Web and social media mining

The large-scale availability of user-generated content on social media platforms has opened up new possibilities for studying and understanding real-world phenomena, trends and events. Social media is a highly heterogeneous source of data that provides real-time information in specific areas of interest, which can assist public safety through the monitoring of crisis events with spatial, temporal and contextual multimodal information. Combining the discovery of social media insights with knowledge retrieved by focused crawling from traditional web sources, our research offers timely in-situ information about changes, concepts and events of interest to specific communities.

Social media dashboard for visualizing, filtering, and clustering Twitter posts into events. (EOPEN EU project)
Fluctuations in the number of tweets containing flood-related keywords from 2017 to 2019, grouped as collected (EOPEN EU project)

PROJECTS

PUBLICATIONS

  1. A. Spyros, A. Kougioumtzidou, A. Papoutsis, E. Darra, D. Kavallieros, A. Tziouvaras, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "A Comprehensive Survey of Manual and Dynamic Approaches for Cybersecurity Taxonomy Generation", Knowledge and Information Systems, 2025 OPEN ACCESS
  2. A. Spyros, I. Koritsas, A. Papoutsis, P. Panagiotou, D. Chatzakou, D. Kavallieros, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "AI-Based Holistic Framework for Cyber Threat Intelligence Management," IEEE Access, vol. 13, pp. 20820-20846, 2025, doi: 10.1109/ACCESS.2025.3533084. OPEN ACCESS
  3. O. Theodosiadou, A. M. Koufakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Change Point Analysis of Time Series Related to Bitcoin Transactions: Towards the Detection of Illegal Activities.", J. Risk Financial Manag., vol. 16, no. 9, 2023. DOI:doi.org/10.3390/jrfm16090408 OPEN ACCESS
  4. A. Konstantinou, D. Chatzakou, O. Theodosiadou, T. Tsikrika, S. Vrochidis and I. Kompatsiaris, “Trend Detection in Crime-related Time Series with Change Point Detection Methods” in International Conference of the Cross-Language Evaluation Forum for European Languages, 18-21 September 2023, Thessaloniki, Greece. Arampatzis, A., et al. Experimental IR Meets Multilinguality, Multimodality, and Interaction. CLEF 2023. Lecture Notes in Computer Science, vol 14163. Springer. https://doi.org/10.1007/978-3-031-42448-9_7 OPEN ACCESS
  5. Α. Bozas, G. Sakkas, Y. Kouloglou , A. Moumtzidou, N. Kalopodis, K. Demestichas, I. Gialampoukidis, A. Giordanis, I. Vourvachis, S. Vrochidis, S., & Kompatsiaris, I. (Yiannis), "Social media sensing for forest wildfires- a case study from Greece".  in SafeAttica 2023: Proceedings 10th International Conference on Civil Protection & New Technologies (SafeAttica), War Museum, Athens, Greece, 20-30 June, 2023. https://doi.org/10.5281/zenodo.10101880 OPEN ACCESS
  6. M. G. Scarpino, M. Matera, P. Bauer, I. Manakos, A. Kita, K. Vlachos, A. Bozas, I. Serral, A. Moumtzidou, I. Gialampoukidis, S. Vrochidis,"WQEMS platform for inland surface water bodies' monitoring: serving user communities and supporting expert analyses", In SPIE 12786: Proceedings Ninth International Conference on Remote Sensing and Geoinformation of the Environment (RSCy2023), Ayia Napa, Cyprus, 3-5 April, 2023  vol. 1278615.
  7. G. M. Scarpino, M. Matera, P. Bauer, I. Manakos, A. Kita, K. Vlachos, A. Bozas, I. Serral, A. Moumtzidou, I. Gialampoukidis & S. Vrochidis, ”WQeMS Platform for Insland and Surface Water Bodies' Monitoring: Serving User Communities and Supporting Experts' Analyses”, In Proceedings of the Ninth International Conference on Remote Sensing and Geoinformation of Environmentʼ 3-5 April, 2023 – Cyprus.
  8. N. Stylianou, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, “Domain-aligned Data Augmentation for Low-resource and Imbalanced Text Classification” in Proceedings of the 45th European Conference on Information Retrieval (ECIR'23), Dublin, Ireland, April 02-06, 2023
  9. Stelios Andreadis, Ilias Gialampoukidis, Andrea Manconi, David Cordeiro, Vasco Conde, Manuela Sagona, Fabrice Brito, Nick Pantelidis, Thanassis Mavropoulos, Nuno Grosso, Stefanos Vrochidis, Ioannis Kompatsiaris (2022). Earthquakes: From Twitter detection to EO data processing. IEEE Geoscience and Remote Sensing Letters, 19, 1-5. OPEN ACCESS
  10. A. Kokkalas, A.T. Patenidis, E.A. Stathopoulos, E.E. Mitsopoulou, S. Diplaris, K. Papadopoulos, S. Vrochidis, K. Votis, D. Tzovaras, and I. Kompatsiaris, "e-Tracer: a Smart, Personalized and Immersive Digital Tourist Software System” in Proceedings of The 24th International Conference on Information Integration and Web Intelligence (iiWAS2022), 28-30 November 2022, Online.
  11. A. Kosmatopoulos, K. Loumponias, O. Theodosiadou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, “Identification of Key Actor Nodes: A Centrality Measure Ranking Aggregation Approach” in the Proceedings of the 2022 IEEE/ACM International Conference on Advances in Social Networks Analysis and Mining (ASONAM), 10-11 November, 2022, Istanbul, Turkey.
  12. E.A. Stathopoulos, A.I. Karageorgiadis, A. Kokkalas, S. Diplaris, S. Vrochidis, and I. Kompatsiaris, "Social Media and Web Sensing with Semantic Integration on the Refugee Crisis", in IEEE 17th International Workshop on Semantic and Social Media Adaptation & Personalization (SMAP), 3-4 November 2022, Online. DOI: 10.1109/SMAP56125.2022.9942201. © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
  13. S. Symeonidis, G. Meditskos, S. Vrochidis, K. Avgerinakis, J. Derdaele, M. Vergauwen, M. Bassier, A. Moghnieh, L. Fraguada, V. Vogler, Y. Shekhawat, L. Wanner, M. Marimon, K. Valsamidou, P. Koulali, A. Tellios, J. Wuyts, E. Lopez, "V4Design: Intelligent analysis and integration of multimedia content for Creative Industries", in IEEE Systems Journal, 2022, DOI:10.1109/JSYST.2022.3217655
  14. G. Sakkas, V. Varela, I. Vourvachis, A. Giordanis, S. Andreadis, I. Gialampoukidis, S. Vrochidis, I. Kompatsiaris, K. Demestichas, S. Kaloudis, R. Kechri, K. Meletis, “SILVANUS: An Integrated Technological and Information Platform for Wildfire Management – North Evia Pilot Area” SafeThessaloniki 2022, 29 September - 1 October 2022, Thessaloniki, Greece. OPEN ACCESS
  15. C. Iliou, T. Kostoulas, T. Tsikrika, V. Katos, S. Vrochidis, and I. Kompatsiaris, “Web Bot Detection Evasion Using Deep Reinforcement Learning”, In Proceedings of the 17th International Conference on Availability, Reliability and Security (ARES 2022), ACM, 23-26 Aug, 2022, DOI:10.1145/3538969.3538994. OPEN ACCESS
  16. M. Caballero, D. Kavallieros, A. Spyros, A. Tavernarakis, A. Tziouvaras, S. Bonacina, K. Chandrarmouli, M. Coroiu, L. Chen, T. Dounia, I. Giannoulakis, N. Gligoricx , E. Kafetzakis, T. Kasig, V. Koumaras, T. Krousarlis , K. Lapidaki, A. Markakis, S. Marin, M. Manulis, S. Menesidou, S. Nifakos, L. Meng, S. Mhiri, M. Nat, K. Ntafloukas, D. Oniga, D. Papamartzivanos, S. Papastergiou, K. Sanchez, C. Sakkas, K. Stelliou, L. Trujillo, T. Tsikrika, E. Venegas, S. Vrochidis, and D. Xydias. "ICT in Healthcare: the role of IoT and the SECANT solution", in Proceedings of the 2022 IEEE International Conference on Cyber Security and Resilience (CSR), 27-29 July, 2022, pp. 104-111. OPEN ACCESS
  17. A. Spyros, A. Papoutsis, I. Koritsas, N. Mengidis, C. Iliou, D. Kavallieros, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Towards Continuous Enrichment of Cyber Threat Intelligence: A Study on a Honeypot Dataset". Ιn Proceedings of the 2022 IEEE International Conference on Cyber Security and Resilience (CSR), 27-29 July, 2022, pp. 267-272, DOI:10.1109/CSR54599.2022.9850295. OPEN ACCESS
  18. N. Mengidis, M. Bozhilova, C. Ceresola, C. Colabuono, M. Cooke, G. Depaix, A. Genchev, G. Koykov, W. Mees, M. Merialdo, A. Voulgaridis, T. Tsikrika, K. Votis, S. Vrochidis, “Leveraging Cyber Ranges for Prototyping, Certification and Training: The ECHO case” in Proceedings of the 2022 IEEE International Conference on Cyber Security and Resilience (CSR), July 27-29, 2022, pp. 299-304,  DOI:10.1109/CSR54599.2022.9850278. OPEN ACCESS
  19. K. Loumponias, A. Kosmatopoulos, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "A Faster Converging Negative Sampling for the Graph Embedding Process in Community Detection and Link Prediction Tasks.", In Proceedings of the 3rd International Conference on Deep Learning Theory and Applications - DeLTA; ISBN 978-989-758-584-5; ISSN 2184-9277, SciTePress, pages 86-93. DOI: 10.5220/0011142000003277.
  20. R. Karlović, H. Nitsch, S. E. Fikenscher, D. Osterman, S. Menexis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris,and A. Sahar (2022). "The Threat of Behavioral Radicalization Online: Conceptual Challenges and Technical Solutions Provided by the PROPHETS (Preventing Radicalization Online through the Proliferation of Harmonized ToolkitS) Project". In G. Markarian, R. Karlovic, H. Nitsch and K. Chandramouli (eds.) Security Technologies and Social Implications: A European Perspective. (accepted for publication).
  21. S. Andreadis, N. Pantelidis, I. Gialampoukidis, S. Vrochidis, and I. Kompatsiaris, "Water quality issues: Can we detect a creeping crisis with social media data?", In the proceedings of the 27th IEEE Symposium on Computers and Communications (IEEE ISCC 2022), 30 June - 3 July 2022, Rhodes, Greece.
  22. E.A. Stathopoulos, A. Shvets, R. Carlini, S. Diplaris, S. Vrochidis, L. Wanner, and I. Kompatsiaris, “Social Media and Web Sensing on Interior and Urban Design”, IEEE Symposium on Computers and Communications (ISCC), 30 June - 3 July 2022, Rhodes, Greece. DOI:10.1109/ISCC55528.2022.9912803 OPEN ACCESS © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
  23. S. Andreadis, M. Elias, T. Mavropoulos, C. Papadopoulos, N. Pantelidis, I. Gialampoukidis, S. Vrochidis, and I. Kompatsiaris, "SPARQL querying for validating the usage of automatically georeferenced social media data as human sensors for air quality". In Proceedings of the 2022 IEEE 14th Image, Video, and Multidimensional Signal Processing Workshop (IVMSP 2022), 26-29 June 2022, Nafplio, Greece. DOI: 10.1109/IVMSP54334.2022.9816191
  24. T. Papadimos, N. Pantelidis, S. Andreadis, A. Bozas, I. Gialampoukidis, S. Vrochidis, and I. Kompatsiaris, "Real-time Alert Framework for Fire Incidents Using Multimodal Event Detection on Social Media Streams". In Proceedings of the 19th International Conference on Information Systems for Crisis Response and Management, 22-25 May 2022, Tarbes, France. OPEN ACCESS © © 2022 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.
  25. P. Kyriakidis, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Leveraging Transformer Self Attention Encoder for Crisis Event Detection in Short Texts", 44th European Conference on Information Retrieval (ECIR2022), Stavanger, Norway, April 10–14, 2022, Proceedings, Part II Apr 2022, pp. 163–171. DOI:https://doi.org/10.1007/978-3-030-99739-7_19. OPEN ACCESS
  26. S. Andreadis, I. Gialampoukidis, A. Bozas, A. Moumtzidou, R. Fiorin, F. Lombardo, A. Karakostas, D. Norbiato, S. Vrochidis, M. Ferri, and I. Kompatsiaris, "WaterMM: Water Quality in Social Multimedia Task at MediaEval 2021". In Proceedings of the MediaEval 2021 Workshop (MediaEval'21), 12-15 December 2021.
  27. O. Theodosiadou, K. Pantelidou, N. Bastas, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Change Point Detection in Terrorism-Related Online Content Using Deep Learning Derived Indicators". Information 2021, 12, 274. OPEN ACCESS
  28. A. Kosmatopoulos, K. Loumponias, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Random-Walk Graph Embeddings and the Influence of Edge Weighting Strategies in Community Detection Tasks". In Proceedings of the 2021 Workshop on Open Challenges in Online Social Networks (OASIS ’21), August 30, 2021, Virtual Event, Ireland. ACM, New York, NY, USA. OPEN ACCESS
  29. P. Panagiotou, C. Iliou, K. Apostolou, T. Tsikrika, S. Vrochidis, P. Chatzimisios, I. Kompatsiaris, "Towards Selecting Informative Content for Cyber Threat Intelligence", In the proceedings of the 2021 IEEE International Conference on Cyber Security and Resilience (IEEE CSR) – Workshops, Virtual Conference, July 26 (Mon) – 28 (Wed), 2021, pp. 354-359, DOI:10.1109/CSR51186.2021.9527909. OPEN ACCESS
  30. P. Evangelatos, C. Iliou, T. Mavropoulos, K. Apostolou, T. Tsikrika, S. Vrochidis and I. Kompatsiaris,"Named Entity Recognition in Cyber Threat Intelligence Using Transformer-based Models", in the proceedings of the 2021 IEEE International Conference on Cyber Security and Resilience (IEEE CSR) – Workshops, Virtual Conference, July 26 (Mon) – 28 (Wed), 2021, pp. 348-353, DOI:10.1109/CSR51186.2021.9527981. OPEN ACCESS
  31. C. Iliou, T. Kostoulas, T. Tsikrika, V. Katos, S. Vrochidis, and I. Kompatsiaris, "Web Bot Detection Evasion Using Generative Adversarial Networks", In Proceedings of the 2021 IEEE International Conference on Cyber Security and Resilience, IEEE, 26-28 July, 2021. DOI:10.1109/CSR51186.2021.9527915. OPEN ACCESS
  32. S. Andreadis, I. Gialampoukidis, A. Manconi, D. Cordeiro, V. Conde, M. Sagona, F. Brito, N. Pantelidis, T. Mavropoulos, N. Grosso, S. Vrochidis and I. Kompatsiaris, "Earthquakes: from Twitter detection to EO data processing", In the proceedings of the 5th International Conference on Dynamics of Disasters (DOD 2021), Virtual, 15-18 July 2021.
  33. I. Gialampoukidis, S. Andreadis, S. Vrochidis, and I. Kompatsiaris, "Multimodal data fusion of social media and satellite images for emergency response and decision-making", 2021 IEEE International Geoscience and Remote Sensing Symposium (IGARSS 2021), 11 July 2021, Online, pp. 228-231, IEEE. OPEN ACCESS
  34. C. Iliou, T. Kostoulas, T. Tsikrika, V. Katos, S. Vrochidis, I. Kompatsiaris. "Detection of advanced web bots by combining web logs with mouse behavioural biometrics". Digital Threats: Research and Practice (DTRAP), 2021, Volume 2, Issue 3, 3 September 2021, DOI:10.1145/3447815. OPEN ACCESS
  35. S. Andreadis, I. Gialampoukidis, V. Sitokonstantinou, B. Coloru, H. Vervaeren, E. López, V. Kalogirou, P. Syropoulou, E. B. Kosmatopoulos, S. Vrochidis, E. Li Santi, G. Vingione, I. Kompatsiaris, "CALLISTO: Copernicus Artificial Intelligence Services and data fusion with other distributed data sources and processing at the edge to support DIAS and HPC infrastructures",In Proceedings of the Big Data from Space 2021,Virtual, 18-20 May 2021. OPEN ACCESS
  36. S. Symeonidis, S. Diplaris, N. Heise, T. Pistola, A. Tsanousa, G. Tzanetis, E. Batziou, C. Stentoumis, I. Kalisperakis, S. Freitag, Y. Shekhawat, R. Paradiso, M. Pacelli, J. Codinak, S. Millek, M. Marimonk, M. Ferri, D. Norbiato, M. Monego, A. Karakostas and S. Vrochidis, "xR4DRAMA: Enhancing situation awareness using immersive (XR) technologies". In 2021 IEEE International Conference on Intelligent Reality (ICIR), Piscataway, NJ, USA, 2021, pp. 1-8. https://doi.org/10.1109/ICIR51845.2021.00010
  37. W. Yao, A. Moumtzidou , C. O. Dumitru, S. Andreadis, I. Gialampoukidis, S. Vrochidis, M. Datcu, I. Kompatsiaris, "Early and Late Fusion of Multiple Modalities in Sentinel Imagery and Social Media Retrieval" , in 11th IAPR International Workshop on Pattern Recognition in Remote Sensing (PRRS 2020/2021), in conjunction with the International Conference on Pattern Recognition (ICPR 2020), 10 January 2021. OPEN ACCESS
  38. B. Akhgar, M. Gercke, S. Vrochidis, H. Gibson (2021). Dark Web investigation. 288 Pages, Springer.
  39. D. Chatzakou, J. Soler-Company, T. Tsikrika, L. Wanner, S. Vrochidis, I. Kompatsiaris, "User Identity Linkage in Social Media Using Linguistic and Social Interaction Features", In Proceedings of the 2020 ACM on Web Science Conference, (WEBSCI 2020), July 6-10 2020. OPEN ACCESS
  40. N. Bastas, G. Kalpakis, T. Tsikrika, S. Vrochidis & Y. Kompatsiaris, "A comparative study of clustering methods using word embeddings", in Proceedings of the 2019 European Intelligence and Security Informatics Conference (EISIC 2019), Oulu, Finland, 24-26 November 2019. https://ieeexplore.ieee.org/document/9108898
  41. P. Mitzias, E. Kontopoulos, J. Staite, T. Day, G. Kalpakis, T. Tsikrika, H. Gibson, S. Vrochidis, B. Akhgar, & Υ. Kompatsiaris, "Deploying Semantic Web Technologies for Information Fusion of Terrorism related Content and Threat Detection on the Web", Proceedings of the Security Analytics and Cyber Threat Intelligence on the Web (SACTI 2019) workshop, in conjunction with the IEEE/WIC/ACM International Conference on Web Intelligence (WI 2019), Thessaloniki, Greece, 14-17 October 2019. OPEN ACCESS
  42. P. Alvanitopoulos, S. Diplaris, B. de Gelder, A. Shvets, M. Benayoun, P, Koulali, A. Moghnieh, Y. Shekhawat, C. Stentoumis, T. Hosmer, R. Anadol, M. Borreguero, A. Martin, P. Sciama, K. Avgerinakis, P. Petrantonakis, A. Briassouli, S. Mille, A. Tellios, L. Fraguada, H. Sprengel, I. Kalisperakis, N. Cabanas, S. Nikolopoulos, S. Skouras, V. Vogler, D. Zavraka, J. Piesk, L. Grammatikopoulos, L. Wanner, T. Klein, S. Vrochidis, I. Kompatsiaris, "MindSpaces: Art-driven adaptive outdoors and indoors design", in Ninth International Conference on Digital Presentation and Preservation of Cultural and Scientific Heritage — DiPP2019, Burgas, Bulgaria, 26–28 September, 2019, pp 391-400. OPEN ACCESS
  43. C. Iliou, T. Kostoulas, T. Tsikrika, V. Katos, S. Vrochidis, and Y. Kompatsiaris, "Towards a framework for detecting advanced Web bots", Iin Proceedings of the 14th International Conference on Availability, Reliability and Security, p. 18. ACM, 2019. OPEN ACCESS
  44. E. Kamateri, T. Tsikrika, S. Symeonidis, S. Vrochidis, W. Minker and Y. Kompatsiaris, "A Test Collection for Passage Retrieval Evaluation of Spanish Health-Related Resources", 41st European Conference on Information Retrieval (ECIR 2019), 14-18 April 2019, Cologne, Germany. https://doi.org/10.1007/978-3-030-15719-7_19
  45. G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Identifying terrorism-related key actors in multidimensional social networks", in Proc. 25th Int. Conf. on Multimedia Modeling (MMM2019), Thessaloniki, Greece, Jan. 2019. OPEN ACCESS
  46. I. Gialampoukidis, A. Moumtzidou, M. G. Scarpino, G. Palumbo, S. Vrochidis, I. Kompatsiaris, F. Zaffanella, D. Norbiato, M. Ferri, & G.Vingione, "Earth Observation and Social Multimedia Data Fusion for Natural Hazards and Water Management: The H2020 EOPEN Project Paradigm", in 2nd International Conference Citizen Observatories for natural hazards and Water Management, Venice, 2018. OPEN ACCESS
  47. S. Andreadis, I. Gialampoukidis, R. Fiorin, F. Lombardo, D. Norbiato, A. Karakostas, M. Ferri, S. Vrochidis and I. Kompatsiaris, "Social Media Observations for Flood Event Monitoring in Italy over a One-Year Period", in 2nd International Conference Citizen Observatories for natural hazards and Water Management (COWM 2018), 27-30 November 2018, Venezia, Italy. OPEN ACCESS
  48. C. Iliou, T. Tsikrika, G. Kalpakis, S. Vrochidis, I. Kompatsiaris, "Adaptive focused crawling using online learning: A study on content related to Islamic extremism", in 5th International conference ‘Internet Science’ (INSCI’2018), 24-26 October 2018, St. Petersburg, Russia. OPEN ACCESS
  49. S. Andreadis, A. Moumtzidou, I. Gialampoukidis, S. Vrochidis and I. Kompatsiaris, "A Flood Monitoring Tool for Urban Areas Using Satellite, Weather and Social Data", in US-Serbia & West Balkan Data Science Workshop 2018 - Big Data and Critical Infrastructures, 26-28 August 2018, Belgrade, Serbia. (poster presentation) OPEN ACCESS
  50. E. Kosmidis, P. Syropoulou, S. Tekes, P. Schneider, E. Spyromitros-Xioufis, M. Riga, P. Charitidis, A. Moumtzidou, S. Papadopoulos, S. Vrochidis, I. Kompatsiaris, I. Stavrakas, G. Hloupis, A. Loukidis, K. Kourtidis, A.Georgoulias, and G. Alexandri. "hackAIR: Towards raising Awareness about Air Quality in Europe by developing a Collective Online Platform". ISPRS International Journal of Geo-Information , 7, 12 May 2018. OPEN ACCESS
  51. G. Kalpakis, T. Tsikrika, I. Gialampoukidis, S. Papadopoulos, S. Vrochidis, I., Kompatsiaris, "Analysis of Suspended Terrorism-Related Content on Social Media", Community-Oriented Policing and Technological Innovations, 107-118. OPEN ACCESS
  52. G. Kalpakis, T. Tsikrika, I. Gialampoukidis, S. Papadopoulos, S. Vrochidis, I. Kompatsiaris. "Analysis of Suspended Terrorism-Related Content on Social Media". In Community-Oriented Policing and Technological Innovations, Springer Briefs in Policing, Springer, 27 April 2018. OPEN ACCESS
  53. A. Moumtzidou, S. Andreadis, I. Gialampoukidis, A. Karakostas, S. Vrochidis and I. Kompatsiaris, "Flood relevance estimation from visual and textual content in social media streams", in WWW 2018 Workshop on Exploitation of Social Media for Emergency Relief and Preparedness (SMERP), 23 April 2018, Lyon, France. OPEN ACCESS
  54. L. Wanner, E. Andre, J. Blat, S. Dasiopoulou, M. Farrus, T. Fraga, E. Kamateri, F. Lingenfelser, G. Llorach, O. Martinez, G. Meditskos, S. Mille, W. Minker, L. Pragst, D. Schiller, A. Stam, L. Stellingwerff, F. Sukno, B. Vieru, S. Vrochidis, "Design of knowledge-based agent as a social companion", in Proceedings of the International Conference on Health and Social Care Information Systems and Technologies (HCist), Barcelona, Catalonia, November 2017.
  55. E. Batziou, I. Gialampoukidis, S. Vrochidis, I. Antoniou, I. Kompatsiaris, "Unsupervised Keyword Extraction Using the GoW Model and Centrality Scores", in International Conference on Internet Science, pp. 344-351. Springer, Cham, 2017. OPEN ACCESS
  56. S. Andreadis, I. Gialampoukidis, S. Vrochidis, I. Kompatsiaris, "A Topic Detection and Visualisation System on Social Media Posts", in International Conference on Internet Science, pp. 421-427. Springer, Cham, 2017.
  57. I. Gialampoukidis, S. Vrochidis and I. Kompatsiaris, "Crater monitoring through social media observations", in European Planetary Science Congress 2017, 17–22 September 2017.
  58. C. Iliou, G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris. "Hybrid Focused Crawling on the Surface and the Dark Web". EURASIP Journal on Information Security, vol. 2017, no. 11, 4 July 2017. OPEN ACCESS
  59. B. Akhgar, P. Bertrand, C. Chalanouli, T. Day, I. Fragkiadakis, H. Gibson, D. Kavallieros, E. Kermitsis, I. Kompatsiaris, E. Kyriakou, G. Leventakis, E. Lissaris, S. Mille, D. Myttas, T. Tsikrika, S. Vrochidis, U. Williamson. "TENSOR: Retrieval and Analysis of Heterogeneous Online Content for Terrorist Activity Recognition". Proceedings of the Estonian Academy of Se-curity Sciences: Secure Societies, 15 June 2017. OPEN ACCESS
  60. I. Gialampoukidis, G. Kalpakis, T. Tsikrika, S. Papadopoulos, S. Vrochidis, I. Kompatsiaris, "Detection of Terrorism-related Twitter Communities using Centrality Scores", in Proceedings of International Workshop on Multimedia Forensics and Security (MFSec 2017), Bucharest, Romania, June 06, 2017. OPEN ACCESS
  61. T. Mavropoulos, D. Liparas, S. Symeonidis, S. Vrochidis and I. Kompatsiaris,"A Hybrid Approach for Bio-medical Relation Extraction Using Finite State Automata and Random Forest-Weighted Fusion", in Proceedings of the 18th International Conference on Computational Linguistics and Intelligent Text Processing (CICLing 2017), April 17-23, 2017, Budapest, Hungary.
  62. T. Tsikrika, B. Akhgar, V. Katos, S. Vrochidis, P. Burnap, M. L. Williams, "1st International Workshop on Search and Mining Terrorist Online Content & Advances in Data Science for Cyber Security and Risk on the Web". In Proceedings of the Tenth ACM International Conference on Web Search and Data Mining (WSDM 2017), pp. 823-824, Cambridge, UK, February 2017. OPEN ACCESS
  63. G. Kalpakis, T. Tsikrika, N. Cunningham, C. Iliou, S. Vrochidis, J. Middleton, I. Kompatsiaris. "OSINT and the Dark Web". In Open Source Intelligence Investigation - From Strategy to Implementation, B. Akhgar, P. S. Bayerl, F. Sampson (Eds.), Springer, 3 January 2017. OPEN ACCESS
  64. I. Gialampoukidis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris,"Community Detection in Complex Networks Based on DBSCAN* and a Martingale Process", in 11th International Workshop on Semantic and Social Media Adaptation and Personalization (SMAP), 2016, pp. 1-6. IEEE.
  65. A.. Satsiou, G. Panos, I. Praggidis, S. Vrochidis, S. Papadopoulos, C. Keratidis, P. Syropoulou, H. Y. Liu (Eds.). (2016). Collective Online Platforms for Financial and Environmental Awareness: First International Workshop on the Internet for Financial Collective Awareness and Intelligence. IFIN 2016 and First International Workshop on Internet and Social Media for Environmental Monitoring, ISEM 2016, Florence, Italy, 12 September, 2016 (Vol. 10078). Springer. OPEN ACCESS
  66. C. Iliou, G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris,"Hybrid Focused Crawling for Homemade Ex-plosives Discovery on Surface and Dark Web", 11th International Conference on Availability, Reliability and Security (ARES 2016), Salzburg, Austria, Aug 2016. DOI: 10.1109/ARES.2016.66
  67. I. Gialampoukidis, D. Liparas, S. Vrochidis, I. Kompatsiaris, "Query-based Topic Detection Using Concepts and Named Entities", in 1st International Workshop on Multimodal Media Data Analytics (MMDA 2016), The Hague, Netherlands, August 30, 2016.
  68. I. Gialampoukidis, G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris,"Key player identification in terrorism-related social media networks using centrality measures", in Intelligence and Security Informatics Conference (EISIC), 2016 European, pp. 112-115. IEEE, 2016. DOI: 10.1109/EISIC.2016.029
  69. G. Kalpakis, T. Tsikrika, C. Iliou, T. Mironidis, S. Vrochidis, J. Middleton, U. Williamson, I. Kompatsiaris,"In-teractive Discovery and Retrieval of Web Resources Containing Home Made Explosive Recipes", in 4th International Conference on Human Aspects of Information Security, Privacy and Trust, Toronto, Canada, 17 - 22 July 2016.
  70. I. Gialampoukidis, S. Vrochidis, I. Kompatsiaris, "A Hybrid framework for news clustering based on the DBSCAN-Martingale and LDA", in Machine Learning and Data Mining in Pattern Recognition, pp. 170-184, Springer International Publishing, 2016. DOI: 10.1007/978-3-319-41920-6_13
  71. A. Moumtzidou, S. Papadopoulos, S. Vrochidis I. Kompatsiaris, K. Kourtidis, G. Hloupis, I. Stavrakas, K. Papachristopoulou, C. Keratidis, "Collection of Multimodal Environmental Data for Air Quality Estimation", in Proc. of 1st International Workshop on the Social Web for Environmental and Ecological Monitoring (SWEEM), Cologne, Germany, 17 May 2016. OPEN ACCESS
  72. T. Tsikrika, A. Latas, A. Moumtzidou, E. Chatzilari, S. Vrochidis and I. Kompatsiaris,"Discovery of Environmental Web Resources Based on the Combination of Multimedia Evidence", in 2nd International Workshop on Environmental Multimedia Retrieval (EMR 2015), Shanghai, China, June 23, 2015. https://doi.org/10.1145/2764873.2764876
  73. A. Moumtzidou, S. Vrochidis, I. Kompatsiaris. "Discovery, Analysis and Retrieval of Multimodal Environmental Information". Third Edition. IGI Global, 1 June 2015. 4528-4542. OPEN ACCESS
  74. T. Tsikrika, A. Moumtzidou, S. Vrochidis and I. Kompatsiaris. "Focussed Crawling of Environmental Web Resources Based on the Combination of Multimedia Evidence, Multimedia Tools and Applications". May 2015, pp 1-25, 31 May 2015. OPEN ACCESS
  75. L. Wanner, H. Bosch, N. Bouayad-Agha, G. Casamayor, T. Ertl, D. Hilbring, L. Johansson, K. Karatzas, A. Karppinen, I. Kompatsiaris, T. Koskentalo, S. Mille, J. Mossgraber, A. Moumtzidou, M. Myllynen, E. Pianta, M. Rospocher, L. Serafini, V. Tarvainen, S. Tonelli, S. Vrochidis. "Getting the environmental information across: From the web to the user". Expert Systems, 15 December 2014. OPEN ACCESS
  76. L. Johansson, V. Epitropou, K. Karatzas, A. Karppinen, L. Wanner, S. Vrochidis, A. Bassoukos, J. Kukkonen, I. Kompatsiaris. "Fusion of meteorological and air quality data extracted from the web for personalized environmental information services". Environmental Modeling and Software Journal, 2015, Volume 64, February 2015, pp. 143–155, 12 December 2014. OPEN ACCESS
  77. T. Tsikrika, A. Moumtzidou, S. Vrochidis and I. Kompatsiaris, "Focused Crawling of Environmental Web Resources: A Pilot Study on the Combination of Multimedia Evidence", in Proceedings of 1st International Workshop on Environmental Multimedia Retrieval (EMR 2014), Glasgow, UK, April 1, 2014. DOI: 10.1007/s11042-015-2624-3
  78. A. Moumtzidou, S. Vrochidis, E. Chatzilari and I. Kompatsiaris, "Discovery of Environmental Resources based on Heatmap Recognition", in Proceedings of the IEEE International Conference on Image Processing (ICIP 2013), Melbourne, Australia, September 15-18, 2013.
  79. A. Moumtzidou, S. Vrochidis, I. Kompatsiaris, "Discovery of Weather Forecast Web Resources based on Ontology and Content-driven Hierarchical Classification", in Proceedings of 14th International Conference on Engineering Applications of Neural Networks (EANN 2013), Halkidiki, Greece, 13-16 September, 2013. Communi-cations in Computer and Information Science, Springer Berlin Heidelberg, Vol. 383, pp. 223-232.
  80. A. Moumtzidou, V. Epitropou, S. Vrochidis, K. Karatzas, S. Voth, A. Bassoukos, J. Mossgraber, A. Karppinen, J. Kukkonen and I. Kompatsiaris. "A Model for Environmental Data Extraction from Multimedia and its Evaluation against various Chemical Weather Forecasting Datasets". Journal of Ecological Informatics, pp. 69-82, 2014, special issue, ISSN 1574-9541, 4 September 2013. OPEN ACCESS
  81. L. Wanner, H. Bosch, S. Vrochidis, N. Bouayad-Agha, G. Casamayor, L. Johansson, A. Karppinen, A. Moumtzidou, I. Kompatsiaris, T. Ertl, "Involving the Expert in the Delivery of Environmental Information from the Web", EnviroInfo 2013, Hambourg, September 2-4, 2013, pp. 561-568.
  82. S. Vrochidis, H. Bosch, A. Moumtzidou, F. Heimerl, T. Ertl, I. Kompatsiaris,"An Environmental Search Engine based on Interactive Visual Classification", in Proceedings of the 1st ACM international workshop on Multimedia analysis for ecological data (MAED 2012), pp. 49-52, November 2, 2012, Nara, Japan. https://doi.org/10.1145/2390832.2390845
  83. A. Moumtzidou, V. Epitropou, S. Vrochidis, S. Voth, A. Bassoukos, K. Karatzas, J. Mossgraber, I. Kompatsiaris, A. Karppinen and J. Kukkonen, "Environmental Data Extraction from Multimedia Resources", in Proceedings of the 1st ACM international workshop on Multimedia analysis for ecological data (MAED 2012), pp. 13-18, November 2, 2012, Nara, Japan. https://doi.org/10.1145/2390832.2390836
  84. S. Vrochidis, V. Epitropou, A. Bassoukos, S. Voth, K. Karatzas, A. Moumtzidou, J. Mossgraber, I. Kompatsiaris, A. Karppinen, J. Kukkonen,"Extraction of environmental data from on-line environmental information sources", in 3rd Intelligent Systems for Quality of Life information Services Workshop (ISQL 2012), September 29, 2012, Halkidiki, Greece. Artificial Intelligence Applications and Innovations, IFIP Advances in Information and Communication Technology Volume 382, pp 361-370.
  85. A. Moumtzidou, S. Vrochidis, S. Tonelli, I. Kompatsiaris and E. Pianta,"Discovery of Environmental Nodes in the Web", in Proceedings of the 5th IRF Conference, Austria, Vienna, July 2-3, 2012. https://doi.org/10.1007/978-3-642-31274-8_5
  86. L. Wanner, M. Rospocher, S. Vrochidis, H. Bosch, N. Bouayad-Agha, U. Bugel, G. Casamayor, T. Ertl, D. Hil-bring, A. Karppinen, I. Kompatsiaris, T. Koskentalo, S. Mille, J. Mossgraber, A. Moumtzidou, M. Myllynen, E. Pianta, H. Saggion, L. Serafini, V. Tarvainen and S. Tonelli, "Personalized Environmental Service Configuration and Delivery Orchestration: The PESCaDO Demonstrator", in Proceedings of the 9nth Extended Semantic Web Conference (ESWC 2012), Heraclion, Crete, Greece, May 27-31, 2012. https://doi.org/10.1007/978-3-662-46641-4_41
  87. L. Wanner, S. Vrochidis, S. Tonelli, J. Mossgraber, H. Bosch, A. Karppinen, M. Myllynen, M. Rospocher, N. Bouayad-Agha, U. Brugel, G. Casamayor, T. Ertl, I. Kompatsiaris, T. Koskentalo, S. Mille, A. Moumtzidou, E. Pianta, H. Saggion, L. Serafini, V. Tarvainen, "Building an Environmental Information System for Personalized Content Delivery", in International Symposium on Environmental Software Systems (ISESS 2011), Brno, Czech Republic, June 2011. https://doi.org/10.1007/978-3-642-22285-6_19