Συνέδρια

@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}

}

@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}

}

@conference{Mikalef2016,

title = {IT flexibility and competitive performance: The mediating role of IT-enabled dynamic capabilities},

author = {P. Mikalef and A. Pateli and R. Van De Wetering},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84995752467&partnerID=40&md5=9d7caebb1f36b7e9a51eb336e8187b68},

year  = {2016},

date = {2016-01-01},

journal = {24th European Conference on Information Systems, ECIS 2016},

note = {cited By 50},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Mikalef2016b,

title = {IT flexibility and competitive performance: The mediating role of IT-enabled dynamic capabilities},

author = {P. Mikalef and A. Pateli and R. Van De Wetering},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84995752467&partnerID=40&md5=9d7caebb1f36b7e9a51eb336e8187b68},

year  = {2016},

date = {2016-01-01},

journal = {24th European Conference on Information Systems, ECIS 2016},

note = {cited By 50},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@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}

}

@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},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Rill2012305,

title = {A phrase-based opinion list for the German language},

author = {S. Rill and S. Adolph and J. Drescher and D. Reinel and J. Scheidt and O. Schütz and F. Wogenstein and R. V. Zicari and N. Korfiatis},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84893221549&partnerID=40&md5=8a09c211f7064dd16744cbfd88b4dfbb},

year  = {2012},

date = {2012-01-01},

journal = {11th Conference on Natural Language Processing, KONVENS 2012: Empirical Methods in Natural Language Processing - Proceedings of the Conference on Natural Language Processing 2012},

volume = {5},

pages = {305-313},

note = {cited By 11},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@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},

tppubtype = {conference}

}

@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},

tppubtype = {conference}

}

@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}

}

@conference{Mikalef20121,

title = {Exploring the business potential of social media: An utilitarian and hedonic motivation approach},

author = {P. Mikalef and M. Giannakos and A. Pateli},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876997516&partnerID=40&md5=b29a06576167ee7ead4e440489db18ee},

year  = {2012},

date = {2012-01-01},

journal = {25th Bled eConference - eDependability: Reliable and Trustworthy eStructures, eProcesses, eOperations and eServices for the Future, Proceedings},

pages = {1-14},

note = {cited By 18},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@conference{Wu20113710,

title = {The influences of negativity and review quality on the helpfulness of online reviews},

author = {P. F. Wu and H. Van Der Heijden and N. T. Korfiatis},

url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84884638213&partnerID=40&md5=21004c1b5f862817dcd30364df7b0d20},

year  = {2011},

date = {2011-01-01},

journal = {International Conference on Information Systems 2011, ICIS 2011},

volume = {5},

pages = {3710-3719},

note = {cited By 58},

keywords = {},

pubstate = {published},

tppubtype = {conference}

}

@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}

}

@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}

}

@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}

}

@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}

}

@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}

}