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Dionisis Margaris, Assistant Professor

Department of Digital Systems
University of the Peloponnese
Valioti's building, Kladas, 23100
Sparta, Greece
E-mail: margaris [at] uop.gr

My profile at DBLP | ResearchGate | ORCiD

Education:
Academic positions:
Publications:

Publications in International Journals
  1. Rating Prediction Quality Enhancement in Low-Density Collaborative Filtering Datasets. (2023),
    Dionisis Margaris, C. Vassilakis, D. Spiliotopoulos, S. Ougiaroglou,
    Special Issue on "Semantic Web Technology and Recommender Systems", Big Data and Cognitive Computing, 7(2), 59. (DOI).

  2. kClusterHub: An AutoML-Driven Tool for Effortless Partition-Based Clustering over Varied Data Types. (2023),
    K. Gratsos, S. Ougiaroglou, D. Margaris,
    Future Internet, 15(10), 341. (DOI).

  3. Chatbots for Cultural Venues: A Topic-Based Approach. (2023),
    Vasilis Bouras, Dimitris Spiliotopoulos, Dionisis Margaris, Costas Vassilakis, Konstantinos Kotis, Angeliki Antoniou, George Lepouras, Manolis Wallace, Vassilis Poulopoulos,
    Feature Papers in Algorithms for Multidisciplinary Applications, Algorithms, 16(7), 339. (DOI).

  4. Disruptive Technologies for Parliaments: A Literature Review. (2023),
    D. Koryzis, D. Margaris, C. Vassilakis, K. Kotis, D. Spiliotopoulos,
    Special Issue on "Smart Data and Systems for the Internet of Things", Future Internet, 15(2), 66. (DOI).

  5. On Producing Accurate Rating Predictions in Sparse Collaborative Filtering Datasets. (2022),
    D. Margaris, C. Vassilakis, D. Spiliotopoulos,
    Special Issue on "Information Retrieval, Recommender Systems and Adaptive Systems", Information, 13(6), 302. (DOI).

  6. Fast Training Set Size Reduction Using Simple Space Partitioning Algorithms. (2022),
    S. Ougiaroglou, T. Mastromanolis, G. Evangelidis, D. Margaris,
    Special Issue on "Computing and Embedded Artificial Intelligence", Information, 13(12), 572. (DOI).

  7. On Exploiting Rating Prediction Accuracy Features in Dense Collaborative Filtering Datasets. (2022),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis,
    Special Issue on "Recommendation Algorithms and Web Mining", Information, 13(9), 428. (DOI).

  8. On Addressing the Low Rating Prediction Coverage in Sparse Datasets using Virtual Ratings. (2021),
    D. Margaris, D. Spiliotopoulos, G. Karagiorgos, C. Vassilakis, D. Vasilopoulos,
    SN Computer Science, Volume 2, Issue 4, Article 255. (DOI).

  9. Augmenting Black Sheep Neighbour Importance for Enhancing Rating Prediction Accuracy in Collaborative Filtering. (2021),
    D. Margaris, D. Spiliotopoulos, C. Vassilakis,
    Special Issue on "New Trends in Artificial Intelligence for Recommender Systems and Collaborative Filtering", Applied Sciences, 11(18), 8369. (DOI).

  10. Improving Collaborative Filtering's Rating Prediction Accuracy by Introducing the Experiencing Period Criterion. (2020),
    D. Margaris, D. Spiliotopoulos, C. Vassilakis, D. Vasilopoulos,
    Special Issue on "Information, Intelligence, Systems and applications", Neural Computing and Applications, 35(1), pp. 193-210, Springer. (DOI).

  11. What makes a review a reliable rating in recommender systems? (2020),
    D. Margaris, C. Vassilakis, D. Spiliotopoulos,
    Information Processing and Management, ELSEVIER, Volume 57, Issue 6, Article 102304. (DOI).

  12. An Adaptive Social Network-Aware Collaborative Filtering Algorithm for Improved Rating Prediction Accuracy. (2020),
    D. Margaris, A. Kobusinska, D. Spiliotopoulos, C. Vassilakis,
    Access, IEEE, Volume 8, Issue 1, pp. 68301-68310. (DOI).

  13. A Fine-grained Social Network Recommender System. (2020),
    M. Aivazoglou, A. Roussos, D. Margaris, C. Vassilakis, S. Ioannidis, J. Polakis, D. Spiliotopoulos,
    Social Network Analysis and Mining, Volume 10, Issue 1, 2020, 8, SPRINGER-VERLAG. (DOI)

  14. An integer programming-based algorithm for optimizing the WS-BPEL scenario. (2020),
    D. Margaris, D. Spiliotopoulos, A. Kardiasmenos, D. Pantazopoulos,
    International Journal of Web Engineering and Technology, Vol. 15, No. 3, pp. 307-332, Interscience Publishers. (DOI)

  15. An algorithm for density enrichment of sparse collaborative filtering datasets, using robust predictions as derived ratings. (2020),
    D. Margaris    , D. Spiliotopoulos, G. Karagiorgos, C. Vassilakis,
    Special Issue on "Algorithms for Personalization Techniques and Recommender Systems", Algorithms, 13(7), 174. (DOI)

  16. Improving collaborative filtering's rating prediction coverage in sparse datasets by exploiting the "friend of a friend" concept. (2020),
    D. Margaris    , C. Vassilakis,
    International Journal of Big Data Intelligence, Volume 7, No. 1, pp. 47-57, Inderscience Publishers. (DOI)

  17. Improving collaborative filtering's rating prediction accuracy by considering users' dynamic rating variability. (2020),
    D. Margaris    , C. Vassilakis,
    International Journal of Big Data Intelligence, Volume 7, No. 2, pp. 59-71, Inderscience Publishers. (DOI)

  18. Data Assisted Persona Construction using Social Media Data. (2020),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis,
    Special Issue on "Big Data Analytics for Cultural Heritage", Big Data and Cognitive Computing, 4(3), 21. (DOI)

  19. A Semantic Mixed Reality Framework for Shared Cultural Experiences Ecosystems. (2020),
    C. Vassilakis, K. Kotis, D. Spiliotopoulos, D. Margaris, V. Kasapakis, C.-N. Anagnostopoulos, G. Santipantakis, G.A. Vouros,
    T. Kotsilieris, V. Petukhova, A. Malchanau, I. Lykouretzou, K.M. Helin, A. Revenko, N. Gligoric, B. Pokric,
    Special Issue on "Big Data Analytics for Cultural Heritage", Big Data and Cognitive Computing, 4(2), 6. (DOI)

  20. Multimodal interaction: correlates of learners' metacognitive skill training negotiation experience. (2020),
    D. Spiliotopoulos, E. Makri, C. Vassilakis, D. Margaris,
    Information, 11(8), 381. (DOI)

  21. Human behaviour in multimodal interaction: main effects of civic action and interpersonal and problem-solving skills. (2020),
    E. Makri, D. Spiliotopoulos, C. Vassilakis, D. Margaris,
    Journal of Ambient Intelligence and Humanized Computing, Volume 11, Issue 12, pp. 5991-6006, Springer. (DOI)

  22. Handling uncertainty in social media textual information for improving venue recommendation formulation quality in social networks. (2019),
    D. Margaris    , C. Vassilakis, D. Spiliotopoulos,
    Social Network Analysis and Mining, Volume 9, Issue 1, 2019, 64, SPRINGER-VERLAG. (DOI)

  23. Enhancing Rating Prediction Quality through Improving the Accuracy of Detection of Shifts in Rating Practices. (2018),
    D. Margaris    , C. Vassilakis,
    Transactions on Large-Scale Data- and Knowledge-Centered Systems, Volume XXXVII, pp. 151-191, 2018, SPRINGER. (DOI)

  24. Query personalization using social networks information and collaborative filtering techniques. (2018),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    SI: Recommender Systems for Large-Scale Social Networks, Future Generation Computer Systems, Volume 78, Part 1, 2018, pp. 440-450, ELSEVIER. (DOI)

  25. Exploiting Rating Abstention Intervals for Addressing Concept Drift in Social Network Recommender Systems. (2018),
    D. Margaris    , C. Vassilakis,
    Special Issue on "Advances in Recommender Systems", Informatics, 5(2), 21. (DOI)

  26. Enhancing User Rating Database Consistency through Pruning. (2017),
    D. Margaris    , C. Vassilakis,
    Transactions on Large-Scale Data- and Knowledge-Centered Systems, Volume XXXIV, 2017, pp. 33-64, SPRINGER. (DOI)

  27. Exploiting Internet of Things Information to Enhance Venues' Recommendation Accuracy. (2017),
    D. Margaris    , C. Vassilakis,
    Service Oriented Computing & Applications, Volume 11, Issue 4, 2017, pp. 393-409, SPRINGER. (DOI)

  28. Using Time Clusters for Following Users' Shifts in Rating Practice. (2017),
    D. Margaris    , C. Vassilakis,
    Complex Systems Informatics and Modeling Quarterly (CSIMQ), Article 75, Issue 13, December 2017/January 2018 (invited), pp. 22-42. (DOI)

  29. Recommendation Information Diffusion in Social Networks Considering User Influence and Semantics. (2016),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Social Network Analysis and Mining, Volume 6, Issue 1, 2016, pp. 1-22, SPRINGER-VERLAG. (DOI)

  30. An integrated framework for adapting WS-BPEL scenario execution using QoS and collaborative filtering techniques. (2015),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Science of Computer Programming, Volume 98, Part 4, 2015, pp. 707-734, ELSEVIER. (DOI)

Guest Editing of Special Issues of Journals
  1. Editorial for the Special Issue on "Modern Recommender Systems: Approaches, Challenges and Applications". (2019),
    C. Vassilakis, D. Margaris,
    Information, Multidisciplinary Digital Publishing Institute (MDPI), Volume 10, Issue 7, Article 230. (DOI)

Publications in Books
  1. Identifying Reliable Recommenders in Users' Collaborating Filtering and Social Neighborhoods. (2021),
    D. Margaris    , D. Spiliotopoulos, C. Vassilakis,
    chapter in 'Big Data and Social Media Analytics', Lecture Notes on Social Networks, pp. 51-76, Springer, Cham. (DOI)

  2. Safe travelling period recommendation to high attack risk destinations based on past attack information. (2021),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis,
    chapter in 'Big Data and Social Media Analytics', Lecture Notes on Social Networks, pp. 77-100, Springer, Cham. (DOI)

  3. Knowledge-Based Leisure Time Recommendations in Social Networks. (2017),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    chapter in 'Current Trends on Knowledge-Based Systems: Theory and Applications', pp. 23-48, SPRINGER-VERLAG. (DOI)

Publications in International Conferences Proceedings
  1. A User Interface for Tuning QoS parameters in Recommendation-Based Business Process Scenario Adaptation. (2023),
    K. Sgardelis, D. Margaris, D. Spiliotopoulos, C. Vassilakis,
    Proceedings of the 19th International Conference on Web Information Systems and Technologies (WEBIST 2023), 2023.

  2. A web tool for k-means clustering. (2023),
    K. Gratsos, S. Ougiaroglou, D. Margaris,
    Proceedings of the 3rd International Conference on Novel & Intelligent Digital System (NIDS 2023), pp 91–101, 2023. (DOI)

  3. Anchoring Effect Mitigation for Complex Recommender System Design. (2022),
    D. Margaris, D. Spiliotopoulos, C. Vassilakis,
    Proceedings of the HCI International 2022, vol 13516, Springer, Cham, pp. 424-436, 2022. (DOI)

  4. Persona Finetuning for Online Gaming using Recommender System Techniques. (2022),
    D. Spiliotopoulos, D. Margaris, Kostas N. Koutrakis, Panos I. Philippopoulos, C. Vassilakis,
    Proceedings of the HCI International 2022, vol 13517, Springer, Cham, pp. 656-668, 2022. (DOI)

  5. Quality of Experience Illustrator User Interface for Cloud Provider Recommendations. (2022),
    P. Kokkinos, D. Margaris, D. Spiliotopoulos,
    Proceedings of the HCI International 2022, vol 1580, Springer, Cham, pp. 308-315, 2022. (DOI)

  6. Trust- and Rating- based Recommendations for On-line Social Networks. (2021),
    A. Kobusinska, D. Margaris, J. Peikert,
    Proceedings of the 30th IEEE International Conference on Computer Communications and Networks (ICCCN 2021), pp. 1-11. (DOI)

  7. A User Interface for Personalising WS-BPEL Scenarios. (2021),
    D. Margaris    , D. Spiliotopoulos, D. Vasilopoulos, C. Vassilakis,
    Proceedings of the HCI International 2021 - HCI in Business, Government and Organizations, LNCS 12783, pp. 399-416. (DOI)

  8. An Interface for User-centered Process and Correlation between Large Datasets. (2021),
    D. Spiliotopoulos, T. Giannakopoulos, C. Vassilakis, M. Wallace, M. Lantzouni, V. Poulopoulos, D. Margaris,
    Proceedings of the HCI International 2021 - Design, User Experience, and Usability: UX Research and Design, LNCS 12779, pp. 477-494. (DOI)

  9. Neighbourhood Aging Factors for Limited Information Social Network Collaborative Filtering. (2020),
    D. Margaris    , D. Spiliotopoulos, C. Vassilakis,
    Proceedings of the 2020 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2020), pp 877-883, The Hague, Netherlands. (DOI)

  10. On Recommending Safe Periods to Travel to High Risk Destinations based on Past Attack Information. (2020),
    D. Spiliotopoulos, C. Vassilakis, D. Margaris,
    Proceedings of the 2020 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2020), pp 854-861, The Hague, Netherlands. (DOI)

  11. Database Knowledge Enrichment Utilizing Trending Topics from Twitter. (2020),
    C. Vassilakis, D. Maniataki, G. Lepouras, A. Antoniou, D. Spiliotopoulos, V. Poulopoulos, M. Wallace and D. Margaris,
    Proceedings of the 2020 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2020), pp 870-876, The Hague, Netherlands. (DOI)

  12. A User Interface for Personalized Web Service Selection in Business Processes. (2020),
    D. Margaris, D. Spiliotopoulos, C. Vassilakis, G. Karagiorgos,
    Proceedings of the HCI International 2020 - Late Breaking Papers: Interaction, Knowledge and Social Media, LNCS 12427, pp. 560-573. (DOI)

  13. Policy Making Analysis and Practitioner User Experience. (2020),
    D. Koryzis, F. Fitsilis, D. Spiliotopoulos, T. Theocharopoulos, D. Margaris, C. Vassilakis,
    Proceedings of the HCI International 2020 - Late Breaking Papers: User Experience Design and Case Studies, LNCS 12423, pp. 415-431. (DOI)

  14. MOOC Accessibility from the Educator Perspective. (2020),
    D. Spiliotopoulos, V. Poulopoulos, D. Margaris, E. Makri, C. Vassilakis,
    Proceedings of the HCI International 2020 - Late Breaking Papers: Universal Access and Inclusive Design, LNCS 12426, pp 114-125. (DOI)

  15. Semantics-driven Conversational Interfaces for Museum Chatbots. (2020),
    D. Spiliotopoulos, K. Kotis, C. Vassilakis, D. Margaris,
    Proceedings of the HCII 2020: Culture and Computing, pp 255-266, Copenhagen, Denmark, SPRINGER. (DOI)

  16. Talking' triples to Museum Chatbots. (2020),
    S. Varitimiadis, K. Kotis, D. Spiliotopoulos, C. Vassilakis, D. Margaris,
    Proceedings of the HCII 2020: Culture and Computing, pp 281-299, Copenhagen, Denmark, SPRINGER. (DOI)

  17. Improving Collaborative Filtering's Rating Prediction Accuracy by Introducing the Common Item Rating Past Criterion. (2019),
    D. Margaris    , D. Vasilopoulos, C. Vassilakis, D. Spiliotopoulos,
    Proceedings of the 10th IEEE International Conference on Information, Intelligence, Systems and Applications (IEEE IISA 2019), pp. 1-8, Patras, Greece. (DOI)
    BEST PAPER AWARD!

  18. Improving Collaborative Filtering's Rating Prediction Coverage in Sparse Datasets through the Introduction of Virtual Near Neighbors. (2019),
    D. Margaris    , D. Vasilopoulos, C. Vassilakis, D. Spiliotopoulos,
    Proceedings of the 10th IEEE International Conference on Information, Intelligence, Systems and Applications (IEEE IISA 2019), pp. 1-8, Patras, Greece. (DOI)

  19. A Methodology for Generated Text Annotation for High Quality Speech Synthesis. (2019),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis, V. Petukhova, K. Kotis,
    Proceedings of the 10th IEEE International Conference on Information, Intelligence, Systems and Applications (IEEE IISA 2019), pp. 1-8, Patras, Greece. (DOI)

  20. Social Relations versus Near Neighbours: Reliable Recommenders in Limited Information Social Network Collaborative Filtering for Online Advertising. (2019),
    D. Margaris    , D. Spiliotopoulos, C. Vassilakis,
    Proceedings of the 2019 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2019), pp. 1160-1167, Vancouver, Canada. (DOI)

  21. Data-driven Country Safety Monitoring Terrorist Attack Prediction. (2019),
    D. Spiliotopoulos, C. Vassilakis, D. Margaris,
    Proceedings of the 2019 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM 2019), pp 1128-1135, Vancouver, Canada. (DOI)

  22. Exploiting recommender service to enhance efficiency of replication. (2019),
    A. Kobusinska, M. Boron, A. Kerebinska, D. Margaris,
    Proceedings of the 2019 IEEE International Conference on Service-Oriented Computing and Applications (IEEE SOCA 2019), pp. 64-72, Kaohsiung, Taiwan. (DOI)

  23. Improving Collaborative Filtering's Rating Prediction Quality by Exploiting the Item Adoption Eagerness Information. (2019),
    D. Margaris    , D. Spiliotopoulos, C. Vassilakis,
    Proceedings of the 2019 IEEE/WIC/ACM International Conference on Web Intelligence (WI 2019), pp. 342-347, Thessaloniki, Greece. (DOI)

  24. A Mixed-reality Interaction-driven Game-based Learning Framework. (2019),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis, V. Petukhova, K. Kotis,
    Proceedings of the 11th ACM International Conference on Management of Digital EcoSystems (ACM MEDES 2019), pp. 229-236, Limassol, Cyprus. (DOI)

  25. Citizen Engagement for Transparent and Accountable Policy Modelling. (2019),
    D. Spiliotopoulos, D. Margaris, C. Vassilakis,
    Proceedings of the 11th ACM International Conference on Management of Digital EcoSystems (ACM MEDES 2019), pp. 158-165, Limassol, Cyprus. (DOI)

  26. Improving Collaborative Filtering's Rating Prediction Accuracy by Considering Users' Rating Variability. (2018),
    D. Margaris    , C. Vassilakis,
    Proceedings of the 4th IEEE International Conference on Big Data Intelligence and Computing (IEEE DataCom 2018), pp. 1022-1027, Athens, Greece. (DOI)

  27. Improving Collaborative Filtering's Rating Prediction Coverage in Sparse Datasets by Exploiting User Dissimilarity. (2018),
    D. Margaris    , C. Vassilakis,
    Proceedings of the 4th IEEE International Conference on Big Data Intelligence and Computing (IEEE DataCom 2018), pp. 1054-1059, Athens, Greece. (DOI)

  28. Improving Collaborative Filtering's Rating Prediction Quality by Considering Shifts in Rating Practices. (2017),
    D. Margaris    , C. Vassilakis,
    Proceedings of the 19th IEEE International Conference on Business Informatics (IEEE CBI '17), pp. 158-166, Thessaloniki, Greece. (DOI)

  29. Improving Collaborative Filtering's Rating Prediction Quality in Dense Datasets, by Pruning Old Ratings. (2017),
    D. Margaris    , C. Vassilakis,
    Proceedings of 22nd IEEE Symposium on Computers and Communications (IEEE ISCC 2017), pp. 1168-1174, Heraklion, Crete, Greece. (DOI)

  30. Improving QoS Delivered by WS-BPEL Scenario Adaptation through Service Execution Parallelization. (2016),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 31th ACM Symposium on Applied Computing (ACM SAC 2016), pp. 1590-1596, Pisa, Italy. (DOI)

  31. Pruning and Aging for User Histories in Collaborative Filtering. (2016),
    D. Margaris    , C. Vassilakis,
    Proceedings of the 7th IEEE Symposium Series on Computational Intelligence (IEEE SSCI 2016), pp. 1-8, Athens, Greece. (DOI)

  32. A hybrid framework for WS-BPEL scenario execution adaptation, using monitoring and feedback data. (2015),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 30th ACM Symposium on Applied Computing (ACM SAC 2015), pp. 1672-1679, Salamanca, Spain. (DOI)

  33. A collaborative filtering algorithm with clustering for personalized web service selection in business processes. (2015),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 9th IEEE International Conference on Research Challenges in Information Science (IEEE RCIS 2015), pp. 169-180, Athens, Greece. (DOI)

  34. On Replacement Service Selection in WS-BPEL Scenario Adaptation. (2015),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 8th IEEE Service-Oriented Computing and Applications (IEEE SOCA 2015), pp. 10-17, Rome, Italy. (DOI)

  35. An integrated framework for QoS-based adaptation and exception resolution in WS-BPEL scenarios. (2013),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 28th ACM Symposium on Applied Computing (ACM SAC 2013), pp. 1900-1906, Coimbra, Portugal. (DOI)

  36. Adapting WS-BPEL scenario execution using collaborative filtering techniques. (2013),
    D. Margaris    , C. Vassilakis, P. Georgiadis,
    Proceedings of the 7th IEEE International Conference on Research Challenges in Information Science (IEEE RCIS 2013), pp. 174-184, Paris, France. (DOI)

  37. SBST for On-Line Detection of Hard Faults in Multiprocessor Applications Under Energy Constraints. (2010),
    A. Merentitis, D. Margaris, N. Kranitis, A. Paschalis, D. Gizopoulos,
    Proceedings of the 16th IEEE International On-Line Testing Symposium (IEEE IOLTS 2010), pp. 62-67, Corfu, Greece. (DOI)


Editor in International Journals:

Guest Editor
Workshop Organizing Committee Member:


Presentations:


Reviewer in International Journals and Conferences:


Future Generation Computer Systems (Certificate of Outstanding Contribution in Reviewing),
PLOS One, Social Network Analysis and Mining, Information Processing & Management, Applied Sciences, Access, Algorithms,
Applied Soft Computing, Information,International Journal of Computational Science and Engineering, Expert Systems with Applications,
ISPRS International Journal of Geo-Information, International Journal of Data Science and Analytics, International Journal of Data Science and Analytics
2019 IEEE/ACM ASONAM 2019, 22nd IEEE ISCC 2017


International Conferences Programme Committee Member: