Nikolas Mitrou - Academia.edu (original) (raw)
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Papers by Nikolas Mitrou
Kluwer Academic Publishers eBooks, Dec 2, 2005
This paper has a twofold objective. First, it aims at reviewing the basic ATM traffic control fun... more This paper has a twofold objective. First, it aims at reviewing the basic ATM traffic control functions, as defined by the standards, addressing popular methods that are used for performance analysis of ATM multiplexing and, then, bending critically over controversial issues in this area; among these issues is the suitability of statistical models for traffic control, the effectiveness of rate-based
European Transactions on Telecommunications, Mar 1, 2009
As peer‐to‐peer (P2P) applications become more mature and demanding, there is a need for the unde... more As peer‐to‐peer (P2P) applications become more mature and demanding, there is a need for the underlying technologies to provide more adaptive characteristics, according to the application's requirements. In this paper, we present K‐Umbrella, a K‐ary distributed hash table (DHT), which allows us to efficiently route through the use of a fixed‐size routing table. By controlling a number of parameters, our algorithm is able to trade‐off between efficiency, fault‐tolerance and decentralisation according to the application's requirements. Through a detailed analysis of our algorithms and an extensive set of simulations, we will show that our protocol is able to offer an improved alternative to current DHT algorithms. Copyright © 2007 John Wiley & Sons, Ltd.
Journal of ICT standardisation, Jun 8, 2021
Lecture Notes in Computer Science, 2004
Springer eBooks, 2004
... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitr... more ... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitris Gritzalis Stefanos Gritzalis Yu Gu Isabelle Guerin Lassous Ratul Guha Chao Gui Fabrice Guillemin Mina Guirguis Liang Guo Minaxi Gupta Prabhanjan Gurumohan Mohan ...
IEEE Vehicular Technology Magazine, Dec 1, 2019
The available bit rate (ABR) service is being designed as a low-cost transport service over ATM n... more The available bit rate (ABR) service is being designed as a low-cost transport service over ATM networks, which will be using the bandwidth remaining available after servicing connections of another, high-priority class. The penalty paid is the lack of QoS guarantees in terms of transport delays figures. Thus, an adaptive shaping mechanism is necessary for the ABR connections at each multiplexing or switching stage for effective bandwidth enforcement and adjusting their traffic profiles according to the prevailing congestion conditions. An adaptive shaping mechanism related with the ABR service is analyzed and modeled on the basis of effective rates defined for the multiplexed connections. The traffic shaper is used to enforce the contracted effective rate for the ABR class and to allocate peak rates to the high priority class (burst spacer). The traffic shaper system is presented as an implementation perspective and specific ideas concerning its hardware realization are given
Routing in a Peer-to-Peer environment faces a number of challenges, mainly due to its distributed... more Routing in a Peer-to-Peer environment faces a number of challenges, mainly due to its distributed nature. In this paper we evaluate a new distributed hash table architecture that is able to provide efficient routing through a fixed-size table. By introducing a set of base algorithms, multiple replication schemas, virtual nodes and a variable repair mechanism, we are able to ensure successful lookups of published keywords. Along with theoretical analysis of our proposed work, we present extensive simulation results that testify and evaluate our protocol.
Springer eBooks, 1986
Fan filters in seismic data processing, directional filters in image processing and 2-D equalizer... more Fan filters in seismic data processing, directional filters in image processing and 2-D equalizers are but a few examples of 2-Dimensional systems described explicitly in the frequency domain. Current methods for handling such systems in a discrete form require an NxN sampling grid resulting in considerable design complexity and a high implementation cost.
... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitr... more ... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitris Gritzalis Stefanos Gritzalis Yu Gu Isabelle Guerin Lassous Ratul Guha Chao Gui Fabrice Guillemin Mina Guirguis Liang Guo Minaxi Gupta Prabhanjan Gurumohan Mohan ...
It is well known that the success of future cellular systems, especially, UMTS, will be coupled w... more It is well known that the success of future cellular systems, especially, UMTS, will be coupled with the cost-efficient provision of QoS levels that are comparable with those of fixed systems. In this respect, planning tools, and sophisticated network and service management platforms, will play an important role in the commercial success of UMTS. This paper presents an approach, i.e., framework and set of problems, for managing UMTS networks. The areas addressed are the cost-effective accommodation of service provider requests, the management of the CDMA-based radio interface, and the development of an interactive (with the management mechanisms) simulation platform, for validation purposes.
Journal of Library Administration, 2018
Kluwer Academic Publishers eBooks, Dec 2, 2005
This paper has a twofold objective. First, it aims at reviewing the basic ATM traffic control fun... more This paper has a twofold objective. First, it aims at reviewing the basic ATM traffic control functions, as defined by the standards, addressing popular methods that are used for performance analysis of ATM multiplexing and, then, bending critically over controversial issues in this area; among these issues is the suitability of statistical models for traffic control, the effectiveness of rate-based
European Transactions on Telecommunications, Mar 1, 2009
As peer‐to‐peer (P2P) applications become more mature and demanding, there is a need for the unde... more As peer‐to‐peer (P2P) applications become more mature and demanding, there is a need for the underlying technologies to provide more adaptive characteristics, according to the application's requirements. In this paper, we present K‐Umbrella, a K‐ary distributed hash table (DHT), which allows us to efficiently route through the use of a fixed‐size routing table. By controlling a number of parameters, our algorithm is able to trade‐off between efficiency, fault‐tolerance and decentralisation according to the application's requirements. Through a detailed analysis of our algorithms and an extensive set of simulations, we will show that our protocol is able to offer an improved alternative to current DHT algorithms. Copyright © 2007 John Wiley & Sons, Ltd.
Journal of ICT standardisation, Jun 8, 2021
Lecture Notes in Computer Science, 2004
Springer eBooks, 2004
... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitr... more ... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitris Gritzalis Stefanos Gritzalis Yu Gu Isabelle Guerin Lassous Ratul Guha Chao Gui Fabrice Guillemin Mina Guirguis Liang Guo Minaxi Gupta Prabhanjan Gurumohan Mohan ...
IEEE Vehicular Technology Magazine, Dec 1, 2019
The available bit rate (ABR) service is being designed as a low-cost transport service over ATM n... more The available bit rate (ABR) service is being designed as a low-cost transport service over ATM networks, which will be using the bandwidth remaining available after servicing connections of another, high-priority class. The penalty paid is the lack of QoS guarantees in terms of transport delays figures. Thus, an adaptive shaping mechanism is necessary for the ABR connections at each multiplexing or switching stage for effective bandwidth enforcement and adjusting their traffic profiles according to the prevailing congestion conditions. An adaptive shaping mechanism related with the ABR service is analyzed and modeled on the basis of effective rates defined for the multiplexed connections. The traffic shaper is used to enforce the contracted effective rate for the ABR class and to allocate peak rates to the high priority class (burst spacer). The traffic shaper system is presented as an implementation perspective and specific ideas concerning its hardware realization are given
Routing in a Peer-to-Peer environment faces a number of challenges, mainly due to its distributed... more Routing in a Peer-to-Peer environment faces a number of challenges, mainly due to its distributed nature. In this paper we evaluate a new distributed hash table architecture that is able to provide efficient routing through a fixed-size table. By introducing a set of base algorithms, multiple replication schemas, virtual nodes and a variable repair mechanism, we are able to ensure successful lookups of published keywords. Along with theoretical analysis of our proposed work, we present extensive simulation results that testify and evaluate our protocol.
Springer eBooks, 1986
Fan filters in seismic data processing, directional filters in image processing and 2-D equalizer... more Fan filters in seismic data processing, directional filters in image processing and 2-D equalizers are but a few examples of 2-Dimensional systems described explicitly in the frequency domain. Current methods for handling such systems in a discrete form require an NxN sampling grid resulting in considerable design complexity and a high implementation cost.
... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitr... more ... Jose-L. Gonzalez-Sanchez Pawan Goyal Enrico Gregori Costas Grekas Luigi Alfredo Grieco Dimitris Gritzalis Stefanos Gritzalis Yu Gu Isabelle Guerin Lassous Ratul Guha Chao Gui Fabrice Guillemin Mina Guirguis Liang Guo Minaxi Gupta Prabhanjan Gurumohan Mohan ...
It is well known that the success of future cellular systems, especially, UMTS, will be coupled w... more It is well known that the success of future cellular systems, especially, UMTS, will be coupled with the cost-efficient provision of QoS levels that are comparable with those of fixed systems. In this respect, planning tools, and sophisticated network and service management platforms, will play an important role in the commercial success of UMTS. This paper presents an approach, i.e., framework and set of problems, for managing UMTS networks. The areas addressed are the cost-effective accommodation of service provider requests, the management of the CDMA-based radio interface, and the development of an interactive (with the management mechanisms) simulation platform, for validation purposes.
Journal of Library Administration, 2018
In addition to tools offering RDF views over databases, a variety of tools exist that allow expor... more In addition to tools offering RDF views over databases, a variety of tools exist that allow exporting database contents into RDF graphs; tools proven that in many cases demonstrate better performance than the former. However, in cases when database contents are exported into RDF, it is not always optimal or even necessary to dump the whole database contents every time. In this paper, the problem of incremental generation and storage of the resulting RDF graph is investigated. An implementation of the R2RML standard is used in order to express mappings that associate tuples from the source database to triples in the resulting RDF graph. Next, a methodology is proposed that enables incremental generation and storage of an RDF graph based on a source relational database, and it is evaluated through a set of performance measurements. Finally, a discussion is presented regarding the authors’ most important findings and conclusions.
As far as digital repositories are concerned, numerous benefits emerge from the disposal of their... more As far as digital repositories are concerned, numerous benefits emerge from the disposal of their contents as Linked Open Data (LOD). This leads more and more repositories towards this direction. However, several factors need to be taken into account in doing so, among which is whether the transition needs to be materialized in real-time or in asynchronous time intervals. In this paper we provide the problem framework in the context of digital repositories, we discuss the benefits and drawbacks of both approaches and draw our conclusions after evaluating a set of performance measurements. Overall, we argue that in contexts with infrequent data updates, as is the case with digital repositories, persistent RDF views are more efficient than real-time SPARQL-to-SQL rewriting systems in terms of query response times, especially when expensive SQL queries are involved.
