FCT – Multimodal Data Fusion and Analytics Group

Object Detection and Recognition in Visual Content Understanding

D. Touska, K. Gkountakos, O. Theodosiadou, T. Tsikrika, S. Vrochidis, "Object Detection and Recognition in Visual Content Understanding", CERTH, Thessaloniki, Greece, Tech. Rep. INFINITY project H2020, 2023.

Artificial Intelligence to counter Cyber-Terrorism

S. Bianchi, M. Mancuso, C. Paternoster, G. Kalpakis, T. Tsikrika, S. Vrochidis, D. Kozhuharova, and B. Jaeger. “Artificial Intelligence to counter Cyber-Terrorism. ” in Proceedings International Conference on Cybersecurity and Cybercrime, 5-7 December 2023, Vol. 10

Real-time Threat Assessment based on Hidden Markov Models

O. Theodosiadou, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, “Real-time Threat Assessment based on Hidden Markov Models”, Risk Analysis 2023, vol. 43, no. 10, pp. 2069-2081, October 2023, https://doi.org/10.1111/risa.14105.

M4D-MKLab/ITI-CERTH Participation in TREC Deep Learning Track 2022

A-M. Koufakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, “M4D-MKLab/ITI-CERTH Participation in TREC Deep Learning Track 2022” in Proc. Text REtrieval Conference (TREC) 2022 Workshop, Gaithersburg, MD, USA, 14-18 Nov. 2022.

ITI-CERTH participation in ActEV and AVS Tracks of TRECVID 2022

K. Gkountakos, D. Galanopoulos, D. Touska, K. Ioannidis, S. Vrochidis, V. Mezaris, I. Kompatsiaris, “ITI-CERTH participation in ActEV and AVS Tracks of TRECVID 2022”, Proc. TRECVID 2022 Workshop, Gaithersburg, MD, USA, 6 Dec. 2022.

Graph-Based Data Association in Multiple Object Tracking: A Survey

D. Touska, K. Gkountakos, K. Ioannidis, T. Tsikrika, S. Vrochidis and I. Kompatsiaris, "Graph-Based Data Association in Multiple Object Tracking: A Survey", 2023, In Proceedings of the 29th International Conference on Multimedia Modeling (MMM 2023), 9 - 12 January 2023, Bergen, Norway.

Automatic Visual Recognition of Unexploded Ordnances Using Supervised Deep Learning

G. Begkas, P. Giannakeris, K. Ioannidis, G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris. “Automatic Visual Recognition of Unexploded Ordnances Using Supervised Deep Learning” in Proceedings of the 2022 International Conference on Multimedia Retrieval, Newark, NJ, USA, June 27-30, 2022, pp. 286-294, DOI:https://doi.org/10.1145/3512527.3531383.

Vehicle Color Identification Framework using Pixel-level Color Estimation from Segmentation Masks of Car Parts

K. Stavrothanasopoulos, K. Gkountakos, K. Ioannidis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Vehicle Color Identification Framework using Pixel-level Color Estimation from Segmentation Masks of Car Parts". Fifth IEEE International Conference on Image Processing, Applications and Systems (IPAS 2022), 07-09 December, 2022, Genova, Italy.

Selective Word Substitution for Contextualized Data Augmentation

K. Pantelidou, D. Chatzakou, T. Tsikrika, S. Vrochidis, I. Kompatsiaris. "Selective Word Substitution for Contextualized Data Augmentation". In Proc. of the 27th International Conference on Natural Language & Information Systems (NLDB), Valencia, Spain, 15-17 June 2022, pp.508-516.

M4D-MKLab/ITI-CERTH Participation in TREC Deep Learning Track 2021

A-Μ Koufakis, T. Tsikrika, S. Vrochidis, & I. Kompatsiaris, "M4D-MKLab/ITI-CERTH Participation in TREC Deep Learning Track 2021". Text REtrieval Conference (TREC).

ITI-CERTH participation in ActEV and AVS Tracks of TRECVID 2021

K. Gkountakos, D. Galanopoulos, D. Touska, K. Ioannidis, S. Vrochidis, V. Mezaris, I. Kompatsiaris, "ITI-CERTH participation in ActEV and AVS Tracks of TRECVID 2021" in Proc. TRECVID 2021 Workshop, Gaithersburg, MD, USA (Virtual), 2021.

Study of 3D Digitisation Modalities for Crime Scene Investigation

G. Galanakis,; X.Zabulis,; T.Evdaimon,;S.-E. Fikenscher,; S.Allertseder,; T.Tsikrika,; S. Vrochidis "A Study of 3D Digitisation Modalities for Crime Scene Investigation". Forensic. Sci. 2021, 1, 56–85.

Spatio-temporal activity detection and recognition in untrimmed surveillance videos

Κ. Gkountakos, D. Touska, K. Ioannidis, T. Tsikrika, S. Vrochidis, & I. Kompatsiaris. "Spatio-temporal activity detection and recognition in untrimmed surveillance videos". In Proceedings of the 2021 International Conference on Multimedia Retrieval, August 2021.

Crowd Violence Detection from Video Footage

K. Gkountakos, K. Ioannidis, T.Tsikrika, S. Vrochidis, & Ι. Kompatsiaris, "Crowd Violence Detection from Video Footage". In 2021 International Conference on Content-Based Multimedia Indexing (CBMI). IEEE June 2021.

ITI-CERTH participation in TRECVID 2019

K. Gkountakos, K. Ioannidis, S. Vrochidis, I. Kompatsiaris, "ITI-CERTH participation in TRECVID 2019", Proc. TRECVID 2019 Workshop, Gaithersburg, MD, USA, Nov. 2019.

ITI-CERTH participation in TRECVID 2020

K. Gkountakos, D. Galanopoulos, M. Mpakratsas, D. Touska, A. Moumtzidou, K. Ioannidis, I. Gialampoukidis, S. Vrochidis, V. Mezaris, I. Kompatsiaris, "ITI-CERTH participation in TRECVID 2020", Proc. TRECVID 2020 Workshop, Gaithersburg, MD, USA, Dec. 2020.

Dark Web Ιnvestigation

B. Akhgar, M. Gercke, S. Vrochidis, H. Gibson (2021). Dark Web investigation. 288 Pages, Springer.

OSINT and the Dark Web

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.

Analysis of Suspended Terrorism-Related Content on Social Media

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.

Visual Recognition of Abnormal Activities in Video Streams

K. Gkountakos, K. Ioannidis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris. "Visual Recognition of Abnormal Activities in Video Streams". In Technology Development for Security Practitioners (pp. 151-165). Cham: Springer International Publishing.

Query reformulation based on word embeddings: A comparative study

P. Panagiotou, G. Kalpakis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris. "Query reformulation based on word embeddings: A comparative study". Technology Advances and Support for Security Practitioners of the Security Informatics and Law Enforcement book series.

Hybrid Focused Crawling on the Surface and the Dark Web

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.

TENSOR: Retrieval and Analysis of Heterogeneous Online Content for Terrorist Activity Recognition

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.

Probabilistic density-based estimation of the number of clusters using the DBSCAN-martingale process

I. Gialampoukidis, S. Vrochidis, I. Kompatsiaris, and I. Antoniou. “Probabilistic density-based estimation of the number of clusters using the DBSCAN-martingale process”. Pattern Recognition Letters, Vol. 123, pp 23-30, 4 March 2019.

Concept Detection on Multimedia Web Resources about Home Made Explosives

G. Kalpakis, T. Tsikrika, F. Markatopoulou, N. Pittaras, S. Vrochidis, V. Mezaris, I. Patras, and I. Kompatsiaris, "Concept Detection on Multimedia Web Resources about Home Made Explosives", in Proceedings of the International Workshop on Multimedia Forensics and Security (MFSec 2015), held in conjunction with the 10th International Conference on Availability, Reliability and Security, Toulouse, France, 2015. DOI: 10.1109/ARES.2015.85

A Framework for the Discovery, Analysis, and Retrieval of Multimedia Homemade Explosives Information on the Web

T. Tsikrika, G. Kalpakis, S. Vrochidis, I. Kompatsiaris, I. Paraskakis, I. Kavasidis, J. Middleton, and U. Williamson, "A Framework for the Discovery, Analysis, and Retrieval of Multimedia Homemade Explosives Information on the Web", in Proceedings of the International Workshop on Multimedia Forensics and Security (MFSec 2015), held in conjunction with the 10th International Conference on Availability, Reliability and Security, Toulouse, France, 2015. https://doi.org/10.1109/ARES.2015.86

MFSec ’17: Proceedings of the 2nd International Workshop on Multimedia Forensics and Security

M. Zampoglou, S. Vrochidis, A. Rocha, V. Katos (Eds.). (2017). MFSec '17: Proceedings of the 2nd International Workshop on Multimedia Forensics and Security. Bucharest, Romania, 2017. Association for Computing Machinery, 30 June 2017.

Identifying terrorism-related key actors in multidimensional social networks

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.

Detection of Ter-rorism-related Twitter Communities using Centrality Scores

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.

Analysis of Suspended Terrorism-Related Content on Social Media

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.

Towards a framework for detecting advanced Web bots

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.

VERGE in VBS 2020

S. Andreadis, A. Moumtzidou, K. Apostolidis, K. Gkountakos, D. Galanopoulos, E. Michail, I. Gialampoukidis, S. Vrochidis, V. Mezaris, I. Kompatsiaris, "VERGE in VBS 2020", Proc. 26th Int. Conf. on Multimedia Modeling (MMM2020), 5-8 January 2020, Daejeon Convention Center (DCC), Korea

A comparative study of clustering methods using word embeddings

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

An extensible framework for interactive real-time visualizations of large-scale heterogeneous multimedia information from online sources

A. Katmada, G. Kalpakis, T. Tsikrika, S. Vrochidis & Y. Kompatsiaris, "An extensible framework for interactive real-time visualizations of large-scale heterogeneous multimedia information from online sources", in Proceedings of the International Conference on Multimedia Modeling (MMM2020), Special Session on “Multimedia Analytics: Perspectives, Tools and Applications”, Daejeon, Korea, 5-8 January 2020.

A Crowd Analysis Framework for Detecting Violence Scenes

K. Gkountakos, K. Ioannidis, T. Tsikrika, S. Vrochidis, I. Kompatsiaris,"A Crowd Analysis Framework for Detecting Violence Scenes", in Proceedings of the 2020 International Conference on Multimedia Retrieval (ICMR ‘20), June 8–11, 2020, Dublin, Ireland.

Semantic Web Technologies in Fighting Crime and Terrorism: The CONNEXIONs Approach

A. Koufakis, D. Chatzakou, G. Meditskos, T. Tsikrika, S. Vrochidis, I. Kompatsiaris, "Semantic Web Technologies in Fighting Crime and Terrorism: The CONNEXIONs Approach", Invited talk in 1st International Workshop on IoT infrastructures for safety in pervasive environments (IoT4SAFE), 2 June, 2020.

A modified Single-Shot multibox Detector for beyond Real-Time Object Detection

G. Orfanidis, K. Ioannidis, A. Tefas, S. Vrochidis, Y. Kompatsiaris, "A modified Single-Shot multibox Detector for beyond Real-Time Object Detection", 25th International Conference on Pattern Recognition, (ICPR 2020), 10 & 15 January 2021, Milan, Italy.