management and cross-layer optimization in Software Defined radio environments. Future Internet, 11(2). https://doi.org/10.3390/fi11020037
@article{Stamou2019,
title = {Autonomic Network Management and cross-layer optimization in Software Defined radio environments},
author = {A. Stamou and G. Kakkavas and K. Tsitseklis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85061190116&doi=10.3390%2ffi11020037&partnerID=40&md5=458dca75a6acc2729e6c5b6043737655},
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year = {2019},
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abstract = {The demand for Autonomic Network Management (ANM) and optimization is as intense as ever, even though significant research has been devoted towards this direction. This paper addresses such need in Software Defined (SDR) based Cognitive Radio Networks (CRNs). We propose a new framework forANMand network reconfiguration combining Software Defined Networks (SDN) with SDR via Network Function Virtualization (NFV) enabled Virtual Utility Functions (VUFs). This is the first approach combining ANM with SDR and SDN via NFV, demonstrating how these state-of-the-art technologies can be effectively combined to achieve reconfiguration flexibility, improved performance and efficient use of available resources. In order to show the feasibility of the proposed framework, we implemented its main functionalities in a cross-layer resource allocation mechanism for CRNs over real SDR testbeds provided by the Orchestration and Reconfiguration Control Architecture (ORCA) EU project. We demonstrate the efficacy of our framework, and based on the obtained results, we identify aspects that can be further investigated for improving the applicability and increasing performance of our broader framework. © 2019 by the authors.},
note = {cited By 10},
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The demand for Autonomic Network Management (ANM) and optimization is as intense as ever, even though significant research has been devoted towards this direction. This paper addresses such need in Software Defined (SDR) based Cognitive Radio Networks (CRNs). We propose a new framework forANMand network reconfiguration combining Software Defined Networks (SDN) with SDR via Network Function Virtualization (NFV) enabled Virtual Utility Functions (VUFs). This is the first approach combining ANM with SDR and SDN via NFV, demonstrating how these state-of-the-art technologies can be effectively combined to achieve reconfiguration flexibility, improved performance and efficient use of available resources. In order to show the feasibility of the proposed framework, we implemented its main functionalities in a cross-layer resource allocation mechanism for CRNs over real SDR testbeds provided by the Orchestration and Reconfiguration Control Architecture (ORCA) EU project. We demonstrate the efficacy of our framework, and based on the obtained results, we identify aspects that can be further investigated for improving the applicability and increasing performance of our broader framework. © 2019 by the authors.
Rey, Á. M. D., Yang, L. X., & Karyotis, V. A. (2019). Mathematical models for malware propagation. Security and Communication Networks, 2019. https://doi.org/10.1155/2019/6046353
@article{Rey2019,
title = {Mathematical models for malware propagation},
author = {Á. M. D. Rey and L. -X. Yang and V. A. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060084175&doi=10.1155%2f2019%2f6046353&partnerID=40&md5=9219676dc581f3dae9893a149eab04c4},
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note = {cited By 0},
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Stai, E., Milaiou, E., Karyotis, V., & Papavassiliou, S. (2018). Temporal dynamics of information diffusion in twitter: Modeling and experimentation. IEEE Transactions on Computational Social Systems, 5(1), 256–264.
@article{stai2018temporal,
title = {Temporal dynamics of information diffusion in twitter: Modeling and experimentation},
author = {Eleni Stai and Eirini Milaiou and Vasileios Karyotis and Symeon Papavassiliou},
year = {2018},
date = {2018-01-01},
journal = {IEEE Transactions on Computational Social Systems},
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Karyotis, V., Tsitseklis, K., Sotiropoulos, K., & Papavassiliou, S. (2018). Big data clustering via community detection and hyperbolic network embedding in IoT applications. Sensors, 18(4), 1205.
@article{karyotis2018big,
title = {Big data clustering via community detection and hyperbolic network embedding in IoT applications},
author = {Vasileios Karyotis and Konstantinos Tsitseklis and Konstantinos Sotiropoulos and Symeon Papavassiliou},
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Karyotis, V., Tsitseklis, K., Sotiropoulos, K., & Papavassiliou, S. (2018). Big data clustering via community detection and hyperbolic network embedding in IoT applications. Sensors (Switzerland), 18(4). https://doi.org/10.3390/s18041205
@article{Karyotis2018,
title = {Big data clustering via community detection and hyperbolic network embedding in IoT applications},
author = {V. Karyotis and K. Tsitseklis and K. Sotiropoulos and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85045428827&doi=10.3390%2fs18041205&partnerID=40&md5=0f53454f4ddc5ba09779ce173c69b61f},
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year = {2018},
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abstract = {In this paper, we present a novel data clustering framework for big sensory data produced by IoT applications. Based on a network representation of the relations among multi-dimensional data, data clustering is mapped to node clustering over the produced data graphs. To address the potential very large scale of such datasets/graphs that test the limits of state-of-the-art approaches, we map the problem of data clustering to a community detection one over the corresponding data graphs. Specifically, we propose a novel computational approach for enhancing the traditional Girvan-Newman (GN) community detection algorithm via hyperbolic network embedding. The data dependency graph is embedded in the hyperbolic space via Rigel embedding, allowing more efficient computation of edge-betweenness centrality needed in the GN algorithm. This allows for more efficient clustering of the nodes of the data graph in terms of modularity, without sacrificing considerable accuracy. In order to study the operation of our approach with respect to enhancing GN community detection, we employ various representative types of artificial complex networks, such as scale-free, small-world and random geometric topologies, and frequently-employed benchmark datasets for demonstrating its efficacy in terms of data clustering via community detection. Furthermore, we provide a proof-of-concept evaluation by applying the proposed framework over multi-dimensional datasets obtained from an operational smart-city/building IoT infrastructure provided by the Federated Interoperable Semantic IoT/cloud Testbeds and Applications (FIESTA-IoT) testbed federation. It is shown that the proposed framework can be indeed used for community detection/data clustering and exploited in various other IoT applications, such as performing more energy-efficient smart-city/building sensing. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.},
note = {cited By 9},
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In this paper, we present a novel data clustering framework for big sensory data produced by IoT applications. Based on a network representation of the relations among multi-dimensional data, data clustering is mapped to node clustering over the produced data graphs. To address the potential very large scale of such datasets/graphs that test the limits of state-of-the-art approaches, we map the problem of data clustering to a community detection one over the corresponding data graphs. Specifically, we propose a novel computational approach for enhancing the traditional Girvan-Newman (GN) community detection algorithm via hyperbolic network embedding. The data dependency graph is embedded in the hyperbolic space via Rigel embedding, allowing more efficient computation of edge-betweenness centrality needed in the GN algorithm. This allows for more efficient clustering of the nodes of the data graph in terms of modularity, without sacrificing considerable accuracy. In order to study the operation of our approach with respect to enhancing GN community detection, we employ various representative types of artificial complex networks, such as scale-free, small-world and random geometric topologies, and frequently-employed benchmark datasets for demonstrating its efficacy in terms of data clustering via community detection. Furthermore, we provide a proof-of-concept evaluation by applying the proposed framework over multi-dimensional datasets obtained from an operational smart-city/building IoT infrastructure provided by the Federated Interoperable Semantic IoT/cloud Testbeds and Applications (FIESTA-IoT) testbed federation. It is shown that the proposed framework can be indeed used for community detection/data clustering and exploited in various other IoT applications, such as performing more energy-efficient smart-city/building sensing. © 2018 by the authors. Licensee MDPI, Basel, Switzerland.
Stai, E., Milaiou, E., Karyotis, V., & Papavassiliou, S. (2018). Temporal Dynamics of Information Diffusion in Twitter: Modeling and Experimentation. IEEE Transactions on Computational Social Systems, 5(1), 256-264. https://doi.org/10.1109/TCSS.2017.2784184
@article{Stai2018256,
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url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85040913521&doi=10.1109%2fTCSS.2017.2784184&partnerID=40&md5=7974b86c93a772693bc3d1ec0fa67f3e},
doi = {10.1109/TCSS.2017.2784184},
issn = {2329924X},
year = {2018},
date = {2018-01-01},
journal = {IEEE Transactions on Computational Social Systems},
volume = {5},
number = {1},
pages = {256-264},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Twitter constitutes an accessible platform for studying and experimenting with the dynamics of information dissemination. By exploiting this and using real data, in this paper, we study the temporal dynamics of topic-specific information spread in Twitter, where we assume that each topic corresponds to a hashtag. We develop an epidemic model for information spread in Twitter and we validate it using real data for several hashtags chosen so as to cover a variety of characteristics. Contrary to the existing works in literature, which define the informed Twitter users as those who have produced/reproduced tweets with a specific hashtag, our model considers as informed a superset of Twitter users who have seen/produced/reproduced tweets with a specific hashtag. Thus, it does not underestimate the extent of information propagation in the network. The evaluation results indicate a satisfactory performance of the proposed epidemic model for all hashtag types examined; while more importantly, they allow studying the impact of several factors, such as the need of time-varying infection rates depending on the hashtag type. © 2014 IEEE.},
note = {cited By 40},
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Twitter constitutes an accessible platform for studying and experimenting with the dynamics of information dissemination. By exploiting this and using real data, in this paper, we study the temporal dynamics of topic-specific information spread in Twitter, where we assume that each topic corresponds to a hashtag. We develop an epidemic model for information spread in Twitter and we validate it using real data for several hashtags chosen so as to cover a variety of characteristics. Contrary to the existing works in literature, which define the informed Twitter users as those who have produced/reproduced tweets with a specific hashtag, our model considers as informed a superset of Twitter users who have seen/produced/reproduced tweets with a specific hashtag. Thus, it does not underestimate the extent of information propagation in the network. The evaluation results indicate a satisfactory performance of the proposed epidemic model for all hashtag types examined; while more importantly, they allow studying the impact of several factors, such as the need of time-varying infection rates depending on the hashtag type. © 2014 IEEE.
Stai, E., Karyotis, V., Bitsaki, A.-C., & Papavassiliou, S. (2017). Strategy evolution of information diffusion under time-varying user behavior in generalized networks. Computer Communications, 100, 91–103.
@article{stai2017strategy,
title = {Strategy evolution of information diffusion under time-varying user behavior in generalized networks},
author = {Eleni Stai and Vasileios Karyotis and Antonia-Chrysanthi Bitsaki and Symeon Papavassiliou},
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Stai, E., Sotiropoulos, K., Karyotis, V., & Papavassiliou, S. (2017). Hyperbolic embedding for efficient computation of path centralities and adaptive routing in large-scale complex commodity networks. IEEE Transactions on Network Science and Engineering, 4(3), 140–153.
@article{stai2017hyperbolic,
title = {Hyperbolic embedding for efficient computation of path centralities and adaptive routing in large-scale complex commodity networks},
author = {Eleni Stai and Konstantinos Sotiropoulos and Vasileios Karyotis and Symeon Papavassiliou},
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Karyotis, V. (2017). A Markov random field framework for modeling malware propagation in complex communications networks. IEEE Transactions on Dependable and Secure Computing, 16(4), 551–564.
@article{karyotis2017markov,
title = {A Markov random field framework for modeling malware propagation in complex communications networks},
author = {Vasileios Karyotis},
year = {2017},
date = {2017-01-01},
journal = {IEEE Transactions on Dependable and Secure Computing},
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Stai, E., Sotiropoulos, K., Karyotis, V., & Papavassiliou, S. (2017). Hyperbolic Embedding for Efficient Computation of Path Centralities and Adaptive Routing in Large-Scale Complex Commodity Networks. IEEE Transactions on Network Science and Engineering, 4(3), 140-153. https://doi.org/10.1109/TNSE.2017.2690258
@article{Stai2017140,
title = {Hyperbolic Embedding for Efficient Computation of Path Centralities and Adaptive Routing in Large-Scale Complex Commodity Networks},
author = {E. Stai and K. Sotiropoulos and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029930433&doi=10.1109%2fTNSE.2017.2690258&partnerID=40&md5=0a5e420781c16b09d6ecee7b614924c3},
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abstract = {Computing the most central nodes in large-scale commodity networks is rather important for improving routing and associated applications. In this paper, we introduce a novel framework for the analysis and efficient computation of routing path-based centrality measures, focusing on betweenness and traffic load centrality. The proposed framework enables efficient approximation and in special cases accurate computation of the aforementioned measures in large-scale complex networks, as well as improving/adapting commodity (traffic) routing by identifying and alleviating key congestion points. It capitalizes on network embedding in hyperbolic space and exploits properties of greedy routing over hyperbolic coordinates. We show the computational benefits and approximation precision of our approach by comparing it with state-of-the-art path centrality computation techniques. We demonstrate its applicability on real topologies, characteristic of actual large-scale commodity networks, e.g., data, utility networks. Focusing on two graph embedding types, Rigel and greedy, we compare their impact on the performance of our framework. Then, we exemplify and statistically analyze the dynamic routing adaptation, via the variation of the minimum-depth spanning tree employed for greedy embedding in hyperbolic space. Notably, this allows for efficient routing adaptation according to a simple, distributed computation that can be applied during network operation to alleviate arising bottlenecks. © 2013 IEEE.},
note = {cited By 10},
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Computing the most central nodes in large-scale commodity networks is rather important for improving routing and associated applications. In this paper, we introduce a novel framework for the analysis and efficient computation of routing path-based centrality measures, focusing on betweenness and traffic load centrality. The proposed framework enables efficient approximation and in special cases accurate computation of the aforementioned measures in large-scale complex networks, as well as improving/adapting commodity (traffic) routing by identifying and alleviating key congestion points. It capitalizes on network embedding in hyperbolic space and exploits properties of greedy routing over hyperbolic coordinates. We show the computational benefits and approximation precision of our approach by comparing it with state-of-the-art path centrality computation techniques. We demonstrate its applicability on real topologies, characteristic of actual large-scale commodity networks, e.g., data, utility networks. Focusing on two graph embedding types, Rigel and greedy, we compare their impact on the performance of our framework. Then, we exemplify and statistically analyze the dynamic routing adaptation, via the variation of the minimum-depth spanning tree employed for greedy embedding in hyperbolic space. Notably, this allows for efficient routing adaptation according to a simple, distributed computation that can be applied during network operation to alleviate arising bottlenecks. © 2013 IEEE.
Stai, E., Karyotis, V., Bitsaki, A. C., & Papavassiliou, S. (2017). Strategy evolution of information diffusion under time-varying user behavior in generalized networks. Computer Communications, 100, 91-103. https://doi.org/10.1016/j.comcom.2016.12.013
@article{Stai201791,
title = {Strategy evolution of information diffusion under time-varying user behavior in generalized networks},
author = {E. Stai and V. Karyotis and A. -C. Bitsaki and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85009355077&doi=10.1016%2fj.comcom.2016.12.013&partnerID=40&md5=2df1b79f484ed668c1646c1607709f69},
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year = {2017},
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volume = {100},
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publisher = {Elsevier B.V.},
abstract = {Modern generalized networks, where physical devices and social players are combined to support seamless and more flexible services, are strongly driven by user behavior and its evolution. A typical example of behavior-affected processes is the information diffusion by users in generalized networks. In this paper, we focus on user strategy selection with respect to information diffusion in generalized networks, and study its evolutionary dynamics and their benefits, as user behavior/interests change over the course of time. We model information diffusion in generalized networks through graphical evolutionary game theory (graphical EGT) and analyze the evolution of the system and its Evolutionary Stable States (ESS) for time-varying fitness values due to time-varying user interests. We perform extensive evaluations based on numerical and simulation results, and study the impact of several parameters on the derived ESS curves (i.e., ESS points over time). Such parameters involve user interests and their fitness values, and the degree distributions and network type of the layers of the generalized network. We thoroughly evaluate via numerical analysis and appropriate examples the existence of ESS loci for the system dynamics depending on the associated parameters. Also, we discuss the relation between (graphical) EGT-based information diffusion analysis and the epidemics-based information diffusion modeling and analysis that is frequently applied in the literature. Our modeling and evaluations can be used to predict the evolution of the cumulative behavior, allowing for efficient design and control of information campaigns. © 2016},
note = {cited By 10},
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Modern generalized networks, where physical devices and social players are combined to support seamless and more flexible services, are strongly driven by user behavior and its evolution. A typical example of behavior-affected processes is the information diffusion by users in generalized networks. In this paper, we focus on user strategy selection with respect to information diffusion in generalized networks, and study its evolutionary dynamics and their benefits, as user behavior/interests change over the course of time. We model information diffusion in generalized networks through graphical evolutionary game theory (graphical EGT) and analyze the evolution of the system and its Evolutionary Stable States (ESS) for time-varying fitness values due to time-varying user interests. We perform extensive evaluations based on numerical and simulation results, and study the impact of several parameters on the derived ESS curves (i.e., ESS points over time). Such parameters involve user interests and their fitness values, and the degree distributions and network type of the layers of the generalized network. We thoroughly evaluate via numerical analysis and appropriate examples the existence of ESS loci for the system dynamics depending on the associated parameters. Also, we discuss the relation between (graphical) EGT-based information diffusion analysis and the epidemics-based information diffusion modeling and analysis that is frequently applied in the literature. Our modeling and evaluations can be used to predict the evolution of the cumulative behavior, allowing for efficient design and control of information campaigns. © 2016
Stai, E., Karyotis, V., & Papavassiliou, S. (2016). A hyperbolic space analytics framework for big network data and their applications. IEEE Network, 30(1), 11–17.
@article{stai2016hyperbolic,
title = {A hyperbolic space analytics framework for big network data and their applications},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Karyotis, V., Stai, E., & Papavassiliou, S. (2016). On the evolution of complex network topology under network churn. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 9674, 227-240. https://doi.org/10.1007/978-3-319-33936-8_18
@article{Karyotis2016227,
title = {On the evolution of complex network topology under network churn},
author = {V. Karyotis and E. Stai and S. Papavassiliou},
editor = {Mamatas L. Matta I. Papadimitriou P.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84978959144&doi=10.1007%2f978-3-319-33936-8_18&partnerID=40&md5=d66eefa06bcaa59521adbf8ba126608e},
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journal = {Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)},
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abstract = {The future Internet is becoming more diverse, incorporating heterogeneous access networks. The latter are characterized by numerous devices that join/leave the network dynamically, creating intense churn patterns. New approaches to analyze and quantify churn-induced network evolution are required. In this paper, we address such need by introducing a new analysis framework that maps network evolution into trajectories in multi-dimensional vector spaces. Each network instance is characterized by a feature vector, indicating network properties of interest. To demonstrate the potentials of this approach, we exemplify and study the effect of edge churn on various complex topologies, frequently emerging in various communications environments. We investigate via simulation the impact of network evolution, by quantifying its effect on key network analysis metrics, such as the clustering coefficient and the plethora of centrality metrics, employed at large for analyzing topologies and designing applications. The proposed framework aspires to establish more holistic and efficient complex network control. © IFIP International Federation for Information Processing 2016.},
note = {cited By 1; Conference of 14th IFIP WG 6.2 International Conference on Wired/Wireless Internet Communications, WWIC 2016 ; Conference Date: 25 May 2016 Through 27 May 2016; Conference Code:176559},
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The future Internet is becoming more diverse, incorporating heterogeneous access networks. The latter are characterized by numerous devices that join/leave the network dynamically, creating intense churn patterns. New approaches to analyze and quantify churn-induced network evolution are required. In this paper, we address such need by introducing a new analysis framework that maps network evolution into trajectories in multi-dimensional vector spaces. Each network instance is characterized by a feature vector, indicating network properties of interest. To demonstrate the potentials of this approach, we exemplify and study the effect of edge churn on various complex topologies, frequently emerging in various communications environments. We investigate via simulation the impact of network evolution, by quantifying its effect on key network analysis metrics, such as the clustering coefficient and the plethora of centrality metrics, employed at large for analyzing topologies and designing applications. The proposed framework aspires to establish more holistic and efficient complex network control. © IFIP International Federation for Information Processing 2016.
Stai, E., Karyotis, V., & Papavassiliou, S. (2016). A hyperbolic space analytics framework for big network data and their applications. IEEE Network, 30(1), 11-17. https://doi.org/10.1109/MNET.2016.7389825
@article{Stai201611,
title = {A hyperbolic space analytics framework for big network data and their applications},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962018671&doi=10.1109%2fMNET.2016.7389825&partnerID=40&md5=452d87373227f1a5a381b819787d5630},
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abstract = {Big data analytics have generated a paradigm shift in modern data analysis and decision making in almost every aspect of human society. Nowadays, massive amounts of generated network and correlated (networked) data pose critical computational and storage challenges, requiring the development of radical techniques to manage, process, and analyze them more efficiently. We propose embedding such data and their correlations in hyperbolic metric spaces as one approach aspiring to radically change current practices. In this article, we explore the potential that such data embedding and the corresponding hyperbolic space based data analytics can offer to networks, their applications, and their services. We demonstrate how this approach may lead to more efficient and scalable problem solving within diverse application domains, such as network design/analysis, network resource allocation optimization, and network economics/marketing, paving the way for more diverse and effective solutions in the future. © 2016 IEEE.},
note = {cited By 26},
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Big data analytics have generated a paradigm shift in modern data analysis and decision making in almost every aspect of human society. Nowadays, massive amounts of generated network and correlated (networked) data pose critical computational and storage challenges, requiring the development of radical techniques to manage, process, and analyze them more efficiently. We propose embedding such data and their correlations in hyperbolic metric spaces as one approach aspiring to radically change current practices. In this article, we explore the potential that such data embedding and the corresponding hyperbolic space based data analytics can offer to networks, their applications, and their services. We demonstrate how this approach may lead to more efficient and scalable problem solving within diverse application domains, such as network design/analysis, network resource allocation optimization, and network economics/marketing, paving the way for more diverse and effective solutions in the future. © 2016 IEEE.
Karyotis, V., & Papavassiliou, S. (2015). Macroscopic malware propagation dynamics for complex networks with churn. IEEE Communications Letters, 19(4), 577–580.
@article{karyotis2015macroscopic,
title = {Macroscopic malware propagation dynamics for complex networks with churn},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2015). Analysis and control of information diffusion dictated by user interest in generalized networks. Computational Social Networks, 2(1), 1–31.
@article{stai2015analysis,
title = {Analysis and control of information diffusion dictated by user interest in generalized networks},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2015). Analysis and control of information diffusion dictated by user interest in generalized networks. Computational Social Networks, 2(1). https://doi.org/10.1186/s40649-015-0025-4
@article{Stai2015,
title = {Analysis and control of information diffusion dictated by user interest in generalized networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85046497377&doi=10.1186%2fs40649-015-0025-4&partnerID=40&md5=0ae92df0fd82896146427461de5385ee},
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issn = {21974314},
year = {2015},
date = {2015-01-01},
journal = {Computational Social Networks},
volume = {2},
number = {1},
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abstract = {The diffusion of useful information in generalized networks, such as those consisting of wireless physical substrates and social network overlays is very important for theoretical and practical applications. Contrary to previous works, we focus on the impact of user interest and its features (e.g., interest periodicity) on the dynamics and control of diffusion of useful information within such complex wireless-social systems. By considering the impact of temporal and topical variations of users interests, e.g., seasonal periodicity of interest in summer vacation advertisements which spread more effectively during Spring–Summer months, we develop an epidemic-based mathematical framework for modeling and analyzing such information dissemination processes and use three indicative operational scenarios to demonstrate the solutions and results that can be obtained by the corresponding differential equation-based formalism. We then develop an optimal control framework subject to the above information diffusion modeling that allows controlling the trade-off between information propagation efficiency and the associated cost, by considering and leveraging on the impact that user interests have on the diffusion processes. By analysis and extensive simulations, significant outcomes are obtained on the impact of each network layer and the associated interest parameters on the dynamics of useful information diffusion. Furthermore, several behavioral properties of the optimal control of the useful information diffusion with respect to the number of infected/informed nodes and the evolving user interest are shown through analysis and verified via simulations. Specifically, a key finding is that low interest-related diffusion can be aided by utilizing proper optimal controls. Our work in this paper paves the way towards this user-centered information diffusion framework. © 2015, Stai et al.},
note = {cited By 9},
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The diffusion of useful information in generalized networks, such as those consisting of wireless physical substrates and social network overlays is very important for theoretical and practical applications. Contrary to previous works, we focus on the impact of user interest and its features (e.g., interest periodicity) on the dynamics and control of diffusion of useful information within such complex wireless-social systems. By considering the impact of temporal and topical variations of users interests, e.g., seasonal periodicity of interest in summer vacation advertisements which spread more effectively during Spring–Summer months, we develop an epidemic-based mathematical framework for modeling and analyzing such information dissemination processes and use three indicative operational scenarios to demonstrate the solutions and results that can be obtained by the corresponding differential equation-based formalism. We then develop an optimal control framework subject to the above information diffusion modeling that allows controlling the trade-off between information propagation efficiency and the associated cost, by considering and leveraging on the impact that user interests have on the diffusion processes. By analysis and extensive simulations, significant outcomes are obtained on the impact of each network layer and the associated interest parameters on the dynamics of useful information diffusion. Furthermore, several behavioral properties of the optimal control of the useful information diffusion with respect to the number of infected/informed nodes and the evolving user interest are shown through analysis and verified via simulations. Specifically, a key finding is that low interest-related diffusion can be aided by utilizing proper optimal controls. Our work in this paper paves the way towards this user-centered information diffusion framework. © 2015, Stai et al.
Karyotis, V., & Papavassiliou, S. (2015). Macroscopic malware propagation dynamics for complex networks with churn. IEEE Communications Letters, 19(4), 577-580. https://doi.org/10.1109/LCOMM.2015.2399925
@article{Karyotis2015577,
title = {Macroscopic malware propagation dynamics for complex networks with churn},
author = {V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84927730777&doi=10.1109%2fLCOMM.2015.2399925&partnerID=40&md5=70ea29f069651e438d8b63decdc8a8f6},
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abstract = {In this letter, a queueing-based approach for modeling malware propagation in complex networks with churn (dynamic node variation) is introduced. The proposed methodology captures the dynamics of SIS-type malware, especially in time-varying networks, where nodes enter and leave due to their limited energy reserves, or as the outcome of malware attacks. We demonstrate the developed model in various complex networks, showing how it can be exploited for analytically quantifying network reliability and further used for increasing the robustness of the network against generic malware attacks. © 2015 IEEE.},
note = {cited By 22},
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In this letter, a queueing-based approach for modeling malware propagation in complex networks with churn (dynamic node variation) is introduced. The proposed methodology captures the dynamics of SIS-type malware, especially in time-varying networks, where nodes enter and leave due to their limited energy reserves, or as the outcome of malware attacks. We demonstrate the developed model in various complex networks, showing how it can be exploited for analytically quantifying network reliability and further used for increasing the robustness of the network against generic malware attacks. © 2015 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2015). On the impact of network evolution on NUM resource allocation problems in wireless multihop networks. Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), 9143, 62-75. https://doi.org/10.1007/978-3-319-19662-6_5
@article{Stai201562,
title = {On the impact of network evolution on NUM resource allocation problems in wireless multihop networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
editor = {Ruehrup S. Papavassiliou S.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84949024570&doi=10.1007%2f978-3-319-19662-6_5&partnerID=40&md5=9f0317d3b63d47b67de012a4df648216},
doi = {10.1007/978-3-319-19662-6_5},
issn = {03029743},
year = {2015},
date = {2015-01-01},
journal = {Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)},
volume = {9143},
pages = {62-75},
publisher = {Springer Verlag},
abstract = {Network churn is one of the primary reasons for network topology evolution, creating a dynamic environment that all designed and developed mechanisms have to cope with. In this work, we focus on studying the impact of network evolution on the resource allocation mechanisms in wireless multihop networks, and thus set the scene for more pragmatic network optimization. More specifically, we study the impact of topology evolution in the form of node and edge churn on the Network Utility Maximization (NUM) mechanism, where the latter is employed as a form of intelligent resource allocation framework and implementation. Our study in this paper serves as a stepping stone for a more realistic consideration of cross-layer design, capable of coping with the dynamic nature of the evolutionary changes that take place in each network inevitably. This work aspires to stimulate the interest and further research on improving and developing network optimization and control mechanisms under more realistic operational conditions. © Springer International Publishing Switzerland 2015.},
note = {cited By 0; Conference of 14th International Conference on Ad-Hoc Networks and Wireless, ADHOC-NOW 2015 ; Conference Date: 29 June 2015 Through 1 July 2015; Conference Code:157969},
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Network churn is one of the primary reasons for network topology evolution, creating a dynamic environment that all designed and developed mechanisms have to cope with. In this work, we focus on studying the impact of network evolution on the resource allocation mechanisms in wireless multihop networks, and thus set the scene for more pragmatic network optimization. More specifically, we study the impact of topology evolution in the form of node and edge churn on the Network Utility Maximization (NUM) mechanism, where the latter is employed as a form of intelligent resource allocation framework and implementation. Our study in this paper serves as a stepping stone for a more realistic consideration of cross-layer design, capable of coping with the dynamic nature of the evolutionary changes that take place in each network inevitably. This work aspires to stimulate the interest and further research on improving and developing network optimization and control mechanisms under more realistic operational conditions. © Springer International Publishing Switzerland 2015.
Anifantis, E., Karyotis, V., & Papavassiliou, S. (2014). A spatio-stochastic framework for cross-layer design in cognitive radio networks. IEEE Transactions on Parallel and Distributed Systems, 25(11), 2762–2771.
@article{anifantis2014spatio,
title = {A spatio-stochastic framework for cross-layer design in cognitive radio networks},
author = {Evangelos Anifantis and Vasileios Karyotis and Symeon Papavassiliou},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Parallel and Distributed Systems},
volume = {25},
number = {11},
pages = {2762--2771},
publisher = {IEEE},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2014). Exploiting socio-physical network interactions via a utility-based framework for resource management in mobile social networks. IEEE Wireless Communications, 21(1), 10–17.
@article{stai2014exploiting,
title = {Exploiting socio-physical network interactions via a utility-based framework for resource management in mobile social networks},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
year = {2014},
date = {2014-01-01},
journal = {IEEE Wireless Communications},
volume = {21},
number = {1},
pages = {10--17},
publisher = {IEEE},
keywords = {},
pubstate = {published},
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Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2014). Discovering and exploiting spectrum power correlations in cognitive radio networks: an experimentally driven approach. EURASIP Journal on Wireless Communications and Networking, 2014(1), 1–14.
@article{arkoulis2014discovering,
title = {Discovering and exploiting spectrum power correlations in cognitive radio networks: an experimentally driven approach},
author = {Stamatios Arkoulis and Evangelos Anifantis and Vasileios Karyotis and Symeon Papavassiliou and Nikolaos Mitrou},
year = {2014},
date = {2014-01-01},
journal = {EURASIP Journal on Wireless Communications and Networking},
volume = {2014},
number = {1},
pages = {1--14},
publisher = {SpringerOpen},
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Anifantis, E., Stai, E., Karyotis, V., & Papavassiliou, S. (2014). Exploiting social features for improving cognitive radio infrastructures and social services via combined MRF and back pressure cross-layer resource allocation. Computational Social Networks, 1(1), 1–27.
@article{anifantis2014exploiting,
title = {Exploiting social features for improving cognitive radio infrastructures and social services via combined MRF and back pressure cross-layer resource allocation},
author = {Evangelos Anifantis and Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
year = {2014},
date = {2014-01-01},
journal = {Computational Social Networks},
volume = {1},
number = {1},
pages = {1--27},
publisher = {SpringerOpen},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Anifantis, E., Stai, E., Karyotis, V., & Papavassiliou, S. (2014). Exploiting social features for improving cognitive radio infrastructures and social services via combined MRF and back pressure cross-layer resource allocation. Computational Social Networks, 1(1). https://doi.org/10.1186/s40649-014-0004-1
@article{Anifantis2014,
title = {Exploiting social features for improving cognitive radio infrastructures and social services via combined MRF and back pressure cross-layer resource allocation},
author = {E. Anifantis and E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85029244666&doi=10.1186%2fs40649-014-0004-1&partnerID=40&md5=c42a9d50f41455d96e48947cf21d6431},
doi = {10.1186/s40649-014-0004-1},
issn = {21974314},
year = {2014},
date = {2014-01-01},
journal = {Computational Social Networks},
volume = {1},
number = {1},
publisher = {SpringerOpen},
abstract = {The observed unbalance of spectrum utilization combined with the proliferation of wireless devices and the growth of online social networks call for a joint study of cognitive radios (CRs) and social networking towards improving the operation of both the underlying CR-capable communications infrastructures and of the corresponding dynamic networks. In this work, we address such issue and focus on the twofold direction of resource allocation in CRs and social feature exploitation with the aim of providing a holistic cross-layer optimization framework that jointly considers information from the social layer as well as the traditional network protocol layers. We combine Markov random field (MRF) cross-layer decisions with back pressure (BP) features for the allocation of resources, in order to improve the operation of CRs that act as social network substrate. Espousing the recent advances in the field of dynamic spectrum allocation, the proposed BP-enhanced MRF (BPeMRF) network optimization serves the purpose of improving in a low complexity manner the capacity of agile infrastructures, which are required to adapt fast according to the demands of the volatile CR environment and the overlaying dynamic online social networks. In addition, within the proposed socially enhanced BPeMRF (SeBPeMRF) approach, we leverage emerging social information to further enhance performance. The obtained results exhibit the efficacy of BPeMRF/SeBPeMRF regarding the above objectives and demonstrate significant promise for further improving the corresponding infrastructures and services. © 2014, Anifantis et al.; licensee Springer.},
note = {cited By 8},
keywords = {},
pubstate = {published},
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}
The observed unbalance of spectrum utilization combined with the proliferation of wireless devices and the growth of online social networks call for a joint study of cognitive radios (CRs) and social networking towards improving the operation of both the underlying CR-capable communications infrastructures and of the corresponding dynamic networks. In this work, we address such issue and focus on the twofold direction of resource allocation in CRs and social feature exploitation with the aim of providing a holistic cross-layer optimization framework that jointly considers information from the social layer as well as the traditional network protocol layers. We combine Markov random field (MRF) cross-layer decisions with back pressure (BP) features for the allocation of resources, in order to improve the operation of CRs that act as social network substrate. Espousing the recent advances in the field of dynamic spectrum allocation, the proposed BP-enhanced MRF (BPeMRF) network optimization serves the purpose of improving in a low complexity manner the capacity of agile infrastructures, which are required to adapt fast according to the demands of the volatile CR environment and the overlaying dynamic online social networks. In addition, within the proposed socially enhanced BPeMRF (SeBPeMRF) approach, we leverage emerging social information to further enhance performance. The obtained results exhibit the efficacy of BPeMRF/SeBPeMRF regarding the above objectives and demonstrate significant promise for further improving the corresponding infrastructures and services. © 2014, Anifantis et al.; licensee Springer.
Anifantis, E., Karyotis, V., & Papavassiliou, S. (2014). A spatio-stochastic framework for cross-layer design in cognitive radio networks. IEEE Transactions on Parallel and Distributed Systems, 25(11), 2762-2771. https://doi.org/10.1109/TPDS.2013.2297108
@article{Anifantis20142762,
title = {A spatio-stochastic framework for cross-layer design in cognitive radio networks},
author = {E. Anifantis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84908084132&doi=10.1109%2fTPDS.2013.2297108&partnerID=40&md5=9868e8f746e1006f0805ae57204a9eeb},
doi = {10.1109/TPDS.2013.2297108},
issn = {10459219},
year = {2014},
date = {2014-01-01},
journal = {IEEE Transactions on Parallel and Distributed Systems},
volume = {25},
number = {11},
pages = {2762-2771},
publisher = {IEEE Computer Society},
abstract = {In this paper, we address the problem of distributed resource management for secondary users in Cognitive Radio Networks (CRNs), through a topology aware and frequency agile cross-layer approach. We exploit the theory of spatial processes and propose a Markov Random Field (MRF) based framework, which enables secondary CRN users to achieve efficient and viable mechanisms in the lower protocol stack layers by exchanging local only information. Specifically, through Gibbs sampling secondary users can optimize in a distributed and parallel manner their channel allocation, medium access and routing without resolving to otherwise computationally demanding optimization approaches. Through analysis and simulation we exhibit the efficacy of the proposed framework and show that a semi-parallel implementation can significantly reduce the required overhead cost compared to the sequential Gibbs sampling approach, while retaining a very close performance to the latter. We also study the emerging trade-offs by demonstrating the performance benefits in terms of channel assignment, medium access and data flow. © 2014 IEEE.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we address the problem of distributed resource management for secondary users in Cognitive Radio Networks (CRNs), through a topology aware and frequency agile cross-layer approach. We exploit the theory of spatial processes and propose a Markov Random Field (MRF) based framework, which enables secondary CRN users to achieve efficient and viable mechanisms in the lower protocol stack layers by exchanging local only information. Specifically, through Gibbs sampling secondary users can optimize in a distributed and parallel manner their channel allocation, medium access and routing without resolving to otherwise computationally demanding optimization approaches. Through analysis and simulation we exhibit the efficacy of the proposed framework and show that a semi-parallel implementation can significantly reduce the required overhead cost compared to the sequential Gibbs sampling approach, while retaining a very close performance to the latter. We also study the emerging trade-offs by demonstrating the performance benefits in terms of channel assignment, medium access and data flow. © 2014 IEEE.
Mavromoustakis, C. X., Pallis, E., Mastorakis, G., Karyotis, V., Anifantis, E., & Papavassiliou, S. (2014). Cross-Layer Based Resource Management Frameworks for Mobile Cognitive Radio Networks. Modeling and Optimization in Science and Technologies, 3, 285-322. https://doi.org/10.1007/978-3-319-06704-9-13
@article{Mavromoustakis2014285,
title = {Cross-Layer Based Resource Management Frameworks for Mobile Cognitive Radio Networks},
author = {C. X. Mavromoustakis and E. Pallis and G. Mastorakis and V. Karyotis and E. Anifantis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84959362682&doi=10.1007%2f978-3-319-06704-9-13&partnerID=40&md5=be185735c550b2ac5ccdb7fb9dfb5aa2},
doi = {10.1007/978-3-319-06704-9-13},
issn = {21967326},
year = {2014},
date = {2014-01-01},
journal = {Modeling and Optimization in Science and Technologies},
volume = {3},
pages = {285-322},
publisher = {Springer Verlag},
abstract = {Resource management has been one of the most important aspects of Mobile Cognitive Radio Networks (MCRNs) since their inception. It engulfs fundamental network operations such as spectrum management, bandwidth allocation, channel access, data routing, transmission power assignment and energy management. All such mechanisms are necessary for achieving the delay/throughput requirements desired by modern network services and users. Compared to traditional wireless mobile networks, the MCRN environment poses additional challenges and complicated requirements to the above functions and resource management in general, which eventually lead to an urgent need for reconsideration of the employed wireless protocol stack. The objective in MCRNs would be to apply more efficient protocol hierarchies and achieve better management of the common available resources for both secondary and primary users, at the minimum possible cost and by leaving the minimum possible resource footprint, as required for all modern communications systems. The cross-layer design approach has been proven extremely useful towards this direction, especially for network types such as sensor, mesh and cognitive radios. It allowed exploiting the most appropriate network mechanisms, while bypassing monolithic and outdated requirements when possible. In this chapter, we focus exactly on this aspect of protocol architectures and network management, and present state-of-the-art cross-layer based resource management approaches for MCRNs. Initially, we present three important resource management frameworks, and then we provide directions for developing generic and adaptive resource management protocol architectures for MCRNs, based on cross-layer and component-based design principles emerging from the previously presented approaches. This is the first attempt to highlight the suitability of combining cross-layer with component-based network design, and this work will also sketch qualitatively the potential benefits of such approach. Finally, some practical considerations for the proposed architecture, along with directions for future research conclude the chapter. © 2014 Springer International Publishing Switzerland.},
note = {cited By 2},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Resource management has been one of the most important aspects of Mobile Cognitive Radio Networks (MCRNs) since their inception. It engulfs fundamental network operations such as spectrum management, bandwidth allocation, channel access, data routing, transmission power assignment and energy management. All such mechanisms are necessary for achieving the delay/throughput requirements desired by modern network services and users. Compared to traditional wireless mobile networks, the MCRN environment poses additional challenges and complicated requirements to the above functions and resource management in general, which eventually lead to an urgent need for reconsideration of the employed wireless protocol stack. The objective in MCRNs would be to apply more efficient protocol hierarchies and achieve better management of the common available resources for both secondary and primary users, at the minimum possible cost and by leaving the minimum possible resource footprint, as required for all modern communications systems. The cross-layer design approach has been proven extremely useful towards this direction, especially for network types such as sensor, mesh and cognitive radios. It allowed exploiting the most appropriate network mechanisms, while bypassing monolithic and outdated requirements when possible. In this chapter, we focus exactly on this aspect of protocol architectures and network management, and present state-of-the-art cross-layer based resource management approaches for MCRNs. Initially, we present three important resource management frameworks, and then we provide directions for developing generic and adaptive resource management protocol architectures for MCRNs, based on cross-layer and component-based design principles emerging from the previously presented approaches. This is the first attempt to highlight the suitability of combining cross-layer with component-based network design, and this work will also sketch qualitatively the potential benefits of such approach. Finally, some practical considerations for the proposed architecture, along with directions for future research conclude the chapter. © 2014 Springer International Publishing Switzerland.
Karyotis, V., & Papavassiliou, S. (2014). Evaluation of malware spreading in wireless multihop networks with churn. Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST, 140, 63-74. https://doi.org/10.1007/978-3-319-13329-4_6
@article{Karyotis201463,
title = {Evaluation of malware spreading in wireless multihop networks with churn},
author = {V. Karyotis and S. Papavassiliou},
editor = {Papavassiliou S. Gallais A. Mitton N.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84915750171&doi=10.1007%2f978-3-319-13329-4_6&partnerID=40&md5=a87d7ee86d6d9c71332184f75a466edb},
doi = {10.1007/978-3-319-13329-4_6},
issn = {18678211},
year = {2014},
date = {2014-01-01},
journal = {Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, LNICST},
volume = {140},
pages = {63-74},
publisher = {Springer Verlag},
abstract = {Modeling malware spreading in wireless networks has attracted significant interest lately, since this will increase the robustness of such networks that constitute the lion’s share of Internet access nowadays. However, all of previous works have considered networks with fixed number of devices. In this work, we focus on users that can dynamically join and leave the network (node churn) as a result of the effects of malware, or their own operation, i.e. energy depletion. We adopt and adapt a queuing-based model for malware spreading for the case of wireless distributed networks with churn. The corresponding methodology captures the dynamics of SIS-type malware, where nodes are always prone to receive new or already spreading infections over a long period. The employed framework can be exploited for quantifying network reliability and study network behavior, which can be further used for increasing the robustness of the system against the most severe attacks. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2014.},
note = {cited By 3; Conference of 6th International ICST Conference on Ad Hoc Networks, ADHOCNETS 2014 ; Conference Date: 18 August 2014 Through 19 August 2014; Conference Code:111559},
keywords = {},
pubstate = {published},
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Modeling malware spreading in wireless networks has attracted significant interest lately, since this will increase the robustness of such networks that constitute the lion’s share of Internet access nowadays. However, all of previous works have considered networks with fixed number of devices. In this work, we focus on users that can dynamically join and leave the network (node churn) as a result of the effects of malware, or their own operation, i.e. energy depletion. We adopt and adapt a queuing-based model for malware spreading for the case of wireless distributed networks with churn. The corresponding methodology captures the dynamics of SIS-type malware, where nodes are always prone to receive new or already spreading infections over a long period. The employed framework can be exploited for quantifying network reliability and study network behavior, which can be further used for increasing the robustness of the system against the most severe attacks. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2014.
Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2014). Discovering and exploiting spectrum power correlations in cognitive radio networks: An experimentally driven approach. Eurasip Journal on Wireless Communications and Networking, 2014. https://doi.org/10.1186/1687-1499-2014-17
@article{Arkoulis2014,
title = {Discovering and exploiting spectrum power correlations in cognitive radio networks: An experimentally driven approach},
author = {S. Arkoulis and E. Anifantis and V. Karyotis and S. Papavassiliou and N. Mitrou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898839082&doi=10.1186%2f1687-1499-2014-17&partnerID=40&md5=4789636b51a25eda2ceb6d599b8fbb4d},
doi = {10.1186/1687-1499-2014-17},
issn = {16871472},
year = {2014},
date = {2014-01-01},
journal = {Eurasip Journal on Wireless Communications and Networking},
volume = {2014},
publisher = {Hindawi Publishing Corporation},
abstract = {In this paper, we focus on increasing the spectrum awareness of cognitive radio users through statistical processing of spectrum sensing data, obtained via wideband energy-detection-based sensing techniques. Based on observations over real spectrum power measurements, we advocate the existence of correlation properties in the sensed power of measured neighboring channels and propose an inference methodology for exploiting them towards acquiring a more accurate view of the underlying wireless environment. To highlight the benefits of the proposed correlation-based inference methodology on cognitive radio systems, we emphasize on enhancements of white space discovery and channel selection processes, while we thoroughly discuss the impact of our findings on existing relevant approaches. Based on a systematic wireless spectrum survey in the metropolitan area of Athens, Greece, we validate our proposed methodology and assess the achieved performance improvements through the obtained measurement data, confirming its potential value in future cognitive radio networks. © 2014 Arkoulis et al.; licensee Springer.},
note = {cited By 6},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we focus on increasing the spectrum awareness of cognitive radio users through statistical processing of spectrum sensing data, obtained via wideband energy-detection-based sensing techniques. Based on observations over real spectrum power measurements, we advocate the existence of correlation properties in the sensed power of measured neighboring channels and propose an inference methodology for exploiting them towards acquiring a more accurate view of the underlying wireless environment. To highlight the benefits of the proposed correlation-based inference methodology on cognitive radio systems, we emphasize on enhancements of white space discovery and channel selection processes, while we thoroughly discuss the impact of our findings on existing relevant approaches. Based on a systematic wireless spectrum survey in the metropolitan area of Athens, Greece, we validate our proposed methodology and assess the achieved performance improvements through the obtained measurement data, confirming its potential value in future cognitive radio networks. © 2014 Arkoulis et al.; licensee Springer.
Stai, E., Karyotis, V., & Papavassiliou, S. (2014). Exploiting socio-physical network interactions via a utility-based framework for resource management in mobile social networks. IEEE Wireless Communications, 21(1), 10-17. https://doi.org/10.1109/MWC.2014.6757892
@article{Stai201410,
title = {Exploiting socio-physical network interactions via a utility-based framework for resource management in mobile social networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896446369&doi=10.1109%2fMWC.2014.6757892&partnerID=40&md5=f25c02100f1cd76420991d05f7580ad9},
doi = {10.1109/MWC.2014.6757892},
issn = {15361284},
year = {2014},
date = {2014-01-01},
journal = {IEEE Wireless Communications},
volume = {21},
number = {1},
pages = {10-17},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Mobile social networks have the lion's share in modern mobile telecommunications, and their interaction with the underlying infrastructure networks has attracted significant attention due to its impact on resource management. In this article, we present and demonstrate a framework for addressing such interplay between online social networks and wireless communications by exploiting principles from the theory of utility-based engineering and elements from social network analysis. We aim at a holistic design framework that allows the joint development of improved resource management mechanisms for future mobile wireless infrastructures and their social counterparts. We demonstrate the proposed methodology and reveal the key aspects of designing and exploiting convenient utility functions within the framework of network science in order to better manage the available resources, improve infrastructures, and eventually obtain from them the maximum possible benefit. We establish the above principles and emerging design potentials in future complex networks by presenting two tangible examples where personalized advertising and topology control in MSNs are used to exploit and validate different network and individual socio-utility maximization features, respectively. © 2014 IEEE.},
note = {cited By 16},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Mobile social networks have the lion's share in modern mobile telecommunications, and their interaction with the underlying infrastructure networks has attracted significant attention due to its impact on resource management. In this article, we present and demonstrate a framework for addressing such interplay between online social networks and wireless communications by exploiting principles from the theory of utility-based engineering and elements from social network analysis. We aim at a holistic design framework that allows the joint development of improved resource management mechanisms for future mobile wireless infrastructures and their social counterparts. We demonstrate the proposed methodology and reveal the key aspects of designing and exploiting convenient utility functions within the framework of network science in order to better manage the available resources, improve infrastructures, and eventually obtain from them the maximum possible benefit. We establish the above principles and emerging design potentials in future complex networks by presenting two tangible examples where personalized advertising and topology control in MSNs are used to exploit and validate different network and individual socio-utility maximization features, respectively. © 2014 IEEE.
Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2013). On the optimal, fair and channel-aware cognitive radio network reconfiguration. Computer Networks, 57(8), 1739–1757.
@article{arkoulis2013optimal,
title = {On the optimal, fair and channel-aware cognitive radio network reconfiguration},
author = {Stamatios Arkoulis and Evangelos Anifantis and Vasileios Karyotis and Symeon Papavassiliou and Nikolaos Mitrou},
year = {2013},
date = {2013-01-01},
journal = {Computer Networks},
volume = {57},
number = {8},
pages = {1739--1757},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Cheng, S.-M., Karyotis, V., Chen, P.-Y., Chen, K.-C., & Papavassiliou, S. (2013). Diffusion models for information dissemination dynamics in wireless complex communication networks. Journal of Complex Systems, 2013.
@article{cheng2013diffusion,
title = {Diffusion models for information dissemination dynamics in wireless complex communication networks},
author = {Shin-Ming Cheng and Vasileios Karyotis and Pin-Yu Chen and Kwang-Cheng Chen and Symeon Papavassiliou},
year = {2013},
date = {2013-01-01},
journal = {Journal of Complex Systems},
volume = {2013},
publisher = {Hindawi},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2013). On the optimal, fair and channel-aware cognitive radio network reconfiguration. Computer Networks, 57(8), 1739-1757. https://doi.org/10.1016/j.comnet.2013.03.004
@article{Arkoulis20131739,
title = {On the optimal, fair and channel-aware cognitive radio network reconfiguration},
author = {S. Arkoulis and E. Anifantis and V. Karyotis and S. Papavassiliou and N. Mitrou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878115702&doi=10.1016%2fj.comnet.2013.03.004&partnerID=40&md5=f0b5125bfb88b55dda37a775e106f7ff},
doi = {10.1016/j.comnet.2013.03.004},
issn = {13891286},
year = {2013},
date = {2013-01-01},
journal = {Computer Networks},
volume = {57},
number = {8},
pages = {1739-1757},
abstract = {In this work, we focus on the Joint Channel Assignment and Routing (JCAR) problem in Cognitive Radio Networks (CRNs) and especially on the optimal reconfiguration of secondary networks under the presence of primary users. Secondary CRN users need to adapt their transmission channels promptly, while effectively limit additional or escalating system modifications triggered by the intertweaved primary user activity. Our approach takes into consideration the underlying spectrum switching dynamics and concurrently aims at a fair resource allocation among the active network flows. We take an optimization perspective and formulate the JCAR and network reconfiguration problems as mixed integer linear programs, addressing fairness concerns as well. We propose a heuristic approach which is based on a sequential reduced search space methodology, in order to obtain efficiently solutions of otherwise tough and demanding reconfiguration problems. The operation, effectiveness and performance of the proposed mechanisms are evaluated through analysis and simulations under various working conditions. The obtained numerical results indicate the benefits of the proposed schemes in terms of overhead performance and their scaling properties with respect to more realistic and thus demanding topologies. © 2013 Elsevier B.V. All rights reserved.},
note = {cited By 16},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this work, we focus on the Joint Channel Assignment and Routing (JCAR) problem in Cognitive Radio Networks (CRNs) and especially on the optimal reconfiguration of secondary networks under the presence of primary users. Secondary CRN users need to adapt their transmission channels promptly, while effectively limit additional or escalating system modifications triggered by the intertweaved primary user activity. Our approach takes into consideration the underlying spectrum switching dynamics and concurrently aims at a fair resource allocation among the active network flows. We take an optimization perspective and formulate the JCAR and network reconfiguration problems as mixed integer linear programs, addressing fairness concerns as well. We propose a heuristic approach which is based on a sequential reduced search space methodology, in order to obtain efficiently solutions of otherwise tough and demanding reconfiguration problems. The operation, effectiveness and performance of the proposed mechanisms are evaluated through analysis and simulations under various working conditions. The obtained numerical results indicate the benefits of the proposed schemes in terms of overhead performance and their scaling properties with respect to more realistic and thus demanding topologies. © 2013 Elsevier B.V. All rights reserved.
Manolakos, A., Karyotis, V., & Papavassiliou, S. (2012). A cross-layer-based topology control framework for wireless multihop networks. IEEE transactions on vehicular technology, 61(6), 2858–2864.
@article{manolakos2012cross,
title = {A cross-layer-based topology control framework for wireless multihop networks},
author = {Alexandros Manolakos and Vasileios Karyotis and Symeon Papavassiliou},
year = {2012},
date = {2012-01-01},
journal = {IEEE transactions on vehicular technology},
volume = {61},
number = {6},
pages = {2858--2864},
publisher = {IEEE},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Manolakos, A., Karyotis, V., & Papavassiliou, S. (2012). A cross-layer-based topology control framework for wireless multihop networks. IEEE Transactions on Vehicular Technology, 61(6), 2858-2864. https://doi.org/10.1109/TVT.2012.2195340
@article{Manolakos20122858,
title = {A cross-layer-based topology control framework for wireless multihop networks},
author = {A. Manolakos and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84863934355&doi=10.1109%2fTVT.2012.2195340&partnerID=40&md5=bea0ce8fe0f4f424b10374cd64e99860},
doi = {10.1109/TVT.2012.2195340},
issn = {00189545},
year = {2012},
date = {2012-01-01},
journal = {IEEE Transactions on Vehicular Technology},
volume = {61},
number = {6},
pages = {2858-2864},
abstract = {In this paper, we propose a distributed and asynchronous topology control framework for wireless multihop networks, aiming at improving the quality-of-service capabilities of such systems. The proposed mechanisms exploit cross-layer information such as physical-layer signal-to-interference-plus- noise ratio (SINR) values and medium-access-control (MAC)/network-layer connectivity to effectively allocate resources. Based on properly defined utility functions, we cast the transmission power allocation problem as a noncooperative game and then show that it belongs to the class of potential games. We obtain structural properties of the defined game and its variations and demonstrate their effectiveness. Through analysis and simulation, we explore the behavior of the proposed framework and compare it with the most relevant approach in the literature. It is shown that the proposed unifying game-theoretic framework achieves three key goals for multihop ad hoc networks, i.e., reduced transmission power, high-quality links, and connectivity maintenance. © 1967-2012 IEEE.},
note = {cited By 5},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we propose a distributed and asynchronous topology control framework for wireless multihop networks, aiming at improving the quality-of-service capabilities of such systems. The proposed mechanisms exploit cross-layer information such as physical-layer signal-to-interference-plus- noise ratio (SINR) values and medium-access-control (MAC)/network-layer connectivity to effectively allocate resources. Based on properly defined utility functions, we cast the transmission power allocation problem as a noncooperative game and then show that it belongs to the class of potential games. We obtain structural properties of the defined game and its variations and demonstrate their effectiveness. Through analysis and simulation, we explore the behavior of the proposed framework and compare it with the most relevant approach in the literature. It is shown that the proposed unifying game-theoretic framework achieves three key goals for multihop ad hoc networks, i.e., reduced transmission power, high-quality links, and connectivity maintenance. © 1967-2012 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2012). Topology enhancements in wireless multihop networks: A top-down approach. IEEE Transactions on Parallel and Distributed Systems, 23(7), 1344-1357. https://doi.org/10.1109/TPDS.2011.250
@article{Stai20121344,
title = {Topology enhancements in wireless multihop networks: A top-down approach},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861741202&doi=10.1109%2fTPDS.2011.250&partnerID=40&md5=0254f54df82f0e88a0a260e40d8ab384},
doi = {10.1109/TPDS.2011.250},
issn = {10459219},
year = {2012},
date = {2012-01-01},
journal = {IEEE Transactions on Parallel and Distributed Systems},
volume = {23},
number = {7},
pages = {1344-1357},
abstract = {Contemporary traffic demands call for efficient infrastructures capable of sustaining increasing volumes of social communications. In this work, we focus on improving the properties of wireless multihop networks with social features through network evolution. Specifically, we introduce a framework, based on inverse Topology Control (iTC), for distributively modifying the transmission radius of selected nodes, according to social paradigms. Distributed iTC mechanisms are proposed for exploiting evolutionary network churn in the form of edge/node modifications, without significantly impacting available resources. We employ continuum theory for analytically describing the proposed top-down approach of infusing social features in physical topologies. Through simulations, we demonstrate how these mechanisms achieve their goal of reducing the average path length, so as to make a wireless multihop network scale like a social one, while retaining its original multihop character. We study the impact of the proposed topology modifications on the operation and performance of the network with respect to the average throughput, delay, and energy consumption of the induced network. © 2012 IEEE.},
note = {cited By 16},
keywords = {},
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Contemporary traffic demands call for efficient infrastructures capable of sustaining increasing volumes of social communications. In this work, we focus on improving the properties of wireless multihop networks with social features through network evolution. Specifically, we introduce a framework, based on inverse Topology Control (iTC), for distributively modifying the transmission radius of selected nodes, according to social paradigms. Distributed iTC mechanisms are proposed for exploiting evolutionary network churn in the form of edge/node modifications, without significantly impacting available resources. We employ continuum theory for analytically describing the proposed top-down approach of infusing social features in physical topologies. Through simulations, we demonstrate how these mechanisms achieve their goal of reducing the average path length, so as to make a wireless multihop network scale like a social one, while retaining its original multihop character. We study the impact of the proposed topology modifications on the operation and performance of the network with respect to the average throughput, delay, and energy consumption of the induced network. © 2012 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2011). Topology enhancements in wireless multihop networks: A top-down approach. IEEE Transactions on Parallel and Distributed Systems, 23(7), 1344–1357.
@article{stai2011topology,
title = {Topology enhancements in wireless multihop networks: A top-down approach},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
year = {2011},
date = {2011-01-01},
journal = {IEEE Transactions on Parallel and Distributed Systems},
volume = {23},
number = {7},
pages = {1344--1357},
publisher = {IEEE},
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Karyotis, V., Fazio, M., Papavassiliou, S., & Puliafito, A. (2011). Comparison of efficient random walk strategies for wireless multi-hop networks. Computer Communications, 34(10), 1258–1267.
@article{karyotis2011comparison,
title = {Comparison of efficient random walk strategies for wireless multi-hop networks},
author = {Vasileios Karyotis and Maria Fazio and Symeon Papavassiliou and Antonio Puliafito},
year = {2011},
date = {2011-01-01},
journal = {Computer Communications},
volume = {34},
number = {10},
pages = {1258--1267},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Stai, E., Karyotis, V., & Papavassiliou, S. (2011). A socially-driven topology improvement framework with applications in content distribution and trust management. Journal of Internet Services and Applications, 2(2), 113–127.
@article{stai2011socially,
title = {A socially-driven topology improvement framework with applications in content distribution and trust management},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
year = {2011},
date = {2011-01-01},
journal = {Journal of Internet Services and Applications},
volume = {2},
number = {2},
pages = {113--127},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2011). A socially-driven topology improvement framework with applications in content distribution and trust management. Journal of Internet Services and Applications, 2(2), 113-127. https://doi.org/10.1007/s13174-011-0024-0
@article{Stai2011113,
title = {A socially-driven topology improvement framework with applications in content distribution and trust management},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84857595353&doi=10.1007%2fs13174-011-0024-0&partnerID=40&md5=81a4c8ac5441e15ef0402d39ccca4cbe},
doi = {10.1007/s13174-011-0024-0},
issn = {18674828},
year = {2011},
date = {2011-01-01},
journal = {Journal of Internet Services and Applications},
volume = {2},
number = {2},
pages = {113-127},
abstract = {Contemporary networking infrastructures are required to be capable of adapting to the increasing trends of user demands, as well as the impairments of their operational environment. In this work, by exploiting the power varying capabilities of multihop wireless networks and inspired by social structures of the higher protocol layers, we develop a distributed and dynamic physical topology modification framework for weighted and directed multihop networks. The operational robustness and effectiveness of the proposed framework is demonstrated in two highly popular application areas, namely QoS-oriented content distribution and trust management in wireless multihop networks. We focus on the emerging trade-offs of topology modification, and through analysis and simulation, we demonstrate how social features can be used in improving the physical network topology and corresponding performance. © 2011 The Brazilian Computer Society.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Contemporary networking infrastructures are required to be capable of adapting to the increasing trends of user demands, as well as the impairments of their operational environment. In this work, by exploiting the power varying capabilities of multihop wireless networks and inspired by social structures of the higher protocol layers, we develop a distributed and dynamic physical topology modification framework for weighted and directed multihop networks. The operational robustness and effectiveness of the proposed framework is demonstrated in two highly popular application areas, namely QoS-oriented content distribution and trust management in wireless multihop networks. We focus on the emerging trade-offs of topology modification, and through analysis and simulation, we demonstrate how social features can be used in improving the physical network topology and corresponding performance. © 2011 The Brazilian Computer Society.
Karyotis, V., Fazio, M., Papavassiliou, S., & Puliafito, A. (2011). Comparison of efficient random walk strategies for wireless multi-hop networks. Computer Communications, 34(10), 1258-1267. https://doi.org/10.1016/j.comcom.2011.01.001
@article{Karyotis20111258,
title = {Comparison of efficient random walk strategies for wireless multi-hop networks},
author = {V. Karyotis and M. Fazio and S. Papavassiliou and A. Puliafito},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79955708234&doi=10.1016%2fj.comcom.2011.01.001&partnerID=40&md5=06a7f2bacc2f23dd6cbd25c27205ee8b},
doi = {10.1016/j.comcom.2011.01.001},
issn = {01403664},
year = {2011},
date = {2011-01-01},
journal = {Computer Communications},
volume = {34},
number = {10},
pages = {1258-1267},
abstract = {Wireless multi-hop networks have drawn great attention from research and business communities, since they suit well diverse application scenarios, such as environmental monitoring, military support in hostile environments and emergency applications. However, this challenging communication paradigm requires solutions able to fit specific requirements in terms of resource constrains, node mobility and quality of service. Random Walks (RWs) are probabilistic approaches to perform distributed operations, such as data search and retrieval. They are effective and have relatively small overhead compared to classic schemes, such as flooding. To further improve performance of RWs, hybrid solutions may be employed. Such strategies increase system performance at the cost of additional energy consumption. In this work, we propose two novel schemes that exploit local topological information in order to increase the hybrid RW protocols performance. Through simulations, we compare hybrid protocols with a traditional RW solution, studying their performance in static and mobile scenarios. An analysis of the trade-off between the number of node revisits and energy consumption allows to identify the more fitting protocols for different application scenarios in wireless multi-hop networks. Advantages and drawbacks of different RW strategies are highlighted, along with research challenges that need to be investigated in the future. © 2011 Elsevier B.V. All rights reserved.},
note = {cited By 4},
keywords = {},
pubstate = {published},
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}
Wireless multi-hop networks have drawn great attention from research and business communities, since they suit well diverse application scenarios, such as environmental monitoring, military support in hostile environments and emergency applications. However, this challenging communication paradigm requires solutions able to fit specific requirements in terms of resource constrains, node mobility and quality of service. Random Walks (RWs) are probabilistic approaches to perform distributed operations, such as data search and retrieval. They are effective and have relatively small overhead compared to classic schemes, such as flooding. To further improve performance of RWs, hybrid solutions may be employed. Such strategies increase system performance at the cost of additional energy consumption. In this work, we propose two novel schemes that exploit local topological information in order to increase the hybrid RW protocols performance. Through simulations, we compare hybrid protocols with a traditional RW solution, studying their performance in static and mobile scenarios. An analysis of the trade-off between the number of node revisits and energy consumption allows to identify the more fitting protocols for different application scenarios in wireless multi-hop networks. Advantages and drawbacks of different RW strategies are highlighted, along with research challenges that need to be investigated in the future. © 2011 Elsevier B.V. All rights reserved.
Karyotis, V., & Valagiannopoulos, C. (2010). Analytic stochastic propagation model for urban streets. IET microwaves, antennas & propagation, 4(1), 91–98.
@article{karyotis2010analytic,
title = {Analytic stochastic propagation model for urban streets},
author = {VA Karyotis and CA Valagiannopoulos},
year = {2010},
date = {2010-01-01},
journal = {IET microwaves, antennas & propagation},
volume = {4},
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publisher = {IET Digital Library},
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Karyotis, V. (2010). Markov random fields for malware propagation: The case of chain networks. IEEE communications letters, 14(9), 875–877.
@article{karyotis2010markov,
title = {Markov random fields for malware propagation: The case of chain networks},
author = {Vasileios Karyotis},
year = {2010},
date = {2010-01-01},
journal = {IEEE communications letters},
volume = {14},
number = {9},
pages = {875--877},
publisher = {IEEE},
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Karyotis, V., Pittalà, F., Fazio, M., Papavassiliou, S., & Puliafito, A. (2010). Topology-aware hybrid random walk protocols for wireless multihop networks. Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering, 32 LNICST, 107-118. https://doi.org/10.1007/978-3-642-11817-3_10
@article{Karyotis2010107,
title = {Topology-aware hybrid random walk protocols for wireless multihop networks},
author = {V. Karyotis and F. Pittalà and M. Fazio and S. Papavassiliou and A. Puliafito},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885893498&doi=10.1007%2f978-3-642-11817-3_10&partnerID=40&md5=90023c1d624d4f2bb70f6f595786f39c},
doi = {10.1007/978-3-642-11817-3_10},
issn = {18678211},
year = {2010},
date = {2010-01-01},
journal = {Lecture Notes of the Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering},
volume = {32 LNICST},
pages = {107-118},
address = {Athens},
abstract = {The proliferation of wireless multihop networks has made various operations, such as search and retrieval of distributed data a significant concern. Various methods have been proposed for performing such tasks efficiently, especially when all network nodes need to be visited at least once. Random walks are probabilistic approaches for performing the aforementioned operations effectively and with relatively small overhead compared to other typically-employed schemes, such as flooding. Recently, a hybrid random walk scheme has been proposed for increasing the desired performance, at the cost of additional consumed resources. In this work, we adopt the paradigm of hybrid random walk protocols and propose two novel hybrid schemes that exploit local topological information, aiming at further increasing the performance of random walk protocols in multihop networks. We consider different jump configurations of the hybrid random walk protocols and various degrees of mobility. Through analysis and simulation, the simple random walk model appears more appropriate for energy-constrained networks such as sensor networks, while the hybrid ones are more appealing for less energy-stringent, performance-oriented multihop networks, such as vehicular and mesh networks. The simple hybrid protocol occupies the middle ground, being appealing for ad hoc networks with medium to low node densities and average energy requirements. © 2010 ICST Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering.},
note = {cited By 2; Conference of 1st International Conference on Mobile Networks and Management, MONAMI 2009 ; Conference Date: 13 October 2009 Through 14 October 2009; Conference Code:86048},
keywords = {},
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The proliferation of wireless multihop networks has made various operations, such as search and retrieval of distributed data a significant concern. Various methods have been proposed for performing such tasks efficiently, especially when all network nodes need to be visited at least once. Random walks are probabilistic approaches for performing the aforementioned operations effectively and with relatively small overhead compared to other typically-employed schemes, such as flooding. Recently, a hybrid random walk scheme has been proposed for increasing the desired performance, at the cost of additional consumed resources. In this work, we adopt the paradigm of hybrid random walk protocols and propose two novel hybrid schemes that exploit local topological information, aiming at further increasing the performance of random walk protocols in multihop networks. We consider different jump configurations of the hybrid random walk protocols and various degrees of mobility. Through analysis and simulation, the simple random walk model appears more appropriate for energy-constrained networks such as sensor networks, while the hybrid ones are more appealing for less energy-stringent, performance-oriented multihop networks, such as vehicular and mesh networks. The simple hybrid protocol occupies the middle ground, being appealing for ad hoc networks with medium to low node densities and average energy requirements. © 2010 ICST Institute for Computer Sciences, Social-Informatics and Telecommunications Engineering.
Karyotis, V. (2010). Markov Random Fields for malware propagation: The case of chain networks. IEEE Communications Letters, 14(9), 875-877. https://doi.org/10.1109/LCOMM.2010.072910.100866
@article{Karyotis2010875,
title = {Markov Random Fields for malware propagation: The case of chain networks},
author = {V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957705451&doi=10.1109%2fLCOMM.2010.072910.100866&partnerID=40&md5=0aa0a66743c86b11f726b5b39925249c},
doi = {10.1109/LCOMM.2010.072910.100866},
issn = {10897798},
year = {2010},
date = {2010-01-01},
journal = {IEEE Communications Letters},
volume = {14},
number = {9},
pages = {875-877},
abstract = {Epidemic and stochastic models have been employed for describing the dynamic behavior of malware outbreaks. However, most of them lack a holistic treatment of the problem. In this work, we model malware propagation as a Markov Random Field and employ Gibbs sampling for the analysis of the system. We demonstrate the proposed framework for the case of a chain network, a model often emerging in both wired and wireless multi-hop networks. © 2010 IEEE.},
note = {cited By 13},
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Epidemic and stochastic models have been employed for describing the dynamic behavior of malware outbreaks. However, most of them lack a holistic treatment of the problem. In this work, we model malware propagation as a Markov Random Field and employ Gibbs sampling for the analysis of the system. We demonstrate the proposed framework for the case of a chain network, a model often emerging in both wired and wireless multi-hop networks. © 2010 IEEE.
Karyotis, V., & Papavassiliou, S. (2009). 8 Topology Control in Cooperative Wireless Ad Hoc Networks. Cooperative Wireless Communications, 167.
@article{karyotis20098,
title = {8 Topology Control in Cooperative Wireless Ad Hoc Networks},
author = {Vasileios Karyotis and Symeon Papavassiliou},
year = {2009},
date = {2009-01-01},
journal = {Cooperative Wireless Communications},
pages = {167},
publisher = {CRC Press},
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Smirnov, M., Tiemann, J., Chaparadza, R., Rebahi, Y., Papavassiliou, S., Karyotis, V., Pouli, V., Merekoulias, V., Gulyas, A., Heszberger, Z., & others (2009). Demystifying self-awareness of autonomic systems. ICT Mobile Summit, Santander, Spain, 10-12 June 2009.
@article{smirnov2009demystifying,
title = {Demystifying self-awareness of autonomic systems},
author = {Mikhail Smirnov and Jens Tiemann and Ranganai Chaparadza and Yacine Rebahi and Symeon Papavassiliou and Vassilis Karyotis and Vassiliki Pouli and Vassilis Merekoulias and András Gulyas and Zalán Heszberger and others},
year = {2009},
date = {2009-01-01},
journal = {ICT Mobile Summit, Santander, Spain, 10-12 June 2009},
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Karyotis, V. A., & Valagiannopoulos, C. A. (2009). Analytic stochastic propagation model for urban streets. IET Microwaves, Antennas and Propagation, 4(1), 91-98. https://doi.org/10.1049/iet-map.2008.0131
@article{Karyotis200991,
title = {Analytic stochastic propagation model for urban streets},
author = {V. A. Karyotis and C. A. Valagiannopoulos},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-72849134420&doi=10.1049%2fiet-map.2008.0131&partnerID=40&md5=87c58f1e3acdd4abc8930feae1f6dad4},
doi = {10.1049/iet-map.2008.0131},
issn = {17518725},
year = {2009},
date = {2009-01-01},
journal = {IET Microwaves, Antennas and Propagation},
volume = {4},
number = {1},
pages = {91-98},
abstract = {Stochastic ray propagation is a method to retain analytic description in topologies where application of Maxwell's equations would be ineffective or impossible. In this paper, a probabilistic model describing ray propagation along an urban street is analysed and discussed. The proposed model bears the simplicity of an analytic approach, and even though not fully descriptive of all propagation mechanisms, it provides informative results of wireless propagation in the event of a first-stage analysis. Based on the presented probabilistic formulation, explicit expressions of the power across and at the end of the street are obtained and used to evaluate the behaviour of the considered structure. We confirm our analysis through simulation, by computing the distribution of ray paths along the street. We identify the probabilistic propagation mechanism as the dominant factor for the received power at the end of the street for a travelling wave antenna. By considering multiple distributed point sources across the beginning of the street, the coincidence between the numerical average of the received power and the expected value of the corresponding random variable is exhibited. The proposed formulation can be further used as a basis for analysing similar problems, yielding useful and indicative results. © 2010 The Institution of Engineering and Technology.},
note = {cited By 3},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Stochastic ray propagation is a method to retain analytic description in topologies where application of Maxwell's equations would be ineffective or impossible. In this paper, a probabilistic model describing ray propagation along an urban street is analysed and discussed. The proposed model bears the simplicity of an analytic approach, and even though not fully descriptive of all propagation mechanisms, it provides informative results of wireless propagation in the event of a first-stage analysis. Based on the presented probabilistic formulation, explicit expressions of the power across and at the end of the street are obtained and used to evaluate the behaviour of the considered structure. We confirm our analysis through simulation, by computing the distribution of ray paths along the street. We identify the probabilistic propagation mechanism as the dominant factor for the received power at the end of the street for a travelling wave antenna. By considering multiple distributed point sources across the beginning of the street, the coincidence between the numerical average of the received power and the expected value of the corresponding random variable is exhibited. The proposed formulation can be further used as a basis for analysing similar problems, yielding useful and indicative results. © 2010 The Institution of Engineering and Technology.
Karyotis, V., Kakalis, A., & Papavassiliou, S. (2008). Malware-propagative mobile ad hoc networks: asymptotic behavior analysis. Journal of Computer Science and Technology, 23(3), 389–399.
@article{karyotis2008malware,
title = {Malware-propagative mobile ad hoc networks: asymptotic behavior analysis},
author = {Vasileios Karyotis and Anastasios Kakalis and Symeon Papavassiliou},
year = {2008},
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journal = {Journal of Computer Science and Technology},
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publisher = {Springer US},
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Valagiannopoulos, C. A., & Karyotis, V. A. (2008). Stochastic ray propagation for two parallel urban streets: Exact and approximate results. IEEE Antennas and Wireless Propagation Letters, 7, 381–384.
@article{valagiannopoulos2008stochastic,
title = {Stochastic ray propagation for two parallel urban streets: Exact and approximate results},
author = {Constantine A Valagiannopoulos and Vasileios A Karyotis},
year = {2008},
date = {2008-01-01},
journal = {IEEE Antennas and Wireless Propagation Letters},
volume = {7},
pages = {381--384},
publisher = {IEEE},
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Karyotis, V., Kakalis, A., & Papavassiliou, S. (2008). 移动自组网的恶意软件传播: 渐进行为分析. 计算机科学技术学报, 23(3), 389–399.
@article{karyotis2008移动自组网的恶意软件传播,
title = {移动自组网的恶意软件传播: 渐进行为分析},
author = {Vasileios Karyotis and Anastasios Kakalis and Symeon Papavassiliou},
year = {2008},
date = {2008-01-01},
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Valagiannopoulos, C. A., & Karyotis, V. A. (2008). Stochastic ray propagation for two parallel urban streets: Exact and approximate results. IEEE Antennas and Wireless Propagation Letters, 7, 381-384. https://doi.org/10.1109/LAWP.2008.2000856
@article{Valagiannopoulos2008381,
title = {Stochastic ray propagation for two parallel urban streets: Exact and approximate results},
author = {C. A. Valagiannopoulos and V. A. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77957984570&doi=10.1109%2fLAWP.2008.2000856&partnerID=40&md5=5ebc441ed0bcebce0fc0f962ce75b6d0},
doi = {10.1109/LAWP.2008.2000856},
issn = {15361225},
year = {2008},
date = {2008-01-01},
journal = {IEEE Antennas and Wireless Propagation Letters},
volume = {7},
pages = {381-384},
abstract = {In this letter, an analytic stochastic model for the propagation of plane waves in two parallel urban streets is developed. The received power at the end of the topology is obtained and three solution cases of significant and practical interest are identified and studied in detail. In addition, a linear approximation method is proposed for the same problem. Numerical results are provided to analyze the nature of the propagation with respect to the parameters, symmetry of the topology and the applicability of the approximation method. The proposed analytic model is simple, yet it can capture the basic mechanism of propagation and can be used as an early indication before the application of large-scale methods in practical scenarios. © 2008 IEEE.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this letter, an analytic stochastic model for the propagation of plane waves in two parallel urban streets is developed. The received power at the end of the topology is obtained and three solution cases of significant and practical interest are identified and studied in detail. In addition, a linear approximation method is proposed for the same problem. Numerical results are provided to analyze the nature of the propagation with respect to the parameters, symmetry of the topology and the applicability of the approximation method. The proposed analytic model is simple, yet it can capture the basic mechanism of propagation and can be used as an early indication before the application of large-scale methods in practical scenarios. © 2008 IEEE.
Karyotis, V., Kakalis, A., & Papavassiliou, S. (2008). Malware-propagative mobile ad hoc networks: Asymptotic behavior analysis. Journal of Computer Science and Technology, 23(3), 389-399. https://doi.org/10.1007/s11390-008-9141-z
@article{Karyotis2008389,
title = {Malware-propagative mobile ad hoc networks: Asymptotic behavior analysis},
author = {V. Karyotis and A. Kakalis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-44649129992&doi=10.1007%2fs11390-008-9141-z&partnerID=40&md5=1404069b5474265cb5c3f551cfc609c6},
doi = {10.1007/s11390-008-9141-z},
issn = {10009000},
year = {2008},
date = {2008-01-01},
journal = {Journal of Computer Science and Technology},
volume = {23},
number = {3},
pages = {389-399},
abstract = {In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyzed. Considering the Susceptible-Infected-Susceptible (SIS) node infection paradigm we propose a probabilistic model, on the basis of the theory of closed queuing networks, that aims at describing the aggregated behavior of the system when attacked by malicious nodes. Because of its nature, the model is also able to deal more effectively with the stochastic behavior of attackers and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative large scale ad hoc networking environments. Using the Norton equivalent of the closed queuing network, we obtain analytical results for its steady state behavior, which in turn is used for identifying the critical parameters affecting the operation of the network. Finally, through modeling and simulation, some additional numerical results are obtained with respect to the behavior of the system when multiple attackers are present, and regarding the time-dependent evolution and impact of an attack. © 2008 Science Press, Beijing, China and Springer Science + Business Media, LLC, USA.},
note = {cited By 25},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from either an attacker or their already infected neighbors, is analyzed. Considering the Susceptible-Infected-Susceptible (SIS) node infection paradigm we propose a probabilistic model, on the basis of the theory of closed queuing networks, that aims at describing the aggregated behavior of the system when attacked by malicious nodes. Because of its nature, the model is also able to deal more effectively with the stochastic behavior of attackers and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative large scale ad hoc networking environments. Using the Norton equivalent of the closed queuing network, we obtain analytical results for its steady state behavior, which in turn is used for identifying the critical parameters affecting the operation of the network. Finally, through modeling and simulation, some additional numerical results are obtained with respect to the behavior of the system when multiple attackers are present, and regarding the time-dependent evolution and impact of an attack. © 2008 Science Press, Beijing, China and Springer Science + Business Media, LLC, USA.
Karyotis, V., & Papavassiliou, S. (2007). Risk-based attack strategies for mobile ad hoc networks under probabilistic attack modeling framework. Computer Networks, 51(9), 2397–2410.
@article{karyotis2007risk,
title = {Risk-based attack strategies for mobile ad hoc networks under probabilistic attack modeling framework},
author = {Vasileios Karyotis and Symeon Papavassiliou},
year = {2007},
date = {2007-01-01},
journal = {Computer Networks},
volume = {51},
number = {9},
pages = {2397--2410},
publisher = {Elsevier},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Karyotis, V., Grammatikou, M., & Papavassiliou, S. (2007). A closed queueing network model for malware spreading over non-propagative Ad Hoc networks. Proc. Mediterranean Ad Hoc Netw, 129–136.
@article{karyotis2007closed,
title = {A closed queueing network model for malware spreading over non-propagative Ad Hoc networks},
author = {Vasileios Karyotis and Mary Grammatikou and Symeon Papavassiliou},
year = {2007},
date = {2007-01-01},
journal = {Proc. Mediterranean Ad Hoc Netw},
pages = {129--136},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Karyotis, V., & Papavassiliou, S. (2007). Risk-based attack strategies for mobile ad hoc networks under probabilistic attack modeling framework. Computer Networks, 51(9), 2397-2410. https://doi.org/10.1016/j.comnet.2007.01.028
@article{Karyotis20072397,
title = {Risk-based attack strategies for mobile ad hoc networks under probabilistic attack modeling framework},
author = {V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34247478945&doi=10.1016%2fj.comnet.2007.01.028&partnerID=40&md5=3b4a5a51628b08d67a280b66e916e260},
doi = {10.1016/j.comnet.2007.01.028},
issn = {13891286},
year = {2007},
date = {2007-01-01},
journal = {Computer Networks},
volume = {51},
number = {9},
pages = {2397-2410},
abstract = {In this paper, we introduce and design a modeling framework that allows for the study and analysis of attack propagation in mobile ad hoc networks. The choice of a statistical approach for the problem is motivated by the dynamic characteristics of the ad hoc topology and the stochastic nature of threat propagation. Based on this probabilistic modeling framework, we study the impact of topology and mobility in the propagation of software threats over ad hoc networks. We design topology control algorithms that indicate how to properly adjust an attacker's transmission radius, according to the measured topological characteristics and availability of its resources, in the process of infecting a network more effectively. Then based on these topology control algorithms we develop different attack strategies that may range from independent attacks to cooperative scenarios in order to increase the negative impact of an attack on the network. Our performance evaluation results demonstrate that the proposed topology control algorithms and respective attack strategies effectively balance the tradeoffs between the potential network damage and the attackers' lifetime, and as a result significantly outperform any other flat and threshold-based approaches. © 2007 Elsevier B.V. All rights reserved.},
note = {cited By 7},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this paper, we introduce and design a modeling framework that allows for the study and analysis of attack propagation in mobile ad hoc networks. The choice of a statistical approach for the problem is motivated by the dynamic characteristics of the ad hoc topology and the stochastic nature of threat propagation. Based on this probabilistic modeling framework, we study the impact of topology and mobility in the propagation of software threats over ad hoc networks. We design topology control algorithms that indicate how to properly adjust an attacker's transmission radius, according to the measured topological characteristics and availability of its resources, in the process of infecting a network more effectively. Then based on these topology control algorithms we develop different attack strategies that may range from independent attacks to cooperative scenarios in order to increase the negative impact of an attack on the network. Our performance evaluation results demonstrate that the proposed topology control algorithms and respective attack strategies effectively balance the tradeoffs between the potential network damage and the attackers' lifetime, and as a result significantly outperform any other flat and threshold-based approaches. © 2007 Elsevier B.V. All rights reserved.
Karyotis, V., Papavassiliou, S., Grammatikou, M., & Maglaris, V. (2006). A novel framework for mobile attack strategy modelling and vulnerability analysis in wireless ad hoc networks. International Journal of Security and Networks, 1(3-4), 255–265.
@article{karyotis2006novel,
title = {A novel framework for mobile attack strategy modelling and vulnerability analysis in wireless ad hoc networks},
author = {Vasileios Karyotis and Symeon Papavassiliou and Mary Grammatikou and Vasilis Maglaris},
year = {2006},
date = {2006-01-01},
journal = {International Journal of Security and Networks},
volume = {1},
number = {3-4},
pages = {255--265},
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Karyotis, V., Papavassiliou, S., Grammatikou, M., & Maglaris, V. (2006). A novel framework for mobile attack strategy modelling and vulnerability analysis in wireless ad hoc networks. International Journal of Security and Networks, 1(3-4), 255-265. https://doi.org/10.1504/ijsn.2006.011785
@article{Karyotis2006255,
title = {A novel framework for mobile attack strategy modelling and vulnerability analysis in wireless ad hoc networks},
author = {V. Karyotis and S. Papavassiliou and M. Grammatikou and V. Maglaris},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-44649095872&doi=10.1504%2fijsn.2006.011785&partnerID=40&md5=dd37dfa2eae19ab7d7aa98d61b09c164},
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year = {2006},
date = {2006-01-01},
journal = {International Journal of Security and Networks},
volume = {1},
number = {3-4},
pages = {255-265},
abstract = {Global dissemination of information and tools for computer networks, has allowed for major system attacks affecting critical network points and resulting in significant network performance degradation. In this paper, we present a probabilistic modelling framework for the propagation of an energy-constrained mobile threat in a wireless ad hoc network. The motivation behind this approach can be found in the topology-constrained character of the ad hoc setting, its dynamic nature and the stochastic characteristics of the interactions among the involved events. The introduced formulation is used to identify and evaluate different attack strategies and approaches. Through modelling and simulation, we evaluate the impact of various parameters associated with the operational characteristics of the mobile attacker on an outbreak spreading and the network evolution. Furthermore, a new metric, which indicates the overall infection-capability of each attack strategy is proposed and used to characterise the potential of each strategy to harm the network. © 2006 Inderscience Enterprises Ltd.},
note = {cited By 24},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Global dissemination of information and tools for computer networks, has allowed for major system attacks affecting critical network points and resulting in significant network performance degradation. In this paper, we present a probabilistic modelling framework for the propagation of an energy-constrained mobile threat in a wireless ad hoc network. The motivation behind this approach can be found in the topology-constrained character of the ad hoc setting, its dynamic nature and the stochastic characteristics of the interactions among the involved events. The introduced formulation is used to identify and evaluate different attack strategies and approaches. Through modelling and simulation, we evaluate the impact of various parameters associated with the operational characteristics of the mobile attacker on an outbreak spreading and the network evolution. Furthermore, a new metric, which indicates the overall infection-capability of each attack strategy is proposed and used to characterise the potential of each strategy to harm the network. © 2006 Inderscience Enterprises Ltd.
Lazaridis, M., Daras, P., Kastrinogiannis, T., & Karyotis, V. (0000). Annotation and Annotation Propagation Algorithms. .
@article{lazaridisannotation,
title = {Annotation and Annotation Propagation Algorithms},
author = {M Lazaridis and P Daras and T Kastrinogiannis and V Karyotis},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Simplot-Ryl, D., Wu, K., Miši'c, V. B., Cai, L., Chen, L.-J., Dobre, O., Erol-Kantarci, M., Karyotis, V., Kantarci, B., Korpeoglu, I., & others (0000). WWASN 2012 Organizing Committee. .
@article{simplotwwasn,
title = {WWASN 2012 Organizing Committee},
author = {David Simplot-Ryl and Kui Wu and Vojislav B Miši'c and Lin Cai and Ling-Jyh Chen and Octavia Dobre and Melike Erol-Kantarci and Vasileios Karyotis and Burak Kantarci and Ibrahim Korpeoglu and others},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abhari, A., Ammari, H. M., Cai, L., Chen, L.-J., Cheng, H. T., Chen, Y. P., Cheng, Y., Cuhadar, A., Frey, H., Karyotis, V., & others (0000). WWASN 2010 Program Committee. .
@article{abhariwwasn,
title = {WWASN 2010 Program Committee},
author = {Abdolreza Abhari and Habib M Ammari and Lin Cai and Ling-Jyh Chen and Ho Ting Cheng and Yuanzhu Peter Chen and Yu Cheng and Aysegül Cuhadar and Hannes Frey and Vasileios Karyotis and others},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Papavassiliou, S., & Karyotis, V. (0000). Evolutionary autonomic design framework for self-organizing Future Internet. .
@article{papavassiliouevolutionary,
title = {Evolutionary autonomic design framework for self-organizing Future Internet},
author = {Symeon Papavassiliou and Vasileios Karyotis},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Stojmenovic, S. I., Wu, K., Miši'c, V. B., Cai, L., Chen, L.-J., Dobre, O., Erol-Kantarci, M., Karyotis, V., Kantarci, B., Korpeoglu, I., & others (0000). WWASN 2013. .
@article{ivanwwasn,
title = {WWASN 2013},
author = {SITE Ivan Stojmenovic and Kui Wu and Vojislav B Miši'c and Lin Cai and Ling-Jyh Chen and Octavia Dobre and Melike Erol-Kantarci and Vasileios Karyotis and Burak Kantarci and Ibrahim Korpeoglu and others},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Karyotis, V., Kastrinogiannis, T., Malavazos, C., & Mavridou, E. (0000). Personalized UI. .
@article{karyotispersonalized,
title = {Personalized UI},
author = {V Karyotis and T Kastrinogiannis and C Malavazos and E Mavridou},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Karyotis, V., Manolakos, A., & Papavassiliou, S. (0000). On Topology Control and Non-Uniform Node Deployment in Arbitrary Ad Hoc Networks. .
@article{karyotistopology,
title = {On Topology Control and Non-Uniform Node Deployment in Arbitrary Ad Hoc Networks},
author = {Vasileios Karyotis and Alexandros Manolakos and Symeon Papavassiliou},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Aristomenopoulos, G., Karyotis, V., Anyfantis, V., Tsiropoulou, E.-E., Stah, E., Pouli, V., Katsaros, G., & Vlahopoulos, P. (0000). Deliverable Title D10. 2 Advanced Quality of Experience (QoE) Autonomic Networking and Multimedia Content Delivery. .
@article{aristomenopoulosdeliverable,
title = {Deliverable Title D10. 2 Advanced Quality of Experience (QoE) Autonomic Networking and Multimedia Content Delivery},
author = {Giorgos Aristomenopoulos and Vasileios Karyotis and Vangelis Anyfantis and Eirini-Eleni Tsiropoulou and Elena Stah and Vassiliki Pouli and Giannis Katsaros and Panagiotis Vlahopoulos},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Sanna, A., Lamberti, F., Paravati, G., Ciminiera, L., Pogacnik, J. T. U., Kafetzoglou, S., Karyotis, V., Kastrinogiannis, V. M., & ITI, P. D. (0000). State-of-the-art report on applicable tools and technologies and market survey. Technology, 1, 5.
@article{sanna1state,
title = {State-of-the-art report on applicable tools and technologies and market survey},
author = {A Sanna and F Lamberti and G Paravati and L Ciminiera and Jernej Trnkoczy UoL Pogacnik and S Kafetzoglou and V Karyotis and V Merekoulias Kastrinogiannis and P Daras ITI},
journal = {Technology},
volume = {1},
pages = {5},
keywords = {},
pubstate = {published},
tppubtype = {article}
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Sing, J. K., Peng, K., Gandhi, S. J., Sauser, B., Hu, F., Karyotis, V., Stai, E., Papavassiliou, S., Jara-Valera, A. J., Panic, S., & others (0000). OTHER COMMUNICATIONS BOOKS FROM AUERBACH. .
@article{singother,
title = {OTHER COMMUNICATIONS BOOKS FROM AUERBACH},
author = {Jamuna Kanta Sing and Kun Peng and S Jimmy Gandhi and Brian Sauser and Fei Hu and Vasileios Karyotis and Eleni Stai and Symeon Papavassiliou and Antonio J Jara-Valera and Stefan Panic and others},
keywords = {},
pubstate = {published},
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Books
Karyotis, V., Vitoropoulou, M., Kalatzis, N., Roussaki, I., & Papavassiliou, S. (2019). Efficient and socio-aware recommendation approaches for bigdata networked systems. Institution of Engineering and Technology. https://doi.org/10.1049/PBPC035F_ch4
@book{Karyotis201941,
title = {Efficient and socio-aware recommendation approaches for bigdata networked systems},
author = {V. Karyotis and M. Vitoropoulou and N. Kalatzis and I. Roussaki and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099450309&doi=10.1049%2fPBPC035F_ch4&partnerID=40&md5=ae7b353bd55c8bdfc06d9fd8ea9177c1},
doi = {10.1049/PBPC035F_ch4},
isbn = {9781785619755},
year = {2019},
date = {2019-01-01},
journal = {Big Data Recommender Systems: Algorithms, Architectures, Big Data, Security and Trust},
pages = {41-70},
publisher = {Institution of Engineering and Technology},
abstract = {In this chapter, we present several approaches designed for providing efficient recommendations in large web systems characterized by bigdata scales. The key feature of the considered approaches is that they all rely on different elements and properties of social/complex network analysis for addressing various deficiencies of legacy and current recommendation systems when very large operational scales emerge. The main challenges of recommendations addressed by the presented approaches are the diversity (novelty) of recommendations, the cold-start problem, scalability and noise filtering issues, as well as the efficiency of developing these approaches and integrating them in operational systems. This chapter aspires to provide an educated overview, leading to a solid fundamental background on how social/complex network analysis can be exploited for more effective recommendations in stringent environments characterized by large scales ofusers, items and associated data, cumulatively referred to as big network data. Furthermore, our work aims at highlighting the design principles that are more interesting for enabling the extension of the presented approaches and their combination with other current state-of-the-art techniques, thus leading to more socioaware and efficient recommendation approaches in the near and longer term future. © The Institution of Engineering and Technology 2020.},
note = {cited By 5},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
In this chapter, we present several approaches designed for providing efficient recommendations in large web systems characterized by bigdata scales. The key feature of the considered approaches is that they all rely on different elements and properties of social/complex network analysis for addressing various deficiencies of legacy and current recommendation systems when very large operational scales emerge. The main challenges of recommendations addressed by the presented approaches are the diversity (novelty) of recommendations, the cold-start problem, scalability and noise filtering issues, as well as the efficiency of developing these approaches and integrating them in operational systems. This chapter aspires to provide an educated overview, leading to a solid fundamental background on how social/complex network analysis can be exploited for more effective recommendations in stringent environments characterized by large scales ofusers, items and associated data, cumulatively referred to as big network data. Furthermore, our work aims at highlighting the design principles that are more interesting for enabling the extension of the presented approaches and their combination with other current state-of-the-art techniques, thus leading to more socioaware and efficient recommendation approaches in the near and longer term future. © The Institution of Engineering and Technology 2020.
Karyotis, V., & Stai, E. (2017). Hyperbolic big data analytics for dynamic network management and optimization. CRC Press. https://doi.org/10.1201/b21278
@book{Karyotis2017177,
title = {Hyperbolic big data analytics for dynamic network management and optimization},
author = {V. Karyotis and E. Stai},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052714130&doi=10.1201%2fb21278&partnerID=40&md5=538cccccfa15d20aa1230ee5bb1891df},
doi = {10.1201/b21278},
isbn = {9781498784870; 9781498784863},
year = {2017},
date = {2017-01-01},
journal = {Big Data and Computational Intelligence in Networking},
pages = {177-207},
publisher = {CRC Press},
abstract = {178Massive numbers of devices, growing user populations and voluminous amounts of produced/exchanged information are expected in the complex cyber-physical networks of the future. The new scales of operation give rise to a big network data era, where multi-layer networks form and users become content producers/consumers (prosumers). The challenges associated with the forthcoming networking environments require radical rethinking of current network analysis, management and operation practices. This chapter will focus on this effort, and more specifically on reinventing the machinery for computing key network metrics that allow improving network management/operation, while also developing more efficient overlay applications within demanding operational environments. Special attention is given to the impact of network evolution on the computation of such metrics, an aspect relatively neglected until recently. In order to efficiently compute key metrics associated with social or structural features of the network and track them when the infrastructure evolves, a big data analytics methodology, denoted as Hyperbolic Data Analytics (HDA), is applied. HDA is based on the embedding of graphs in the hyperbolic space, leading to more efficient management/operation, typically by exploiting hidden network structure. HDA is a characteristic example of developing computational intelligence over big network data and exploiting them for improving/optimizing both infrastructures and applications/services. HDA will provide the means for computing efficiently network analysis metrics, the evolution of which indicates the evolution of the corresponding network’s structure. © 2018 by Taylor and Francis Group, LLC.},
note = {cited By 1},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
178Massive numbers of devices, growing user populations and voluminous amounts of produced/exchanged information are expected in the complex cyber-physical networks of the future. The new scales of operation give rise to a big network data era, where multi-layer networks form and users become content producers/consumers (prosumers). The challenges associated with the forthcoming networking environments require radical rethinking of current network analysis, management and operation practices. This chapter will focus on this effort, and more specifically on reinventing the machinery for computing key network metrics that allow improving network management/operation, while also developing more efficient overlay applications within demanding operational environments. Special attention is given to the impact of network evolution on the computation of such metrics, an aspect relatively neglected until recently. In order to efficiently compute key metrics associated with social or structural features of the network and track them when the infrastructure evolves, a big data analytics methodology, denoted as Hyperbolic Data Analytics (HDA), is applied. HDA is based on the embedding of graphs in the hyperbolic space, leading to more efficient management/operation, typically by exploiting hidden network structure. HDA is a characteristic example of developing computational intelligence over big network data and exploiting them for improving/optimizing both infrastructures and applications/services. HDA will provide the means for computing efficiently network analysis metrics, the evolution of which indicates the evolution of the corresponding network’s structure. © 2018 by Taylor and Francis Group, LLC.
Stai, E., Karyotis, V., Katsinis, G., Tsiropoulou, E. E., & Papavassiliou, S. (2016). A hyperbolic big data analytics framework within complex and social networks. CRC Press. https://doi.org/10.1201/9781315396705
@book{Stai20163,
title = {A hyperbolic big data analytics framework within complex and social networks},
author = {E. Stai and V. Karyotis and G. Katsinis and E. E. Tsiropoulou and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85052946845&doi=10.1201%2f9781315396705&partnerID=40&md5=dc97e825ebad699a5d839eec43778648},
doi = {10.1201/9781315396705},
isbn = {9781315396699; 9781498726849},
year = {2016},
date = {2016-01-01},
journal = {Big Data in Complex and Social Networks},
pages = {3-36},
publisher = {CRC Press},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Stai, E., Karyotis, V., & Papavassiliou, S. (2016). Modeling and control of user interest dictated information dissemination in communications and social networks. Nova Science Publishers, Inc..
@book{Stai201645,
title = {Modeling and control of user interest dictated information dissemination in communications and social networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85156108074&partnerID=40&md5=283dfb537c58ae4ad64224391ac08e60},
isbn = {9781634852432; 9781634852258},
year = {2016},
date = {2016-01-01},
journal = {Advances in Social Networking Research},
pages = {45-88},
publisher = {Nova Science Publishers, Inc.},
abstract = {Information dissemination is one of the most critical processes in modern societies and one of the most important reasons for the proliferation of communications networks, especially of online social networks that have enabled global information exchange at rapid scales. This chapter will focus on information dissemination models that compared to the current literature, they specifically take into account aspects related to user interest and its temporal variability in the dynamics of information spreading. We focus on a dissemination framework regarding solely useful information, where users of communications and online social networks are willing to accept information and potentially further propagate it to their uninformed peers, depending on the interest each user has on specific topics. This is a novel perspective to consider information dissemination under inhomogeneous mixing, since the time-varying user interests affect significantly the outcome and the dynamics of information propagation and have an impact on its control process. Such models can be employed for further improving information dissemination analysis and control methodologies, and they can be exploited in various application domains, e.g., from infrastructure design and management, to marketing and advertising improvement. This chapter addresses both the modeling of information dissemination, especially via epidemics and evolutionary game theoretic techniques, as well as their control via optimal control frameworks and dual optimization techniques. © 2016 Nova Science Publishers, Inc. All rights reserved.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Information dissemination is one of the most critical processes in modern societies and one of the most important reasons for the proliferation of communications networks, especially of online social networks that have enabled global information exchange at rapid scales. This chapter will focus on information dissemination models that compared to the current literature, they specifically take into account aspects related to user interest and its temporal variability in the dynamics of information spreading. We focus on a dissemination framework regarding solely useful information, where users of communications and online social networks are willing to accept information and potentially further propagate it to their uninformed peers, depending on the interest each user has on specific topics. This is a novel perspective to consider information dissemination under inhomogeneous mixing, since the time-varying user interests affect significantly the outcome and the dynamics of information propagation and have an impact on its control process. Such models can be employed for further improving information dissemination analysis and control methodologies, and they can be exploited in various application domains, e.g., from infrastructure design and management, to marketing and advertising improvement. This chapter addresses both the modeling of information dissemination, especially via epidemics and evolutionary game theoretic techniques, as well as their control via optimal control frameworks and dual optimization techniques. © 2016 Nova Science Publishers, Inc. All rights reserved.
Karyotis, V., & Khouzani, M. H. R. (2016). Malware Diffusion Models for Modern Complex Networks: Theory and Applications. Elsevier Inc.. https://doi.org/10.1016/C2014-0-02168-5
@book{Karyotis20161,
title = {Malware Diffusion Models for Modern Complex Networks: Theory and Applications},
author = {V. Karyotis and M. H. R. Khouzani},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84966747178&doi=10.1016%2fC2014-0-02168-5&partnerID=40&md5=06baba5b752e60adbf37584ad2514605},
doi = {10.1016/C2014-0-02168-5},
isbn = {9780128027141},
year = {2016},
date = {2016-01-01},
journal = {Malware Diffusion Models for Modern Complex Networks: Theory and Applications},
pages = {1-296},
publisher = {Elsevier Inc.},
abstract = {Malware Diffusion Models for Wireless Complex Networks: Theory and Applications provides a timely update on malicious software (malware), a serious concern for all types of network users, from laymen to experienced administrators. As the proliferation of portable devices, namely smartphones and tablets, and their increased capabilities, has propelled the intensity of malware spreading and increased its consequences in social life and the global economy, this book provides the theoretical aspect of malware dissemination, also presenting modeling approaches that describe the behavior and dynamics of malware diffusion in various types of wireless complex networks. Sections include a systematic introduction to malware diffusion processes in computer and communications networks, an analysis of the latest state-of-the-art malware diffusion modeling frameworks, such as queuing-based techniques, calculus of variations based techniques, and game theory based techniques, also demonstrating how the methodologies can be used for modeling in more general applications and practical scenarios. Presents a timely update on malicious software (malware), a serious concern for all types of network users, from laymen to experienced administrators. Systematically introduces malware diffusion processes, providing the relevant mathematical background. Discusses malware modeling frameworks and how to apply them to complex wireless networks. Provides guidelines and directions for extending the corresponding theories in other application domains, demonstrating such possibility by using application models in information dissemination scenarios. © 2016 Elsevier Inc. All rights reserved.},
note = {cited By 34},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Malware Diffusion Models for Wireless Complex Networks: Theory and Applications provides a timely update on malicious software (malware), a serious concern for all types of network users, from laymen to experienced administrators. As the proliferation of portable devices, namely smartphones and tablets, and their increased capabilities, has propelled the intensity of malware spreading and increased its consequences in social life and the global economy, this book provides the theoretical aspect of malware dissemination, also presenting modeling approaches that describe the behavior and dynamics of malware diffusion in various types of wireless complex networks. Sections include a systematic introduction to malware diffusion processes in computer and communications networks, an analysis of the latest state-of-the-art malware diffusion modeling frameworks, such as queuing-based techniques, calculus of variations based techniques, and game theory based techniques, also demonstrating how the methodologies can be used for modeling in more general applications and practical scenarios. Presents a timely update on malicious software (malware), a serious concern for all types of network users, from laymen to experienced administrators. Systematically introduces malware diffusion processes, providing the relevant mathematical background. Discusses malware modeling frameworks and how to apply them to complex wireless networks. Provides guidelines and directions for extending the corresponding theories in other application domains, demonstrating such possibility by using application models in information dissemination scenarios. © 2016 Elsevier Inc. All rights reserved.
Karyotis, V., Stai, E., & Papavassiliou, S. (2013). Evolutionary dynamics of complex communications networks. CRC Press.
@book{Karyotis20131,
title = {Evolutionary dynamics of complex communications networks},
author = {V. Karyotis and E. Stai and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904483613&partnerID=40&md5=62e7c97f5554f50887c7864862c82d57},
isbn = {9781466518414; 9781466518407},
year = {2013},
date = {2013-01-01},
journal = {Evolutionary Dynamics of Complex Communications Networks},
pages = {1-277},
publisher = {CRC Press},
abstract = {Until recently, most network design techniques employed a bottom-up approach with lower protocol layer mechanisms affecting the development of higher ones. This approach, however, has not yielded fascinating results in the case of wireless distributed networks. Addressing the emerging aspects of modern network analysis and design, Evolutionary Dynamics of Complex Communications Networks introduces and develops a top-bottom approach where elements of the higher layer can be exploited in modifying the lowest physical topology-closing the network design loop in an evolutionary fashion similar to that observed in natural processes. This book provides a complete overview of contemporary design approaches from the viewpoint of network science and complex/social network analysis. A significant part of the text focuses on the classification and analysis of various network modification mechanisms for wireless decentralized networks that exploit social features from relevant online social networks. Each chapter begins with learning objectives and introductory material and slowly builds to more detailed analysis and advanced concepts. Each chapter also identifies open issues, while by the end of the book, potential research directions are summarized for the more interested researcher or graduate student. The approach outlined in the book will help network designers and administrators increase the value of their infrastructure without requiring any significant additional investment. Topics covered include: basic network graph models and properties, cognitive methods and evolutionary computing, complex and social network analysis metrics and features, and analysis and development of the distinctive structure and features of complex networks. Considering all aspects of modern network analysis and design, the text covers the necessary material and background to make it a suitable source of reference for graduate students, postdoctoral researchers, and scientists. © 2014 by Taylor & Francis Group, LLC.},
note = {cited By 33},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Until recently, most network design techniques employed a bottom-up approach with lower protocol layer mechanisms affecting the development of higher ones. This approach, however, has not yielded fascinating results in the case of wireless distributed networks. Addressing the emerging aspects of modern network analysis and design, Evolutionary Dynamics of Complex Communications Networks introduces and develops a top-bottom approach where elements of the higher layer can be exploited in modifying the lowest physical topology-closing the network design loop in an evolutionary fashion similar to that observed in natural processes. This book provides a complete overview of contemporary design approaches from the viewpoint of network science and complex/social network analysis. A significant part of the text focuses on the classification and analysis of various network modification mechanisms for wireless decentralized networks that exploit social features from relevant online social networks. Each chapter begins with learning objectives and introductory material and slowly builds to more detailed analysis and advanced concepts. Each chapter also identifies open issues, while by the end of the book, potential research directions are summarized for the more interested researcher or graduate student. The approach outlined in the book will help network designers and administrators increase the value of their infrastructure without requiring any significant additional investment. Topics covered include: basic network graph models and properties, cognitive methods and evolutionary computing, complex and social network analysis metrics and features, and analysis and development of the distinctive structure and features of complex networks. Considering all aspects of modern network analysis and design, the text covers the necessary material and background to make it a suitable source of reference for graduate students, postdoctoral researchers, and scientists. © 2014 by Taylor & Francis Group, LLC.
Karyotis, V., & Papavassiliou, S. (2010). Mobility-induced capacity-delay tradeoffs in wireless multihop networks. Nova Science Publishers, Inc..
@book{Karyotis2010137,
title = {Mobility-induced capacity-delay tradeoffs in wireless multihop networks},
author = {V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84896200241&partnerID=40&md5=1bccb2aa11aaa0c9d16fc2153b0d90e1},
isbn = {9781608761869},
year = {2010},
date = {2010-01-01},
journal = {Cluster Computing and Multi-Hop Network Research},
pages = {137-162},
publisher = {Nova Science Publishers, Inc.},
abstract = {Wireless mobile multihop networks, such as ad hoc and sensor networks, have become rather popular in realizing seamless distributed computation and accommodating autonomic behavior. In these networks, the lack of central infrastructure, the spatio-temporal dynamic nature of wireless communications along with their mobilityinduced dynamic topology, pose additional challenges on the traffic-carrying capacity of the system and raise concerns on the delay performance of packet delivery mechanisms. Despite such impediments of the wireless multihop environment, it has been recently shown that mobility can be exploited by various relay techniques for increasing the capacity of such networks. However, the throughput-effectiveness of the mobilityexploiting relay methods takes place at the cost of a greater number of intermediate hops traversed by packets traveling in the network in order to reach their final destination and additional buffering required at the intermediate nodes, revealing an inherent tradeoff between capacity and delay in mobile multihop networks. In this chapter, we first briefly review various mobility models, and then focus on the inherent mobilityinduced tradeoff between capacity and delay in multihop networks. Mobility is treated as both a constructive (increasing capacity), as well as a destructive (increasing delay) factor in wireless infrastructureless networks. Formal problem settings are presented, followed by applications and protocols that could be used in actual networks for increasing performance and realizing viable networking services. We also provide a qualitative and quantitative comparison among the various protocols, from which directions for future research studies are indicated. © 2010 by Nova Science Publishers, Inc. All rights reserved.},
note = {cited By 0},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Wireless mobile multihop networks, such as ad hoc and sensor networks, have become rather popular in realizing seamless distributed computation and accommodating autonomic behavior. In these networks, the lack of central infrastructure, the spatio-temporal dynamic nature of wireless communications along with their mobilityinduced dynamic topology, pose additional challenges on the traffic-carrying capacity of the system and raise concerns on the delay performance of packet delivery mechanisms. Despite such impediments of the wireless multihop environment, it has been recently shown that mobility can be exploited by various relay techniques for increasing the capacity of such networks. However, the throughput-effectiveness of the mobilityexploiting relay methods takes place at the cost of a greater number of intermediate hops traversed by packets traveling in the network in order to reach their final destination and additional buffering required at the intermediate nodes, revealing an inherent tradeoff between capacity and delay in mobile multihop networks. In this chapter, we first briefly review various mobility models, and then focus on the inherent mobilityinduced tradeoff between capacity and delay in multihop networks. Mobility is treated as both a constructive (increasing capacity), as well as a destructive (increasing delay) factor in wireless infrastructureless networks. Formal problem settings are presented, followed by applications and protocols that could be used in actual networks for increasing performance and realizing viable networking services. We also provide a qualitative and quantitative comparison among the various protocols, from which directions for future research studies are indicated. © 2010 by Nova Science Publishers, Inc. All rights reserved.
Karyotis, V., & Papavassiliou, S. (2009). Topology Control in Cooperative Wireless Ad Hoc Networks. CRC Press. https://doi.org/10.1201/9781420064704-13
@book{Karyotis2009167,
title = {Topology Control in Cooperative Wireless Ad Hoc Networks},
author = {V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85145638692&doi=10.1201%2f9781420064704-13&partnerID=40&md5=438fd0b19a7689539a8d1e8ab2c9869e},
doi = {10.1201/9781420064704-13},
isbn = {9781420064704; 9781420064698},
year = {2009},
date = {2009-01-01},
journal = {Cooperative Wireless Communications},
pages = {167-189},
publisher = {CRC Press},
abstract = {In this chapter, we present a framework for topology control (TC) as a cooperation mechanism in ad hoc networks and then describe several TC approaches within this framework.We present a classification of the current TCmechanisms, discuss the functionality and the key principles of the individual existing protocols, and provide a qualitative comparison of their characteristics according to several distinct features and performance parameters. Throughout our discussion special emphasis is placed on themain objectives of TC, namely reducing interference and energy consumption, whilemaintaining connectivity and adapting quickly to the dynamic changes of the ad hoc networking environment. The overall evaluation of the relative performances makes it apparent that no single mechanism can strike an absolute balance among all requirements, and application-specific considerations are needed for choosing an appropriate solution. © 2009 by Taylor & Francis Group, LLC.},
note = {cited By 4},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
In this chapter, we present a framework for topology control (TC) as a cooperation mechanism in ad hoc networks and then describe several TC approaches within this framework.We present a classification of the current TCmechanisms, discuss the functionality and the key principles of the individual existing protocols, and provide a qualitative comparison of their characteristics according to several distinct features and performance parameters. Throughout our discussion special emphasis is placed on themain objectives of TC, namely reducing interference and energy consumption, whilemaintaining connectivity and adapting quickly to the dynamic changes of the ad hoc networking environment. The overall evaluation of the relative performances makes it apparent that no single mechanism can strike an absolute balance among all requirements, and application-specific considerations are needed for choosing an appropriate solution. © 2009 by Taylor & Francis Group, LLC.
Conferences
Kallitsis, G., Karyotis, V., & Papavassiliou, S. (2023). A Joint Wireless Data-Power Exchange Approach for Distributed Energy Harvesting Networks. In (pp. 209-215). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/CSCN60443.2023.10453207
@conference{Kallitsis2023209,
title = {A Joint Wireless Data-Power Exchange Approach for Distributed Energy Harvesting Networks},
author = {G. Kallitsis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85187794022&doi=10.1109%2fCSCN60443.2023.10453207&partnerID=40&md5=013d00ec2a1c7681d6502d149b99035d},
doi = {10.1109/CSCN60443.2023.10453207},
isbn = {9798350395389},
year = {2023},
date = {2023-01-01},
journal = {2023 IEEE Conference on Standards for Communications and Networking, CSCN 2023},
pages = {209-215},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {This work addresses the problem of efficient joint wireless data-energy transfer in distributed networks. We consider devices capable of exchanging data and energy wirelessly, aiming at optimal data/energy transfer scheduling. Wireless Power Transfer resembles energy-harvesting but it bears its own peculiarities. We formulate mathematically the evolution of the data queue and battery state of each node according to a back-pressure inspired approach, and define an optimization problem aiming at better energy balancing. We employ a dual Lagrange multiplier solution, and through simulation and analysis, we identify the critical parameters determining the behavior of the system. This is a cornerstone work towards developing a more generic framework within the conceived 6G architecture, and here we demonstrate its theoretical and practical potentials. © 2023 IEEE.},
note = {cited By 0; Conference of 2023 IEEE Conference on Standards for Communications and Networking, CSCN 2023 ; Conference Date: 6 November 2023 Through 8 November 2023; Conference Code:197830},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
This work addresses the problem of efficient joint wireless data-energy transfer in distributed networks. We consider devices capable of exchanging data and energy wirelessly, aiming at optimal data/energy transfer scheduling. Wireless Power Transfer resembles energy-harvesting but it bears its own peculiarities. We formulate mathematically the evolution of the data queue and battery state of each node according to a back-pressure inspired approach, and define an optimization problem aiming at better energy balancing. We employ a dual Lagrange multiplier solution, and through simulation and analysis, we identify the critical parameters determining the behavior of the system. This is a cornerstone work towards developing a more generic framework within the conceived 6G architecture, and here we demonstrate its theoretical and practical potentials. © 2023 IEEE.
Kourouthanassis, P., Bardaki, C., Sourvinos, A., Karyotis, V., & Mylonas, P. (2023). Platform Architecture and Functionality for Efficient and Intelligent Logistics. In . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/SMAP59435.2023.10255183
@conference{Kourouthanassis2023,
title = {Platform Architecture and Functionality for Efficient and Intelligent Logistics},
author = {P. Kourouthanassis and C. Bardaki and A. Sourvinos and V. Karyotis and P. Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85174950955&doi=10.1109%2fSMAP59435.2023.10255183&partnerID=40&md5=62b36f77637e60fe562c2d390d065332},
doi = {10.1109/SMAP59435.2023.10255183},
isbn = {9798350327717},
year = {2023},
date = {2023-01-01},
journal = {2023 18th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2023},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {This paper describes the layered architecture and functionality of an intelligent logistics platform for logistics companies to centrally coordinate their transportation operations. It offers real-Time tracking, tracing, and reporting capabilities to logistics stakeholders, as well as dynamic scheduling and routing of deliveries forming shipments and routes with optimized resources allocation and costs. The optimization of shipments scheduling and routing is performed drawing on the backpressure technique, which, to the best of our knowledge, has never been applied to optimize supply chain transport operations. The algorithm combines a variety of factors that affect transportation operations (such as the capacity and current inventory of each node in the transportation network and the fleet characteristics) and proposes dynamically shipments and optimal paths for the company fleet and couriers for last-mile delivery. © 2023 IEEE.},
note = {cited By 0; Conference of 18th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2023 ; Conference Date: 25 September 2023 Through 26 September 2023; Conference Code:192944},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
This paper describes the layered architecture and functionality of an intelligent logistics platform for logistics companies to centrally coordinate their transportation operations. It offers real-Time tracking, tracing, and reporting capabilities to logistics stakeholders, as well as dynamic scheduling and routing of deliveries forming shipments and routes with optimized resources allocation and costs. The optimization of shipments scheduling and routing is performed drawing on the backpressure technique, which, to the best of our knowledge, has never been applied to optimize supply chain transport operations. The algorithm combines a variety of factors that affect transportation operations (such as the capacity and current inventory of each node in the transportation network and the fleet characteristics) and proposes dynamically shipments and optimal paths for the company fleet and couriers for last-mile delivery. © 2023 IEEE.
Kakkavas, G., Diamanti, M., Nyarko, K. N., Gabriel, M., Karyotis, V., Mosner, K., & Papavassiliou, S. (2022). Realistic Field Trial Evaluation of a Tele-operated Support Service for Remote Driving over 5G. In (pp. 58-63). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/CSCN57023.2022.10051034
@conference{Kakkavas202258,
title = {Realistic Field Trial Evaluation of a Tele-operated Support Service for Remote Driving over 5G},
author = {G. Kakkavas and M. Diamanti and K. Nseboah Nyarko and M. Gabriel and V. Karyotis and K. Mosner and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85150026185&doi=10.1109%2fCSCN57023.2022.10051034&partnerID=40&md5=59fc87d2140bee67e8a0dff69646d92d},
doi = {10.1109/CSCN57023.2022.10051034},
isbn = {9781665476218},
year = {2022},
date = {2022-01-01},
journal = {2022 IEEE Conference on Standards for Communications and Networking, CSCN 2022},
pages = {58-63},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this paper, we focus on the development and realistic field trial evaluation of a Tele-operated Support (TeSo) service for remote driving over 5G mobile communications. The presented prototype was created within the context of the transport vertical of the "5G HEalth, AquacultuRe and Transport (5G-HEART)"5G PPP Phase 3 project and was meti culously tested and evaluated in several realistic test cases over a commercial 5G Non-Standalone (NSA) deployment. A vehicle equipped with appropriate sensors and actuators was actively controlled from a distance of 36 km, exchanging sensor data and video streams in the uplink and vehicle-control commands in the downlink with the remote operations center. This work is among the first experimentally-driven quantitative analyses of such an application with a real pilot using an actual vehicle. Our objective was to validate the feasibility of the proposed TeSo service by evaluating relevant performance metrics, such as latency, jitter, throughput, and loss rate. Moreover, our extensive testing aimed to identify salient features and emerging challenges from the prototype, which can aid in a two-fold manner: first, paving the way for the eventual commercialization of the service, and second, guiding standardization effort for a relevant emerging market in the near future. © 2022 IEEE.},
note = {cited By 1; Conference of 2022 IEEE Conference on Standards for Communications and Networking, CSCN 2022 ; Conference Date: 28 November 2022 Through 30 November 2022; Conference Code:186982},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
In this paper, we focus on the development and realistic field trial evaluation of a Tele-operated Support (TeSo) service for remote driving over 5G mobile communications. The presented prototype was created within the context of the transport vertical of the "5G HEalth, AquacultuRe and Transport (5G-HEART)"5G PPP Phase 3 project and was meti culously tested and evaluated in several realistic test cases over a commercial 5G Non-Standalone (NSA) deployment. A vehicle equipped with appropriate sensors and actuators was actively controlled from a distance of 36 km, exchanging sensor data and video streams in the uplink and vehicle-control commands in the downlink with the remote operations center. This work is among the first experimentally-driven quantitative analyses of such an application with a real pilot using an actual vehicle. Our objective was to validate the feasibility of the proposed TeSo service by evaluating relevant performance metrics, such as latency, jitter, throughput, and loss rate. Moreover, our extensive testing aimed to identify salient features and emerging challenges from the prototype, which can aid in a two-fold manner: first, paving the way for the eventual commercialization of the service, and second, guiding standardization effort for a relevant emerging market in the near future. © 2022 IEEE.
Karyotis, V., Stai, E., Kourouthanasis, P., & Mylonas, P. (2022). A Framework for a Holistic Information System for Small-Medium Logistics Enterprises. In . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/SMAP56125.2022.9941923
@conference{Karyotis2022,
title = {A Framework for a Holistic Information System for Small-Medium Logistics Enterprises},
author = {V. Karyotis and E. Stai and P. Kourouthanasis and P. Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85143080514&doi=10.1109%2fSMAP56125.2022.9941923&partnerID=40&md5=4336f1e08c3b52f517432d35bb184469},
doi = {10.1109/SMAP56125.2022.9941923},
isbn = {9781665487276},
year = {2022},
date = {2022-01-01},
journal = {2022 17th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2022},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Logistic or freight networks have gained considerable interest lately, calling for intelligent methods in order to deal with the increasing load requirements while maintaining sustainable costs. In this work, we focus on addressing the needs of small-medium freight companies so that they can cope with the emerging challenges in the post-COVID era. More specifically, we initially identify the requirements and the architecture of a candidate holistic information system that such a company would need to ensure optimal deliveries and efficiency of its operation. Then we focus on the scheduling-routing component of the proposed information system framework. We review the proposed solutions and propose a novel one based on the concept of backpressure joint scheduling-routing inspired from telecommunication networks. We believe that this approach can seamlessly and efficiently provide the means for small-scale companies, and larger ones as well, to optimize their operations and improve their offered quality of service. © 2022 IEEE.},
note = {cited By 1; Conference of 17th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2022 ; Conference Date: 3 November 2022 Through 4 November 2022; Conference Code:184277},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Logistic or freight networks have gained considerable interest lately, calling for intelligent methods in order to deal with the increasing load requirements while maintaining sustainable costs. In this work, we focus on addressing the needs of small-medium freight companies so that they can cope with the emerging challenges in the post-COVID era. More specifically, we initially identify the requirements and the architecture of a candidate holistic information system that such a company would need to ensure optimal deliveries and efficiency of its operation. Then we focus on the scheduling-routing component of the proposed information system framework. We review the proposed solutions and propose a novel one based on the concept of backpressure joint scheduling-routing inspired from telecommunication networks. We believe that this approach can seamlessly and efficiently provide the means for small-scale companies, and larger ones as well, to optimize their operations and improve their offered quality of service. © 2022 IEEE.
Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2022). On the Fair Energy Sharing in Networks with Wireless Charging-capable Devices. In (pp. 375-380). IEEE Computer Society. https://doi.org/10.1109/WiMob55322.2022.9941704
@conference{Vitoropoulou2022375,
title = {On the Fair Energy Sharing in Networks with Wireless Charging-capable Devices},
author = {M. Vitoropoulou and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85142721925&doi=10.1109%2fWiMob55322.2022.9941704&partnerID=40&md5=455b20e124f40d5cbe8d019cc7744863},
doi = {10.1109/WiMob55322.2022.9941704},
issn = {21619646},
year = {2022},
date = {2022-01-01},
journal = {International Conference on Wireless and Mobile Computing, Networking and Communications},
volume = {2022-October},
pages = {375-380},
publisher = {IEEE Computer Society},
abstract = {The emerging technology of Wireless Power Trans-fer (WPT) has enabled mobile devices to replenish their batteries and increase their lifetime by exchanging energy with other devices in vicinity. In this paper, we study the problem of peer-to-peer WPT in a network of battery-constrained devices for which we aim to provide a fair energy allocation via mutual exchanges. In this respect, devices of lowest battery level remain functional for longer time, while respecting and satisfying a given set of wireless charging constraints. By taking into consideration the skewed energy availability in the network, as well as the loss induced by wireless energy transfer, we formulate and analyze three energy allocation schemes based on the concepts of lexicographic optimization and algorithmic graph theory, which, under different optimization criteria, aim to extend network lifetime. The performance of the proposed schemes is evaluated and compared in terms of energy efficiency and balancing quality through modeling and simulation over synthetic networks. © 2022 IEEE.},
note = {cited By 0; Conference of 18th International Conference on Wireless and Mobile Computing, Networking and Communications, WiMob 2022 ; Conference Date: 10 October 2022 Through 12 October 2022; Conference Code:184410},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The emerging technology of Wireless Power Trans-fer (WPT) has enabled mobile devices to replenish their batteries and increase their lifetime by exchanging energy with other devices in vicinity. In this paper, we study the problem of peer-to-peer WPT in a network of battery-constrained devices for which we aim to provide a fair energy allocation via mutual exchanges. In this respect, devices of lowest battery level remain functional for longer time, while respecting and satisfying a given set of wireless charging constraints. By taking into consideration the skewed energy availability in the network, as well as the loss induced by wireless energy transfer, we formulate and analyze three energy allocation schemes based on the concepts of lexicographic optimization and algorithmic graph theory, which, under different optimization criteria, aim to extend network lifetime. The performance of the proposed schemes is evaluated and compared in terms of energy efficiency and balancing quality through modeling and simulation over synthetic networks. © 2022 IEEE.
Kakkavas, G., Nyarko, K. N., Lahoud, C., Kuhnert, D., Kuffner, P., Gabriel, M., Ehsanfar, S., Diamanti, M., Karyotis, V., Mobner, K., & Papavassiliou, S. (2022). Teleoperated Support for Remote Driving over 5G Mobile Communications. In (pp. 280-285). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/MeditCom55741.2022.9928745
@conference{Kakkavas2022280,
title = {Teleoperated Support for Remote Driving over 5G Mobile Communications},
author = {G. Kakkavas and K. N. Nyarko and C. Lahoud and D. Kuhnert and P. Kuffner and M. Gabriel and S. Ehsanfar and M. Diamanti and V. Karyotis and K. Mobner and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85142211184&doi=10.1109%2fMeditCom55741.2022.9928745&partnerID=40&md5=3e3e5e2f323069f97498c9b24937265b},
doi = {10.1109/MeditCom55741.2022.9928745},
isbn = {9781665498258},
year = {2022},
date = {2022-01-01},
journal = {2022 IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2022},
pages = {280-285},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {The fifth-generation (5G) mobile communications promise far more capabilities than competing technologies and are expected to enable a wide range of vertical use cases. Among them, remote driving has attracted much interest from both academia and the industry, either as a stepping stone on the road to fully autonomous driving or as its complement constituting a fallback/backup service. This paper presents the design, development, and evaluation of a teleoperated support (TeSo) service over 5G mobile communications, realized within the framework of the '5G HEalth, AquacultuRe and Transport (5G-HEART)' EU project. We present an end-to-end service architecture and a complete implementation, accompanied by validation trials and performance measurements in a real pilot over a commercial 5G network deployment with an actual vehicle that has been extended to support a variety of experimentation options. With this work, we demonstrate the feasibility of the proposed TeSo service, and we quantify various performance metrics of interest, such as latency, jitter, throughput, and loss rate for longer-term reference use. © 2022 IEEE.},
note = {cited By 4; Conference of 2nd IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2022 ; Conference Date: 5 September 2022 Through 8 September 2022; Conference Code:183951},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The fifth-generation (5G) mobile communications promise far more capabilities than competing technologies and are expected to enable a wide range of vertical use cases. Among them, remote driving has attracted much interest from both academia and the industry, either as a stepping stone on the road to fully autonomous driving or as its complement constituting a fallback/backup service. This paper presents the design, development, and evaluation of a teleoperated support (TeSo) service over 5G mobile communications, realized within the framework of the '5G HEalth, AquacultuRe and Transport (5G-HEART)' EU project. We present an end-to-end service architecture and a complete implementation, accompanied by validation trials and performance measurements in a real pilot over a commercial 5G network deployment with an actual vehicle that has been extended to support a variety of experimentation options. With this work, we demonstrate the feasibility of the proposed TeSo service, and we quantify various performance metrics of interest, such as latency, jitter, throughput, and loss rate for longer-term reference use. © 2022 IEEE.
Kakkavas, G., Kalntis, M., Karyotis, V., & Papavassiliou, S. (2021). Future Network Traffic Matrix Synthesis and Estimation Based on Deep Generative Models. In . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICCCN52240.2021.9522222
@conference{Kakkavas2021,
title = {Future Network Traffic Matrix Synthesis and Estimation Based on Deep Generative Models},
author = {G. Kakkavas and M. Kalntis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114962425&doi=10.1109%2fICCCN52240.2021.9522222&partnerID=40&md5=b55537afb9ced698d9c0012a1d046d67},
doi = {10.1109/ICCCN52240.2021.9522222},
issn = {10952055},
year = {2021},
date = {2021-01-01},
journal = {Proceedings - International Conference on Computer Communications and Networks, ICCCN},
volume = {2021-July},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Traffic matrices (TMs) contain information that is essential for network management, traffic engineering, and anomaly detection. However, constructing a TM through direct traffic measurements has a high administrative and computational cost. A more feasible approach is to estimate the TM from the easily obtainable link load measurements. In this paper, we address the issue of traffic matrix estimation (TME) from link loads using a deep generative model - namely, a variational autoencoder (VAE) - to solve the respective ill-posed inverse problem. In particular, we train the VAE with historical data (previously observed TMs) and we leverage the trained decoder to transform TME into a minimization problem in the latent space, which in turn can be solved by employing a gradient-based optimizer. Furthermore, the trained decoder can be used for traffic matrix synthesis, i.e., for generating synthetic TM examples that have 'similar' properties to the samples of the training set. Finally, we explore the incremental optimization of the sequence of objectives constructed from the sequence of decoders that we obtain at different stages of the VAE training. The performance of the proposed methods is evaluated using a publicly available dataset of actual traffic matrices recorded in a real backbone network. © 2021 IEEE.},
note = {cited By 9; Conference of 30th International Conference on Computer Communications and Networks, ICCCN 2021 ; Conference Date: 19 July 2021 Through 22 July 2021; Conference Code:171515},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Traffic matrices (TMs) contain information that is essential for network management, traffic engineering, and anomaly detection. However, constructing a TM through direct traffic measurements has a high administrative and computational cost. A more feasible approach is to estimate the TM from the easily obtainable link load measurements. In this paper, we address the issue of traffic matrix estimation (TME) from link loads using a deep generative model - namely, a variational autoencoder (VAE) - to solve the respective ill-posed inverse problem. In particular, we train the VAE with historical data (previously observed TMs) and we leverage the trained decoder to transform TME into a minimization problem in the latent space, which in turn can be solved by employing a gradient-based optimizer. Furthermore, the trained decoder can be used for traffic matrix synthesis, i.e., for generating synthetic TM examples that have 'similar' properties to the samples of the training set. Finally, we explore the incremental optimization of the sequence of objectives constructed from the sequence of decoders that we obtain at different stages of the VAE training. The performance of the proposed methods is evaluated using a publicly available dataset of actual traffic matrices recorded in a real backbone network. © 2021 IEEE.
Kakkavas, G., Diamanti, M., Gabriel, M., Lahoud, C., Akula, P., Karyotis, V., Mosner, K., & Papavassiliou, S. (2021). Demo Proposal: Tele-Operated Support over 4G/5G Mobile Communications. In (pp. 466-467). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/MeditCom49071.2021.9647643
@conference{Kakkavas2021466,
title = {Demo Proposal: Tele-Operated Support over 4G/5G Mobile Communications},
author = {G. Kakkavas and M. Diamanti and M. Gabriel and C. Lahoud and P. Akula and V. Karyotis and K. Mosner and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124480634&doi=10.1109%2fMeditCom49071.2021.9647643&partnerID=40&md5=23eca4195ba809f048a4b486e8c8fa8f},
doi = {10.1109/MeditCom49071.2021.9647643},
isbn = {9781665445054},
year = {2021},
date = {2021-01-01},
journal = {2021 IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2021},
pages = {466-467},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {This demonstration presents the design and implementation of a remote driving (tele-operated) support service over mobile communications with an actual vehicle, in the framework of the 5G-HEART project. Also, it evaluates the performance of existing cellular technologies, which is essential for better understanding and planning remote driving through 5G. © 2021 IEEE.},
note = {cited By 3; Conference of 2021 IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2021 ; Conference Date: 7 September 2021 Through 10 September 2021; Conference Code:175865},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
This demonstration presents the design and implementation of a remote driving (tele-operated) support service over mobile communications with an actual vehicle, in the framework of the 5G-HEART project. Also, it evaluates the performance of existing cellular technologies, which is essential for better understanding and planning remote driving through 5G. © 2021 IEEE.
Spatharakis, D., Avgeris, M., Kakkavas, G., Papadakis-Vlachopapadopoulos, K., Dimolitsas, I., Dechouniotis, D., Karyotis, V., & Papavassiliou, S. (2021). Industrial Robotics Experimentation over Federated Next Generation Internet Testbeds. In (pp. 464-465). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/MeditCom49071.2021.9647524
@conference{Spatharakis2021464,
title = {Industrial Robotics Experimentation over Federated Next Generation Internet Testbeds},
author = {D. Spatharakis and M. Avgeris and G. Kakkavas and K. Papadakis-Vlachopapadopoulos and I. Dimolitsas and D. Dechouniotis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124454326&doi=10.1109%2fMeditCom49071.2021.9647524&partnerID=40&md5=8da4aa260a74d925bc45c3a505c0ef64},
doi = {10.1109/MeditCom49071.2021.9647524},
isbn = {9781665445054},
year = {2021},
date = {2021-01-01},
journal = {2021 IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2021},
pages = {464-465},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Modern Industry 4.0 applications require the interplay between industrial equipment, robots, and network infrastructure. This article demonstrates the experimental capabilities of the NETMODE testbed, part of the MESON project, on Industry 4.0 and remote driving scenarios. © 2021 IEEE.},
note = {cited By 0; Conference of 2021 IEEE International Mediterranean Conference on Communications and Networking, MeditCom 2021 ; Conference Date: 7 September 2021 Through 10 September 2021; Conference Code:175865},
keywords = {},
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}
Modern Industry 4.0 applications require the interplay between industrial equipment, robots, and network infrastructure. This article demonstrates the experimental capabilities of the NETMODE testbed, part of the MESON project, on Industry 4.0 and remote driving scenarios. © 2021 IEEE.
Krommyda, M., Tsitseklis, K., Kantere, V., Karyotis, V., & Papavassiliou, S. (2021). Visualizing and exploring big datasets based on semantic community detection. In Y., Z. D. V. Y. V. (Ed.), (pp. 678-681). OpenProceedings.org. https://doi.org/10.5441/002/edbt.2021.82
@conference{Krommyda2021678,
title = {Visualizing and exploring big datasets based on semantic community detection},
author = {M. Krommyda and K. Tsitseklis and V. Kantere and V. Karyotis and S. Papavassiliou},
editor = {Zeinalipour D. Velegrakis Y. Velegrakis Y.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113712934&doi=10.5441%2f002%2fedbt.2021.82&partnerID=40&md5=ad58b2f6a115ba3527775b9d93438610},
doi = {10.5441/002/edbt.2021.82},
issn = {23672005},
year = {2021},
date = {2021-01-01},
journal = {Advances in Database Technology - EDBT},
volume = {2021-March},
pages = {678-681},
publisher = {OpenProceedings.org},
abstract = {The extended use of the RDF model has made available many datasets from heterogeneous sources that are of interest to a wide audience. Their exploration, however, is a highly demanding task requiring extensive training and knowledge of the SPARQL language. In this demo, we present an innovative system, which supports the exploration of large RDF datasets without requiring any knowledge about the RDF or SPARQL. The system is based on a novel algorithm that detects semantically similar communities capitalizing on hyperbolic network embedding and a weighted similarity metric. The detected communities are visualized in a user-friendly way and presented to the user through a two level abstraction interface with a toolbox of exploration functionalities. © 2021 Copyright held by the owner/author(s).},
note = {cited By 0; Conference of Advances in Database Technology - 24th International Conference on Extending Database Technology, EDBT 2021 ; Conference Date: 23 March 2021 Through 26 March 2021; Conference Code:171234},
keywords = {},
pubstate = {published},
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The extended use of the RDF model has made available many datasets from heterogeneous sources that are of interest to a wide audience. Their exploration, however, is a highly demanding task requiring extensive training and knowledge of the SPARQL language. In this demo, we present an innovative system, which supports the exploration of large RDF datasets without requiring any knowledge about the RDF or SPARQL. The system is based on a novel algorithm that detects semantically similar communities capitalizing on hyperbolic network embedding and a weighted similarity metric. The detected communities are visualized in a user-friendly way and presented to the user through a two level abstraction interface with a toolbox of exploration functionalities. © 2021 Copyright held by the owner/author(s).
Nikiforos, M. N., Malakopoulou, M., Stylidou, A., Alvanou, A. G., Karyotis, V., & Kourouthanassis, P. (2020). Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms. In . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/SMAP49528.2020.9248472
@conference{Nikiforos2020,
title = {Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms},
author = {M. N. Nikiforos and M. Malakopoulou and A. Stylidou and A. -G. Alvanou and V. Karyotis and P. Kourouthanassis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85097598439&doi=10.1109%2fSMAP49528.2020.9248472&partnerID=40&md5=e8ab00020bbab229e12e04a952b494b2},
doi = {10.1109/SMAP49528.2020.9248472},
isbn = {9781728159195},
year = {2020},
date = {2020-01-01},
journal = {SMAP 2020 - 15th International Workshop on Semantic and Social Media Adaptation and Personalization},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Web-based learning platforms are now offering a considerable amount of training options, exhibiting great variability, similar to the one encountered by a potential customer in electronic shops. To mitigate this, efficient and effective recommendations engines are needed, capable of satisfying the specific needs of each user, while achieving the best possible promotion of available onlinetraining. This paper discusses the design of a potential generic architecture for online education recommender systems, specifically targeted for promoting online courses and web-based learning material. From an algorithmic perspective, the system relies on item-based and user-based collaborativefiltering approaches. It extends this approach with a genetic algorithm, thus increasing its potential impact. Overall, the paper paves the ground for the specification of generic principles governing the design of personalized online education platforms as well as identifying metrics for evaluating their performance. © 2020 IEEE.},
note = {cited By 3; Conference of 15th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2020 ; Conference Date: 29 October 2020 Through 30 October 2020; Conference Code:164932},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Web-based learning platforms are now offering a considerable amount of training options, exhibiting great variability, similar to the one encountered by a potential customer in electronic shops. To mitigate this, efficient and effective recommendations engines are needed, capable of satisfying the specific needs of each user, while achieving the best possible promotion of available onlinetraining. This paper discusses the design of a potential generic architecture for online education recommender systems, specifically targeted for promoting online courses and web-based learning material. From an algorithmic perspective, the system relies on item-based and user-based collaborativefiltering approaches. It extends this approach with a genetic algorithm, thus increasing its potential impact. Overall, the paper paves the ground for the specification of generic principles governing the design of personalized online education platforms as well as identifying metrics for evaluating their performance. © 2020 IEEE.
Tsitseklis, K., Kakkavas, G., Karyotis, V., & Papavassiliou, S. (2019). A Realistic Evaluation of MRF-based Resource Allocation for SDR Cognitive Radio Networks. In K., O. S. T. H.-P. A. (Ed.), (pp. 185-192). IEEE Computer Society. https://doi.org/10.1109/LCN44214.2019.8990725
@conference{Tsitseklis2019185,
title = {A Realistic Evaluation of MRF-based Resource Allocation for SDR Cognitive Radio Networks},
author = {K. Tsitseklis and G. Kakkavas and V. Karyotis and S. Papavassiliou},
editor = {Oteafy S. Tan H.-P. Andersson K.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85080939926&doi=10.1109%2fLCN44214.2019.8990725&partnerID=40&md5=5ece1109bea717561dba60bfdc872500},
doi = {10.1109/LCN44214.2019.8990725},
isbn = {9781728110288},
year = {2019},
date = {2019-01-01},
journal = {Proceedings - Conference on Local Computer Networks, LCN},
volume = {2019-October},
pages = {185-192},
publisher = {IEEE Computer Society},
abstract = {In this paper, we focus on the development and realistic evaluation of a resource allocation approach for cognitive radios implemented with Software Defined Radio (SDR) technology over two testbeds of the ORCA federation. Our cross-layer approach is based on a Markov Random Field (MRF) framework realizing a distributed computation among the secondary nodes of cognitive radios. This is the first implementation and real experimental evaluation of such a mechanism. New SDR functions for implementing various cognitive radio functionalities, such as spectrum sensing, distributed node synchronization, etc., were developed in GNU Radio from scratch. We demonstrated the feasibility of the MRF-based resource allocation approach and quantified various performance metrics of interest, such as allocation fairness and collision percentage. Through this development, several design principles of broader interest for SDR emerged (e.g., for spectrum sensing and collision detection design), while salient features of our framework requiring further research and development were discovered (e.g., need for parallel implementation). © 2019 IEEE.},
note = {cited By 0; Conference of 44th Annual IEEE Conference on Local Computer Networks, LCN 2019 ; Conference Date: 14 October 2019 Through 17 October 2019; Conference Code:157724},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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In this paper, we focus on the development and realistic evaluation of a resource allocation approach for cognitive radios implemented with Software Defined Radio (SDR) technology over two testbeds of the ORCA federation. Our cross-layer approach is based on a Markov Random Field (MRF) framework realizing a distributed computation among the secondary nodes of cognitive radios. This is the first implementation and real experimental evaluation of such a mechanism. New SDR functions for implementing various cognitive radio functionalities, such as spectrum sensing, distributed node synchronization, etc., were developed in GNU Radio from scratch. We demonstrated the feasibility of the MRF-based resource allocation approach and quantified various performance metrics of interest, such as allocation fairness and collision percentage. Through this development, several design principles of broader interest for SDR emerged (e.g., for spectrum sensing and collision detection design), while salient features of our framework requiring further research and development were discovered (e.g., need for parallel implementation). © 2019 IEEE.
Tsanikidis, C., Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2018). On the Energy-Efficient Coverage of Network Regions with Convex Opaque Obstacles. In (pp. 135-141). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/PIMRC.2018.8580878
@conference{Tsanikidis2018135,
title = {On the Energy-Efficient Coverage of Network Regions with Convex Opaque Obstacles},
author = {C. Tsanikidis and M. Vitoropoulou and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85060539317&doi=10.1109%2fPIMRC.2018.8580878&partnerID=40&md5=d3a99b40001d185764422a49efa7cf7e},
doi = {10.1109/PIMRC.2018.8580878},
isbn = {9781538660096},
year = {2018},
date = {2018-01-01},
journal = {IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC},
volume = {2018-September},
pages = {135-141},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this paper we propose a topology control based approach for addressing the coverage problem in a planar region containing convex opaque obstacles. Such environments represent typical cases of realistic wireless sensor networks and Internet-of-Things deployments. Assuming the devices have the capability to modify their sensing ranges, our goal is to maximize the area covered by randomly dispersed sensors, while reducing their sensing energy consumption as much as possible despite the presence of convex obstacles. To address the former, we introduce a relevant framework capitalizing on the notion of the visibility polygon and propose two algorithms, a centralized (and a randomized version thereof) and a distributed one, which aim to maximize the ratio of covered area to consumed energy, while ensuring a minimum coverage percentage. Through analysis and simulation we demonstrate that the proposed schemes achieve energy efficient coverage, outperforming the plain assignment of maximum sensing range across the network. © 2018 IEEE.},
note = {cited By 0; Conference of 29th IEEE Annual International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC 2018 ; Conference Date: 9 September 2018 Through 12 September 2018; Conference Code:143803},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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In this paper we propose a topology control based approach for addressing the coverage problem in a planar region containing convex opaque obstacles. Such environments represent typical cases of realistic wireless sensor networks and Internet-of-Things deployments. Assuming the devices have the capability to modify their sensing ranges, our goal is to maximize the area covered by randomly dispersed sensors, while reducing their sensing energy consumption as much as possible despite the presence of convex obstacles. To address the former, we introduce a relevant framework capitalizing on the notion of the visibility polygon and propose two algorithms, a centralized (and a randomized version thereof) and a distributed one, which aim to maximize the ratio of covered area to consumed energy, while ensuring a minimum coverage percentage. Through analysis and simulation we demonstrate that the proposed schemes achieve energy efficient coverage, outperforming the plain assignment of maximum sensing range across the network. © 2018 IEEE.
Karyotis, V., Tsitseklis, K., Sotiropoulos, K., & Papavassiliou, S. (2018). Enhancing Community Detection for Big Sensor Data Clustering via Hyperbolic Network Embedding. In (pp. 266-271). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/PERCOMW.2018.8480134
@conference{Karyotis2018266,
title = {Enhancing Community Detection for Big Sensor Data Clustering via Hyperbolic Network Embedding},
author = {V. Karyotis and K. Tsitseklis and K. Sotiropoulos and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85056458909&doi=10.1109%2fPERCOMW.2018.8480134&partnerID=40&md5=082f7ba01a225e8ccef49047803f02bd},
doi = {10.1109/PERCOMW.2018.8480134},
isbn = {9781538632277},
year = {2018},
date = {2018-01-01},
journal = {2018 IEEE International Conference on Pervasive Computing and Communications Workshops, PerCom Workshops 2018},
pages = {266-271},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this paper we present a novel big data clustering approach for measurements obtained from pervasive sensor networks. To address the potential very large scale of such datasets, we map the problem of data clustering to a community detection one. Datasets are cast in the form of graphs, representing the relations among individual observations and data clustering is mapped to node clustering (community detection) in the data graph. We propose a novel computational approach for enhancing the traditional Girvan-Newman (GN) community detection algorithm via hyperbolic network embedding. The data dependency graph is embedded in the hyperbolic space via Rigel embedding, making it possible to compute more efficiently the hyperbolic edge-betweenness centrality (HEBC) needed in the modified GN algorithm. This allows for more efficient clustering of the nodes of the data graph without significantly sacrificing accuracy. We demonstrate the efficacy of our approach with artificial network and data topologies, and real benchmark datasets. The proposed methodology can be used for efficient clustering of datasets obtained from massive pervasive smart city/building sensor networks, such as the FIESTA-IoT platform, and exploited in various applications such as lower-cost sensing. © 2018 IEEE.},
note = {cited By 1; Conference of 2018 IEEE International Conference on Pervasive Computing and Communications Workshops, PerCom Workshops 2018 ; Conference Date: 19 March 2018 Through 23 March 2018; Conference Code:140607},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
In this paper we present a novel big data clustering approach for measurements obtained from pervasive sensor networks. To address the potential very large scale of such datasets, we map the problem of data clustering to a community detection one. Datasets are cast in the form of graphs, representing the relations among individual observations and data clustering is mapped to node clustering (community detection) in the data graph. We propose a novel computational approach for enhancing the traditional Girvan-Newman (GN) community detection algorithm via hyperbolic network embedding. The data dependency graph is embedded in the hyperbolic space via Rigel embedding, making it possible to compute more efficiently the hyperbolic edge-betweenness centrality (HEBC) needed in the modified GN algorithm. This allows for more efficient clustering of the nodes of the data graph without significantly sacrificing accuracy. We demonstrate the efficacy of our approach with artificial network and data topologies, and real benchmark datasets. The proposed methodology can be used for efficient clustering of datasets obtained from massive pervasive smart city/building sensor networks, such as the FIESTA-IoT platform, and exploited in various applications such as lower-cost sensing. © 2018 IEEE.
Papadis, N., Stai, E., & Karyotis, V. (2017). A path-based recommendations approach for online systems via hyperbolic network embedding. In (pp. 973-980). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ISCC.2017.8024652
@conference{Papadis2017973,
title = {A path-based recommendations approach for online systems via hyperbolic network embedding},
author = {N. Papadis and E. Stai and V. Karyotis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85030552382&doi=10.1109%2fISCC.2017.8024652&partnerID=40&md5=e493e583b0401de9bed050de76373b57},
doi = {10.1109/ISCC.2017.8024652},
issn = {15301346},
year = {2017},
date = {2017-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {973-980},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this paper we introduce and demonstrate new recommendation algorithms for large-scale online systems, such as e-shops and cloud services. The proposed algorithms are based on the combination of network embedding in hyperbolic space with greedy routing, exploiting properties of hyperbolic metric spaces. Contrary to the existing recommender systems that rank products in order to propose the highest ranked ones to the users, our proposed recommender system creates a progressive path of recommendations towards a final (known or inferred) target product using greedy routing over networks embedded in hyperbolic space. Thus, it prepares the user by intermediate recommendations for maximizing the chances that he/she accepts the recommendation of the target product(s). This casts the problem of locating a suitable recommendation as a path problem, where leveraging on the efficiency of greedy routing in graphs embedded in hyperbolic spaces and exploiting special network structure, if any, pays dividends. Two variants of our recommendation approach are provided, namely Hyperbolic Recommendation-Known Destination (HRKD), Hyperbolic Recommendation-Unknown Destination (HRUD), when the target product is known or unknown, respectively. We demonstrate how the proposed approach can be used for producing efficient recommendations in online systems, along with studying the impact of the several parameters involved in its performance via proper emulation of user activity over suitably defined graphs. © 2017 IEEE.},
note = {cited By 2; Conference of 2017 IEEE Symposium on Computers and Communications, ISCC 2017 ; Conference Date: 3 July 2017 Through 7 July 2017; Conference Code:130537},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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In this paper we introduce and demonstrate new recommendation algorithms for large-scale online systems, such as e-shops and cloud services. The proposed algorithms are based on the combination of network embedding in hyperbolic space with greedy routing, exploiting properties of hyperbolic metric spaces. Contrary to the existing recommender systems that rank products in order to propose the highest ranked ones to the users, our proposed recommender system creates a progressive path of recommendations towards a final (known or inferred) target product using greedy routing over networks embedded in hyperbolic space. Thus, it prepares the user by intermediate recommendations for maximizing the chances that he/she accepts the recommendation of the target product(s). This casts the problem of locating a suitable recommendation as a path problem, where leveraging on the efficiency of greedy routing in graphs embedded in hyperbolic spaces and exploiting special network structure, if any, pays dividends. Two variants of our recommendation approach are provided, namely Hyperbolic Recommendation-Known Destination (HRKD), Hyperbolic Recommendation-Unknown Destination (HRUD), when the target product is known or unknown, respectively. We demonstrate how the proposed approach can be used for producing efficient recommendations in online systems, along with studying the impact of the several parameters involved in its performance via proper emulation of user activity over suitably defined graphs. © 2017 IEEE.
Karyotis, V., Stai, E., & Papavassiliou, S. (2016). A component-based cross-layer framework for software defined wireless networks. In M., V. V. P. G. B. (Ed.), . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/NTMS.2016.7792426
@conference{Karyotis2016,
title = {A component-based cross-layer framework for software defined wireless networks},
author = {V. Karyotis and E. Stai and S. Papavassiliou},
editor = {Vassiliou V. Pau G. Badra M.},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85011284151&doi=10.1109%2fNTMS.2016.7792426&partnerID=40&md5=20e00845b790f63c4550f376c4bbc308},
doi = {10.1109/NTMS.2016.7792426},
isbn = {9781509029143},
year = {2016},
date = {2016-01-01},
journal = {2016 8th IFIP International Conference on New Technologies, Mobility and Security, NTMS 2016},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Network architectures that exhibit cognitive behavior, such as self-adaptation and reconfiguration, are becoming extremely popular paradigms for the future heterogeneous wireless networks. Towards this direction, in this paper, we leverage on the component-based approach to achieve modular cross-layer design and propose a protocol stack with adaptive features that allows autonomous decision-making using local ambient information. The proposed framework allows segregating control from the data plane and combining different techniques, such as backpressure and Markov Random Fields (MRFs), for more efficient adaptation and flexibility against network variations. We demonstrate the effectiveness of the proposed approach and the component-based features of the architecture by presenting hybrid control plane mechanisms that combine the aforementioned techniques in a modular fashion. Finally, we provide directions for practically exploiting the proposed architecture. © 2016 IEEE.},
note = {cited By 3; Conference of 8th IFIP International Conference on New Technologies, Mobility and Security, NTMS 2016 ; Conference Date: 21 November 2016 Through 23 November 2016; Conference Code:125557},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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Network architectures that exhibit cognitive behavior, such as self-adaptation and reconfiguration, are becoming extremely popular paradigms for the future heterogeneous wireless networks. Towards this direction, in this paper, we leverage on the component-based approach to achieve modular cross-layer design and propose a protocol stack with adaptive features that allows autonomous decision-making using local ambient information. The proposed framework allows segregating control from the data plane and combining different techniques, such as backpressure and Markov Random Fields (MRFs), for more efficient adaptation and flexibility against network variations. We demonstrate the effectiveness of the proposed approach and the component-based features of the architecture by presenting hybrid control plane mechanisms that combine the aforementioned techniques in a modular fashion. Finally, we provide directions for practically exploiting the proposed architecture. © 2016 IEEE.
Stai, E., Sotiropoulos, K., Karyotis, V., & Papavassiliou, S. (2016). Hyperbolic Traffic Load Centrality for large-scale complex communications networks. In . Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICT.2016.7500371
@conference{Stai2016,
title = {Hyperbolic Traffic Load Centrality for large-scale complex communications networks},
author = {E. Stai and K. Sotiropoulos and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84979205129&doi=10.1109%2fICT.2016.7500371&partnerID=40&md5=f46ed087a57f7adf10247c593797f09b},
doi = {10.1109/ICT.2016.7500371},
isbn = {9781509019908},
year = {2016},
date = {2016-01-01},
journal = {2016 23rd International Conference on Telecommunications, ICT 2016},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Estimating accurately important nodes for routing in modern and future networks is a key process with numerous benefits. Towards this goal, in this paper we propose Hyperbolic Traffic Load Centrality (HTLC), as a novel alternative to the Traffic Load Centrality (TLC) metric, used for ranking nodes with respect to their importance in the routing operation. HTLC is based on network embedding in hyperbolic space, while assuming paths paved by greedy routing over hyperbolic coordinates, which requires less computational effort than shortest path routing (in terms of hop distances) used for TLC. Greedy routing in hyperbolic space also yields paths with lengths very close to the shortest ones for the social networks of interest bearing the scale-free property. Through analysis and simulation, we demonstrate that HTLC requires significantly lower computational time than TLC, and despite being more suitable for greedy routing constraints over hyperbolic space, it nevertheless achieves a close approximation of TLC for networks with scale-free properties when assuming shortest path routing. Thus, it can substitute TLC when analyzing very large network topologies. © 2016 IEEE.},
note = {cited By 3; Conference of 23rd International Conference on Telecommunications, ICT 2016 ; Conference Date: 16 May 2016 Through 18 May 2016; Conference Code:122441},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Estimating accurately important nodes for routing in modern and future networks is a key process with numerous benefits. Towards this goal, in this paper we propose Hyperbolic Traffic Load Centrality (HTLC), as a novel alternative to the Traffic Load Centrality (TLC) metric, used for ranking nodes with respect to their importance in the routing operation. HTLC is based on network embedding in hyperbolic space, while assuming paths paved by greedy routing over hyperbolic coordinates, which requires less computational effort than shortest path routing (in terms of hop distances) used for TLC. Greedy routing in hyperbolic space also yields paths with lengths very close to the shortest ones for the social networks of interest bearing the scale-free property. Through analysis and simulation, we demonstrate that HTLC requires significantly lower computational time than TLC, and despite being more suitable for greedy routing constraints over hyperbolic space, it nevertheless achieves a close approximation of TLC for networks with scale-free properties when assuming shortest path routing. Thus, it can substitute TLC when analyzing very large network topologies. © 2016 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2015). User interest dictated information diffusion over generalized networks. In (pp. 1569-1574). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICCW.2015.7247403
@conference{Stai20151569,
title = {User interest dictated information diffusion over generalized networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84947782089&doi=10.1109%2fICCW.2015.7247403&partnerID=40&md5=8bce0fc40e131b95ca1f4d2950923df7},
doi = {10.1109/ICCW.2015.7247403},
isbn = {9781467363051},
year = {2015},
date = {2015-01-01},
journal = {2015 IEEE International Conference on Communication Workshop, ICCW 2015},
pages = {1569-1574},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {In this paper we address the diffusion of useful information in generalized networks each consisting of a wireless physical substrate and a social network overlay. Contrary to previous works, we consider the effect of user interest and features thereof on the spreading dynamics of useful information within these complex wireless-social networks, e.g., how interest periodicity affects the diffusion of summer vacation advertisements, etc. We develop an epidemic based mathematical framework for such processes and use three indicative operational scenarios to demonstrate the solutions and results that can be obtained by the corresponding differential equation based formalism. By analysis and simulation, significant outcomes were obtained on the impact of each topological layer and the associated interest parameters on the dynamics of information diffusion. © 2015 IEEE.},
note = {cited By 3; Conference of IEEE International Conference on Communication Workshop, ICCW 2015 ; Conference Date: 8 June 2015 Through 12 June 2015; Conference Code:115891},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
In this paper we address the diffusion of useful information in generalized networks each consisting of a wireless physical substrate and a social network overlay. Contrary to previous works, we consider the effect of user interest and features thereof on the spreading dynamics of useful information within these complex wireless-social networks, e.g., how interest periodicity affects the diffusion of summer vacation advertisements, etc. We develop an epidemic based mathematical framework for such processes and use three indicative operational scenarios to demonstrate the solutions and results that can be obtained by the corresponding differential equation based formalism. By analysis and simulation, significant outcomes were obtained on the impact of each topological layer and the associated interest parameters on the dynamics of information diffusion. © 2015 IEEE.
Anifantis, E., Stai, E., Karyotis, V., & Papavassiliou, S. (2014). An MRF cross-layer resource allocation approach with back-pressure features for QoS in dynamic social and cognitive communications. In (pp. 323-328). Toronto, ON: Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/INFCOMW.2014.6849252
@conference{Anifantis2014323,
title = {An MRF cross-layer resource allocation approach with back-pressure features for QoS in dynamic social and cognitive communications},
author = {E. Anifantis and E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84904464894&doi=10.1109%2fINFCOMW.2014.6849252&partnerID=40&md5=463d49bdd460007c5de0f1e577e099d8},
doi = {10.1109/INFCOMW.2014.6849252},
issn = {0743166X},
year = {2014},
date = {2014-01-01},
journal = {Proceedings - IEEE INFOCOM},
pages = {323-328},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
address = {Toronto, ON},
abstract = {Future dynamic wireless and online social networks will require more agile and efficient infrastructures to support the anticipated user traffic and service requirements. In response, in this work, we propose a novel spectrum-agile resource allocation approach that combines Markov Random Field (MRF) cross-layer decisions for the allocation of resources at the lower protocol layers with Back-pressure (BP) features at the higher ones, in order to achieve the above objectives. The BP-enhanced MRF (BPeMRF) network optimization serves the purpose of improving the capacity of agile infrastructures in a low complexity manner, while espousing the recent developments in dynamic spectrum environments (cognitive radios), which are required to adapt fast according to the demands of overlaying dynamic online social networks. The obtained results exhibit the efficacy of BPeMRF regarding the above objectives and demonstrate significant promise for further improving the corresponding infrastructures. © 2014 IEEE.},
note = {cited By 0; Conference of 2014 IEEE Conference on Computer Communications Workshops, INFOCOM WKSHPS 2014 ; Conference Date: 27 April 2014 Through 2 May 2014; Conference Code:106378},
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pubstate = {published},
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Future dynamic wireless and online social networks will require more agile and efficient infrastructures to support the anticipated user traffic and service requirements. In response, in this work, we propose a novel spectrum-agile resource allocation approach that combines Markov Random Field (MRF) cross-layer decisions for the allocation of resources at the lower protocol layers with Back-pressure (BP) features at the higher ones, in order to achieve the above objectives. The BP-enhanced MRF (BPeMRF) network optimization serves the purpose of improving the capacity of agile infrastructures in a low complexity manner, while espousing the recent developments in dynamic spectrum environments (cognitive radios), which are required to adapt fast according to the demands of overlaying dynamic online social networks. The obtained results exhibit the efficacy of BPeMRF regarding the above objectives and demonstrate significant promise for further improving the corresponding infrastructures. © 2014 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2012). Wireless multi-hop network topology control optimization and trade-off analysis. In . Newark, NJ. https://doi.org/10.1109/SARNOF.2012.6222762
@conference{Stai2012,
title = {Wireless multi-hop network topology control optimization and trade-off analysis},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84864192762&doi=10.1109%2fSARNOF.2012.6222762&partnerID=40&md5=fd5c79d7ba03ff42c960abe9460da9c0},
doi = {10.1109/SARNOF.2012.6222762},
isbn = {9781467314640},
year = {2012},
date = {2012-01-01},
journal = {35th IEEE Sarnoff Symposium, SARNOFF 2012 - Conference Proceedings},
address = {Newark, NJ},
abstract = {Future communications require distributed, adjustable and energy-efficient wireless topologies. Network churn based topology modification mechanisms have been shown to achieve such goals by infusing small-world properties in multi-hop radio networks, thus improving network reconfiguration and end-to-end capabilities. Towards further enhancing such mechanisms, in this work, we present an optimization methodology that analyzes and properly balances the underlying node and edge churn sub-mechanisms of network churn modification. The emerging optimization is non-linear in the general case and we employ sequential quadratic programming and decomposition methods to tackle it. By exploiting the obtained solutions, we demonstrate the efficacy of the optimization and analyze the inherent wireless trade-off between energy consumption and average path length. We show that when energy consumption is of interest, node churn based control should be preferred, while in order to increase performance, edge churn is more suitable. Thus, the proposed optimization methodology enables efficient and targeted control of multi-hop wireless communications for the Future Internet at various scales and operational demands. © 2012 IEEE.},
note = {cited By 3; Conference of 35th IEEE Sarnoff Symposium, SARNOFF 2012 ; Conference Date: 21 May 2012 Through 22 May 2012; Conference Code:91462},
keywords = {},
pubstate = {published},
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Future communications require distributed, adjustable and energy-efficient wireless topologies. Network churn based topology modification mechanisms have been shown to achieve such goals by infusing small-world properties in multi-hop radio networks, thus improving network reconfiguration and end-to-end capabilities. Towards further enhancing such mechanisms, in this work, we present an optimization methodology that analyzes and properly balances the underlying node and edge churn sub-mechanisms of network churn modification. The emerging optimization is non-linear in the general case and we employ sequential quadratic programming and decomposition methods to tackle it. By exploiting the obtained solutions, we demonstrate the efficacy of the optimization and analyze the inherent wireless trade-off between energy consumption and average path length. We show that when energy consumption is of interest, node churn based control should be preferred, while in order to increase performance, edge churn is more suitable. Thus, the proposed optimization methodology enables efficient and targeted control of multi-hop wireless communications for the Future Internet at various scales and operational demands. © 2012 IEEE.
Anifantis, E., Karyotis, V., & Papavassiliou, S. (2012). A Markov Random Field framework for channel assignment in Cognitive Radio networks. In (pp. 770-775). Lugano. https://doi.org/10.1109/PerComW.2012.6197617
@conference{Anifantis2012770,
title = {A Markov Random Field framework for channel assignment in Cognitive Radio networks},
author = {E. Anifantis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861557370&doi=10.1109%2fPerComW.2012.6197617&partnerID=40&md5=b61b3a30d3184b4e48a981017504ed6c},
doi = {10.1109/PerComW.2012.6197617},
isbn = {9781467309073},
year = {2012},
date = {2012-01-01},
journal = {2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012},
pages = {770-775},
address = {Lugano},
abstract = {In order to alleviate the absence of hierarchical coordination among secondary users of Cognitive Radio networks and to enable fast and efficient reconfiguration of pervasive ad hoc networks, spatially localized and frequency agile mechanisms are required across the wireless protocol stack. In this paper, we introduce a framework for distributed and adaptable radio channel allocation in wireless Cognitive Radio networks, which is based on the theory of Markov Random Fields and Gibbs sampling. By exchanging local only information, secondary users are able to assign efficiently available channels according to desired operational requirements, even if these requirements change over time. Through analysis and simulation we show the applicability of the framework and demonstrate its distributed operation. We study the emerging trade-offs of the proposed approach by demonstrating the performance benefits obtained in radio channel allocation and by analyzing the inherent costs. © 2012 IEEE.},
note = {cited By 14; Conference of 2012 IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2012 ; Conference Date: 19 March 2012 Through 23 March 2012; Conference Code:89907},
keywords = {},
pubstate = {published},
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In order to alleviate the absence of hierarchical coordination among secondary users of Cognitive Radio networks and to enable fast and efficient reconfiguration of pervasive ad hoc networks, spatially localized and frequency agile mechanisms are required across the wireless protocol stack. In this paper, we introduce a framework for distributed and adaptable radio channel allocation in wireless Cognitive Radio networks, which is based on the theory of Markov Random Fields and Gibbs sampling. By exchanging local only information, secondary users are able to assign efficiently available channels according to desired operational requirements, even if these requirements change over time. Through analysis and simulation we show the applicability of the framework and demonstrate its distributed operation. We study the emerging trade-offs of the proposed approach by demonstrating the performance benefits obtained in radio channel allocation and by analyzing the inherent costs. © 2012 IEEE.
Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2012). Channel switching-aware optimal reconfiguration in cognitive radio networks. In . Poznan: VDE VERLAG GMBH.
@conference{Arkoulis2012,
title = {Channel switching-aware optimal reconfiguration in cognitive radio networks},
author = {S. Arkoulis and E. Anifantis and V. Karyotis and S. Papavassiliou and N. Mitrou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84878108973&partnerID=40&md5=a631a6c05a3f572b63382ff7dff08d38},
year = {2012},
date = {2012-01-01},
journal = {18th European Wireless Conference, EW 2012},
publisher = {VDE VERLAG GMBH},
address = {Poznan},
abstract = {Secondary users in Cognitive Radio networks (CRNs) require intelligent reconfiguration mechanisms, in order to respond promptly and limit properly additional and escalating system adaptations triggered by the interweaved primary network activity. In this work, we focus on the Joint Channel Assignment and Routing (JCAR) problem in CRNs and especially on the optimal reconfiguration of secondary networks by mainly taking into account the underlying spectrum switching distance parameter. We formulate the JCAR and network reconfiguration problems as mixed integer linear programs, addressing fairness as well. The proposed formulation addresses the trade-off between low reconfiguration cost and flow demand satisfaction. Through analysis and simulations we demonstrate the operation and effectiveness of the proposed mechanisms. The obtained numerical results indicate and quantify the underlying reconfiguration trade-off, while demonstrating the benefits achieved by the proposed solutions. © 2012 VDE VERLAG GMBH.},
note = {cited By 2; Conference of 18th European Wireless Conference, EW 2012 ; Conference Date: 18 April 2012 Through 20 April 2012; Conference Code:107593},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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Secondary users in Cognitive Radio networks (CRNs) require intelligent reconfiguration mechanisms, in order to respond promptly and limit properly additional and escalating system adaptations triggered by the interweaved primary network activity. In this work, we focus on the Joint Channel Assignment and Routing (JCAR) problem in CRNs and especially on the optimal reconfiguration of secondary networks by mainly taking into account the underlying spectrum switching distance parameter. We formulate the JCAR and network reconfiguration problems as mixed integer linear programs, addressing fairness as well. The proposed formulation addresses the trade-off between low reconfiguration cost and flow demand satisfaction. Through analysis and simulations we demonstrate the operation and effectiveness of the proposed mechanisms. The obtained numerical results indicate and quantify the underlying reconfiguration trade-off, while demonstrating the benefits achieved by the proposed solutions. © 2012 VDE VERLAG GMBH.
Anifantis, E., Karyotis, V., & Papavassiliou, S. (2011). Time-based cross-layer adaptations in wireless cognitive radio ad hoc networks. In (pp. 1044-1049). Corfu. https://doi.org/10.1109/ISCC.2011.5983980
@conference{Anifantis20111044,
title = {Time-based cross-layer adaptations in wireless cognitive radio ad hoc networks},
author = {E. Anifantis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052767331&doi=10.1109%2fISCC.2011.5983980&partnerID=40&md5=925f8322af534b652bdaf193a6214697},
doi = {10.1109/ISCC.2011.5983980},
issn = {15301346},
year = {2011},
date = {2011-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {1044-1049},
address = {Corfu},
abstract = {Secondary ad hoc users of Cognitive Radio networks experience constant fluctuations of their link quality due to dynamic traffic behavior of their primary network counterparts. Several cognitive-aware MAC and routing protocols have been proposed in order to counterfeit properly such spectrum variations. In this paper, we introduce a vertical time-based control mechanism in the traditional protocol stack, aiming at properly balancing the inherent trade-off between instant local adaptations at MAC layer, against slower, but more globally aware rerouting reaction mechanisms. Based on localized and independent node decisions, an optimal feedback policy is proposed in order to exploit the most appropriate protocol layer in each case and provide per link channel assignments, such that flow rate requirements are satisfied with the least cost. We use Markov theory to examine the coexistence of primary and secondary networks, while the optimal decision policy is derived via a Markov Decision Process (MDP) and linear programming. Analysis and simulations are used for performance evaluation and together they confirm that the proposed time-based cross-layer feedback strategy contributes to higher network performance regarding flow rate requirements, sensing and rerouting costs. © 2011 IEEE.},
note = {cited By 4; Conference of 16th IEEE Symposium on Computers and Communications, ISCC'11 ; Conference Date: 28 June 2011 Through 1 July 2011; Conference Code:86395},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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Secondary ad hoc users of Cognitive Radio networks experience constant fluctuations of their link quality due to dynamic traffic behavior of their primary network counterparts. Several cognitive-aware MAC and routing protocols have been proposed in order to counterfeit properly such spectrum variations. In this paper, we introduce a vertical time-based control mechanism in the traditional protocol stack, aiming at properly balancing the inherent trade-off between instant local adaptations at MAC layer, against slower, but more globally aware rerouting reaction mechanisms. Based on localized and independent node decisions, an optimal feedback policy is proposed in order to exploit the most appropriate protocol layer in each case and provide per link channel assignments, such that flow rate requirements are satisfied with the least cost. We use Markov theory to examine the coexistence of primary and secondary networks, while the optimal decision policy is derived via a Markov Decision Process (MDP) and linear programming. Analysis and simulations are used for performance evaluation and together they confirm that the proposed time-based cross-layer feedback strategy contributes to higher network performance regarding flow rate requirements, sensing and rerouting costs. © 2011 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2011). Enhancing trust establishment in wireless multi-hop networks via preferential attachment. In (pp. 630-635). Corfu. https://doi.org/10.1109/ISCC.2011.5983909
@conference{Stai2011630,
title = {Enhancing trust establishment in wireless multi-hop networks via preferential attachment},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052746899&doi=10.1109%2fISCC.2011.5983909&partnerID=40&md5=e95d4225c4ab66999437fc5a93e04a0a},
doi = {10.1109/ISCC.2011.5983909},
issn = {15301346},
year = {2011},
date = {2011-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {630-635},
address = {Corfu},
abstract = {In this paper the problem of enhancing trust establishment in multi-hop wireless networks is addressed. Exploiting small-world features and based on preferential attachment and initial node trust values, we design inverse Topology Control methods that achieve to reduce the mean hop-distance between two nodes and increase the average trust value of the shortest paths. Based on continuum theory a mathematical framework is developed for the overall socially-motivated trust-based network churn mechanism. Analytical and simulation results exhibit the effectiveness of the proposed approaches for enhancing physical topologies, increasing the average trust path values, and thus further securing future communications systems. © 2011 IEEE.},
note = {cited By 0; Conference of 16th IEEE Symposium on Computers and Communications, ISCC'11 ; Conference Date: 28 June 2011 Through 1 July 2011; Conference Code:86395},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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In this paper the problem of enhancing trust establishment in multi-hop wireless networks is addressed. Exploiting small-world features and based on preferential attachment and initial node trust values, we design inverse Topology Control methods that achieve to reduce the mean hop-distance between two nodes and increase the average trust value of the shortest paths. Based on continuum theory a mathematical framework is developed for the overall socially-motivated trust-based network churn mechanism. Analytical and simulation results exhibit the effectiveness of the proposed approaches for enhancing physical topologies, increasing the average trust path values, and thus further securing future communications systems. © 2011 IEEE.
Chen, P. Y., Karyotis, V., Papavassiliou, S., & Chen, K. C. (2011). Topology control in multi-channel cognitive radio networks with non-uniform node arrangements. In (pp. 1033-1037). Corfu. https://doi.org/10.1109/ISCC.2011.5983978
@conference{Chen20111033,
title = {Topology control in multi-channel cognitive radio networks with non-uniform node arrangements},
author = {P. -Y. Chen and V. Karyotis and S. Papavassiliou and K. -C. Chen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-80052726013&doi=10.1109%2fISCC.2011.5983978&partnerID=40&md5=41185dafcd379a147857d49251d7d3fd},
doi = {10.1109/ISCC.2011.5983978},
issn = {15301346},
year = {2011},
date = {2011-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {1033-1037},
address = {Corfu},
abstract = {Cognitive Radio (CR) techniques have been developed to allow ad hoc users to communicate with each other by exploiting the licensed bands of primary systems without disturbing the entrenched users. In this work, we take current approaches one step ahead and combine Topology Control (TC) techniques with CR technology, in order to improve operation and performance, even under the stringent and non-uniform arrangements of CR networks (CRNs). We propose a novel node-degree based Topology Control approach, denoted by Enhanced Cognitive Nearest Random Neighbor (e-CNRN), for multi-channel CRNs, aiming at maintaining network connectivity and adapting to environmental changes such as primary user activity and channel conditions. Compared with TC protocols in conventional ad hoc networks, e-CNRN requires only minimal local information and is specially designed to perform under non-uniform node arrangements, rendering e-CNRN a generic and robust distributed TC approach, especially suitable for multichannel CRNs as well. In addition, we leverage e-CNRN for distributively establishing a virtual common control channel for multi-channel CRNs. Through analysis and simulations we validate that e-CNRN guarantees network connectivity, while achieving efficient power control. © 2011 IEEE.},
note = {cited By 4; Conference of 16th IEEE Symposium on Computers and Communications, ISCC'11 ; Conference Date: 28 June 2011 Through 1 July 2011; Conference Code:86395},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Cognitive Radio (CR) techniques have been developed to allow ad hoc users to communicate with each other by exploiting the licensed bands of primary systems without disturbing the entrenched users. In this work, we take current approaches one step ahead and combine Topology Control (TC) techniques with CR technology, in order to improve operation and performance, even under the stringent and non-uniform arrangements of CR networks (CRNs). We propose a novel node-degree based Topology Control approach, denoted by Enhanced Cognitive Nearest Random Neighbor (e-CNRN), for multi-channel CRNs, aiming at maintaining network connectivity and adapting to environmental changes such as primary user activity and channel conditions. Compared with TC protocols in conventional ad hoc networks, e-CNRN requires only minimal local information and is specially designed to perform under non-uniform node arrangements, rendering e-CNRN a generic and robust distributed TC approach, especially suitable for multichannel CRNs as well. In addition, we leverage e-CNRN for distributively establishing a virtual common control channel for multi-channel CRNs. Through analysis and simulations we validate that e-CNRN guarantees network connectivity, while achieving efficient power control. © 2011 IEEE.
Arnautovic, E., Vallée, M., Rehm, S. V., Müthel, M., Mulvenna, M., Baumgarten, M., Karyotis, V., Papavassiliou, S., Hadjiantonis, A. M., & Stathis, K. (2010). Towards self-managing systems inspired by economic organizations. In (pp. 888-895). Istanbul. https://doi.org/10.1109/ICSMC.2010.5641875
@conference{Arnautovic2010888,
title = {Towards self-managing systems inspired by economic organizations},
author = {E. Arnautovic and M. Vallée and S. -V. Rehm and M. Müthel and M. Mulvenna and M. Baumgarten and V. Karyotis and S. Papavassiliou and A. M. Hadjiantonis and K. Stathis},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-78751548552&doi=10.1109%2fICSMC.2010.5641875&partnerID=40&md5=a4676cbb53e55eff2d82ad2aeb41bad8},
doi = {10.1109/ICSMC.2010.5641875},
issn = {1062922X},
year = {2010},
date = {2010-01-01},
journal = {Conference Proceedings - IEEE International Conference on Systems, Man and Cybernetics},
pages = {888-895},
address = {Istanbul},
abstract = {Today's self-managing systems would ideally be able to adapt themselves (their internal structure or behavior), as well as to autonomously participate in larger, self-organizing systems. Analogously, the enterprises or other socio-economic systems autonomously manage themselves - they make decisions on how to adapt their structure and behavior, and how to organize with other entities in the environment. To connect internal self-adaptive with external self-organizational behavior, an enterprise is "aware" of itself and of its environment, and acts according to this awareness. T his position paper proposes to address the challenges of a complex distributed self-managing system by making entities in such a system able to adapt themselves similarly to how companies manage themselves in socio-economic systems. To enable the knowledge transfer between these two fields, the paper proposes to utilize symbolic models which will be used by self-managing systems for knowledge representation and reasoning. This will make such systems in a way also self-aware and enable both self-adaptive and self-organizing capabilities. The paper discusses research directions to make this approach possible. ©2010 IEEE.},
note = {cited By 1; Conference of 2010 IEEE International Conference on Systems, Man and Cybernetics, SMC 2010 ; Conference Date: 10 October 2010 Through 13 October 2010; Conference Code:83423},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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Today's self-managing systems would ideally be able to adapt themselves (their internal structure or behavior), as well as to autonomously participate in larger, self-organizing systems. Analogously, the enterprises or other socio-economic systems autonomously manage themselves - they make decisions on how to adapt their structure and behavior, and how to organize with other entities in the environment. To connect internal self-adaptive with external self-organizational behavior, an enterprise is "aware" of itself and of its environment, and acts according to this awareness. T his position paper proposes to address the challenges of a complex distributed self-managing system by making entities in such a system able to adapt themselves similarly to how companies manage themselves in socio-economic systems. To enable the knowledge transfer between these two fields, the paper proposes to utilize symbolic models which will be used by self-managing systems for knowledge representation and reasoning. This will make such systems in a way also self-aware and enable both self-adaptive and self-organizing capabilities. The paper discusses research directions to make this approach possible. ©2010 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2010). Socially-inspired topology improvements in wireless multi-hop networks. In . Capetown. https://doi.org/10.1109/ICCW.2010.5503927
@conference{Stai2010,
title = {Socially-inspired topology improvements in wireless multi-hop networks},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77954942474&doi=10.1109%2fICCW.2010.5503927&partnerID=40&md5=82086b2738485e0a51209225fb489b8f},
doi = {10.1109/ICCW.2010.5503927},
isbn = {9781424468263},
year = {2010},
date = {2010-01-01},
journal = {2010 IEEE International Conference on Communications Workshops, ICC 2010},
address = {Capetown},
abstract = {Several graph structures have emerged for describing different network types and the interactions among their entities. Various properties have been identified in each of these network graphs, with no single structure bearing all the desired features that would constitute it an optimal network graph. This work aims for the first time at infusing the desired properties of a small-world network into the core structure of a wireless multi-hop network, thus embedding social structure on an artificial network that emerges in the development of wireless communication services. In this paper, topology control based approaches are proposed, serving the purpose of adding communication links in a multi-hop network in an intelligent and effective manner. Through analysis and simulation, we demonstrate how the proposed methods decrease the average path length between randomly selected node pairs and properly scale the clustering coefficient of a multi-hop network, by exploiting social structure characteristics of small-world networks, thus allowing the development of more demanding services on top of wireless multi-hop networks. ©2010 IEEE.},
note = {cited By 9; Conference of 2010 IEEE International Conference on Communications Workshops, ICC 2010 ; Conference Date: 23 May 2010 Through 27 May 2010; Conference Code:81220},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Several graph structures have emerged for describing different network types and the interactions among their entities. Various properties have been identified in each of these network graphs, with no single structure bearing all the desired features that would constitute it an optimal network graph. This work aims for the first time at infusing the desired properties of a small-world network into the core structure of a wireless multi-hop network, thus embedding social structure on an artificial network that emerges in the development of wireless communication services. In this paper, topology control based approaches are proposed, serving the purpose of adding communication links in a multi-hop network in an intelligent and effective manner. Through analysis and simulation, we demonstrate how the proposed methods decrease the average path length between randomly selected node pairs and properly scale the clustering coefficient of a multi-hop network, by exploiting social structure characteristics of small-world networks, thus allowing the development of more demanding services on top of wireless multi-hop networks. ©2010 IEEE.
Karyotis, V., Manolakos, A., & Papavassiliou, S. (2010). On topology control and non-uniform node deployment in ad hoc networks. In (pp. 522-527). Mannheim. https://doi.org/10.1109/PERCOMW.2010.5470494
@conference{Karyotis2010522,
title = {On topology control and non-uniform node deployment in ad hoc networks},
author = {V. Karyotis and A. Manolakos and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-77954022569&doi=10.1109%2fPERCOMW.2010.5470494&partnerID=40&md5=d8446bdab12527badd4c07caaa7da458},
doi = {10.1109/PERCOMW.2010.5470494},
isbn = {9781424466054},
year = {2010},
date = {2010-01-01},
journal = {2010 8th IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2010},
pages = {522-527},
address = {Mannheim},
abstract = {Topology control has been established as an efficient technique for improving the properties of wireless multihop networks. In this paper we first analyze the impact of non-uniform node placement on the effectiveness of traditional and well established topology control approaches that preserve connectivity with high probability, thus revealing and demonstrating their inefficiency in properly maintaining connectivity in the general case. Then, we propose a randomized topology control approach that provides significant improvements in percentage connectivity guarantees under arbitrary and more realistic node deployments. The proposed approach, referred to as Nearest Random Neighbors (NRN), is compared to the KNeigh technique, one of the dominant Network layer topology control protocols. As opposed to K -Neigh, the NRN mechanism asserts acceptable network connectivity probabilities, even in cases of highly skewed node distributions, while its performance with respect to the average physical node degree remains stable and close to K-Neigh, even as the network density increases dramatically. © 2010 IEEE.},
note = {cited By 2; Conference of 2010 8th IEEE International Conference on Pervasive Computing and Communications Workshops, PERCOM Workshops 2010 ; Conference Date: 29 March 2010 Through 2 April 2010; Conference Code:80840},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Topology control has been established as an efficient technique for improving the properties of wireless multihop networks. In this paper we first analyze the impact of non-uniform node placement on the effectiveness of traditional and well established topology control approaches that preserve connectivity with high probability, thus revealing and demonstrating their inefficiency in properly maintaining connectivity in the general case. Then, we propose a randomized topology control approach that provides significant improvements in percentage connectivity guarantees under arbitrary and more realistic node deployments. The proposed approach, referred to as Nearest Random Neighbors (NRN), is compared to the KNeigh technique, one of the dominant Network layer topology control protocols. As opposed to K -Neigh, the NRN mechanism asserts acceptable network connectivity probabilities, even in cases of highly skewed node distributions, while its performance with respect to the average physical node degree remains stable and close to K-Neigh, even as the network density increases dramatically. © 2010 IEEE.
Stai, E., Karyotis, V., & Papavassiliou, S. (2010). Enhanced service provisioning in wireless multi-hop networks via socially-driven inverse topology control. In (pp. 1378-1382). IEEE Computer Society. https://doi.org/10.1109/GLOCOMW.2010.5700164
@conference{Stai20101378,
title = {Enhanced service provisioning in wireless multi-hop networks via socially-driven inverse topology control},
author = {E. Stai and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-79951938157&doi=10.1109%2fGLOCOMW.2010.5700164&partnerID=40&md5=a340a0d51a3344fdb8e99ba6d0a74a70},
doi = {10.1109/GLOCOMW.2010.5700164},
isbn = {9781424488650},
year = {2010},
date = {2010-01-01},
journal = {2010 IEEE Globecom Workshops, GC'10},
pages = {1378-1382},
publisher = {IEEE Computer Society},
abstract = {Current trends in applications, services and socializing increase demands for network infrastructures, capable of supporting real-time traffic and Quality of Service (QoS). In this work, we aim at improving the inherently stringent wireless multi-hop network structure, based on the notion of inverse Topology Control (iTC). Taking into account socially-induced network churn operations, we focus on infusing social features in wireless multi-hop topologies and thus improving performance at higher protocol layers. We employ analysis and simulation to describe the complete iTC-based network churn mechanisms that resemble social churn and quantitatively study performance benefits at higher protocol layers of wireless multi-hop networks. Embracing such top-down approach for transferring social features at the network layer gives rise to meaningful and desired performance improvements. ©2010 IEEE.},
note = {cited By 2; Conference of 2010 IEEE Globecom Workshops, GC 2010 ; Conference Date: 5 December 2010 Through 10 December 2010; Conference Code:83878},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Current trends in applications, services and socializing increase demands for network infrastructures, capable of supporting real-time traffic and Quality of Service (QoS). In this work, we aim at improving the inherently stringent wireless multi-hop network structure, based on the notion of inverse Topology Control (iTC). Taking into account socially-induced network churn operations, we focus on infusing social features in wireless multi-hop topologies and thus improving performance at higher protocol layers. We employ analysis and simulation to describe the complete iTC-based network churn mechanisms that resemble social churn and quantitatively study performance benefits at higher protocol layers of wireless multi-hop networks. Embracing such top-down approach for transferring social features at the network layer gives rise to meaningful and desired performance improvements. ©2010 IEEE.
Karyotis, V., Kakalis, A., & Papavassiliou, S. (2009). On the tradeoff between MAC-layer and network-layer topology-controlled malware spreading schemes in ad hoc and sensor networks. In (pp. 255-261). Athens, Glyfada. https://doi.org/10.1109/SECURWARE.2009.46
@conference{Karyotis2009255,
title = {On the tradeoff between MAC-layer and network-layer topology-controlled malware spreading schemes in ad hoc and sensor networks},
author = {V. Karyotis and A. Kakalis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-70449478162&doi=10.1109%2fSECURWARE.2009.46&partnerID=40&md5=0552bdd5c36f3858b1ccacc9727da6c9},
doi = {10.1109/SECURWARE.2009.46},
isbn = {9780769536682},
year = {2009},
date = {2009-01-01},
journal = {Proceedings - 2009 3rd International Conference on Emerging Security Information, Systems and Technologies, SECURWARE 2009},
pages = {255-261},
address = {Athens, Glyfada},
abstract = {Significant interest has been raised recently in wireless networks in modeling and dealing effectively with different types of attacks. In this paper, emphasis is placed on the attacker's perspective and based on a probabilistic framework we study intelligent strategies for spreading malicious software, in order to realize the potentials of such attacks. The considered attack schemes are based on the topology control capabilities of wireless nodes and may be realized either at the Network layer by using node degree related information or the MAC layer by setting attackers to sleep for energy conservation purposes. To the best of our knowledge this is the first attempt to adopt the use of sleeping schedules in order to eventually increase attack efficiency. We compare the performance of the two families of strategies using both time-independent and time-dependent attack metrics. Our evaluation analysis reveals an inherent tradeoff between the two families that depends, among others, on the idle energy consumption and the network density. © 2009 IEEE.},
note = {cited By 1; Conference of 2009 3rd International Conference on Emerging Security Information, Systems and Technologies, SECURWARE 2009 ; Conference Date: 18 June 2009 Through 23 June 2009; Conference Code:78000},
keywords = {},
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Significant interest has been raised recently in wireless networks in modeling and dealing effectively with different types of attacks. In this paper, emphasis is placed on the attacker's perspective and based on a probabilistic framework we study intelligent strategies for spreading malicious software, in order to realize the potentials of such attacks. The considered attack schemes are based on the topology control capabilities of wireless nodes and may be realized either at the Network layer by using node degree related information or the MAC layer by setting attackers to sleep for energy conservation purposes. To the best of our knowledge this is the first attempt to adopt the use of sleeping schedules in order to eventually increase attack efficiency. We compare the performance of the two families of strategies using both time-independent and time-dependent attack metrics. Our evaluation analysis reveals an inherent tradeoff between the two families that depends, among others, on the idle energy consumption and the network density. © 2009 IEEE.
Kastrinogiannis, T., Karyotis, V., & Papavassiliou, S. (2008). On the problem of joint power and rate control in CDMA ad hoc networks. In (pp. 78-82). Santorini. https://doi.org/10.1109/ISWPC.2008.4556170
@conference{Kastrinogiannis200878,
title = {On the problem of joint power and rate control in CDMA ad hoc networks},
author = {T. Kastrinogiannis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-51649112462&doi=10.1109%2fISWPC.2008.4556170&partnerID=40&md5=4be2c70b1102cb3ab7c14bbc71e714ab},
doi = {10.1109/ISWPC.2008.4556170},
isbn = {9781424416530},
year = {2008},
date = {2008-01-01},
journal = {3rd International Symposium on Wireless Pervasive Computing, ISWPC 2008, Proceedings},
pages = {78-82},
address = {Santorini},
abstract = {In this work, the problem of joint power and rate control (PRC) in CDMA-based ad hoc networks is considered and analyzed. We propose a game theoretic framework for performing efficient power and rate allocation in CDMA ad hoc networks and develop a distributed PRC algorithm for dynamically selecting the optimal neighboring destination, power and rate values. The objective is to maximize properly-defined node utility functions that reflect a tradeoff between actual achieved throughput and power consumption. The PRC algorithm selects opportunistically the destination nodes, by exploiting current channel state information, as expressed by the experienced SINR of the receivers, while it assures the convergence at the game's unique Nash Equilibrium point in terms of power and rate transmission vectors. We demonstrate the performance of the proposed algorithm in two different network scenarios with respect to the allocated transmission power, received node performance satisfaction, actual achieved throughput and the convergence of the non-cooperative game. © 2008 IEEE.},
note = {cited By 1; Conference of 3rd International Symposium on Wireless Pervasive Computing, ISWPC 2008 ; Conference Date: 7 May 2008 Through 9 May 2008; Conference Code:73424},
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In this work, the problem of joint power and rate control (PRC) in CDMA-based ad hoc networks is considered and analyzed. We propose a game theoretic framework for performing efficient power and rate allocation in CDMA ad hoc networks and develop a distributed PRC algorithm for dynamically selecting the optimal neighboring destination, power and rate values. The objective is to maximize properly-defined node utility functions that reflect a tradeoff between actual achieved throughput and power consumption. The PRC algorithm selects opportunistically the destination nodes, by exploiting current channel state information, as expressed by the experienced SINR of the receivers, while it assures the convergence at the game's unique Nash Equilibrium point in terms of power and rate transmission vectors. We demonstrate the performance of the proposed algorithm in two different network scenarios with respect to the allocated transmission power, received node performance satisfaction, actual achieved throughput and the convergence of the non-cooperative game. © 2008 IEEE.
Kastrinogiannis, T., Karyotis, V., & Papavassiliou, S. (2008). An opportunistic combined power and rate allocation approach in CDMA ad hoc networks. In . Princeton, NJ. https://doi.org/10.1109/SARNOF.2008.4520063
@conference{Kastrinogiannis2008,
title = {An opportunistic combined power and rate allocation approach in CDMA ad hoc networks},
author = {T. Kastrinogiannis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-49049084291&doi=10.1109%2fSARNOF.2008.4520063&partnerID=40&md5=c888c8b990338c4a5b0e820a185b7a52},
doi = {10.1109/SARNOF.2008.4520063},
isbn = {1424418437; 9781424418435},
year = {2008},
date = {2008-01-01},
journal = {Proceedings of the 2008 IEEE Sarnoff Symposium, SARNOFF},
address = {Princeton, NJ},
abstract = {In this paper, we address the problem of joint power and rate allocation in wireless CDMA ad hoc networks. A generic framework for efficiently assigning power and rate is proposed, in order to minimize power consumption and interference, and maximize overall goodput under the imposed physical limitations. The problem is formulated as a non-cooperative game where users selfishly aim at maximizing their performance by means of a utility function. Allowing only one receiver per transmitter at a time we reduce the problem to a special case of a generic game, namely point-to-point game (PTPG). The existence of a Nash equilibrium point of the PTPG is shown and a novel opportunistic and distributed power and rate control (PRC) algorithm is proposed for achieving PTPG's equilibrium.},
note = {cited By 3; Conference of 2008 IEEE Sarnoff Symposium, SARNOFF ; Conference Date: 28 April 2008 Through 30 April 2008; Conference Code:72891},
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pubstate = {published},
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In this paper, we address the problem of joint power and rate allocation in wireless CDMA ad hoc networks. A generic framework for efficiently assigning power and rate is proposed, in order to minimize power consumption and interference, and maximize overall goodput under the imposed physical limitations. The problem is formulated as a non-cooperative game where users selfishly aim at maximizing their performance by means of a utility function. Allowing only one receiver per transmitter at a time we reduce the problem to a special case of a generic game, namely point-to-point game (PTPG). The existence of a Nash equilibrium point of the PTPG is shown and a novel opportunistic and distributed power and rate control (PRC) algorithm is proposed for achieving PTPG's equilibrium.
Karyotis, V., Grammatikou, M., & Papavassiliou, S. (2007). On the asymptotic behavior of malware-propagative mobile ad hoc networks. In . Pisa. https://doi.org/10.1109/MOBHOC.2007.4428662
@conference{Karyotis2007,
title = {On the asymptotic behavior of malware-propagative mobile ad hoc networks},
author = {V. Karyotis and M. Grammatikou and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-50249169440&doi=10.1109%2fMOBHOC.2007.4428662&partnerID=40&md5=b4dae755dc5ed6d0015834da1dd02d25},
doi = {10.1109/MOBHOC.2007.4428662},
isbn = {1424414555; 9781424414550},
year = {2007},
date = {2007-01-01},
journal = {2007 IEEE Internatonal Conference on Mobile Adhoc and Sensor Systems, MASS},
address = {Pisa},
abstract = {In this paper we study the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from an attacker or their already infected neighbors. Considering the Susceptible-Infected-Susceptible (SIS) node infection paradigm we propose a probabilistic model, based on the theory of closed queueing networks, that aims at describing the aggregated behavior of the system when attacked by a malicious node. Due to its nature the model is able to deal more effectively with the stochastic behavior of the attacker and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative ad hoc networking environments, where the number of nodes is large. Using the Norton equivalent of the closed queueing network, we obtain analytical results for its steady state behavior, which in turn can be used to identify the critical parameters affecting the operation of the network. ©2007 IEEE.},
note = {cited By 3; Conference of 2007 IEEE Internatonal Conference on Mobile Adhoc and Sensor Systems, MASS ; Conference Date: 8 October 2007 Through 11 October 2007; Conference Code:73246},
keywords = {},
pubstate = {published},
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In this paper we study the spreading of malicious software over ad hoc networks, where legitimate nodes are prone to propagate the infections they receive from an attacker or their already infected neighbors. Considering the Susceptible-Infected-Susceptible (SIS) node infection paradigm we propose a probabilistic model, based on the theory of closed queueing networks, that aims at describing the aggregated behavior of the system when attacked by a malicious node. Due to its nature the model is able to deal more effectively with the stochastic behavior of the attacker and the inherent probabilistic nature of the wireless environment. The proposed model is able to describe accurately the asymptotic behavior of malware-propagative ad hoc networking environments, where the number of nodes is large. Using the Norton equivalent of the closed queueing network, we obtain analytical results for its steady state behavior, which in turn can be used to identify the critical parameters affecting the operation of the network. ©2007 IEEE.
Karyotis, V., & Papavassiliou, S. (2007). On the malware spreading over non-propagative wireless ad hoc networks: The attacker's perspective. In (pp. 156-159). Chania, Crete Island. https://doi.org/10.1145/1298239.1298268
@conference{Karyotis2007156,
title = {On the malware spreading over non-propagative wireless ad hoc networks: The attacker's perspective},
author = {V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-42149094983&doi=10.1145%2f1298239.1298268&partnerID=40&md5=d22b4d7ed501e1c1818bf98805ea6ba6},
doi = {10.1145/1298239.1298268},
isbn = {9781595938060},
year = {2007},
date = {2007-01-01},
journal = {Q2SWinet'07: Proceedings of the Third ACM Workshop on Q2S and Security for Wireless and Mobile Networks},
pages = {156-159},
address = {Chania, Crete Island},
abstract = {In this paper, we adopt a probabilistic framework for malware spreading and propose a closed queueing network model that is able to describe analytically the aggregated behavior of an ad hoc network attacked by multiple malicious nodes, In our framework, the attackers are assumed to be capable of initially adapting their transmission radii and thus employing different attack strategies, We take on the attacker's perspective and formulate various optimization problems with respect to the development of different attack strategies, that address the attackers' objective to harm the network and identify the system parameters that can be exploited to achieve this purpose more effectively. Copyright 2007 ACM.},
note = {cited By 4; Conference of Q2SWinet'07: 3rd ACM Workshop on Q2S and Security for Wireless and Mobile Networks ; Conference Date: 22 October 2007 Through 22 October 2007; Conference Code:71773},
keywords = {},
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In this paper, we adopt a probabilistic framework for malware spreading and propose a closed queueing network model that is able to describe analytically the aggregated behavior of an ad hoc network attacked by multiple malicious nodes, In our framework, the attackers are assumed to be capable of initially adapting their transmission radii and thus employing different attack strategies, We take on the attacker's perspective and formulate various optimization problems with respect to the development of different attack strategies, that address the attackers' objective to harm the network and identify the system parameters that can be exploited to achieve this purpose more effectively. Copyright 2007 ACM.
Karyotis, V., Papavassiliou, S., & Grammatikou, M. (2007). On the risk-based operation of mobile attacks in wireless ad hoc networks. In (pp. 1130-1135). Glasgow, Scotland. https://doi.org/10.1109/ICC.2007.192
@conference{Karyotis20071130,
title = {On the risk-based operation of mobile attacks in wireless ad hoc networks},
author = {V. Karyotis and S. Papavassiliou and M. Grammatikou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-38549150430&doi=10.1109%2fICC.2007.192&partnerID=40&md5=9901cf2ecad38b04584e107952cd7393},
doi = {10.1109/ICC.2007.192},
issn = {05361486},
year = {2007},
date = {2007-01-01},
journal = {IEEE International Conference on Communications},
pages = {1130-1135},
address = {Glasgow, Scotland},
abstract = {In this paper we study the propagation of malicious software in wireless ad hoc networks under a probabilistic framework. We design topology control algorithms for the development of effective attack strategies by a malicious mobile node, based on the risk function metric, which indicates the network's vulnerability. Our approach takes on the attacker's perspective, in order to investigate the extent of its attack potentials, which in turn could be used for the effective design of network countermeasures. Our performance evaluation results demonstrate that the proposed risk-based topology control algorithms and respective attack strategies effectively balance the tradeoffs between the potential network damage and the attacker's lifetime, and as a result significantly outperform any other flat and threshold-based approaches. © 2007 IEEE.},
note = {cited By 3; Conference of 2007 IEEE International Conference on Communications, ICC'07 ; Conference Date: 24 June 2007 Through 28 June 2007; Conference Code:71262},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
In this paper we study the propagation of malicious software in wireless ad hoc networks under a probabilistic framework. We design topology control algorithms for the development of effective attack strategies by a malicious mobile node, based on the risk function metric, which indicates the network's vulnerability. Our approach takes on the attacker's perspective, in order to investigate the extent of its attack potentials, which in turn could be used for the effective design of network countermeasures. Our performance evaluation results demonstrate that the proposed risk-based topology control algorithms and respective attack strategies effectively balance the tradeoffs between the potential network damage and the attacker's lifetime, and as a result significantly outperform any other flat and threshold-based approaches. © 2007 IEEE.
Karyotis, V., Papavassiliou, S., & Maglaris, B. (2006). Modeling framework for the study and analysis of mobile attack propagation in wireless ad-hoc networks. In . Institute of Electrical and Electronics Engineers Inc..
@conference{Karyotis2006,
title = {Modeling framework for the study and analysis of mobile attack propagation in wireless ad-hoc networks},
author = {V. Karyotis and S. Papavassiliou and B. Maglaris},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84946234997&partnerID=40&md5=d93e77cc1fd88d269d8f3741b7ab4309},
isbn = {9783800729616},
year = {2006},
date = {2006-01-01},
journal = {12th European Wireless Conference 2006 - Enabling Technologies for Wireless Multimedia Communications, European Wireless 2006},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
abstract = {Independent-operating attacks in modern communication networks have become increasingly popular, affecting significantly the performance of these networks and causing major systems to fail. In this paper, we introduce and design a modeling framework that allows for the study and analysis of mobile attack propagation in wireless ad-hoc networks. Specifically, we study probabilistically the propagation of a worm in a wireless ad-hoc network, in which an energyconstrained malicious node can move freely in the deployment region of the network. The choice of a statistical approach of the problem is motivated by the dynamic characteristics of the ad-hoc topology and the stochastic nature of the worm propagation. Through modeling and simulation, we studied and evaluated the impact of various parameters associated with the operational characteristics of the mobile attack node-such as transmission radius, mobility, energy-on an outbreak spreading and the evolution of the network, and obtained an in-depth understanding of the importance of these parameters both from the network's and the attacker's perspectives.},
note = {cited By 1; Conference of 12th European Wireless Conference on Enabling Technologies for Wireless Multimedia Communications, European Wireless 2006 ; Conference Date: 2 April 2006 Through 5 April 2006; Conference Code:114330},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Independent-operating attacks in modern communication networks have become increasingly popular, affecting significantly the performance of these networks and causing major systems to fail. In this paper, we introduce and design a modeling framework that allows for the study and analysis of mobile attack propagation in wireless ad-hoc networks. Specifically, we study probabilistically the propagation of a worm in a wireless ad-hoc network, in which an energyconstrained malicious node can move freely in the deployment region of the network. The choice of a statistical approach of the problem is motivated by the dynamic characteristics of the ad-hoc topology and the stochastic nature of the worm propagation. Through modeling and simulation, we studied and evaluated the impact of various parameters associated with the operational characteristics of the mobile attack node-such as transmission radius, mobility, energy-on an outbreak spreading and the evolution of the network, and obtained an in-depth understanding of the importance of these parameters both from the network's and the attacker's perspectives.
Karyotis, V., Papavassiliou, S., Grammatikou, M., & Maglaris, B. (2006). On the characterization and evaluation of mobile attack strategies in wireless Ad Hoc networks. In (pp. 29-34). Cagliari, Sardinia: Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ISCC.2006.112
@conference{Karyotis200629,
title = {On the characterization and evaluation of mobile attack strategies in wireless Ad Hoc networks},
author = {V. Karyotis and S. Papavassiliou and M. Grammatikou and B. Maglaris},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547345829&doi=10.1109%2fISCC.2006.112&partnerID=40&md5=9ad3f3b4ab9340cfeb22ec7518d93293},
doi = {10.1109/ISCC.2006.112},
issn = {15301346},
year = {2006},
date = {2006-01-01},
journal = {Proceedings - IEEE Symposium on Computers and Communications},
pages = {29-34},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
address = {Cagliari, Sardinia},
abstract = {The spread of active attacks has become a frequent cause of vast systems breakdown in modern communication networks. In this paper, we first present a probabilistic modeling framework for the propagation of an energy-constrained mobile threat in a wireless ad hoc network. The introduced formulation is used to identify and evaluate different attack strategies and approaches, which in turn can help in the development of efficient countermeasures for such attacks. Through modeling and simulation, we evaluate the impact of various parameters associated with the operational characteristics of the mobile attack node - such as transmission radius, mobility, energy - on an outbreak spreading and the evolution of the network. Furthermore, we introduce a new metric which indicates the overall infection-capability of each attack strategy and characterize their ability to harm the network according to this metric. © 2006 IEEE.},
note = {cited By 4; Conference of 11th IEEE Symposium on Computers and Communications, ISCC 2006 ; Conference Date: 26 June 2006 Through 29 June 2006; Conference Code:69930},
keywords = {},
pubstate = {published},
tppubtype = {conference}
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The spread of active attacks has become a frequent cause of vast systems breakdown in modern communication networks. In this paper, we first present a probabilistic modeling framework for the propagation of an energy-constrained mobile threat in a wireless ad hoc network. The introduced formulation is used to identify and evaluate different attack strategies and approaches, which in turn can help in the development of efficient countermeasures for such attacks. Through modeling and simulation, we evaluate the impact of various parameters associated with the operational characteristics of the mobile attack node - such as transmission radius, mobility, energy - on an outbreak spreading and the evolution of the network. Furthermore, we introduce a new metric which indicates the overall infection-capability of each attack strategy and characterize their ability to harm the network according to this metric. © 2006 IEEE.
Book Sections
Karyotis, V., & Stai, E. (2017). Hyperbolic Big Data Analytics for Dynamic Network Management and Optimization. In Big Data and Computational Intelligence in Networking (pp. 177–208). CRC Press.
@incollection{karyotis2017hyperbolic,
title = {Hyperbolic Big Data Analytics for Dynamic Network Management and Optimization},
author = {Vasileios Karyotis and Eleni Stai},
year = {2017},
date = {2017-01-01},
booktitle = {Big Data and Computational Intelligence in Networking},
pages = {177--208},
publisher = {CRC Press},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
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Stai, E., Karyotis, V., Katsinis, G., Tsiropoulou, E. E., & Papavassiliou, S. (2016). Hyperbolic Big Data Analytics within Complex and Social Networks. In Big Data in Complex and Social Networks (pp. 13–46). Chapman and Hall/CRC.
@incollection{stai2016hyperbolicc,
title = {Hyperbolic Big Data Analytics within Complex and Social Networks},
author = {Eleni Stai and Vasileios Karyotis and Georgios Katsinis and Eirini Eleni Tsiropoulou and Symeon Papavassiliou},
year = {2016},
date = {2016-01-01},
booktitle = {Big Data in Complex and Social Networks},
pages = {13--46},
publisher = {Chapman and Hall/CRC},
keywords = {},
pubstate = {published},
tppubtype = {incollection}
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Karyotis, V., Anifantis, E., & Papavassiliou, S. (2014). Cross-layer based resource management frameworks for mobile cognitive radio networks. In Resource management in mobile computing environments (pp. 285–322). Springer, Cham.
@incollection{karyotis2014cross,
title = {Cross-layer based resource management frameworks for mobile cognitive radio networks},
author = {Vasileios Karyotis and Evangelos Anifantis and Symeon Papavassiliou},
year = {2014},
date = {2014-01-01},
booktitle = {Resource management in mobile computing environments},
pages = {285--322},
publisher = {Springer, Cham},
keywords = {},
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tppubtype = {incollection}
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Proceedings Articles
Stai, E., Karyotis, V., Kourouthanasis, P., & Mylonas, P. (2023). A Backpressure-Based Algorithm for Optimal Scheduling in Freight Management Systems. In Proceedings of the 18th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2023. Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/SMAP59435.2023.10255185
@inproceedings{Stai2023,
title = {A Backpressure-Based Algorithm for Optimal Scheduling in Freight Management Systems},
author = {E. Stai and V. Karyotis and P. Kourouthanasis and P. Mylonas},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85174927621&doi=10.1109%2fSMAP59435.2023.10255185&partnerID=40&md5=0f8a63eea4c972ecb21286a58051de9a},
doi = {10.1109/SMAP59435.2023.10255185},
isbn = {9798350327717},
year = {2023},
date = {2023-01-01},
urldate = {2023-01-01},
booktitle = {Proceedings of the 18th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2023},
journal = {2023 18th International Workshop on Semantic and Social Media Adaptation and Personalization, SMAP 2023},
publisher = {Institute of Electrical and Electronics Engineers Inc.},
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Karyotis, V., Stai, E., Kourouthanasis, P., & Mylonas, P. (2022). A Framework for a Holistic Information System for Small-Medium Logistics Enterprises. In 2022 17th International Workshop on Semantic and Social Media Adaptation & Personalization (SMAP) (pp. 1–6).
@inproceedings{karyotis2022framework,
title = {A Framework for a Holistic Information System for Small-Medium Logistics Enterprises},
author = {Vasileios Karyotis and Eleni Stai and Panos Kourouthanasis and Phivos Mylonas},
year = {2022},
date = {2022-01-01},
booktitle = {2022 17th International Workshop on Semantic and Social Media Adaptation & Personalization (SMAP)},
pages = {1--6},
organization = {IEEE},
keywords = {},
pubstate = {published},
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Krommyda, M., Tsitseklis, K., Kantere, V., Karyotis, V., & Papavassiliou, S. (2021). Visualizing and Exploring Big Datasets based on Semantic Community Detection.. In EDBT (pp. 678–681).
@inproceedings{krommyda2021visualizing,
title = {Visualizing and Exploring Big Datasets based on Semantic Community Detection.},
author = {Maria Krommyda and Konstantinos Tsitseklis and Verena Kantere and Vasileios Karyotis and Symeon Papavassiliou},
year = {2021},
date = {2021-01-01},
booktitle = {EDBT},
pages = {678--681},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Kakkavas, G., Kalntis, M., Karyotis, V., & Papavassiliou, S. (2021). Future Network Traffic Matrix Synthesis and Estimation Based on Deep Generative Models. In 2021 International Conference on Computer Communications and Networks (ICCCN) (pp. 1–8).
@inproceedings{kakkavas2021future,
title = {Future Network Traffic Matrix Synthesis and Estimation Based on Deep Generative Models},
author = {Grigorios Kakkavas and Michail Kalntis and Vasileios Karyotis and Symeon Papavassiliou},
year = {2021},
date = {2021-01-01},
booktitle = {2021 International Conference on Computer Communications and Networks (ICCCN)},
pages = {1--8},
organization = {IEEE},
keywords = {},
pubstate = {published},
tppubtype = {inproceedings}
}
Kakkavas, G., Diamanti, M., Stamou, A., Karyotis, V., Papavassiliou, S., Bouali, F., & Moessner, K. (2021). 5G Network Requirement Analysis and Slice Dimensioning for Sustainable Vehicular Services. In 2021 17th International Conference on Distributed Computing in Sensor Systems (DCOSS) (pp. 495–502).
@inproceedings{kakkavas20215g,
title = {5G Network Requirement Analysis and Slice Dimensioning for Sustainable Vehicular Services},
author = {Grigorios Kakkavas and Maria Diamanti and Adamantia Stamou and Vasileios Karyotis and Symeon Papavassiliou and Faouzi Bouali and Klaus Moessner},
year = {2021},
date = {2021-01-01},
booktitle = {2021 17th International Conference on Distributed Computing in Sensor Systems (DCOSS)},
pages = {495--502},
organization = {IEEE},
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Spatharakis, D., Avgeris, M., Kakkavas, G., Papadakis-Vlachopapadopoulos, K., Dimolitsas, I., Dechouniotis, D., Karyotis, V., & Papavassiliou, S. (2021). Industrial Robotics Experimentation over Federated Next Generation Internet Testbeds. In 2021 IEEE International Mediterranean Conference on Communications and Networking (MeditCom) (pp. 1–2).
@inproceedings{spatharakis2021industrial,
title = {Industrial Robotics Experimentation over Federated Next Generation Internet Testbeds},
author = {Dimitrios Spatharakis and Marios Avgeris and Grigorios Kakkavas and Konstantinos Papadakis-Vlachopapadopoulos and Ioannis Dimolitsas and Dimitrios Dechouniotis and Vasileios Karyotis and Symeon Papavassiliou},
year = {2021},
date = {2021-01-01},
booktitle = {2021 IEEE International Mediterranean Conference on Communications and Networking (MeditCom)},
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Kakkavas, G., Diamanti, M., Gabriel, M., Lahoud, C., Akula, P., Karyotis, V., Mößner, K., & Papavassiliou, S. (2021). Demo Proposal: Tele-Operated Support over 4G/5G Mobile Communications. In 2021 IEEE International Mediterranean Conference on Communications and Networking (MeditCom) (pp. 1–2).
@inproceedings{kakkavas2021demo,
title = {Demo Proposal: Tele-Operated Support over 4G/5G Mobile Communications},
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Vitoropoulou, M., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2021). Caching, Recommendations and Opportunistic Offloading at the Network Edge. In 2021 17th International Conference on Mobility, Sensing and Networking (MSN) (pp. 112–119).
@inproceedings{vitoropoulou2021caching,
title = {Caching, Recommendations and Opportunistic Offloading at the Network Edge},
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Vitoropoulou, M., Tsitseklis, K., Karyotis, V., & Papavassiliou, S. (2021). Caching, Recommendations and Opportunistic Offloading at the Network Edge. In (pp. 112-119). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/MSN53354.2021.00031
@inproceedings{Vitoropoulou2021112,
title = {Caching, Recommendations and Opportunistic Offloading at the Network Edge},
author = {M. Vitoropoulou and K. Tsitseklis and V. Karyotis and S. Papavassiliou},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85128784400&doi=10.1109%2fMSN53354.2021.00031&partnerID=40&md5=b2dead871ec4fdd3a1aba4ab81ae864b},
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abstract = {In this paper, we study the problem of caching at the network edge by taking into account the impact of recommendations on user content requests. We consider a heterogeneous caching network with small cells and mobile users who can offload traffic from the core network by delivering data via Device-to-Device (D2D) communication. Given the user mobility pattern, we derive for each user the expected waiting time to encounter cache-enabled devices and we propose two schemes in order to select the user equipment that will cache content and participate in the offloading. Expressing the user Quality of Experience (QoE) as a function of user-content relevance and its expected delivery delay, we formulate the problem of content placement and recommendations in caching networks as a user QoE maximization problem, which is known to be NP-hard. In order to address it, we provide two heuristic algorithms, the first focusing on user-content relevance and the second focusing on the content delivery delay. We evaluate the performance of our algorithms through simulation over synthetic datasets. The obtained results are compared with a state-of-the-art polynomial-time approximation algorithm and show that the proposed algorithms balance better the trade-off between solution quality and execution time. © 2021 IEEE.},
note = {cited By 1; Conference of 17th International Conference on Mobility, Sensing and Networking, MSN 2021 ; Conference Date: 13 December 2021 Through 15 December 2021; Conference Code:178754},
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In this paper, we study the problem of caching at the network edge by taking into account the impact of recommendations on user content requests. We consider a heterogeneous caching network with small cells and mobile users who can offload traffic from the core network by delivering data via Device-to-Device (D2D) communication. Given the user mobility pattern, we derive for each user the expected waiting time to encounter cache-enabled devices and we propose two schemes in order to select the user equipment that will cache content and participate in the offloading. Expressing the user Quality of Experience (QoE) as a function of user-content relevance and its expected delivery delay, we formulate the problem of content placement and recommendations in caching networks as a user QoE maximization problem, which is known to be NP-hard. In order to address it, we provide two heuristic algorithms, the first focusing on user-content relevance and the second focusing on the content delivery delay. We evaluate the performance of our algorithms through simulation over synthetic datasets. The obtained results are compared with a state-of-the-art polynomial-time approximation algorithm and show that the proposed algorithms balance better the trade-off between solution quality and execution time. © 2021 IEEE.
Kakkavas, G., Diamanti, M., Stamou, A., Karyotis, V., Papavassiliou, S., Bouali, F., & Moessner, K. (2021). 5G Network Requirement Analysis and Slice Dimensioning for Sustainable Vehicular Services. In Proceedings of the 17th Annual International Conference on Distributed Computing in Sensor Systems, DCOS 2021 (pp. 495-502). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/DCOSS52077.2021.00082
@inproceedings{Kakkavas2021495,
title = {5G Network Requirement Analysis and Slice Dimensioning for Sustainable Vehicular Services},
author = {G. Kakkavas and M. Diamanti and A. Stamou and V. Karyotis and S. Papavassiliou and F. Bouali and K. Moessner},
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abstract = {The Fifth Generation (5G) mobile communications together with software defined networking (SDN) and network function virtualization (NFV) are expected to enable a wide range of vertical use-cases. Different vertical industries with diverse service streams and sets of requirements should leverage the advanced capabilities of 5G networks through a single infrastructure to support the desired Quality of Service/Experience (QoS/QoE). In this paper, we focus on the Transport vertical and we study four novel service categories, each one consisting of one or more related scenarios, within the framework of the 5G Health, Aquaculture and Transport (5G-HEART) 5G PPP Phase 3 project. The first pass analysis of the envisioned vehicular services and their underlying operation, combined with the mapping of the mostly high-level functional user requirements to quantitative network Key Performance Indicators (KPIs) via a thorough and concise methodology, is essential for future testing with real pilots. Furthermore, our work paves the way towards efficient network slicing by exploring the interrelations between the identified KPIs and the respective target values that must be simultaneously satisfied over the same physical network infrastructure, in the context of the three 5G generic services. © 2021 IEEE.},
note = {cited By 7; Conference of ; Conference Date: 14 July 2021 Through 16 July 2021; Conference Code:174301},
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The Fifth Generation (5G) mobile communications together with software defined networking (SDN) and network function virtualization (NFV) are expected to enable a wide range of vertical use-cases. Different vertical industries with diverse service streams and sets of requirements should leverage the advanced capabilities of 5G networks through a single infrastructure to support the desired Quality of Service/Experience (QoS/QoE). In this paper, we focus on the Transport vertical and we study four novel service categories, each one consisting of one or more related scenarios, within the framework of the 5G Health, Aquaculture and Transport (5G-HEART) 5G PPP Phase 3 project. The first pass analysis of the envisioned vehicular services and their underlying operation, combined with the mapping of the mostly high-level functional user requirements to quantitative network Key Performance Indicators (KPIs) via a thorough and concise methodology, is essential for future testing with real pilots. Furthermore, our work paves the way towards efficient network slicing by exploring the interrelations between the identified KPIs and the respective target values that must be simultaneously satisfied over the same physical network infrastructure, in the context of the three 5G generic services. © 2021 IEEE.
Nikiforos, M. N., Malakopoulou, M., Stylidou, A., Alvanou, A.-G., Karyotis, V., & Kourouthanassis, P. (2020). Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms. In 2020 15th International Workshop on Semantic and Social Media Adaptation and Personalization (SMA (pp. 1–6).
@inproceedings{nikiforos2020enhancingb,
title = {Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms},
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Kakkavas, G., Karyotis, V., & Papavassiliou, S. (2020). A Distance-based Agglomerative Clustering Algorithm for Multicast Network Tomography. In ICC 2020-2020 IEEE International Conference on Communications (ICC) (pp. 1–7).
@inproceedings{kakkavas2020distance,
title = {A Distance-based Agglomerative Clustering Algorithm for Multicast Network Tomography},
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Nikiforos, M. N., Malakopoulou, M., Stylidou, A., Alvanou, A.-G., Karyotis, V., & Kourouthanassis, P. (2020). Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms. In 2020 15th International Workshop on Semantic and Social Media Adaptation and Personalization (SMA (pp. 1–6).
@inproceedings{nikiforos2020enhancing,
title = {Enhancing Collaborative Filtering Recommendations for Web-based Learning Platforms with Genetic Algorithms},
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Vitoropoulou, M., Tsitseklis, K., Karakoulias, A., Karyotis, V., & Papavassiliou, S. (2020). CAUSE: Caching Aided by USer Equipment. In 2020 International Conferences on Internet of Things (iThings) and IEEE Green Computing and Communications (GreenCom) and IEEE Cyber, Physical and Social Computing (CPSCom) and IEEE Smart Data (SmartData) and IEEE Congress on Cybermatics (Cybermatics) (pp. 713–721).
@inproceedings{vitoropoulou2020cause,
title = {CAUSE: Caching Aided by USer Equipment},
author = {Margarita Vitoropoulou and Konstantinos Tsitseklis and Angelos Karakoulias and Vasileios Karyotis and Symeon Papavassiliou},
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Tsitseklis, K., Kakkavas, G., Karyotis, V., & Papavassiliou, S. (2019). A Realistic Evaluation of MRF-based Resource Allocation for SDR Cognitive Radio Networks. In 2019 IEEE 44th Conference on Local Computer Networks (LCN) (pp. 185–192).
@inproceedings{tsitseklis2019realistic,
title = {A Realistic Evaluation of MRF-based Resource Allocation for SDR Cognitive Radio Networks},
author = {Konstantinos Tsitseklis and Grigorios Kakkavas and Vasileios Karyotis and Symeon Papavassiliou},
year = {2019},
date = {2019-01-01},
booktitle = {2019 IEEE 44th Conference on Local Computer Networks (LCN)},
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Karyotis, V., Tsitseklis, K., Sotiropoulos, K., & Papavassiliou, S. (2018). Enhancing Community Detection for Big Sensor Data Clustering via Hyperbolic Network Embedding. In 2018 IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops) (pp. 266–271).
@inproceedings{karyotis2018enhancing,
title = {Enhancing Community Detection for Big Sensor Data Clustering via Hyperbolic Network Embedding},
author = {Vasileios Karyotis and Konstantinos Tsitseklis and Konstantinos Sotiropoulos and Symeon Papavassiliou},
year = {2018},
date = {2018-01-01},
booktitle = {2018 IEEE International Conference on Pervasive Computing and Communications Workshops (PerCom Workshops)},
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Tsanikidis, C., Vitoropoulou, M., Karyotis, V., & Papavassiliou, S. (2018). On the Energy-Efficient Coverage of Network Regions with Convex Opaque Obstacles. In 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) (pp. 135–141).
@inproceedings{tsanikidis2018energy,
title = {On the Energy-Efficient Coverage of Network Regions with Convex Opaque Obstacles},
author = {Christos Tsanikidis and Margarita Vitoropoulou and Vasileios Karyotis and Symeon Papavassiliou},
year = {2018},
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booktitle = {2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)},
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Karyotis, V., Avgeris, M., Michaloliakos, M., Tsagkaris, K., & Papavassiliou, S. (2018). Utility decisions for QoE-QoS driven applications in practical mobile broadband networks. In 2018 Global Information Infrastructure and Networking Symposium (GIIS) (pp. 1–5).
@inproceedings{karyotis2018utility,
title = {Utility decisions for QoE-QoS driven applications in practical mobile broadband networks},
author = {Vasileios Karyotis and Marios Avgeris and Michalis Michaloliakos and Konstantinos Tsagkaris and Symeon Papavassiliou},
year = {2018},
date = {2018-01-01},
booktitle = {2018 Global Information Infrastructure and Networking Symposium (GIIS)},
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Papadis, N., Stai, E., & Karyotis, V. (2017). A path-based recommendations approach for online systems via hyperbolic network embedding. In 2017 IEEE Symposium on Computers and Communications (ISCC) (pp. 973–980).
@inproceedings{papadis2017path,
title = {A path-based recommendations approach for online systems via hyperbolic network embedding},
author = {Nikolaos Papadis and Eleni Stai and Vasileios Karyotis},
year = {2017},
date = {2017-01-01},
booktitle = {2017 IEEE Symposium on Computers and Communications (ISCC)},
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Karyotis, V., Stai, E., & Papavassiliou, S. (2016). On the Evolution of Complex Network Topology Under Network Churn. In International Conference on Wired/Wireless Internet Communication (pp. 227–240).
@inproceedings{karyotis2016evolution,
title = {On the Evolution of Complex Network Topology Under Network Churn},
author = {Vasileios Karyotis and Eleni Stai and Symeon Papavassiliou},
year = {2016},
date = {2016-01-01},
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Stai, E., Sotiropoulos, K., Karyotis, V., & Papavassiliou, S. (2016). Hyperbolic traffic load centrality for large-scale complex communications networks. In 2016 23rd International Conference on Telecommunications (ICT) (pp. 1–5).
@inproceedings{stai2016hyperbolicb,
title = {Hyperbolic traffic load centrality for large-scale complex communications networks},
author = {Eleni Stai and Konstantinos Sotiropoulos and Vasileios Karyotis and Symeon Papavassiliou},
year = {2016},
date = {2016-01-01},
booktitle = {2016 23rd International Conference on Telecommunications (ICT)},
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Karyotis, V., Stai, E., & Papavassiliou, S. (2016). A component-based cross-layer framework for software defined wireless networks. In 2016 8th IFIP International Conference on New Technologies, Mobility and Security (NTMS) (pp. 1–6).
@inproceedings{karyotis2016component,
title = {A component-based cross-layer framework for software defined wireless networks},
author = {Vasileios Karyotis and Eleni Stai and Symeon Papavassiliou},
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Karyotis, V., & Papavassiliou, S. (2015). Evaluation of Malware Spreading in Wireless Multihop Networks with Churn. In International Conference on Ad Hoc Networks (pp. 63–74).
@inproceedings{karyotis2015evaluation,
title = {Evaluation of Malware Spreading in Wireless Multihop Networks with Churn},
author = {Vasileios Karyotis and Symeon Papavassiliou},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2015). On the Impact of Network Evolution on NUM Resource Allocation Problems in Wireless Multihop Networks. In International Conference on Ad-Hoc Networks and Wireless (pp. 62–75).
@inproceedings{stai2015impact,
title = {On the Impact of Network Evolution on NUM Resource Allocation Problems in Wireless Multihop Networks},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2015). User interest dictated information diffusion over generalized networks. In 2015 IEEE International Conference on Communication Workshop (ICCW) (pp. 1569–1574).
@inproceedings{stai2015user,
title = {User interest dictated information diffusion over generalized networks},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Anifantis, E., Stai, E., Karyotis, V., & Papavassiliou, S. (2014). An MRF cross-layer resource allocation approach with back-pressure features for QoS in dynamic social and cognitive communications. In 2014 IEEE Conference on Computer Communications Workshops (INFOCOM WKSHPS) (pp. 323–328).
@inproceedings{anifantis2014mrf,
title = {An MRF cross-layer resource allocation approach with back-pressure features for QoS in dynamic social and cognitive communications},
author = {Evangelos Anifantis and Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Anifantis, E., Karyotis, V., & Papavassiliou, S. (2012). A markov random field framework for channel assignment in cognitive radio networks. In 2012 IEEE International Conference on Pervasive Computing and Communications Workshops (pp. 770–775).
@inproceedings{anifantis2012markov,
title = {A markov random field framework for channel assignment in cognitive radio networks},
author = {Evangelos Anifantis and Vasileios Karyotis and Symeon Papavassiliou},
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Arkoulis, S., Anifantis, E., Karyotis, V., Papavassiliou, S., & Mitrou, N. (2012). Channel switching-aware optimal reconfiguration in Cognitive Radio Networks. In European Wireless 2012; 18th European Wireless Conference 2012 (pp. 1–8).
@inproceedings{arkoulis2012channel,
title = {Channel switching-aware optimal reconfiguration in Cognitive Radio Networks},
author = {Stamatios Arkoulis and Evangelos Anifantis and Vasileios Karyotis and Symeon Papavassiliou and Nikolaos Mitrou},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2012). Wireless multi-hop network topology control optimization and trade-off analysis. In 2012 35th IEEE Sarnoff Symposium (pp. 1–6).
@inproceedings{stai2012wireless,
title = {Wireless multi-hop network topology control optimization and trade-off analysis},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Chen, P.-Y., Karyotis, V., Papavassiliou, S., & Chen, K.-C. (2011). Topology control in multi-channel cognitive radio networks with non-uniform node arrangements. In 2011 IEEE Symposium on Computers and Communications (ISCC) (pp. 1033–1037).
@inproceedings{chen2011topology,
title = {Topology control in multi-channel cognitive radio networks with non-uniform node arrangements},
author = {Pin-Yu Chen and Vasileios Karyotis and Symeon Papavassiliou and Kwang-Cheng Chen},
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Anifantis, E., Karyotis, V., & Papavassiliou, S. (2011). Time-based cross-layer adaptations in wireless cognitive radio ad hoc networks. In 2011 IEEE Symposium on Computers and Communications (ISCC) (pp. 1044–1049).
@inproceedings{anifantis2011time,
title = {Time-based cross-layer adaptations in wireless cognitive radio ad hoc networks},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2011). Enhancing trust establishment in wireless multi-hop networks via preferential attachment. In 2011 IEEE Symposium on Computers and Communications (ISCC) (pp. 630–635).
@inproceedings{stai2011enhancing,
title = {Enhancing trust establishment in wireless multi-hop networks via preferential attachment},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2010). Socially-inspired topology improvements in wireless multi-hop networks. In 2010 IEEE International Conference on Communications Workshops (pp. 1–6).
@inproceedings{stai2010socially,
title = {Socially-inspired topology improvements in wireless multi-hop networks},
author = {Eleni Stai and Vasileios Karyotis and Symeon Papavassiliou},
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Karyotis, V., Manolakos, A., & Papavassiliou, S. (2010). On topology control and non-uniform node deployment in ad hoc networks. In 2010 8th IEEE International Conference on Pervasive Computing and Communications Workshops (PERCOM Workshops) (pp. 522–527).
@inproceedings{karyotis2010topology,
title = {On topology control and non-uniform node deployment in ad hoc networks},
author = {Vasileios Karyotis and Alexandros Manolakos and Symeon Papavassiliou},
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Stai, E., Karyotis, V., & Papavassiliou, S. (2010). Enhanced service provisioning in wireless multi-hop networks via socially-driven inverse topology control. In 2010 IEEE Globecom Workshops (pp. 1378–1382).
@inproceedings{stai2010enhanced,
title = {Enhanced service provisioning in wireless multi-hop networks via socially-driven inverse topology control},
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Arnautovic, E., Vallée, M., Mulvenna, M., Baumgarten, M., Hadjiantonis, A. M., Rehm, S.-V., Müthel, M., Karyotis, V., Papavassiliou, S., & Stathis, K. (2010). Towards self-managing systems inspired by economic organizations. In 2010 IEEE International Conference on Systems, Man and Cybernetics (pp. 888–895).
@inproceedings{arnautovic2010towards,
title = {Towards self-managing systems inspired by economic organizations},
author = {Edin Arnautovic and Mathieu Vallée and Maurice Mulvenna and Matthias Baumgarten and Antonis M Hadjiantonis and Sven-Volker Rehm and Miriam Müthel and Vasileios Karyotis and Symeon Papavassiliou and Kostas Stathis},
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Karyotis, V., Kakalis, A., & Papavassiliou, S. (2009). On the tradeoff between MAC-layer and network-layer topology-controlled malware spreading schemes in Ad Hoc and Sensor Networks. In 2009 Third International Conference on Emerging Security Information, Systems and Technologies (pp. 255–261).
@inproceedings{karyotis2009tradeoff,
title = {On the tradeoff between MAC-layer and network-layer topology-controlled malware spreading schemes in Ad Hoc and Sensor Networks},
author = {Vasileios Karyotis and Anastasios Kakalis and Symeon Papavassiliou},
year = {2009},
date = {2009-01-01},
booktitle = {2009 Third International Conference on Emerging Security Information, Systems and Technologies},
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Karyotis, V., Pittal`a, F., Fazio, M., Papavassiliou, S., & Puliafito, A. (2009). Topology-Aware Hybrid Random Walk Protocols for Wireless Multihop Networks. In International Conference on Mobile Networks and Management (pp. 107–118).
@inproceedings{karyotis2009topology,
title = {Topology-Aware Hybrid Random Walk Protocols for Wireless Multihop Networks},
author = {Vasileios Karyotis and Fabio Pittal`a and Maria Fazio and Symeon Papavassiliou and Antonio Puliafito},
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Kastrinogiannis, T., Karyotis, V., & Papavassiliou, S. (2008). An opportunistic combined power and rate allocation approach in CDMA ad hoc networks. In 2008 IEEE Sarnoff symposium (pp. 1–5).
@inproceedings{kastrinogiannis2008opportunistic,
title = {An opportunistic combined power and rate allocation approach in CDMA ad hoc networks},
author = {Timotheos Kastrinogiannis and Vasileios Karyotis and Symeon Papavassiliou},
year = {2008},
date = {2008-01-01},
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Kastrinogiannis, T., Karyotis, V., & Papavassiliou, S. (2008). On the problem of joint power and rate control in CDMA ad hoc networks. In 2008 3rd International Symposium on Wireless Pervasive Computing (pp. 78–82).
@inproceedings{kastrinogiannis2008problem,
title = {On the problem of joint power and rate control in CDMA ad hoc networks},
author = {Timotheos Kastrinogiannis and Vasileios Karyotis and Symeon Papavassiliou},
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booktitle = {2008 3rd International Symposium on Wireless Pervasive Computing},
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Karyotis, V., Papavassiliou, S., & Grammatikou, M. (2007). On the risk-based operation of mobile attacks in wireless ad hoc networks. In 2007 IEEE International Conference on Communications (pp. 1130–1135).
@inproceedings{karyotis2007riskb,
title = {On the risk-based operation of mobile attacks in wireless ad hoc networks},
author = {Vasileios Karyotis and Symeon Papavassiliou and Mary Grammatikou},
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booktitle = {2007 IEEE International Conference on Communications},
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Karyotis, V. A., & Papavassiliou, S. (2007). On the malware spreading over non-propagative wireless Ad Hoc networks: The attacker's perspective. In Proceedings of the 3rd ACM workshop on QoS and security for wireless and mobile networks (pp. 156–159).
@inproceedings{karyotis2007malware,
title = {On the malware spreading over non-propagative wireless Ad Hoc networks: The attacker's perspective},
author = {Vasileios A Karyotis and Symeon Papavassiliou},
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Karyotis, V., Grammatikou, M., & Papavassiliou, S. (2007). On the asymptotic behavior of malware-propagative mobile ad hoc networks. In 2007 IEEE International Conference on Mobile Adhoc and Sensor Systems (pp. 1–9).
@inproceedings{karyotis2007asymptotic,
title = {On the asymptotic behavior of malware-propagative mobile ad hoc networks},
author = {Vasileios Karyotis and Mary Grammatikou and Symeon Papavassiliou},
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Karyotis, V., Papavassiliou, S., Grammatikou, M., & Maglaris, B. (2006). On the characterization and evaluation of mobile attack strategies in wireless ad hoc networks. In 11th IEEE Symposium on Computers and Communications (ISCC'06) (pp. 29–34).
@inproceedings{karyotis2006characterization,
title = {On the characterization and evaluation of mobile attack strategies in wireless ad hoc networks},
author = {Vasileios Karyotis and Symeon Papavassiliou and Mary Grammatikou and Basil Maglaris},
year = {2006},
date = {2006-01-01},
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Karyotis, V., Papavassiliou, S., & Maglaris, B. (2006). Modeling framework for the study and analysis of mobile attack propagation in wireless ad-hoc networks. In 12th European Wireless Conference 2006-Enabling Technologies for Wireless Multimedia Communications (pp. 1–6).
@inproceedings{karyotis2006modeling,
title = {Modeling framework for the study and analysis of mobile attack propagation in wireless ad-hoc networks},
author = {Vasileios Karyotis and Symeon Papavassiliou and Basil Maglaris},
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booktitle = {12th European Wireless Conference 2006-Enabling Technologies for Wireless Multimedia Communications},
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Miscellaneous
Rey, Á. M. D., Yang, L.-X., & Karyotis, V. A. (2019). Mathematical Models for Malware Propagation. Hindawi.
@misc{rey2019mathematical,
title = {Mathematical Models for Malware Propagation},
author = {Ángel Mart'in del Rey and Lu-Xing Yang and Vasileios A Karyotis},
year = {2019},
date = {2019-01-01},
journal = {Security and Communication Networks},
volume = {2019},
publisher = {Hindawi},
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pubstate = {published},
tppubtype = {misc}
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Karyotis, V., & Khouzani, M. (2016). Malware Diffusion Models for Modern Complex Networks. Morgan Kaufmann.
@misc{karyotis2016malware,
title = {Malware Diffusion Models for Modern Complex Networks},
author = {Vasileios Karyotis and MHR Khouzani},
year = {2016},
date = {2016-01-01},
publisher = {Morgan Kaufmann},
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Karyotis, V., Stai, E., & Papavassiliou, S. (2014). Evolutionary dynamics of complex communications networks. CRC Press.
@misc{karyotis2014evolutionary,
title = {Evolutionary dynamics of complex communications networks},
author = {Vasileios Karyotis and Eleni Stai and Symeon Papavassiliou},
year = {2014},
date = {2014-01-01},
publisher = {CRC Press},
keywords = {},
pubstate = {published},
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PhD Theses
Karyotis, V. A. (2005). A Base Case Study of the Worm Propogation Problem in the Framework of Topology Control in Wireless Ad-hoc Networks. [Doctoral dissertation, School of Engineering and Applied Science, University of Pennsylvania].
@phdthesis{karyotis2005base,
title = {A Base Case Study of the Worm Propogation Problem in the Framework of Topology Control in Wireless Ad-hoc Networks},
author = {Vasileios A Karyotis},
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