Publications

Books/Monographs

V. Christophides, V. Efthymiou, K. Stefanidis. Entity Resolution in the Web of Data. Synthesis Lectures on The Semantic Web: Theory and Technology, Morgan and Claypool (2015). [print & e-book versions] [institutional access]
A. Quamar, V. Efthymiou, C. Lei, F. Özcan: Natural Language Interfaces to Data. Foundations and Trends in Databases 11(4): 319-414 (2022). [institutional access] [pdf]

Journal articles

T. B. Araújo, V. Efthymiou, V. Christophides, E. Pitoura, K. Stefanidis. TREATS: Fairness-aware Entity Resolution over Streaming Data. Information Systems (to appear)
A. Vassiliades, T. Patkos, V. Efthymiou, A. Bikakis, N. Bassiliades, D. Plexousakis. Extraction of Object-Action and Object-State Associations from Knowledge Graphs. Journal of Web Semantics 81: 100816 (2024) [pdf]
G. Papadakis, V. Efthymiou, E. Thanos, O. Hassanzadeh, P. Christen. An Analysis of One-to-One Matching Algorithms for Entity Resolution. VLDBJ 32(6): 1369-1400 (2023) [pdf] [code]
N. Fanourakis, V. Efthymiou, D. Kotzinos, V. Christophides. Knowledge Graph Embedding Methods for Entity Alignment: An Experimental Review. Data Mining and Knowledge Discovery 37(5): 2070-2137 (2023) [pdf] [code]
C. Lei, A. Quamar, V. Efthymiou, F. Özcan, R. Alotaibi. HERMES: Data Placement and Schema Optimization for Enterprise Knowledge Bases. VLDBJ 32(3): 549-574 (2023) [pdf]
V. Christophides, V. Efthymiou, T. Palpanas, G. Papadakis, K. Stefanidis. An Overview of End-to-End Entity Resolution for Big Data. ACM Computing Surveys 53(6): 127:1-127:42 (2021) [pdf]
J. Sen, C. Lei, A. Quamar, F. Özcan, V. Efthymiou, A. Dalmia, G. Stager, A. Mittal, D. Saha, K. Sankaranarayanan. ATHENA++: Natural Language Querying for Complex Nested SQL Queries. PVLDB 13(11): 2747-2759 (2020) [pdf] [slides] [data]
V. Efthymiou, K. Stefanidis, V. Christophides. Benchmarking Blocking Algorithms for Web Entities. IEEE Transactions on Big Data 6(2): 382-395 (2020) [pdf] [code] [data]
V. Efthymiou, G. Papadakis, G. Papastefanatos, K. Stefanidis, T. Palpanas. Parallel Meta-blocking for Scaling Entity Resolution over Big Heterogeneous Data. Information Systems 65: 137-157 (2017) [pdf] [code & data]
P. Caire, A. Moawad, V. Efthymiou, A. Bikakis, Y. Le Traon. Privacy Challenges in Ambient Intelligence Systems. Journal of Ambient Intelligence and Smart Environments 8(6): 619-644 (2016) [pdf]
V. Efthymiou, M. Koutraki, G. Antoniou. Real-Time Activity Recognition and Assistance in Smart Classrooms. Advances in Distributed Computing and Artificial Intelligence Journal 1(1): 9-22 (2013) [pdf]

Conference and workshop papers

P. Koletsis, P. K. Gemos, C. Chronis, I. Varlamis, V. Efthymiou, G. T. Papadopoulos. Entity Extraction from High-Level Corruption Schemes via Large Language Models. BDA4FCT@IEEE Big Data 2024 [pdf]
T. B. Araújo, V. Efthymiou, K. Stefanidis, R. de Souza Guerra. Fairness-Oriented Entity Resolution Tool for Streaming Data. SBBD 2024 (demo) [pdf] [video (in Portuguese)]
H. Kondylakis, V. Efthymiou, G. Troullinou, E. Ymeralli, D. Plexousakis. Property Graphs at Scale: A Roadmap and Vision for the Future. KG4SDSE@CAiSE 2024 (short) [pdf]
V. Efthymiou, E. Ioannou, M. Karvounis, M. Koubarakis, J. Maciejewski, K. Nikoletos, G. Papadakis, D. Skoutas, Y. Velegrakis, A. Zeakis. Self-configured Entity Resolution with pyJedAI. IEEE BigData 2023 (vision paper) [pdf]
N. Fanourakis, C. Kontousias, V. Efthymiou, V. Christophides, D. Plexousakis. FairER demo: Fairness-Aware and Explainable Entity Resolution. ISWC 2023 (demo) [pdf] [code] [video]
N. Fanourakis, V. Efthymiou, V. Christophides, D. Kotzinos, E. Pitoura, K. Stefanidis. Structural Bias in Knowledge Graphs for the Entity Alignment Task. ESWC 2023 [pdf]
K. Papantoniou, V. Efthymiou, D. Plexousakis. Automating Benchmark Generation for Named Entity Recognition and Entity Linking. ESWC 2023 (poster) [pdf] [code]
E. Chrysostomaki, M. Stratigi, V. Efthymiou, K. Stefanidis, D. Plexousakis. Fair Sequential Group Recommendations in SQUIRREL Movies. TaDA@VLDB 2023 (poster) [pdf] [code]
V. Efthymiou. CosmOntology: Creating an Ontology of the Cosmos. DL4KG@ISWC 2022 (position paper) [pdf] [presentation]
E. Ymeralli, G. Flouris, V. Efthymiou, K. Papantoniou, T. Patkos, G. Petasis, N. Pittaras, G. Roussakis, E. Tzortzakakis. Representing Online Debates in the Context of E-Journalism. SEMAPRO 2022 [pdf] [slides] [presentation] (best paper award)
G. Papadakis, V. Efthymiou, E. Thanos, O. Hassanzadeh. Bipartite Graph Matching Algorithms for Clean-Clean Entity Resolution: An Empirical Evaluation. EDBT 2022 [pdf] [code (within JedAI)] [presentation]
V. Efthymiou, K. Stefanidis, E. Pitoura, V. Christophides. FairER: Entity Resolution with Fairness Constraints. CIKM 2021 (short) [pdf] [code] [slides] [poster]
J. Hao, C. Lei, V. Efthymiou, A. Quamar, F. Özcan, Y. Sun, W. Wang. MEDTO: Medical Data to Ontology Matching using Hybrid Graph Neural Networks. KDD 2021 [pdf]
K. Papantoniou, V. Efthymiou, G. Flouris. EL-NEL: Entity Linking for Greek News Articles. ISWC 2021 (poster) [pdf] [resources] [1′ video] (best poster candidate)
F. Özcan, C. Lei, A. Quamar, V. Efthymiou. Semantic Enrichment of Data for AI Applications. DEEM@SIGMOD 2021 [pdf] [slides]
A. Vassiliades, T. Patkos, V. Efthymiou, A. Bikakis, N. Bassiliades D. Plexousakis. Object-Action Association Extraction from Knowledge Graphs. SEMANTICS 2021 [pdf]
A. Vretinaris, C. Lei, V. Efthymiou, X. Qin, F. Özcan. Medical Entity Disambiguation using Graph Neural Networks. SIGMOD 2021 [pdf] [presentation]
S. Ahmetaj, V. Efthymiou, R. Fagin, P. Kolaitis, C. Lei, F. Özcan, L. Popa. Ontology-Enriched Query Answering on Relational Databases. IAAI 2021 [pdf] [code] [presentation]
R. Alotaibi, C. Lei, A. Quamar, V. Efthymiou, F. Özcan. Property Graph Schema Optimization for Domain-Specific Knowledge Graphs. ICDE 2021 [pdf]
X. Han, L. Hu, J. Sen, Y.B. Dang, B.Y. Gao, V. Isahagian, C. Lei, V. Efthymiou, F. Özcan, A. Quamar, Z. Huang, V. Muthusamy. Bootstrapping Natural Language Querying on Process Automation Data. IEEE SCC 2020 [pdf]
A. Quamar, C. Lei, D. Miller, F. Özcan, J. Kreulen, R. Moore, V. Efthymiou. An Ontology-Based Conversation System for Knowledge Bases. SIGMOD 2020 [pdf]
E. Jiménez-Ruiz, O. Hassanzadeh, V. Efthymiou, J. Chen, K. Srinivas. SemTab 2019: Tabular Data to Knowledge Graph Matching Challenge. ESWC 2020 [pdf] [presentation] [data]
C. Lei, V. Efthymiou, R. Geis, F. Özcan. Expanding Query Answers on Medical Knowledge Bases. EDBT 2020 [pdf] [slides]
V. Efthymiou, G. Papadakis, K. Stefanidis, V. Christophides. MinoanER: Schema-Agnostic, Non-Iterative, Massively Parallel Resolution of Web Entities. EDBT 2019 [pdf] [code]
V. Efthymiou, G. Papadakis, K. Stefanidis, V. Christophides. Simplifying Entity Resolution on Web Data with Schema-agnostic, Non-iterative Matching. ICDE 2018 [pdf]
V. Efthymiou, O. Hassanzadeh, M. Rodriquez-Muro, V. Christophides. Matching Web Tables with Knowledge Base Entities: From Entity Lookups to Entity Embeddings. ISWC 2017 [pdf] [data]
V. Efthymiou, O. Hassanzadeh, M. Sadoghi, M. Rodriquez-Muro. Annotating Web tables through ontology matching. OM@ISWC 2016 [pdf]
V. Efthymiou, P. Zervoudakis, K. Stefanidis, D. Plexousakis. Group Recommendations in MapReduce. IC-ININFO 2016 [pdf] [code]
V. Efthymiou, K. Stefanidis, V. Christophides. Minoan ER: Progressive Entity Resolution in the Web of Data. EDBT 2016 (poster) [pdf]
V. Efthymiou, K. Stefanidis, V. Christophides. Big Data Entity Resolution: From Highly to Somehow Similar Entity Descriptions in the Web. IEEE BigData 2015 [pdf] [code]
V. Efthymiou, G. Papadakis, G. Papastefanatos, K. Stefanidis, T. Palpanas. Parallel Meta-blocking: Realizing Scalable Entity Resolution over Large, Heterogeneous Data. IEEE BigData 2015 [pdf] [code & data]
V. Efthymiou, K. Stefanidis, E. Ntoutsi. Top-k Computations in MapReduce: A Case Study on Recommendations. IEEE BigData 2015 (poster) [pdf] [code & data (generator)]
V. Efthymiou, P. Caire, A. Bikakis. Modeling and Evaluating Cooperation in Multi-Context Systems using Conviviality. BNAIC 2012 [pdf]
P. Caire, A. Bikakis, V. Efthymiou. Conviviality by Design. AISB/IACAP World Congress 2012. [pdf]
A. Moawad, V. Efthymiou, P. Caire, G. Nain, Y. Le Traon. Introducing Conviviality as a New Paradigm for Interactions among IT Objects. AI@IE 2012 [pdf]
A. Bikakis, V. Efthymiou, P. Caire, Y. Le Traon. Introducing Conviviality as a property of Multi-Context Systems. ARCOE 2012 [pdf]
M. Koutraki, V. Efthymiou, G. Antoniou. S-CRETA: Smart Classroom Real-Time Assistance. ISAmI 2012 [pdf]

Tutorials

F. Özcan, A. Quamar, J. Sen, C. Lei, V. Efthymiou. State of the Art and Open Challenges in Natural Language Interfaces to Data. SIGMOD 2020 [short description] [slides]
K. Stefanidis, V. Christophides, V. Efthymiou. Web-scale Blocking, Iterative and Progressive Entity Resolution. ICDE 2017 [short description] [slides]
V. Christophides, O. Corcho, V. Efthymiou, V. Ermolayev, A. Harth, L.D. Ibáñez, N. Keberle, K. Stefanidis, I. Tachmazidis. Improving Quality and Scalability in Semantic Data Management. ESWC 2016 [short description & slides]
K. Stefanidis, V. Efthymiou, M. Herschel, V. Christophides. Entity resolution in the Web of Data, WWW 2014 [short description] [slides]
K. Stefanidis, V. Efthymiou, M. Herschel, V. Christophides. Entity resolution in the Web of Data, CIKM 2013 [short description] [slides]

Patents

A. Quamar, F. Özcan, C. Lei, V. Efthymiou, V. Meduri. Guided Exploration for Conversational Business Intelligence. US 17/188405, 2021 [pdf]
C. Lei, J. Hao, V. Efthymiou, F. Özcan, A. Quamar. Hybrid Graph Neural Network. US 17/161152, US 17/161093, 2021 [pdf]
C. Lei, A. Vretinaris, V. Efthymiou, F. Özcan. Entity Disambiguation Using Graph Neural Networks. US 17/130107, 2020 [pdf]
C. Lei, A. Quamar, V. Efthymiou, F. Özcan, R. Alotaibi. Reducing Response Time for Queries Directed to Domain-Specific Knowledge Graph Using Property Graph Schema Optimization. US 16/800392, 2020 [pdf]