2017
61. P. Alexopoulos, S. Leivaditi (2017), “Modeling, Measuring and Exploiting Concept Drift in the Labour Market Domain“, 2nd Workshop in Detection, Representation and Management of Concept Drift in Linked Open Data, Amsterdam, The Netherlands, 2017. [PDF]
60. R. Denaux , Y. Ren, B. Villazon-Terrazas, P. Alexopoulos, A. Faraotti, H. Wu (2017), “Knowledge Architecture for Organisations” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
59. M. Monti , F. Perego, Y. Zhao, G. Vetere, J.M. Gomez-Perez, P. Alexopoulos, H. Nguyen, G. Webster, B. Villazon-Terrazas, N. Garcia-Santa, J.Z. Pan (2017), “Enterprise Knowledge Graphs: Success Stories” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
58. H. Wu , R. Denaux, P. Alexopoulos, Y. Ren, J.Z. Pan (2017), “Understanding Knowledge Graphs” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
57. A. Moschitti , K. Tymoshenko, P. Alexopoulos, A. Walker, M. Nicosia, G. Vetere, A. Faraotti, M. Monti, J.Z. Pan, H. Wu, Y. Zhao (2017), “Question Answering and Knowledge Graphs” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
56. P. Alexopoulos , Y. Zhao, J.Z. Pan, M. Zhu (2017), “Construction of Enterprise Knowledge Graphs (II)” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
55. B. Villazon-Terrazas , N. Garcia-Santa, Y. Ren, K. Srinivas, M. Rodriguez-Muro, P. Alexopoulos, J.Z. Pan (2017), “Construction of Enterprise Knowledge Graphs (I)” , In Jeff Z. Pan, Guido Vetere, Jose Manuel Gomez-Perez, Honghan Wu (editors), Exploiting Linked Data and Knowledge Graphs in Large Organisations, Springer. 2017.
2016
54. N. Jekjantuk, J.Z. Pan, P. Alexopoulos, “Towards a Meta-Reasoning Framework for Reasoning about Vagueness in OWL Ontologies”, 10th International Conference on Semantic Computing, February 3-5 , 2016, Laguna Hills, California, U.S.A.
2015
53. A. Walker, P. Alexopoulos, A. Starkey, J.Z. Pan, J.M. Gómez-Pérez, A. Siddharthan , “Type Identification for Question Answering – Supervised Learning of Dependency Graph Patterns from Natural Language Questions”, 5th Joint International Semantic Technology Conference, November 11-13 , 2015, Yichang, Hubei, China.
52. P. Alexopoulos, M.Wallace (2015), “Creating Domain-Specific Semantic Lexicons for Aspect-Based Sentiment Analysis”, 10th International Workshop on Semantic Media and Adaptation (SMAP), November 5-6, 2015, Trento, Italy.
51. P. Alexopoulos, R. Denaux, J.M. Gomez-Perez (2015), “Troubleshooting and Optimizing Named Entity Resolution Systems in the Industry”, 12th Extended Semantic Web Conference (ESWC), Portoroz, Slovenia, May 31st – June 4th, 2015. [Slides, Video]
2014
50. P. Alexopoulos, S. Peroni, B. Villazon-Terrazas, J.Z. Pan, J.M. Gomez-Perez (2014), “A Metaontology for Annotating Ontology Entities with Vagueness Descriptions”, In Fernando Bobillo‚ Rommel Carvalho‚ Paulo Cesar G. da Costa‚ Claudia d’Amato‚ Nicola Fanizzi‚ Kathryn B. Laskey‚ Kenneth J. Laskey‚ Thomas Lukasiewicz‚ Matthias Nickles and Michael Pool, editors, Uncertainty Reasoning for the Semantic Web III‚ International Workshops URSW 2011−2013‚ Held at ISWC‚ Revised Selected Papers. Springer. 2014. [BibTex, PDF]
49. P. Alexopoulos, A. Walker, J.M. Gomez Perez, M. Wallace (2014), “Towards Ontology-Based Question Answering in Vague Domains”, 9th International Workshop on Semantic Media and Adaptation (SMAP), November 6-7, 2014, Corfu, Greece. [BibTex, PDF]
48. H. Hastie, M.A Aufaure, P. Alexopoulos, H. Bouchard, H. Cuayáhuitl, N. Dethlefs, M. Gasic, J. Henderson, O. Lemon, X. Liu, P. Mika, T. Potter, V. Rieser, P. Tsiakoulis, Y. Vanrompay, B. Villazon-Terrazas, M. Yazdani, S. Young and Y. Yu. (2014). “Two Alternative Frameworks for Deploying Spoken Dialogue Systems to Mobile Platforms for Evaluation ‘In the Wild’“. Abstract paper in the Workshop on the Semantics and Pragmatics of Dialogue (SemDial). Edinburgh, Scotland, to appear.
47. H. Hastie, M.A. Aufaure, P. Alexopoulos, H. Bouchard, H. Cuayahuitl, N. Dethlefs, M. Gasic, J. Henderson, O. Lemon, X. Liu, P. Mika, N. Ben Mustapha, T. Potter, V. Rieser, B. Thomson, P. Tsiakoulis, Y. Vanrompay, B. Villazon-Terrazas, M. Yazdani, S. Young and Y. Yu (2014), “The PARLANCE mobile app for interactive search in English and Mandarin”. In Proceedings of SIGDIAL 2014, 18-20 June, Philadelphia, USA, 2014
46. P. Alexopoulos, S. Peroni, B. Villazon-Terrazas, J.Z. Pan (2014), “Annotating Ontologies with Descriptions of Vagueness”, Poster presentation at the 11th Extended Semantic Web Conference, Heraklion, Greece, May 25th – 29th, 2014. [BibTex, PDF]
45. P. Alexopoulos, J. Pavlopoulos, Ph. Mylonas (2014), “A Semantic Framework for Harvesting Vague Enterprise Knowledge From Microposts”, International Journal of Artificial Intelligence Tools, Vol. 23, No. 2, 2014. [BibTex]
44. P. Alexopoulos, Ph. Mylonas (2014), “Towards Vagueness-Oriented Quality Assessment of Ontologies”. In Proceedings of the 8th Hellenic Conference on Artificial Intelligence (SETN 2014), Ioannina, Greece, May 15-17 2014. [BibTex]
43. P. Alexopoulos, J. Pavlopoulos (2014), “A Vague Sense Classifier for Detecting Vague Definitions in Ontologies”. In Proceedings of the 14th Conference of the European Chapter of the Association for Computational Linguistics (EACL 2014), Gothenburg, Sweden, 2014. [BibTex, PDF, Slides]
2013
41. P. Alexopoulos, C. Ruiz, B. Villazon-Terrazas, J.M. Gómez-Pérez (2013), “KLocator: An Ontology-Based Framework for Scenario-Driven Geographical Scope Resolution”, International Journal On Advances in Intelligent Systems, vol 6 no 3&4, 2013. [BibTex, PDF]
40. P. Alexopoulos, M. Wallace (2013), “Towards Learning Personalized Semantic Relevance Paths In Dialogue Systems”, 8th International Workshop on Semantic Media and Adaptation, Bayonne, France, 2013. [BibTex, PDF]
39. P. Alexopoulos, B. Villazon-Terrazas, J.Z. Pan (2013), “Towards Vagueness-Aware Semantic Data“, In Proceedings of the 9th International Workshop on Uncertainty Reasoning for the Semantic Web, Sydney, Australia, 2013. [BibTex, PDF, Slides ]
38. Hastie H., M.A Aufaure, P. Alexopoulos, H. Cuayáhuitl, N. Dethlefs, M. Gasic, J. Henderson, O. Lemon, X. Liu, P. Mika, N. Ben Mustapha, V. Rieser, B. Thomson, P. Tsiakoulis, Y. Vanrompay, B. Villazon-Terrazas, S. Young (2013), “Demonstration of the Parlance system: a data-driven, incremental, spoken dialogue system for interactive search”, Demo at 14th Annual Meeting of the Special Interest Group on Discourse and Dialogue, Metz, France, 22-24 August 2013. [BibTex, PDF]
37. P. Alexopoulos, B. Villazon-Terrazas, J.M. Gómez-Pérez (2013) “Knowledge Tagger: Customizable Semantic Entity Resolution using Ontological Evidence”, Demo at the 9th International Conference on Semantic Systems (I-SEMANTICS), Graz, Austria, September 4-6, 2013. [BibTex, PDF]
36. P. Alexopoulos, J.M. Gómez-Pérez (2013), “Towards Purposeful Reuse of Semantic Datasets Through Goal-Driven Summarization”, Proceedings of the 7th International Conference on Advances in Semantic Processing (SEMAPRO 2013), Porto, Portugal, September 29- October 3, 2013 (Best Paper Award). [BibTex, PDF, Slides]
35. P. Alexopoulos, J.M. Gómez-Pérez (2013) “Interactive Acquisition of Fuzzy Ontological Knowledge in Dialogue Systems”. In Proceedings of the 7th international conference on Knowledge capture (K-CAP ’13). Banff, Canada. [BibTex, PDF]
34. P. Alexopoulos (2013), “Scenario-Driven Semantic Entity Resolution Using Ontological Evidence”, Demo at the 2nd UK Ontology Network Workshop, Edinburgh, Scotland, April 11th, 2013.
33. P. Alexopoulos, Marie-Aude Aufaure, Nesrine Ben-Mustapha, Hugues Bouchard, James Henderson,, Beibei Hu,, Peter Mika,, Joel Lang, Jose Manuel Gomez-Perez, Yves Vanrompay (2013), “Semantic Hyperlocal Search for Parlance Mobile Spoken Dialogue System”, Poster presentation at the 10th Extended Semantic Web Conference, Montpelier, France, May 26th – 30th, 2013. [BibTex, PDF]
2012
32. P. Alexopoulos, C. Ruiz, J.M. Gómez-Pérez (2012), “Scenario-Driven Selection and Exploitation of Semantic Data for Optimal Named Entity Disambiguation“, Proceedings of the 1st Semantic Web and Information Extraction Workshop (SWAIE 2012), Galway, Ireland, October 8-12, 2012. [BibTex, PDF, Slides]
31. P. Alexopoulos, M. Wallace (2012), “Improving Automatic Semantic Tag Recommendation through Fuzzy Ontologies”, Proceedings of the 7th International Workshop on Semantic Media Adaptation and Personalization, Luxembourg, 2012. [BibTex, PDF, Slides]
30. P. Alexopoulos, C. Ruiz (2012), “Optimizing Geographical Entity and Scope Resolution in Texts using Non-Geographical Semantic Information”, Proceedings of the 6th International Conference on Advances in Semantic Processing (SEMAPRO 2012), Barcelona, Spain, September 23-28, 2012. [BibTex, PDF]
29. P. Alexopoulos, J. Pavlopoulos, Ph. Mylonas (2012), “Learning Vague Knowledge From Socially Generated Content in an Enterprise Framework”, Proceedings of the 1st Mining Humanistic Data Workshop (MHDW 2012), Halkidiki, Greece, September 27-30, 2012. [BibTex, PDF, Slides]
28. P. Alexopoulos, J.M. Gómez-Pérez (2012), “Dealing with Vagueness in Semantic Business Process Management through Fuzzy Ontologies”, Proceedings of the 7th International Workshop on Semantic Business Process Management, Heraclion, Greece, May 27-31, 2012. [BibTex, PDF]
27. P. Alexopoulos (2012) “IKARUS: A Framework for Engineering and Managing Vague Knowledge“ , PhD Thesis, National Technical University of Athens, May 2012, Athens, Greece. [PDF in Greek]
26. Alvaro Rey G., I. Celino, M. Damova, D. Damljanovic, N. Li, P. Alexopoulos, V. Devedzic (2012), “Semi-Automatic Generation of Quizzes and Learning Artifacts from Linked Data”, 1st Workshop on Linked Learning (Lile2012) at World Wide Web (WWW), Lyon,France. [BibTex, PDF]
25. Wallace M., P. Alexopoulos, Ph. Mylonas (2012), “Identifying Conceptual Layers in the Ontology Development Process” , 7th Hellenic Conference on Artificial Intelligence (SETN 2012), Lamia, Greece, 28-31 May 2012. [BibTex, PDF]
2011
24. P. Alexopoulos, M. Wallace, K. Kafentzis, D. Askounis (2011), “IKARUS-Onto: A Methodology to Develop Fuzzy Ontologies from Crisp Ones” , Knowledge and Information Systems, Volume 32, Issue 3, Page 667-695. [BibTex, PDF]
23. Wallace M., P. Alexopoulos, I. Papafragkos, C. Vassilakis (2011), “Supporting User Roles in Ontology Fuzzification”, Proceedings of the 6th International Workshop on Semantic Media Adaptation and Personalization, Vigo, Spain, 2011. [BibTex, PDF]
22. P. Alexopoulos, J. Pavlopoulos, M. Wallace, K. Kafentzis (2011), “Exploiting Ontological Relations for Automatic Semantic Tag Recommendation”, 7th International Conference on Semantic Systems (I-SEMANTICS), Graz, Austria, September 7-9, 2011. [BibTex, PDF, Slides]
21. Anadiotis G., P. Alexopoulos, K. Kafentzis, E. Konstantinou, M. Stankovic, M. Waeckerle (2011), “Semantics-powered Virtual Communities and Open Innovation for a Structured Deliberation Process”, Workshop on “Semantics in Governance and Policy Modelling” in conjunction with the 8th Extended Semantic Web Conference (ESWC) 2011, May 29 – June 2, 2011, Heraclion, Greece. [BibTex, PDF]
2010
20. P. Alexopoulos, M. Wallace, K. Kafentzis, D. Askounis (2010), “Utilizing Imprecise Knowledge in Ontology-based CBR Systems through Fuzzy Algebra”, International Journal of Fuzzy Systems, Vol. 12, No. 1, March 2010. [BibTex, PDF]
19. P. Alexopoulos, M. Wallace,K. Kafentzis, Ch. Zoumas, D. Askounis (2010), “Semantic-Enabled Information Access: An Application in the Electricity Market Domain”, M. Wallace, Ph. Mylonas, I. Anagnostopoulos, M. Bielikova (Eds), Semantics in Adaptive and Personalised Services: Methods, Tools and Applications, Springer, 2010. [BibTex, PDF]
18. P. Alexopoulos, M. Wallace, K. Kafentzis, D. Askounis (2010), “A Semantic Architecture for Knowledge Intensive CBR through Fuzzy Ontologies”, 15th UK Workshop on Case Based Reasoning, December 14th 2010, Cambridge, UK. [BibTex, PDF]
17. Kotis K., P. Alexopoulos, A. Papasalouros (2010), “Towards a Framework for Trusting the Automated Learning of Social Ontologies”, Knowledge Science, Engineering and Management (KSEM) 2010, Belfast, Northern Ireland, September 1-3. [BibTex, PDF]
16. P. Alexopoulos, M. Wallace, K. Kafentzis, D. Askounis (2010) “Towards a Methodology for the Engineering of Fuzzy Ontologies”, Poster presentation at the 7th Extended Semantic Web Conference, Heraklion, Greece, May 30th – June 3rd. [BibTex, PDF]
15. Anadiotis G., P. Alexopoulos, K. Mpaslis, A. Zosakis, K. Kafentzis, K. Kotis (2010), “Facilitating Dialogue – Using Semantic Web Technology for eParticipation”, 7th Extended Semantic Web Conference, Heraklion, Greece, May 30th – June 3rd. [BibTex, PDF]
2009
14. P. Alexopoulos, M. Wallace, K. Kafentzis, D. Askounis (2009) “Towards Effective Knowledge Management Through Fuzzy Semantics” , The Third International Multi-Conference on Computing in the Global Information Technology 2009, Cannes, France, August 23-29. [BibTex, PDF]
13. P. Alexopoulos, K. Kafentzis, C. Zoumas (2009), “ELMO: An Interoperability Ontology for the Electricity Market”, International Conference on e-Business 2009, Milan, Italy, July 7-10. [BibTex, PDF]
12. P. Alexopoulos, M. Wallace, K. Kafentzis, A. Thomopoulos (2009), “A Fuzzy Knowledge-based Decision Support System for Tender Call Evaluation”, 5th IFIP Conference on Artificial Intelligence Applications & Innovations (AIAI) 2009, Thessaloniki, Greece, April 23-25. [BibTex, PDF]
2008
11. P. Alexopoulos, M. Wallace (2008), “A negotiation strategy for the Temporal Resource Reallocation Problem in Multi-Agent Systems” , International Journal of Internet Protocol Technology (IJIPT), InderScience Publishers, Special Issue on Intelligent Internet-based Systems: Emerging Technologies and Programming Techniques. [BibTex, PDF]
10. P. Alexopoulos, M. Wallace, K. Kafentzis (2008), “A Fuzzy Ontology Framework for Customized Assessment of Semantic Similarity”, 3rd International Workshop on Semantic Media and Adaptation (SMAP 2008), Prague, Czech Republic, December 15-16. [BibTex, PDF]
9. P. Alexopoulos, K. Kafentzis, N. Athanassiadis, X. Benetou, T. Tagaris, C. Jollie, P. Georgolios (2008), “An Adaptive Knowledge-Based Approach for Detecting Fraud across Different e-Government Domains”, J. Filipe and M.S. Obaidat (Eds): ICETE 2007, CCIS 23, pp. 110-121, Springer-Verlag Berlin Heidelberg 2008. [BibTex, PDF]
2007
8. P. Alexopoulos (2007), “Resource Sharing in Multi-Agent Systems through Multi-Stage Negotiation”, 4th IFIP Conference on Artificial Intelligence Applications & Innovations (AIAI) 2007, Athens, Greece, September 19-21. [BibTex, PDF]
7. Dimakopoulos T., K. Kassis, S. Nikoloutsos, P. Alexopoulos, P. Georgolios, K. Kafentzis, X. Benetou, T. Tagaris (2007), “iWebCare: an Integrated Web Services Platform for the Facilitation of Fraud Detection in Health Care e-Government Services”, presented in eGovINTEROP’07 “eGovernment Interoperability Conference 2007”, Paris, France, October 9-12. [BibTex, PDF]
6. P. Alexopoulos, K. Kafentzis, X.Benetou, T. Tagaris, P. Georgolios (2007), “Towards a generic fraud ontology in e-government“, International Conference on e-Business 2007, Barcelona, Spain July 28-31 (included in the conference’s best paper list). [BibTex, PDF]
5. P. Alexopoulos, X.Benetou, T. Tagaris, P. Georgolios, K. Kafentzis (2007), “iWebCare: an Ontological Approach for Fraud Detection in the Healthcare Domain“, International Conference on Information Technologies 2007, Varna, Bulgaria, September 21-23. [BibTex, PDF]
4. Kafentzis Κ., P. Alexopoulos, C. Korakas, V. Goulandris, I. Baseas, P. Georgolios (2007), “Enabling Citizen Participation in Local Governance using ICT“, 3rd National Conference of the Hellenic Society for Systemic Studies 2007, Piraeus, May 26-28. [BibTex, PDF]
3. Kafentzis K., M. Wallace, P. Georgolios, P. Alexopoulos, G. Mentzas (2007), “Semantics Enabled Problem Based Brokering of Organizational Knowledge“, Maglogiannis I., Karpouzis K., Soldatos J., Wallace M. (eds) Emerging Artificial Intelligence Applications in Computer Engineering, IOS Press, 2007. [BibTex, PDF]
2005
2. P. Alexopoulos, “Multi-stage Negotiation“, MSc Thesis, Imperial College London, September 2005, London, United Kingdom.
2004
1. P. Alexopoulos, “A Semantic Web system for retrieval and composition of knowledge web services in an e-business environment“ , Diploma Thesis, National Technical University of Athens, July 2004, Athens, Greece.