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Sourlas V.,University of Thessaly | Gkatzikis L.,University of Thessaly | Flegkas P.,CERTH | Tassiulas L.,University of Thessaly
IEEE Transactions on Network and Service Management | Year: 2013

The main promise of current research efforts in the area of Information-Centric Networking (ICN) architectures is to optimize the dissemination of information within transient communication relationships of endpoints. Efficient caching of information is key to delivering on this promise. In this paper, we look into achieving this promise from the angle of managed replication of information. Management decisions are made in order to efficiently place replicas of information in dedicated storage devices attached to nodes of the network. In contrast to traditional off-line external management systems we adopt a distributed autonomic management architecture where management intelligence is placed inside the network. Particularly, we present an autonomic cache management approach for ICNs, where distributed managers residing in cache-enabled nodes decide on which information items to cache. We propose four on-line intra-domain cache management algorithms with different level of autonomicity and compare them with respect to performance, complexity, execution time and message exchange overhead. Additionally, we derive a lower bound of the overall network traffic cost for a certain category of network topologies. Our extensive simulations, using realistic network topologies and synthetic workload generators, signify the importance of network wide knowledge and cooperation. © 2013 IEEE. Source


Philimis P.,CYRIC | Giusti A.,CYRIC | Torres A.,ATEKNEA | Margaritescu M.,INCDMTM | Giakas G.,CERTH
Romanian Review Precision Mechanics, Optics and Mechatronics | Year: 2015

The Wi-Shoe project aimed to develop a completely non-intrusive wearable shoe-based system used for measuring kinematic gait parameters and energy expenditure during walking. The project answers the actual need of the healthcare and sport sectors for a person-centric product that will allow continuous monitoring of the subject. © 2015, Editura Cefin. All rights reserved. Source


Mahmoudi H.,Aston University | Rodolakis G.,CERTH | Georgiadis L.,Aristotle University of Thessaloniki | Saad D.,Aston University
2013 IEEE International Conference on Communications Workshops, ICC 2013 | Year: 2013

Cognitive Radio has been proposed as a key technology to significantly improve spectrum usage in wireless networks by enabling unlicensed users to access unused resource. We present new algorithms that are needed for the implementation of opportunistic scheduling policies that maximize the throughput utilization of resources by secondary users, under maximum interference constraints imposed by existing primary users. Our approach is based on the Belief Propagation (BP) algorithm, which is advantageous due to its simplicity and potential for distributed implementation. We examine convergence properties and evaluate the performance of the proposed BP algorithms via simulations and demonstrate that the results compare favorably with a benchmark greedy strategy. © 2013 IEEE. Source


Fraternali P.,Polytechnic of Milan | Tagliasacchi M.,Polytechnic of Milan | Martinenghi D.,Polytechnic of Milan | Bozzon A.,Polytechnic of Milan | And 17 more authors.
WWW'12 - Proceedings of the 21st Annual Conference on World Wide Web Companion | Year: 2012

The Cubrik Project is an Integrated Project of the 7th Frame- work Programme that aims at contributing to the multimedia search domain by opening the architecture of multimedia search engines to the integration of open source and third party content annotation and query processing components, and by exploiting the contribution of humans and communities in all the phases of multimedia search, from content processing to query processing and relevance feedback processing. The CUBRIK presentation will showcase the architectural concept and scientific background of the project and demonstrate an initial scenario of human-enhanced content and query processing pipeline. Source


Sourlas V.,UCL | Georgatsos P.,CERTH | Flegkas P.,CERTH
Proceedings - IEEE INFOCOM | Year: 2015

We place in the context of Information-Centric Networks a special class of segment-based caching, named partition-based caching, whereby information items are cached in partitions at different caches in the network. Our rationale lies in exploiting the merits of parallel data transmission, which however may come at the expense of increased network utilization. The study of this cost-benefit trade-off underlines our work. Following a theoretical analysis on the benefits of partition-based caching over single replication caching, we propose three traffic engineering algorithms for assigning content partitions to caches and respective routes. Simulation results indicate that partitionbased caching can indeed improve average content transfer time (up to 65%) at the expense of a tolerable increase in network load (up to 25%), for moderate numbers of content partitions (less than 6), balancing at the same time network load better (at the level of 50%), compared to single replication caching. © 2015 IEEE. Source

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