Unrevised name: Spyridon Kotoulas
Born: 22/06/1982
In: Athens, Greece
1982-1987: Too young to remember
1987-2000: School
2000-2004: BSc in Computer Science, Department of Computer Science, University of Crete
2004-2006: MSc Parallel and Distributed Computer Systems, Vrije Universiteit Amsterdam Mentor: A. S. Tanenbaum Thesis supervisors: R. Siebes, F. van Harmelen, M. van Steen
2006- . . . : Pursuing a phd, Department of Computer Science, Vrije Universiteit Amsterdam Promotor: F. van HarmelenCo-Promotor: R. Siebes
| Oren, E., Kotoulas, S., Anadiotis, G., Siebes, R., Ten Teije, A. & van Harmelen, F. (2009), "MARVIN: distributed reasoning over large-scale Semantic Web data", Journal of Web Semantics. |
BibTeX:
@article{Oren2009,
author = {Oren, Eyal and Kotoulas, Spyros and Anadiotis, George and Siebes, Ronny and Ten Teije, Annette and van Harmelen, Frank},
title = {MARVIN: distributed reasoning over large-scale Semantic Web data},
journal = {Journal of Web Semantics},
year = {2009}
}
|
| Li, P., Zeng, Y., Kotoulas, S., Urbani, J. & Zhong, N. (2009), "The Quest for Parallel Semantic Web Reasoning", In Proceedings of the 2009 International Conference on Active Media Technology, LNCS. |
BibTeX:
@inproceedings{amt2009,
author = {Peiqiang Li and Yi Zeng and Spyros Kotoulas and Jacopo Urbani and Ning Zhong},
title = {The Quest for Parallel Semantic Web Reasoning},
booktitle = {Proceedings of the 2009 International Conference on Active Media Technology, LNCS},
year = {2009},
url = {http://www.few.vu.nl/~kot/papers/AMT09.pdf}
}
|
| Urbani, J., Kotoulas, S., Oren, E. & van Harmelen, F. (2009), "Scalable Distributed Reasoning using MapReduce", In Proceedings of the ISWC '09. |
BibTeX:
@inproceedings{iswc2009,
author = {Jacopo Urbani and Spyros Kotoulas and Eyal Oren and Frank van Harmelen},
title = {Scalable Distributed Reasoning using MapReduce},
booktitle = {Proceedings of the ISWC '09},
year = {2009},
url = {http://www.few.vu.nl/~kot/papers/mapreduce.pdf}
}
|
| Kotoulas, S. & Stegers, R. (2009), "A scalable architecture for peer privacy on the Web", In SPOT at the 6th European Semantic Web Conference (ESWC '09). |
BibTeX:
@inproceedings{scalableprivacy,
author = {Spyros Kotoulas and Ruud Stegers},
title = {A scalable architecture for peer privacy on the Web},
booktitle = {SPOT at the 6th European Semantic Web Conference (ESWC '09)},
year = {2009},
url = {http://www.few.vu.nl/~kot/papers/scalableprivacy.pdf}
}
|
| Anadiotis, G., Kotoulas, S., Lausen, H. & Siebes, R. (2009), "Massively Scalable Web Service Discovery", In Proceedings of the 23rd Intl. Conference on Advanced Information Networking and Applications (AINA '09). |
BibTeX:
@inproceedings{massiveWSdisco,
author = {George Anadiotis and Spyros Kotoulas and Holger Lausen and Ronny Siebes},
title = {Massively Scalable Web Service Discovery},
booktitle = {Proceedings of the 23rd Intl. Conference on Advanced Information Networking and Applications (AINA '09)},
year = {2009},
url = {http://www.few.vu.nl/~kot/papers/wsdisco.pdf}
}
|
| Oren, E., Kotoulas, S., Anadiotis, G., Siebes, R., ten Teije, A. & van Harmelen, F. (2009), "MaRVIN: A platform for large-scale analysis of Semantic Web data", In Proceedings of the WebSci'09: Society On-Line. March 2009. |
BibTeX:
@inproceedings{ORENETAL2009MARVIN,
author = {Eyal Oren and Spyros Kotoulas and George Anadiotis and Ronald Siebes and Annette ten Teije and Frank van Harmelen},
title = {MaRVIN: A platform for large-scale analysis of Semantic Web data},
booktitle = {Proceedings of the WebSci'09: Society On-Line},
year = {2009},
url = {http://www.few.vu.nl/~kot/papers/marvin.pdf}
}
|
| Robertson, D., Giunchiglia, F., van Harmelen, F., Marchese, M., Sabou, M., Schorlemmer, M., nigel shadbolt, Siebes, R., Sierra, C., Walton, C., Dasmahapatra, S., Dupplaw, D., Lewis, P., Yatskevich, M., Kotoulas, S. & Perreau, A. (2008), "Open Knowledge - Coordinating Knowledge Sharing through Peer-to-Peer Interaction". Durham, UK. 04/09/2007 2008. Volume 5118, pp. 1-18. |
| Abstract: The drive to extend the Web by taking advantage of automated symbolic reasoning (the so-called Semantic Web) has been dominated by a traditional model of knowledge sharing, in which the focus is on task-independent standardisation of knowledge. It appears to be difficult, in practice, to standardise in this way because the way in which we represent knowledge is strongly influenced by the ways in which we expect to use it. We present a form of knowledge sharing that is based not on direct sharing of "true" statements about the world but, instead, is based on sharing descriptions of interactions. By making interaction specifications the currency of knowledge sharing we gain a context to interpreting knowledge that can be transmitted between peers, in a manner analogous to the use of electronic institutions in multi-agent systems. The narrower notion of semantic commitment we thus obtain requires peers only to commit to meanings of terms for the purposes and duration of the interactions in which they appear. This lightweight semantics allows networks of interaction to be formed between peers using comparatively simple means of tackling the perennial issues of query routing, service composition and ontology matching. A basic version of the system described in this paper has been built (via the OpenKnowledge project); all its components use established methods; many of these have been deployed in substantial applications; and we summarise a simple means of integration using the interaction specification language itself. |
BibTeX:
@inproceedings{3114,
author = {David Robertson and Fausto Giunchiglia and Frank van Harmelen and Maurizio Marchese and Marta Sabou and Marco Schorlemmer and nigel shadbolt and Ronny Siebes and Carles Sierra and Chris Walton and Srinandan Dasmahapatra and David Dupplaw and Paul Lewis and Mikalai Yatskevich and Spyros Kotoulas and Adrian Perreau },
title = {Open Knowledge - Coordinating Knowledge Sharing through Peer-to-Peer Interaction},
journal = {Languages, Methodologies and Development Tools for Multi-Agent Systems. First InternationalWorkshop, LADS 2007. Revised Selected and Invited Papers},
year = {2008},
volume = {5118},
pages = {1-18}
}
|
| Dupplaw, D., Kotoulas, S., Adrian Perreau de Pinninck Bas & Siebes, R. (2007), "P2P sharing of Interaction Models via the OpenKnowledge Kernel", In Proceedings of BNAIC '07, Utrecht, The Netherlands. |
| Abstract: Web services are pieces of software that can be invoked via a standardized protocol. They can be combined via formalized taskflow languages. The OpenKnowledge system is a fully distributed system using P2P technology, that allows users to publish these taskflows, and programmers to register their web services or publish implementations of them, for the roles described in these workflows. Besides this, the system offers the functionality to select a peer that could coordinate such an interaction model and inform web services when it is their ’turn’. In this paper we describe the architecture and implementation of the OpenKnowledge Kernel which provides the core functionality of the OpenKnowledge system. |
BibTeX:
@inproceedings{BNAIC-kernel,
author = {David Dupplaw and Spyros Kotoulas and Adrian Perreau de Pinninck Bas and Ronny Siebes},
title = {P2P sharing of Interaction Models via the OpenKnowledge Kernel},
booktitle = {Proceedings of BNAIC '07, Utrecht, The Netherlands},
year = {2007}
}
|
| Siebes, R. & Kotoulas, S. (2007), "pRoute: Peer selection using shared term similarity matrices", Web Intelligence and Agent Systems. Vol. 5(1), pp. 89-107. |
| Abstract: Peer-to-Peer systems have proven to be an effective way of sharing data. The focus of this paper is on distributed search based on Peer-to-Peer technology. In this paper we present the pRoute system where peers advertise a short description of the content that they share, namely a set of terms. Peers remember the advertisements of related peers and thereby form a semantic overlay by which we mean that peers with similar content are grouped together. Peers calculate the similarity between their content descriptions by a term similarity function which, in the ideal case, is identical for all peers. In simulation experiments we compare the performance of different advertisement- and forwarding policies with respect to precision, recall and the number of messages. The results indicate precision and recall increase when the policies take semantics into account, without an increase of the number of advertisement- and query messages. |
BibTeX:
@article{DBLP:journals/wias/SiebesK07,
author = {Ronny Siebes and Spyros Kotoulas},
title = {pRoute: Peer selection using shared term similarity matrices},
journal = {Web Intelligence and Agent Systems},
year = {2007},
volume = {5},
number = {1},
pages = {89-107},
url = {http://www.few.vu.nl/~kot/papers/SiebesK07.pdf}
}
|
| Anadiotis, G., Kotoulas, S. & Siebes, R. (2007), "An architecture for peer-to-peer reasoning", In New forms of reasoning for the Semantic Web: scalable, tolerant and dynamic @ International Semantic Web Conference '07. |
| Abstract: Similar to the current Web, the key to realizing the Semantic Web is scale. Arguably, to achieve this, we need a good balance between participation cost and perceived benefit. The major obstacles lie in coping with large numbers of ontologies, authors and physical hosts, inconsistent or inaccurate statements and the large volume of instance data. Our focus is on scalability through distribution. Most current approaches split ontologies into triples and distribute them among peers participating in a structured peer-to-peer overlay. Identifying a series of drawbacks with this, we propose an alternative model where each peer maintains control of its ontologies. |
BibTeX:
@inproceedings{distreasoning,
author = {George Anadiotis and Spyros Kotoulas and Ronny Siebes},
title = {An architecture for peer-to-peer reasoning},
booktitle = {New forms of reasoning for the Semantic Web: scalable, tolerant and dynamic @ International Semantic Web Conference '07},
year = {2007},
url = {http://ftp.informatik.rwth-aachen.de/Publications/CEUR-WS/Vol-291/paper02.pdf}
}
|
| Siebes, R., Dupplaw, D., Kotoulas, S., Adrian Perreau de Pinninck Bas, van Harmelen, F. & Robertson, D. (2007), "The OpenKnowledge System: an interaction-centered approach to knowledge sharing", In Proceedings of the 15th Intl. Conference on Cooperative information systems (CoopIS) in OTM 2007. |
| Abstract: The information that is made available through the semantic web will be accessed through complex programs (web-services, sensors, etc.) that may interact in sophisticated ways. Composition guided simply by the specifications of programs’ inputs and outputs is insufficient to obtain reliable aggregate performance - hence the recognised need for process models to specify the interactions required between programs. These interaction models, however, are traditionally viewed as a consequence of service composition rather than as the focal point for facilitating composition. We describe an operational system that uses models of interaction as the focus for knowledge exchange. Our implementation adopts a peer to peer architecture, thus making minimal assumptions about centralisation of knowledge sources, discovery and interaction control. |
BibTeX:
@inproceedings{IIIA-2007-1588,
author = {Ronny Siebes and David Dupplaw and Spyros Kotoulas and Adrian Perreau de Pinninck Bas and Frank van Harmelen and David Robertson},
title = {The OpenKnowledge System: an interaction-centered approach to knowledge sharing},
booktitle = {Proceedings of the 15th Intl. Conference on Cooperative information systems (CoopIS) in OTM 2007},
year = {2007},
url = {http://www.few.vu.nl/~kot/papers/oksystem.pdf}
}
|
| Robertson, D., Barker, A., Besana, P., Bundy, A., Chen-Burger, Y.-H., Dupplaw, D., Giunchiglia, F., van Harmelen, F., Hassan, F., Kotoulas, S., Lambert, D., Li, G., McGinnis, J., McNeill, F., Osman, N., Adrian Perreau de Pinninck Bas, Siebes, R., Sierra, C. & Walton, C. (2007), "Models of Interaction as a Grounding for Peer-to-Peer Knowledge Sharing", LNCS Advances in Web Semantics. |
| Abstract: Most current attempts to achieve reliable knowledge sharing on a large scale have relied on pre-engineering of content and supply services. This, like traditional knowledge engineering, does not by itself scale to large, open, peer to peer systems because the cost of being precise about the absolute semantics of services and their knowledge rises rapidly as more services participate. We describe how to break out of this deadlock by focusing on semantics related to interaction and using this to avoid dependency on a priori semantic agreement; instead making semantic commitments incrementally at run time. Our method is based on interaction models that are mobile in the sense that they may be transferred to other components, this being a mechanism for service composition and for coalition formation. By shifting the emphasis to interaction (the details of which may be hidden from users) we can obtain knowledge sharing of sufficient quality for sustainable communities of practice without the barrier of complex meta-data provision prior to community formation. |
BibTeX:
@article{IIIA-2007-1589,
author = {David Robertson and Adam Barker and Paolo Besana and Alan Bundy and Yun-Heh Chen-Burger and David Dupplaw and Fausto Giunchiglia and Frank van Harmelen and Fadzil Hassan and Spyros Kotoulas and David Lambert and Guo Li and Jarred McGinnis and Fiona McNeill and Nardine Osman and Adrian Perreau de Pinninck Bas and Ronny Siebes and Carles Sierra and Chris Walton},
title = {Models of Interaction as a Grounding for Peer-to-Peer Knowledge Sharing},
journal = {LNCS Advances in Web Semantics},
year = {2007},
url = {http://www.few.vu.nl/~kot/papers/modelsofinteraction.pdf}
}
|
| Adrian Perreau de Pinninck Bas, Dupplaw, D., Kotoulas, S. & Siebes, R. (2007), "The OpenKnowledge Kernel", In Proceedings of the XXI Intl. Conference on Computer, Information and Systems Science. Vienna, Austria. |
| Abstract: Web services are pieces of software that can be invoked via a standardized protocol. They can be combined via formalized taskflow languages. The OpenKnowledge system is a fully distributed system using P2P technology, that allows users to publish these taskflows, and programmers to register their web services or publish implementations of them, for the roles described in these workflows. Besides this, the system offers the functionality to select a peer that could coordinate such an interaction model and inform web services when it is their ’turn’. In this paper we describe the architecture and implementation of the OpenKnowledge Kernel which provides the core functionality of the OpenKnowledge system. |
BibTeX:
@inproceedings{OKKernel,
author = {Adrian Perreau de Pinninck Bas and David Dupplaw and Spyros Kotoulas and Ronny Siebes},
title = {The OpenKnowledge Kernel},
booktitle = {Proceedings of the XXI Intl. Conference on Computer, Information and Systems Science},
year = {2007},
url = {http://www.few.vu.nl/~kot/papers/OKKernel.pdf}
}
|
| Kotoulas, S. & Siebes, R. (2007), "Scalable discovery of private resources", In IEEE SECOVAL at SECURECOMM. Nice, France. |
| Abstract: Resource discovery is fundamental to a multitude of distributed systems, including grids, web-based applications and multi-agent systems. To achieve scalability at a low cost, many researchers have turned to a peer-to-peer paradigm, leading to the development of a multitude of protocols and algorithms being developed, with implementations still lagging behind. In this paper we consider the privacy implications of peer-to-peer discovery systems and propose a framework for discovery of private resources. Furthermore, we propose and evaluate an architecture and a series of methods using distributed hash tables. Finally, we provide an implementation in the context of the OpenKnowledge project. |
BibTeX:
@inproceedings{privateresources,
author = {Spyros Kotoulas and Ronny Siebes},
title = {Scalable discovery of private resources},
booktitle = {IEEE SECOVAL at SECURECOMM},
year = {2007},
url = {http://www.few.vu.nl/~kot/papers/privateresources.pdf}
}
|
| Kotoulas, S. & Siebes, R. (2007), "Rarity-based routing in peer-to-peer networks", In COPS Workshop at IEEE WETICE. Paris, France. |
| Abstract: The OpenKnowledge project aims at knowledge sharing through open and flexible peer interactions. Within this project, we are developing a system that supports searching, developing and sharing of interactions/workflows consisting of roles implemented by software that can be shared and executed by peers. Its main requirements are openness, scalability, decentralization and robustness. Part of this system is a discovery service, which will be the focus of this paper. This service aspires to fulfill the above requirements featuring a Peer-to-Peer architecture and Distributed Hash Tables (DHTs) to achieve robustness through redundancy and scalability through decentralization. Resources are discovered using a set of attribute-value pairs. A straightforward DHT-based approach that creates a distributed inverted index suffers from a linear increase of messages and replicas with the number of attributes. We try to reduce this number by proposing an efficient multi-attribute routing algorithm. We emulate and test our implementation on the DAS-2 distributed supercomputer. |
BibTeX:
@inproceedings{SK07,
author = {Spyros Kotoulas and Ronny Siebes},
title = {Rarity-based routing in peer-to-peer networks},
booktitle = {COPS Workshop at IEEE WETICE},
year = {2007},
url = {http://www.few.vu.nl/~kot/papers/SK07.pdf}
}
|
| Kotoulas, S., Konstantinidis, K., Kotoulas, L.G. & Andreadis, I. (2006), "An Efficient Peer to Peer Image Retrieval Technique Using Content Addressable Networks", In SETN, LNCS vol 3955., pp. 534-537. |
| Abstract: We present a novel technique for efficient Content Based Peer to Peer Image Retrieval (CBP2PIR) that employs a Content Addressable Network (CAN). A two-stage color histogram based method is described. The first stage defines mapping into the CAN by use of a single fuzzy histogram; while the second stage completes the image retrieval process through a spatially-biased histogram. The proposed system is completely decentralized, non-flooding, and promises high image recall, while minimizing network traffic. |
BibTeX:
@inproceedings{KotoulasKKA06,
author = {Spyros Kotoulas and Konstantinos Konstantinidis and Leonidas G. Kotoulas and Ioannis Andreadis},
title = {An Efficient Peer to Peer Image Retrieval Technique Using Content Addressable Networks},
booktitle = {SETN, LNCS vol 3955},
year = {2006},
pages = {534-537},
url = {http://www.springerlink.com/index/g33m015047r29321.pdf}
}
|
| Kotoulas, S. (2006), "Extracting and incorporating keyword semantics in a DHT-based discovery system". School: Vrije Universiteit Amsterdam. De Boelelaan 1081HV, Amstedam, The Netherlands, August, 2006. |
| Abstract: The focus of this thesis is on peer-to-peer systems where peers describe their services and data by sets of terms. The contribution of this paper is twofold: First, we propose a distributed system that efficiently calculates statistics about these terms. Second, we use these statistics to replicate the term sets among a selection of peers in order to enable clustering and improve the peer selection process. As a side effect, we expect that this process will have a positive influence on the performance of the statistical analysis. We perform an evaluation of the JXTA peer-to-peer infrastructure, focusing on scalability and discovery, revealing a series of programming flaws that lead to grave performance issues. Furthermore, we implement, deploy and evaluate a part of the proposed system using the DAS-2 supercomputer. We use five settings to experiment with our discovery platform, and the best of them yields a large increase in the query throughput of our system, while preserving or increasing recall, compared to the naive approach. |
BibTeX:
@mastersthesis{kotoulasthesis,
author = {Spyros Kotoulas},
title = {Extracting and incorporating keyword semantics in a DHT-based discovery system},
school = {Vrije Universiteit Amsterdam},
year = {2006},
url = {http://www.few.vu.nl/~kot/papers/masterthesis.pdf}
}
|
| Siebes, R. & Kotoulas, S. (2005), "pRoute: Expertise-based Selection using Shared Term Similarity Matrices", In Proceedings of the 17th Belgian-Dutch Conference on Artificial Intelligence. Brussels, Belgium. October 2005., pp. 202-208. Contactforum. |
| Abstract: Finding the right content or experts in a Peer-to-Peer system or Multi-Agent system is a challenging problem especially when it has to be scalable to large networks. The focus of this paper is on distributed search based on using semantic knowledge about the peers in the network. In this paper we present the pRoute system where each peer advertises a short description of its content that its shares that serves as its expertise description. Peers remember the advertisements of related peers and thereby form a semantic overlay by which we mean that peers with similar content are grouped together. Peers calculate the similarity between their content descriptions by a term similarity function which, in the ideal case, is identical for all peers. In simulation experiments we compare the performance of different advertisementand forwarding policies with respect to to precision, recall and the number of messages. Simulation results indicate that precision and recall increases when the policies take semantics into account, without an increase of the number of advertisement- and query messages. |
BibTeX:
@inproceedings{SK05,
author = {Ronny Siebes and Spyros Kotoulas},
title = {pRoute: Expertise-based Selection using Shared Term Similarity Matrices},
booktitle = {Proceedings of the 17th Belgian-Dutch Conference on Artificial Intelligence},
publisher = {Contactforum},
year = {2005},
pages = {202--208},
url = {http://www.few.vu.nl/~kot/papers/SK05.pdf}
}
|
| Anglos, D., Melessanaki, K., Kotoulas, S., Petrakis, A., Hatziapostolou, A., Ferrence, S. & Betancourt, P. (2002), "LIBS: A new tool in archaeometry". |
BibTeX:
@inproceedings{Anglos:02,
author = {Demetrios Anglos and K. Melessanaki and S. Kotoulas and A. Petrakis and A. Hatziapostolou and S. Ferrence and P.P. Betancourt},
title = {LIBS: A new tool in archaeometry},
journal = {Laser Induced Plasma Spectroscopy and Applications, A. Sawchuk, ed., Vol. 81 of OSA Trends in Optics and Photonics Series (Optical Society of America)},
year = {2002},
url = {http://www.opticsinfobase.org/abstract.cfm?URI=LIBS-2002-ThA4}
}
|