Publications

Books

V. Christophides, V. Efthymiou, and K. Stefanidis. Entity Resolution in the Web of Data. Synthesis Lectures on The Semantic Web: Theory and Technology, Morgan and Claypool, August 2015.

Journals

E. Lenzi and K. Stefanidis. ADAPT: Fairness & Diversity for Sequential Group Recommendations. Information Systems, 2025. [Link]
N. Ranasinghe, W. M. Mohammed, K. Stefanidis and J. L. Martinez Lastra. Large Language Models in Human-Robot Collaboration with Cognitive Validation Against Context-induced Hallucinations. IEEE Access, 2025. [Link]
T. Brasileiro Araújo, V. Efthymiou, V. Christophides, E. Pitoura and K. Stefanidis. TREATS: Fairness-aware entity resolution over streaming data. Information Systems, 2025. [Link]
P. Puustinen, M. Stratigi and K. Stefanidis. STracker: A Framework for Identifying Sentiment Changes in Customer Feedbacks. Information Systems, 2025. [Link]
E. Skenderi, J. Huhtamäki, S-M. Laaksonen and K. Stefanidis. INCEPT: A Framework for Duplicate Posts Classification with Combined Text Representations. ACM Transactions on the Web, Vol. 18, No. 3, 2024. [Link]
E. Zimina, K. Järvelin, J. Peltonen, A. Ranta, K. Stefanidis and J. Nummenmaa. Linguistic Summarisation of Multiple Entities in RDF Graphs. Applied Computing and Intelligence, 2024. [Local copy]
G. Troullinou, G. Agathangelos, H. Kondylakis, K. Stefanidis and D. Plexousakis. DIAERESIS: RDF Data Partitioning and Query Processing on SPARK. Semantic Web – Interoperability, Usability, Applicability an IOS Press Journal, 2023.
K. Zioutos, H. Kondylakis and K. Stefanidis. Healthy Personalized Recipe Recommendations for Weekly Meal Planning. Computers , vol. 13, 2024. [Link]
M. Stratigi, E. Pitoura and K. Stefanidis. SQUIRREL: A Framework for Sequential Group Recommendations through Reinforcement Learning. Information Systems, 2023. [Local copy]
T. Brasileiro Araújo, K. Stefanidis, C. Eduardo Santos Pires, J. Nummenmaa and T. Pereira da Nóbrega. Incremental Entity Blocking over Heterogeneous Streaming Data. Information, vol. 13, no. 12, 2022. [Local copy]
E. Pitoura, K. Stefanidis and G. Koutrika. Fairness in Rankings and Recommendations: An Overview. The VLDB Journal, 2021, Springer. [Local copy]
R. Borges and K. Stefanidis. Feature-Blind Fairness in Collaborative Filtering Recommender Systems. Knowledge and Information Systems Journal (KAIS), 2021, Springer. [Local copy]
M. Stratigi, E. Pitoura, J. Nummenmaa and K. Stefanidis. Sequential Group Recommendations based on Satisfaction and Disagreement Scores. Journal of Intelligent Information Systems, 2021, Springer. [Local copy]
E. Skenderi, J. Huhtamäki and K. Stefanidis. Multi-Keyword Classification: A Case Study in Finnish Social Sciences Data Archive. Information, vol. 12, no. 12, 2021. [Link]
P. Puustinen, K. Stefanidis, J. Kekalainen and M. Junkkari. Reinforcement Learning Page Prediction for Hierarchically Ordered Municipal Websites. Information, vol. 12, no. 6, 2021. [Link]
Xiaozhou Li, Zheying Zhang and Kostas Stefanidis. A Data-Driven Approach for Video Game Playability Analysis Based on Players’ Reviews. Information, vol. 12, no. 3, 2021. [Local copy]
V. Christophides, V. Efthymiou, T. Palpanas, G. Papadakis and K. Stefanidis. An Overview of End-to-End Entity Resolution for Big Data. ACM Computing Surveys December, 2020. [Local copy]
V. Efthymiou, K. Stefanidis and V. Christophides. Benchmarking Blocking Algorithms for Web Entities. IEEE Transactions on Big Data 6(2): 382-395 (2020). [Local copy]
M. Stratigi, H. Kondylakis and K. Stefanidis. Multidimensional Group Recommendations in the Health Domain. Algorithms, vol. 13, no. 3, 2020. [Local copy]
Xiaozhou Li, Boyang Zhang, Zheying Zhang and Kostas Stefanidis. A Sentiment-Statistical Approach for Identifying Problematic Mobile App Updates Based on User Reviews. Information, vol. 11, no. 3, 2020. [Local copy]
S. Kumpulainen, H. Keskustalo, B. Zhang and K. Stefanidis. Historical Reasoning in Authentic Research Tasks: Mapping Cognitive and Document Spaces. Journal of the Association for Information Science and Technology (JASIST), vol. 71, no. 2, 2020. https://doi.org/10.1002/asi.24216
P. Fafalios, V. Iosifidis, K. Stefanidis and E. Ntoutsi. Tracking the History and Evolution of Entities: Entity-centric Temporal Analysis of Large Social Media Archives. Springer International Journal on Digital Libraries. 21, 5–17, 2020. [Local copy]
V. Efthymiou, G. Papadakis, G. Papastefanatos, K. Stefanidis and T. Palpanas. Parallel Meta-blocking for Scaling Entity Resolution over Big Heterogeneous Data. Information Systems (IS), vol. 65, 2017. [Local copy]
K. Stefanidis, E. Ntoutsi, M. Petropoulos, K. Norvag, and H-P. Kriegel. A Framework for Modeling, Computing and Presenting Time-aware Recommendations. Transactions on Large-Scale Data- and Knowledge-Centered Systems (TLDKS Journal), Lecture Notes in Computer Science, vol. 8820, pp. 146-172, 2013. Springer. [Local copy]
K. Stefanidis, G. Koutrika and E. Pitoura. A Survey on Representation, Composition and Application of Preferences in Database Systems. ACM Transactions on Database Systems (TODS), vol. 36, no. 3, 2011. [Local copy]
K. Stefanidis, E. Pitoura and P. Vassiliadis. Managing Contextual Preferences. Information Systems, vol. 36, no. 8, pp. 1158-1180, 2011. [Local copy]
E. Pitoura, K. Stefanidis and P. Vassiliadis. Contextual Database Preferences. IEEE Data Engineering Bulletin, vol. 34, no. 2, pp. 19-25, 2011. IEEE Computer Society. [Local copy]
K. Stefanidis, E. Pitoura and P. Vassiliadis. A Context-Aware Preference Database System. International Journal of Pervasive Computing and Communications, vol. 3, no. 4, pp. 439-460, 2007. Emerald Group Publishing Limited. [Local copy]

Book Chapters

K. Stefanidis, E. Ntoutsi, H. Kondylakis and Y. Velegrakis. Social-based Collaborative Filtering. In Encyclopedia of Social Network Analysis and Mining, Springer, 2017. [Local copy]
G. Koloniari, P. Lionakis and K. Stefanidis. Social Search and Querying. In Encyclopedia of Social Network Analysis and Mining, Springer, 2017. [Link]
G. Koutrika, E. Pitoura and K. Stefanidis. Preference-based Query Personalization. In B. Catania, L. Jain (eds.), Advanced Query Processing, Springer. April 2012.

Conferences and Workshops

M. Stratigi, N. Bikakis and K. Stefanidis. Counterfactual Explanations for Group Recommendations. Proceedings of DOLAP 2025. [Local copy]
N. Ebrahimi, Z. Zhang and K. Stefanidis. A Diversity-aware Approach to Bundle Recommendations. Proceedings of DOLAP 2025. [Local copy]
A. Ebrahimi, Z. Zhang and K. Stefanidis. Dynamic User Preferences Optimization in Time-Aware Recommendations. Proceedings of DARLI-AP 2025. [Local copy]

H-M. Attolou, K. Tzompanaki, K. Stefanidis and D. Kotzinos. Why-Not Explainable Graph Recommender. Proceedings of ICDE 2024. [Local copy]
G. Troullinou, K. Stefanidis, D. Plexousakis and H. Kondylakis. DIAERESIS: Knowledge Graph Partitioning for Efficient Query Answering. Proceedings of The WEB Conference 2024. [Local copy]
R. Shafiloo and K. Stefanidis. Examining the Impact of Multi-Objective Recommender Systems on Providers Bias. Proceedings of DARLI-AP 2024. [Local copy]
Md M. Hasan, S. Pervez, M. Stratigi and K. Stefanidis. SQUIRREL 2.0: Fairness & Explanations for Sequential Group Recommendations. Proceedings of DOLAP 2024. [Local copy]
H-M. Attolou, K. Tzompanaki, K. Stefanidis and D. Kotzinos. EMiGRe: Unveiling why your recommendations are not what you expect. Proceedings of ICWE 2024. [Local copy]
Tiago Brasileiro Araujo, Vasilis Efthymiou, Kostas Stefanidis, Rafael de Souza Guerra. Fairness-Oriented Entity Resolution Tool for Streaming Data. Proceedings of SBBD 2024. [Link]
Z. Zhang and K Stefanidis. Data-driven Analysis for Monitoring Software Evolution. Proceedings of ADBIS 2024. [Local copy]
H. Zulfiqar, E. Lenzi and K Stefanidis. Evaluating Diversity in Sequential Group Recommendations. Proceedings of PeRS 2024. [Local copy]
M. Shahzaib Ali and K Stefanidis. Fairness in Group Recommender Systems Using Variational Autoencoders. Proceedings of IDEAS 2024. [Local copy]
Best Paper Award
U. Ahmed and K Stefanidis. Multi-Attribute Bias Mitigation in Recommender ‭Systems‬. Proceedings of IDEAS 2024. [Local copy]

N. Fanourakis, V. Efthymiou, V. Christophides, D. Kotzinos, E. Pitoura and K. Stefanidis. Structural Bias in Knowledge Graphs for the Entity Alignment Task. Proceedings of ESWC 2023. [Local copy]
D. Sacharidis, G. Giannopoulos, G. Papastefanatos and K. Stefanidis. Auditing for Spatial Fairness. Proceedings of EDBT/ICDT, 2023. [Local copy]
K. Katsarou, N. Douss and K. Stefanidis. REFORMIST: Hierarchical Attention Networks for Multi-Domain Sentiment Classification with Active Learning. Proceedings of ACM SAC, 2023. [Local copy]
K. Katsarou, R.M. Jeney and K. Stefanidis. MUTUAL: Multi-Domain Sentiment Classification via Uncertainty Sampling. Proceedings of ACM SAC, 2023. [Local copy]
R. Borges, O. Sahlgren, S. Koivunen, K. Stefanidis, T. Olsson and A. Laitinen. Multi-Objective Fairness in Team Assembly. Proceedings of ADBIS, 2023. [Local copy]
E. Skenderi, S-M. Laaksonen, J. Huhtamäki and K. Stefanidis. Assessing Text Representation Methods on Tag Prediction Task for StackOverflow. Proceedings of HICSS-56, 2023. [Local copy]
E. Chrysostomaki, M. Stratigi, V. Efthymiou, K. Stefanidis and D. Plexousakis. Fair Sequential Group Recommendations in SQUIRREL Movies. Proceedings of TaDA at VLDB 2023. [Local copy]
K. Zioutos, H. Kondylakis and K. Stefanidis. SHARE: A Framework for Personalized and Healthy Recipe Recommendations. Proceedings of EDBT/ICDT Workshops 2023. [Link]
W. Ullah, Z. Zhang and K. Stefanidis. Sentiment Analysis of Mobile Apps Using BERT. Proceedings of IEA/AIE 2023. [Local copy]
A. Yamac, M. Yamac and K. Stefanidis. On Supporting Game-based Learning via Recommendations. Proceedings of ECGBL 2023. [Local copy]

R. Borges and K. Stefanidis. F2VAE: A Framework for Mitigating User Unfairness in Recommendation Systems. Proceedings of ACM SAC 2022. [Local copy]

V. Efthymiou, K. Stefanidis, E. Pitoura and V. Christophides. FairER: Entity Resolution With Fairness Constraints. Proceedings of ACM CIKM 2021. [Local copy]
R. Borges and K. Stefanidis. On Mitigating Popularity Bias in Recommendations via Variational Autoencoders. Proceedings of ACM SAC 2021. [Local copy]
I. Heiska and K. Stefanidis. Multi-Round Recommendations for Stable Groups. Proceedings of PIC 2021. [Local copy]
Best Paper Award
G. Giannopoulos, G. Papastefanatos, D. Sacharidis and K. Stefanidis. Interactivity, Fairness and Explanations in Recommendations. Proceedings of HAAPIE 2021. [Local copy]
G. Vassiliou, G. Troullinou, N. Papadakis, K. Stefanidis, E. Pitoura and H. Kondylakis. Coverage-Based Summaries for RDF KBs. Proceedings of ESWC 2021. [Local copy]
E. Pitoura, K. Stefanidis and G. Koutrika. Fairness in Rankings and Recommenders: Models, Methods and Research Directions. Proceedings of ICDE 2021. [Local copy]
E. Pitoura, K. Stefanidis and G. Koutrika. Fairness-aware Methods in Rankings and Recommenders. Proceedings of MDM 2021. [Local copy]
K. Stefanidis. FRecs - Fairness, Diversity and Transparency in Health Recommenders: Challenges & Objectives. Proceedings of SWH 2021. [Local copy]

T. Brasileiro Araújo, K. Stefanidis, C. Eduardo Santos Pires, J. Nummenmaa and T. Pereira da Nóbrega. Schema-agnostic Blocking for Streaming Data. Proceedings of ACM SAC 2020. [Local copy]
M. Stratigi, J. Nummenmaa, E. Pitoura and K. Stefanidis. Fair Sequential Group Recommendations. Proceedings of ACM SAC 2020. [Local copy]
M. Stratigi, K. Tzompanaki and K. Stefanidis. Why-Not Questions & Explanations for Collaborative Filtering. Proceedings of WISE 2020. [Local copy]
R. Borges and K. Stefanidis. On Measuring Popularity Bias in Collaborative Filtering Data. Proceedings of BigVis 2020. [Local copy]
E. Pitoura, G. Koutrika and K. Stefanidis. Fairness in Rankings and Recommenders. Proceedings of EDBT 2020. [Link]

V. Efthymiou, G. Papadakis, K. Stefanidis and V. Christophides. MinoanER: Schema-Agnostic, Non-Iterative, Massively Parallel Resolution of Web Entities. Proceedings of EDBT 2019. [Local copy]
T. Brasileiro Araújo, C. Eduardo Santos Pires, D. Mestre, T. Nobrega, D. Cassimiro do Nascimento Filho and K. Stefanidis. A Noise Tolerant and Schema-agnostic Blocking Technique for Entity Resolution. Proceedings of ACM SAC 2019. [Local copy]
R. Borges and K. Stefanidis. Enhancing Long Term Fairness in Recommendations with Variational Autoencoders. Proceedings of MEDES 2019. [Local copy]
M. Stratigi, X. Li, K. Stefanidis and Z. Zhang. Ratings vs. Reviews in Recommender Systems: A Case Study on the Amazon Movies Dataset. Proceedings of ADBIS 2019. [Local copy]
L. Machado and K. Stefanidis. Fair Team Recommendations for Multidisciplinary Projects. Proceedings of Web Intelligence 2019. [Local copy]
T. Brasileiro Araújo, K. Stefanidis, C. Eduardo Santos Pires, J. Nummenmaa and T. Nobrega. Incremental Blocking for Entity Resolution over Web Streaming Data. Proceedings of Web Intelligence 2019. [Local copy]
H. Kondylakis and K. Stefanidis. Towards Education and Emotion Based Semantic Group Recommendations for Health. Proceedings of SWH 2019. [Local copy]
J. Gong, Y. Ye and K. Stefanidis. A Hybrid Recommender System for Steam Games. Proceedings of ISIP 2019. [Local copy]
R. Hannula, A. Nikkila and K. Stefanidis. GameRecs: Video Games Group Recommendations. Proceedings of QAUCA 2019. [Local copy]
J. Klancar, K. Paulussen and K. Stefanidis. FIFARecs: A Recommender System for FIFA18. Proceedings of QAUCA 2019. [Local copy]

G. Troullinou, H. Kondylakis, K. Stefanidis and D. Plexousakis. Exploring RDF/S KBs Using Summaries. Proceedings of ISWC 2018. [Local copy]
V. Efthymiou, G. Papadakis, K. Stefanidis and V. Christophides. Simplifying Entity Resolution on Web Data with Schema-agnostic, Non-iterative Matching. Proceedings of ICDE 2018. [Local copy]
E. Zimina, J. Nummenmaa, K. Jarvelin, J. Peltonen and K. Stefanidis. MuG-QA: Multilingual Grammatical Question Answering for RDF Data. Proceedings of PIC 2018. [Local copy]
Best Paper Award
M. Stratigi, H. Kondylakis and K. Stefanidis. FairGRecs: Fair Group Recommendations by Exploiting Personal Health Information. Proceedings of DEXA 2018. [Local copy]
X. Li, Z. Zhang and K. Stefanidis. Mobile App Evolution Analysis based on User Reviews. Proceedings of SOMET 2018. [Local copy]
X. Li, Z. Zhang and K. Stefanidis. Sentiment-aware Analysis of Mobile Apps User Reviews Regarding Particular Updates. Proceedings of ICSEA 2018. [Local copy]
M. Koskela, I. Simola and K. Stefanidis. Open Source Software Recommendations Using Github. Proceedings of TPDL 2018. [Local copy]
G. Agathangelos, G. Troullinou, H. Kondylakis, K. Stefanidis and D. Plexousakis. RDF Query Answering Using Apache Spark: Review and Assessment. Proceedings of ICDE Workshops 2018. [Local copy]
G. Agathangelos, G. Troullinou, H. Kondylakis, K. Stefanidis and D. Plexousakis. Incremental Data Partitioning of RDF Data in SPARK. Proceedings of ESWC 2018. [Local copy]
E. Zimina, J. Nummenmaa, K. Jarvelin, J. Peltonen, K. Stefanidis and Heikki Hyyro. GQA: Grammatical Question Answering for RDF Data. SQA 2018 CHALLENGE – ESWC 2018. [Local copy]
T. Araujo, C. Pires and K. Stefanidis. Noisy-aware Blocking over Heterogeneous Data. Proceedings of ISWC 2018. [Local copy]
G. Troullinou, H. Kondylakis, K. Stefanidis and D. Plexousakis. RDFDigest+: A Summary-driven System for KBs Exploration. Proceedings of ISWC 2018. (Demo Paper) [Local copy]

P. Fafalios, V. Iosifidis, K. Stefanidis and E. Ntoutsi. Multi-aspect Entity-centric Analysis of Big Social Media Archives. Proceedings of TPDL 2017. [Local copy]
V. Papakonstantinou, G. Flouris, I. Fundulaki, K. Stefanidis and G. Roussakis. SPBv: Benchmarking Linked Data Archiving Systems. Proceedings of the Workshop on Benchmarking Linked Data (BLINK) @ ISWC 2017. [Local copy]
M. Kyriakidi, K. Stefanidis and Y. Ioannidis. On Achieving Diversity in Recommender Systems. Proceedings of ExploreDB @ SIGMOD 2017. [Local copy]
K. Stefanidis, V. Christophides and V. Efthymiou. Web-scale Blocking, Iterative and Progressive Entity Resolution. Proceedings of ICDE 2017. [Local copy]
M. Stratigi, H. Kondylakis and K. Stefanidis. Fairness in Group Recommendations in the Health Domain. Proceedings of HDMM @ ICDE 2017. [Local copy]
K. Stefanidis, H. Kondylakis and G. Troullinou. On Recommending Evolution Measures: A Human-aware Approach. Proceedings of DESWeb @ ICDE 2017. [Local copy]

V. Efthymiou, P. Zervoudakis, K. Stefanidis and D. Plexousakis. Group Recommendations in MapReduce. Proceedings of the IC-ININFO 2016. [Local copy]
V. Papakonstantinou, G. Flouris, I. Fundulaki, K. Stefanidis and G. Roussakis. Versioning for Linked Data: Archiving Systems and Benchmarks. Proceedings of the Workshop on Benchmarking Linked Data (BLINK) @ ISWC 2016. [Local copy]
E. Ntoutsi and K. Stefanidis. Recommendations beyond the Ratings Matrix. Proceedings of the Data-Driven Innovation Workshop @ Web Science 2016. [Local copy]
V. Efthymiou, K. Stefanidis and V. Christophides. Minoan ER: Progressive Entity Resolution in the Web of Data. Proceedings of EDBT 2016. [Local copy]
K. Stefanidis and E. Ntoutsi. Cluster-based Contextual Recommendations. Proceedings of EDBT 2016. [Local copy]
G. Troullinou, Y. Roussakis, H. Kondylakis, K. Stefanidis and G. Flouris. Understanding Ontology Evolution Beyond Deltas. Proceedings of EDBT/ICDT Workshops 2016. [Local copy]

V. Efthymiou, K. Stefanidis and V. Christophides. Big Data Entity Resolution: From Highly to Somehow Similar Entity Descriptions in the Web. Proceedings of IEEE BigData 2015. [Local copy]
V. Efthymiou, G. Papadakis, G. Papastefanatos, K. Stefanidis and T. Palpanas. Parallel Meta-blocking: Realizing Scalable Entity Resolution over Large, Heterogeneous Data. Proceedings of IEEE BigData 2015. [Local copy]
V. Efthymiou, K. Stefanidis and E. Ntoutsi. Top-k Computations in MapReduce: A Case Study on Recommendations. Proceedings of IEEE BigData 2015. [Local copy]
Y. Roussakis, I. Chrysakis, K. Stefanidis, G. Flouris and Y. Stavrakas. A Flexible Framework for Understanding the Dynamics of Evolving RDF Datasets. Proceedings of ISWC 2015. [Local copy]
Best Student Paper Award
Y. Roussakis, I. Chrysakis, K. Stefanidis and G. Flouris. D2V: A Tool for Defining, Detecting and Visualizing Changes on the Data Web. Proceedings of ISWC 2015. (Demo Paper) [Local copy]
K. Stefanidis and I. Fundulaki. Keyword Search on RDF Graphs: It is more than just searching for keywords. Proceedings of ESWC 2015. [Local copy]

I. Ntoutsi, K. Stefanidis, K. Rausch and H. P. Kriegel. "Strength Lies in Differences" - Diversifying Friends for Recommendations through Subspace Clustering. Proceedings of CIKM 2014. [Local copy]
G. Koutrika, L. V. S. Lakshmanan, M. Riedewald and K. Stefanidis. Exploratory Search in Databases and the Web. Proceedings of EDBT/ICDT Workshops 2014.
N. Louloudakis, V. Theodosiadis, H. Kondylakis and K. Stefanidis. NaviSoc: A Socially Enhanced Real-time Navigator. Proceedings of Basna 2014, in conjunction with ICDM 2014. [Local copy]
K. Stefanidis and G. Koloniari. Enabling Social Search in Time through Graphs. Proceedings of Web-KR 2014, in conjunction with CIKM 2014. [Local copy]
K. Stefanidis, V. Efthymiou, M. Herschel and V. Christophides. Entity Resolution in the Web of Data (tutorial). Proceedings of WWW 2014. [Short description]
K. Stefanidis, I. Chrysakis and Giorgos Flouris. On Designing Archiving Policies for Evolving RDF Datasets on the Web. Proceedings of ER 2014. [Local copy]
P. Lionakis, K. Stefanidis and G. Koloniari. SQTime: Time-enhanced Social Search Querying. Proceedings of ER 2014. (Demo Paper) [Local copy]
K. Rausch, I. Ntoutsi, K. Stefanidis and H. P. Kriegel. Exploring Subspace Clustering for Recommendations. Proceedings of SSDBM 2014. [Local copy]
A. Zamansky, O. Arieli and K. Stefanidis. Context-aware Distance Semantics for Inconsistent Database Systems. Proceedings of IPMU 2014. [Local copy]

K. Stefanidis, V. Efthymiou, M. Herschel and V. Christophides. Entity Resolution in the Web of Data (tutorial). Proceedings of CIKM 2013. [Short description]
O. Gkorgkas, K. Stefanidis and K. Norvag. A Framework for Grouping and Summarizing Keyword Search Results. Proceedings of ADBIS 2013. [Local copy]
G. Koloniari and K. Stefanidis. Social Search Queries in Time. Proceedings of PersDB 2013, in conjunction with VLDB 2013. [Local copy]

I. Ntoutsi, K. Stefanidis, K. Norvag and H. P. Kriegel. Fast Group Recommendations by Applying User Clustering. Proceedings of ER 2012. [Local copy]
K. Stefanidis, N. Shabib, K. Norvag and J. Krogstie. Contextual Recommendations for Groups. Proceedings of NoCoDA 2012, in conjunction with ER 2012. [Local copy]
K. Stefanidis and E. Pitoura. Finding the Right Set of Users: Generalized Constraints for Group Recommendations. Proceedings of PersDB 2012, in conjunction with VLDB 2012. [Local copy]
K. Stefanidis, I. Ntoutsi, K. Norvag and H. P. Kriegel. A Framework for Time-aware Recommendations. Proceedings of DEXA 2012. [Local copy]
I. Ntoutsi, K. Stefanidis, K. Norvag and H. P. Kriegel. gRecs: A Group Recommendation System based on User Clustering. Proceedings of DASFAA 2012. (Demo Paper) [Local copy]

Y. Tao, S. Papadopoulos, C. Sheng and K. Stefanidis. Nearest Keyword Search in XML Documents. Proceedings of SIGMOD 2011. [Local copy]

K. Stefanidis, M. Drosou and E. Pitoura. PerK: Personalized Keyword Search in Relational Databases. Proceedings of EDBT 2010. [Local copy]
G. Koutrika, E. Pitoura and K. Stefanidis. Representation, Composition and Application of Preferences in Databases (tutorial). Proceedings of ICDE 2010.
D. Souravlias, M. Drosou, K. Stefanidis and E. Pitoura. On Novelty in Publish/Subscribe Delivery. Proceedings of DBRank 2010, in conjunction with ICDE 2010. [Local copy]
E. Koletsou, K. Stefanidis, M. Drosou and E. Pitoura. YMAL: A Recommendation System for Relational Databases. Proceedings of HDMS 2010. (Demo Paper)

M. Drosou, K. Stefanidis and E. Pitoura. Preference-Aware Publish/Subscribe Delivery with Diversity. Proceedings of DEBS 2009. [Local copy]
K. Stefanidis, M. Drosou and E. Pitoura. "You May Also Like" Results in Relational Databases. Proceedings of PersDB 2009, in conjunction with VLDB 2009. [Local copy]

K. Stefanidis and E. Pitoura. Fast Contextual Preference Scoring of Database Tuples. Proceedings of EDBT 2008. [Local copy]
M. Drosou, E. Pitoura and K. Stefanidis. Preferential Publish/Subscribe. Proceedings of PersDB 2008, in conjunction with VLDB 2008. [Local copy]

K. Stefanidis, E. Pitoura and P. Vassiliadis. Adding Context to Preferences. Proceedings of ICDE 2007. [Local copy]
K. Stefanidis and E. Pitoura. Approximate Contextual Preference Scoring in Digital Libraries. Proceedings of PersDL 2007, in conjunction with UM 2007. [Local copy]
K. Stefanidis, E. Pitoura and P. Vassiliadis. On Relaxing Contextual Preference Queries. Proceedings of MCISME 2007, in conjunction with MDM 2007. [Local copy]

K. Stefanidis, E. Pitoura and P. Vassiliadis. Modeling and Storing Context-Aware Preferences. Proceedings of ADBIS 2006. [Local copy]

K. Stefanidis, E. Pitoura and P. Vassiliadis. On Supporting Context-Aware Preferences in Relational Database Systems. Proceedings of MCMP 2005, in conjunction with MDM 2005. [Local copy]

Invited Talks

Kostas Stefanidis. On Exploring Knowledge Bases Using Summaries. Methods Festival 2019, 27 – 29 August 2019, Tampere University, Finland.

Kostas Stefanidis, reporting on joint work with Vassilis Christophides and Vasilis Efthymiou. Blocking for Entity Resolution in the Web of Data: Challenges and Algorithms. 6th International Conference on Integrated Information (IC-ININFO 2016), September 19-22, 2016, Athens, Greece. [Local copy]

Tutorials

Data-driven Analysis for Monitoring Software Evolution. At ADBIS 2024, with Z. Zhang. [Local copy]

Fairness in Rankings and Recommenders: Models, Methods and Research Directions. At ICDE 2021, with E. Pitoura and G. Koutrika. [Local copy]

Fairness-aware Methods in Rankings and Recommenders. At MDM 2021, with E. Pitoura and G. Koutrika. [Local copy]

Fairness in Rankings and Recommenders. At EDBT 2020, with E. Pitoura and G. Koutrika. [Link]

Web-scale Blocking, Iterative and Progressive Entity Resolution. At the 2017 IEEE International Conference on Data Engineering (ICDE 2017), April 19-22, San Diego, California, USA (with Vassilis Christophides and Vasilis Efthymiou). [Description]

Improving Quality and Scalability in Semantic Data Management. In the 13th Extended Semantic Web Conference (ESWC 2016), May 29 - June 2, Heraklion, Greece (with V. Christophides, O. Corcho, V. Efthymiou, V. Ermolayev, A. Harth, L.D. Ibanez, N. Keberle, I. Tachmazidis). [Description]

Seminar on Recommender Systems. In the 3rd MUMIA Training School on Information Retrieval and Interactive Information Access (MUMIA 2014), July 21 - 25, Heraklion, Crete. [Local copy]

Entity Resolution in the Web of Data. In the 23rd International World Wide Web Conference (WWW 2014), April 7 - 11, 2014, Seoul, Korea (with Vasilis Efthymiou, Melanie Herschel and Vassilis Christophides). [short description, Part I, Part II]

Entity Resolution in the Web of Data. In the 22nd International Conference on Information and Knowledge Management (CIKM 2013), October 27 - November 1, 2013, Burlingame, California, USA (with Vasilis Efthymiou, Melanie Herschel and Vassilis Christophides). [short description, Part I, Part II]

Representation, Composition and Application of Preferences in Databases. In the 26th International Conference on Data Engineering (ICDE 2010), March 1-6, 2010, Long Beach, California, USA (with Evaggelia Pitoura and Georgia Koutrika). [Local copy]

National Conferences

Y. Roussakis, I. Chrysakis, K. Stefanidis, G. Flouris and Y. Stavrakas. A Flexible Framework for Understanding the Dynamics of Evolving RDF Datasets. Proceedings of HDMS 2016.
K. Rausch, I. Ntoutsi, K. Stefanidis and H. P. Kriegel. Exploring Subspace Clustering for Recommendations. Proceedings of HDMS 2014.
I. Ntoutsi, K. Stefanidis, K. Norvag and H. P. Kriegel. gRecs: A Collaborative Filtering Framework for Group Recommendations. Proceedings of GfKl 2012. Abstract
K. Stefanidis, M. Drosou and E. Pitoura. PerK: Personalized Keyword Search in Relational Databases. Proceedings of HDMS 2010.
M. Drosou, K. Stefanidis and E. Pitoura. Preference-Aware Publish/Subscribe Delivery with Diversity. Proceedings of HDMS 2009. Abstract (in Greek).
K. Stefanidis and E. Pitoura. Fast Contextual Preference Scoring of Database Tuples. Proceedings of HDMS 2008. [Local copy]
K. Stefanidis, E. Pitoura and P. Vassiliadis. Preference Queries in Context: An Overview. Proceedings of HDMS 2006. Abstract (in Greek).

Technical Reports

E. Pitoura, K. Stefanidis and A. B. Zaslavsky. Context in Databases. Technical Report TR 2004-19, Department of Computer Science, University of Ioannina, Greece. [Local copy]

Magazines

H. Kondylakis, K. Stefanidis, P. Rao. Report on the Fifth International Workshop on Health Data Management in the Era of AI (HeDAI 2023). SIGMOD Record, 53(2): 58-62 (2024).
H. Kondylakis, K. Stefanidis, P. Rao. Report on the Third International Workshop on Semantic Web Meets Health Data Management (SWH 2020). SIGMOD Record, vol. 50, no. 3, p. 32-35, 2021.
H. Kondylakis, K. Stefanidis, P. Rao, D. Parry. Report on the Second International Workshop on Semantic Web Meets Health Data Management (SWH 2019). SIGMOD Record, vol. 49, no. 2, p. 59-62, 2020.
H. Kondylakis, K. Stefanidis, P. Rao. Report on the First International Workshop on Semantic Web Technologies for Health Data Management (SWH 2018). SIGMOD Record, vol. 48, no. 3, p. 41-44, September 2019.
H. Kondylakis, G. Troullinou, K. Stefanidis and D. Plexousakis. Beyond Summaries for Ontology Exploration. ERCIM News, vol. 2018, no. 113, 2018.
S. B. Roy, K. Stefanidis, G. Koutrika, L. Lakshmanan, M. Riedewald. Report on the Third International Workshop on Exploratory Search in Databases and the Web (ExploreDB 2016). SIGMOD Record, vol. 45, no. 3, p. 35-38, September 2016.
K. Stefanidis, G. Flouris, I. Chrysakis and Y. Roussakis. D2V - Understanding the Dynamics of Evolving Data: A Case Study in the Life Sciences. ERCIM News, vol. 2016, no. 105, 2016.
G. Koutrika, L. Lakshmanan, M. Riedewald, M. Sharaf and K. Stefanidis. Report on the Second International Workshop on Exploratory Search in Databases and the Web (ExploreDB 2015). SIGMOD Record, vol. 44, no. 4, p. 49-52, December 2015.
V. Christophides, K. Stefanidis and V. Efthymiou. WebER: Resolving Entities in the Web. European Data Forum, November 2015.
G. Koutrika, L. Lakshmanan, M. Riedewald and K. Stefanidis. Report on the First International Workshop on Exploratory Search in Databases and the Web (ExploreDB 2014). SIGMOD Record, vol. 43, no. 2, p. 49-52, June 2014.
K. Stefanidis and K. Norvag. gRecs: Exploiting the Power of Data Mining Techniques for Efficient Computation of Group Recommendations. ERCIM News, vol. 2013, no. 92, 2013.

Theses

K. Stefanidis. Personalized Data Management: Models, Algorithms and Systems. PhD Thesis, Department of Computer Science, University of Ioannina, Greece, 2009.

K. Stefanidis. Context-Aware Preferences for Database Systems. MSc Thesis, Department of Computer Science, University of Ioannina, Greece, 2005.

K. Stefanidis. Publish/Subscribe Systems in Relational Databases. BSc Thesis, Department of Computer Science, University of Ioannina, Greece, 2003.


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