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ICS Publications

Conferences (23)

Papers in Proceedings (full-paper reviewed)

  1. Fafalios, P. (2022). Historical Research meets Semantic Interoperability: The Documentation System SYNTHESIS and its Application in Art History ResearchInternational Digital Humanities Conference (DH2022), 2022 (abstract published and presented as a long presentation).
  2. Maliaroudakis, E., Boland, K., Dietze, S., Todorov, K., Tzitzikas, Y., & Fafalios, P. (2021). ClaimLinker: Linking Text to a Knowledge Graph of Fact-checked ClaimsIn Companion Proceedings of the Web Conference 2021 (ACM), Ljubljana, Slovenia, Demo Paper, April 19–23, 2021.
  3. Nikas, Ch., Fafalios, P., & Tzitzikas, Y. (2021). Open Domain Question Answering over Knowledge Graphs using Keyword Search, Answer Type Prediction, SPARQL and Pre-trained Neural ModelsInternational Semantic Web Conference (ISWC) 2021.
  4. Fafalios, P., Konsolaki, K., Charami, L., Petrakis, K., Angelakis, D., Tzitzikas, Y., Bekiari, Ch., & Doerr, M. (2021). Towards Semantic Interoperability in Historical Research: Documenting Research Data and Knowledge with SynthesisInternational Semantic Web Conference (ISWC), 2021.
  5. João, R. S. , Fafalios, P., & Dietze, S. (2020). Better together: an ensemble learner for combining the results of ready-made entity linking systemsIn Proceedings of the 35th Annual ACM Symposium on Applied Computing, 2020, (pp. 851-858).
  6. Kadilierakis, G., Fafalios, P., Papadakos, P., & Tzitzikas, Y. (2020). Keyword search over RDF using Document-Centric Information Retrieval SystemsProceedings of the 17th Extended Semantic Web Conference (ESWC'2020), June 2020, Heraklion, Crete.
  7. Dimitrov, D., Baran, E., Fafalios, P., Yu, R., Zhu, X., Zloch, M., & Dietze, S. (2020). TweetsCOV19--A Knowledge Base of Semantically Annotated Tweets about the COVID-19 PandemicIn Proceedings of the 29th ACM International Conference on Information and Knowledge Management, 19-23 October, 2020.
  8. Nikas, Ch., Fafalios, P., & Tzitzikas, Y. (2020). Two-stage Semantic Answer Type Prediction for QA using BERT and Class-Specificity RewardingSeMantic AnsweR Type prediction (SMART) Challenge, 2020 International Semantic Web Conference (ISWC'2020) Challenge, Nov 2020.
  9. Fafalios, P., & Tzitzikas, Y. (2019). How Many and What Types of SPARQL Queries can be Answered through Zero-Knowledge Link Traversal? In proceedings of the 34th ACM 34th ACM/SIGAPP Symposium on Applied Computing (SAC 2019), Limassol, Cyprus, April 2019, (pp. 2267-2274). (ISBN: 978-1-4503-5933-7).
  10. Fafalios, P., Yannakis, T., & Tzitzikas, Y. (2016). Querying the Web of Data with SPARQL-LDIn proceedings of the 20th International Conference on Theory and Practice of Digital Libraries (TPDL'16), Hannover, Germany, September 5-9, 2016 (pp. 175-187).
  11. Fafalios, P., & Tzitzikas, Y. (2015). Entity-based Stochastic Analysis of Search Results for Query Expansion and Results Re-Ranking In proceedings of the Text Retrieval Conference (TREC'15), Gaithersburg, Maryland, USA, November 2015.
  12. Fafalios, P., Baritakis, M., & Tzitzikas, Y. (2014). Configuring Named Entity Extraction through Real-Time Exploitation of Linked DataProceedings of the 4th International Conference on Web Intelligence, Mining and Semantics (WIMS'14) (Article No. 10), Thessaloniki, Greece, 02-04 June 2014. ACM.
  13. Tzitzikas, Y., Minadakis, N., Marketakis, Y., Fafalios, P., Allocca, C., Mountantonakis, M., & Zidianaki, I. (2014). MatWare: Constructing and Exploiting Domain Specific Warehouses by Aggregating Semantic DataIn proceedings of the 11th Extended Semantic Web Conference (ESWC’14), Anissaras, Crete, Greece, May 2014 (pp. 721-736).
  14. Fafalios, P., & Tzitzikas, Y. (2014). Post-Analysis of Keyword-based Search Results using Entity Mining, Linked Data and Link Analysis at Query Time,IEEE 8th International Conference on Semantic Computing (ICSC'14), Newport Beach, California, USA, 16-18 June 2014 (pp. 36-43). IEEE.
  15. Tzitzikas, Y., Allocca, C., Bekiari, Ch., Marketakis, Y., Fafalios, P., Doerr, M., Minadakis, N., Patkos, Th., & Candela, L. (2013). Integrating Heterogeneous and Distributed Information about Marine Species through a Top Level OntologyEmmanouel Garoufallou, Jane Greenberg (Eds.): Integrating Heterogeneous and Distributed Information about Marine Species through a Top Level Ontology. 7th Research Conference, MTSR. Proceedings, Thessaloniki, Greece, November 19-22, 2013 (vol. 390, pp. 289-301). Springer International Publishing (978-3-319-03437-9).
  16. Fafalios, P., Kitsos, I., & Tzitzikas, Y. (2012). Κλιμακώσιμη και Ευέλικτη Υποστήριξη Στιγμιαίας Επισκοπικής Αναζήτης. 11th Hellenic Data Management Symposium (HDMS’12), June, Chania, Crete.
  17. Fafalios, P., Kitsos, I., Marketakis, Y., Baldassarre, C., Salampasis, M., & Tzitzikas, Y. (2012). Web Searching with Entity Mining at Query TimeMultidisciplinary Information Retrieval. 5th International Retrieval Facility Conference, IRFC 2012, Vienna, Austria, 2012 Proceedings,  July 2-3 (vol. 7536, pp. 73-88). Berlin Heidelberg: Springer (978-3-642-31273-1 ).
  18. Fafalios, P., & Tzitzikas, Y. (2011). Exploiting Available Memory and Disk for Scalable Instant Overview Search. Athman Bouguettaya, Manfred Hauswirth, Ling Liu (Eds.): Web Information System Engineering - WISE 2011 - 12th International Conference, Sydney, Australia, 2011. Proceedings, October 13-14. Springer (978-3-642-24433-9).


  1. Kadilierakis, G., Nikas, Ch., Fafalios, P., Papadakos, P., & Tzitzikas, Y. (2020). Elas4RDF: Multi-perspective Triple-centered Keyword Search over RDF using Elasticsearch(Demo Paper), Proceedings of the 17th Extended Semantic Web Conference (ESWC'2020), June 2020, Heraklion, Crete.
  2. Gasquet, M., Brechtel, D., Zloch, M., Tchechmedjiev, A., Boland, K., Fafalios, P., Dietze, S., & Todorov, K. (2019). Exploring Fact-checked Claims and their Descriptive Statistics . In 18th International Semantic Web Conference (ISWC'19), October 26-30, 2019, Auckland, New Zealand.
  3. Fafalios, P., & Tzitzikas, Y. (2015). SPARQL-LD: A SPARQL Extension for Fetching and Querying Linked Data. In proceedings of 14th International Semantic Web Conference (demo paper), ISWC 2015, Bethlehem, Pennsylvania, USA, 11-15 October. (pdf).
  4. Fafalios, P., & Tzitzikas, Y. (2013). X-ENS: semantic enrichment of web search results at real-timeIn Proceedings of the 36th international ACM SIGIR conference on Research and development in information , Dublin, Ireland, 28th July - 01st August, 2013 (pp. 1089-1090). ACM New York, NY, US.
  5. Fafalios, P., Kitsos, G., & Tzitzikas, Y. (2012). Scalable, Flexible and Generic Instant Overview SearchProceedings of the 21st international conference companion on World Wide Web, (WWW 2012), Lyon, France, April 16-20 (pp. 333-336). New York, NY, USA ©2012 : ACM , Demo, (pdf).

Workshops (7)

Papers in Proceedings (full-paper reviewed)

  1. Todorov, K., Fafalios, P., & Dietze, S. (2021). Beyond Facts: Online Discourse and Knowledge Graphs(Preface Paper). Proceedings of the 1st International Workshop on Knowledge Graphs for Online Discourse Analysis (KnOD 2021), co-located with The Web Conference 2021.
  2. Boland, K., Fafalios, P., Tchechmedjiev, A., & Dietze, S. (2019). Modeling and Contextualizing Claims In Second International Workshop on Contextualized Knowledge Graphs (CKG 2019), collocated with ISWC 2019, October 2019, Auckland, New Zealand.
  3. Yannakis, T., Fafalios, P., & Tzitzikas, Y. (2018). Heuristics-based Query Reordering for Federated Queries in SPARQL 1.1 and SPARQL-LD In 2nd Workshop on Querying the Web of Data (QuWeDa), in conjunction with the 15th Extended Semantic Web Conference (ESWC'18), Heraklion, Crete, Greece, June 3-7, 2018.
  4. Mountantonakis, M., Allocca, C., Fafalios, P., Minadakis, N., Marketakis, Y., Lantzaki, Ch., & Tzitzikas, Y. (2014).  Extending VoID for Expressing the Connectivity Metrics of a Semantic Warehouse In 1st Workshop on Dataset Profiling and Federated Search for Linked Data (PROFILES’2014) - co-located with ESWC’14 , Annissaras, Crete, Greece, May 2014.
  5. Tzitzikas, Y., Minadakis, N., Marketakis, Y., Fafalios, P., Allocca, C., & Mountantonakis, M. (2014). Quantifying the Connectivity of a Semantic WarehouseIn proceedings of the 4th International Workshop on Linked Web Data Management (LWDM’2014) - in conjunction with the 17th International Conference on Extending Database Technology (EDBT’2014),  Athens, Greece, March 2014.
  6. Fafalios, P., Salampasis, M., & Tzitzikas, Y. (2013). Exploratory Patent Search with Faceted Search and Configurable Entity MiningIn Proceedings of the 1st International Workshop on Integrating IR technologies for Professional Search, in conjunction with the 35th European Conference on Information Retrieval (ECIR'13), Moscow, Russia, March 2013.

Papers in Proceedings (abstract reviewed)

  1. Fafalios, P., Doerr, K., Kritsotaki, A., Petrakis, K., Samaritakis, G., Axaridou, A., Bruseker, G., Tzitzikas, Y., & Doerr, M. (2021). Challenges and solutions towards creating a semantic network of historical maritime dataAbstract published and presented at Data for History 2021: Modelling Time, Space, Agents. Berlin (virtual conference): 19 May – 30 June 2021.

Books (3)

Chapters (in book)

  1. Fafalios, P., Samaritakis, G., Petrakis, K., Doerr, K., Kritsotaki, A., Axaridou, A., & Doerr, M. (2022). Building and Exploring a Semantic Network of Maritime History Data Mediterranean Seafarers in Transition (Series: Brill's Studies in Maritime History)Vol. 14
  2. Mountantonakis, M., Minadakis, N., Marketakis, Y., Fafalios, P., & Tzitzikas, Y. (2018). Connectivity, Value and Evolution of a Semantic WarehouseBook chapter in 'Innovations, Developments, and Applications of Semantic Web and Information Systems'.  IGI Global, (ISBN ISBN-13: 978-1522550426, ISBN-10: 1522550429).
  3. Fafalios, P., & Tzitzikas, Y. (2014). Exploratory Professional Search through Semantic Post-Analysis of Search ResultsVol. 8830 (pp. 166 - 192), Springer International Publishing Switzerland.

Periodicals (16)

Journal Articles

  1. Boland, K., Fafalios, P., Tchechmedjiev, A., Dietze, S., & Todorov, K. (2022). Beyond facts – a survey and conceptualisation of claims in online discourse analysisSemantic Web13(5), 793-827.
  2. Tzitzikas, Y., Mountantonakis, M., Fafalios, P., & Marketakis, Y. (2022). CIDOC-CRM and Machine Learning: A Survey and Future ResearchMDPI Heritage5(3), 1612-1636,
  3. Roy, A., Fafalios, P., Ekbal, A., Zhu, X., & Dietze, S. (2021).  Exploiting stance hierarchies for cost-sensitive stance detection of Web documentsJournal of Intelligent Information Systems,  DOI:
  4. Petrakis, K., Samaritakis, G., Kalesios, Th., Domingo, E.G., Delis, A., Tzitzikas, Y., Doerr, M., & Fafalios, P. (2021). Digitizing, Curating and Visualizing Archival Sources of Maritime History: the case of ship logbooks of the nineteenth and twentieth centuriesDrassana (journal of the Barcelona Maritime Museum), (28), 60-87, DOI: 10.51829/Drassana.28.649.
  5. Fafalios, P., Petrakis, K., Samaritakis, G., Doerr, K., Kritsotaki, A., Tzitzikas, Y., & Doerr, M. (2021). FAST CAT: Collaborative Data Entry and Curation for Semantic Interoperability in Digital HumanitiesACM Journal on Computing and Cultural Heritage14(4), 1-20, DOI:
  6. Ntoutsi, E, Fafalios, P., Gadiraju, U., Iosifidis, V., Nejdl, W., Vidal, M-E, Ruggieri, S., & Et, al. (2020). Bias in data‐driven artificial intelligence systems—An introductory surveyWiley Interdisciplinary Reviews: Data Mining and Knowledge Discovery 10, no. 3 (2020): e1356.
  7. Nikas, Ch., Kadilierakis, G., Fafalios, P., & Tzitzikas, Y. (2020). Keyword Search over RDF: Is a Single Perspective Enough?Big Data and Cognitive Computing, 4(3), Special Issue Semantic Web Technology and Recommender Systems, August 2020.
  8. Fafalios, P., & Tzitzikas, Y. (2019). Answering SPARQL Queries on the Web of Data through Zero-Knowledge Link TraversalSIGAPP Applied Computing Review, 19(3), November 2019.
  9. Fafalios, P., & Tzitzikas, Y. (2017). Stochastic Re-Ranking of Biomedical Search Results based on Extracted EntitiesJournal of the Association for Information Science and Technology (JASIST).
  10. Mountantonakis, M., Minadakis, N., Marketakis, Y., Fafalios, P., & Tzitzikas, Y. (2016). Quantifying the Connectivity of a Semantic Warehouse and Understanding its Evolution over Time. International Journal on Semantic Web and Information Systems (IJSWIS), accepted for publication.
  11. Tzitzikas, Y., Allocca, C., Bekiari, Ch., Marketakis, Y., Fafalios, P., Doerr, M., Minadakis, N., Patkos, Th., & Candela, L. (2016). Unifying Heterogeneous and Distributed Information about Marine Species through the Top Level Ontology MarineTLO Program: Electronic library and Information Systems, Special Issue on Application of Metadata and Semantics in Science50(1), 16-40, Emerald Group Publishing Limited (pdf).
  12. Fafalios, P., Baritakis, M., & Tzitzikas, Y. (2015). Exploiting Linked Data for Open and Configurable Named Entity ExtractionInternational Journal on Artificial Intelligence Tools24(02), World Scientific (ISSN: 1793-6349).
  13. Fafalios, P., & Tzitzikas, Y. (2015). Type-ahead Exploratory Search through Typo and Word Order Tolerant AutocompletionJournal of Web Engineering14(1&2), 80-116, Rinton Press (ISSN: 1540-9589).
  14. Fafalios, P., Papadakos, P., & Tzitzikas, Y. (2014). Enriching Textual Search Results at Query Time using Entity Mining, Linked Data and Link AnalysisInternational Journal of Semantic Computing8(4), 515-544, World Scientific Publishing Company (1793-351X (print), 1793-7108 (online)).
  15. Fafalios, P., & Papadakos, P. (2014). Theophrastus: On Demand and Real-Time Automatic Annotation and Exploration of (Web) Documents using Open Linked DataJournal of Web Semantics: Science, Services and Agents on the World Wide Web29, 31-38, Elsevier (1570-8268).


  1. Tzitzikas, Y., Allocca, C., Bekiari, Ch., Marketakis, Y., Fafalios, P., & Minadakis, N. (2014).  Ontology-based Integration of Heterogeneous and Distributed Information of the Marine domainERCIM News 2014 (96), Special Theme: Linked Open Data, January 2014.

Talks (1)

Invited Talks

  1. Doerr, M., & Fafalios, P. (2019). Museums as Trusted Source of Knowledge: A Translation into Feasible Digital Services. In Embracing the virtual: European museums respond to the digital challenge", 21-22 November 2019, Acropolis Museum, Athens, Greece .

Technical & Research Reports (2)

M.S. Theses

  1. Fafalios, P. (2012). Indexes and Algorithms for Scalable and Flexible Instant Overview Search.  (pdf).

Ph.D. Theses

  1. Fafalios, P. (2016). Exploiting linked data in exploratory search. May 2016.
Found: 52 publications