Selected Publications and Reports
- “Vasileios Perifanis; George Drosatos; Giorgos Stamatelatos; Pavlos S. Efraimidis, FedPOIRec: Privacy-Preserving Federated POI Recommendation with Social Influence”, accepted in Information Sciences, Elsevier, 2022.
- V. Perifanis, G. Stamatelatos, G. Drosatos, I. Michailidi and P.S. Efraimidis, Predicting Early Dropouts of an Active and Healthy Ageing App, IFMBE Challenge 2022 submission accepted for IUPESM World Conference on Medical Physics and Biomedical Engineering (IUPESM_WC2022).
- Vasileios Perifanis and Pavlos S. Efraimidis, Federated Neural Collaborative Filtering, Knowledge-Based Systems 242 (2022): 108441, Elsevier.
- Draft version: https://arxiv.org/abs/2106.04405
- P. Kostamis, A. Sendros, and P. S. Efraimidis, Exploring Ethereum’s Data Stores: A Cost and Performance Comparison, BRAINS 2021, DOI: https://doi.org/10.1109/BRAINS52497.2021.9569804
@article{stamatelatos2021poigraph, author={Stamatelatos, Giorgos and Drosatos, George and Gyftopoulos, Sotirios and Briola, Helen and Efraimidis, Pavlos S.}, title={Point-of-interest lists and their potential in recommendation systems}, journal={Information Technology {\&} Tourism, Springer}, year={2021}, month={Feb}, day={01}, issn={1943-4294}, doi={10.1007/s40558-021-00195-5}, url={https://doi.org/10.1007/s40558-021-00195-5} } - V. Katos and P. Efraimidis, Privacy in data-driven circular economy, accepted in Encyclopedia of Cryptography, Security and Privacy, Springer.
- A. Tasidou, A. and P. Efraimidis, Economics of Personal Data, accepted in Encyclopedia of Cryptography, Security and Privacy, Springer.
@article{gyftopoulos2020twitter, title={A Twitter-based approach of news media impartiality in multipartite political scenes}, author={Gyftopoulos, Sotirios and Drosatos, George and Stamatelatos, Giorgos and Efraimidis, Pavlos S}, journal={Social Network Analysis and Mining, Springer}, volume={10}, number={36}, pages={36}, year={2020}, doi = {10.1007/s13278-020-00642-x}, url = {https://link.springer.com/article/10.1007%2Fs13278-020-00642-x}, publisher={Springer} } @article{STAMATELATOS2020102172, title = {Revealing the political affinity of online entities through their Twitter followers}, journal = {Information Processing \& Management, Springer}, volume = {57}, number = {2}, pages = {102172}, year = {2020}, issn = {0306-4573}, doi = {10.1016/j.ipm.2019.102172}, url = {http://www.sciencedirect.com/science/article/pii/S0306457319305023}, author = {Giorgos Stamatelatos and Sotirios Gyftopoulos and George Drosatos and Pavlos S. Efraimidis}, keywords = {Social network analysis, Twitter followers, News media, Political affinity} } - Dimitriadis, A., Drosatos, G., Efraimidis, P. S. (2019, November). How much does a zero-permission Android app know about us?. In Proceedings of the Third Central European Cybersecurity Conference (pp. 1-5).
@inproceedings{Briola:2018, author = {Briola, Helen and Drosatos, George and Stamatelatos, Giorgos and Gyftopoulos, Sotirios and Efraimidis, Pavlos S.}, title = {Privacy Leakages about Political Beliefs through Analysis of Twitter Followers}, booktitle = {Proceedings of the 22nd Pan-Hellenic Conference on Informatics (PCI 2018)}, year = {2018}, isbn = {978-1-4503-6610-6/18/11}, location = {Athens, Greece}, pages = {1--6}, numpages = {6}, doi = {10.1145/3291533.3291557}, publisher = {ACM}, address = {New York, NY, USA}, keywords = {Social network analysis, Privacy leakages, Political beliefs, Twitter followers} } @inproceedings{stamatelatos2018deriving, title={Deriving the Political Affinity of Twitter Users from Their Followers}, author={Stamatelatos, Giorgos and Gyftopoulos, Sotirios and Drosatos, George and Efraimidis, Pavlos S}, booktitle={Proceedings of the 11th IEEE International Conference on Social Computing}, doi = {10.1109/BDCloud.2018.00173}, year={2018}, organization={IEEE} } - Sotirios Gyftopoulos; Pavlos Efraimidis; Panagiotis Katsaros, Formal Analysis of DeGroot Influence Problems using Probabilistic Model Checking, Journal of Simulation Modelling Practice and Theory (SIMPAT), 89 (2018): 144-159, Elsevier.
- A.-S. Kleinaki, P. Mytis-Gkometh, G. Drosatos, P. S. Efraimidis and E. Kaldoudi, A Blockchain-based Notarization Service for Biomedical Knowledge Retrieval, Computational and Structural Biotechnology Journal, 16 (2018): 288-297, Elsevier.
- George Drosatos, Kyriakos Bakirlis, Pavlos Efraimidis and Eleni Kaldoudi, Communicating Personalized Risk Factors for Lifestyle Coaching, HealthInf 2018, pp. 571-578.
- P. Mytis-Gkometh, G. Drosatos, P. S. Efraimidis and E. Kaldoudi, Notarization of Knowledge Retrieval from Biomedical Repositories using Blockchain Technology, ICBHI 2017, November 18-21, 2017, Thessaloniki, pp. 69-73, Springer.
- Achilleas Platanitis, Sotirios Gyftopoulos, Pavlos S. Efraimidis, Stochastic Games : Studying a Card Game, accepted in Student’s Conference of Electrical and Computer Engineering (ECESCON) 2017.
- Drosatos, George, Aimilia Tasidou, and Pavlos S. Efraimidis. “Privacy-Enhanced Television Audience Measurements.” ACM Transactions on Internet Technology (TOIT) 17, 1, Article 10 (February 2017), 29 pages. DOI: https://doi.org/10.1145/3009969.
- Remous‐Aris Koutsiamanis and Pavlos S. Efraimidis. “Implementing PacketEconomy: Distributed money‐based QoS in OMNET++.” International Journal of Communication Systems 30.11 (2017).
@inproceedings{gyftopoulos2016solving, title={Solving Influence Problems on the DeGroot Model with a Probabilistic Model Checking Tool}, author={Gyftopoulos, Sotirios and Efraimidis, Pavlos S and Katsaros, Panagiotis}, booktitle={Proceedings of the 20th Pan-Hellenic Conference on Informatics}, pages={31}, year={2016}, organization={ACM} } -
Pavlos S. Efraimidis, George Drosatos, Avi Arampatzis. G. Stamatelatos, Ioannis N. Athanasiadis. A Privacy-by-Design Contextual Suggestion System for Tourism. Journal of Sensor and Actuator Networks, 5(2), 10, special issue on “Techno-Human Collective Systems for Smart Cities Innovation”, 2016.
- A preliminary version of this work appeared as
@inproceedings{drosatos2015pythia, title={Pythia: A Privacy-enhanced Personalized Contextual Suggestion System for Tourism}, author={George Drosatos and Pavlos S. Efraimidis and Avi Arampatzis and Giorgos Stamatelatos and Ioannis N, Athanasiadis}, booktitle={Computer Software and Applications Conference (COMPSAC), 2015 IEEE 39th Annual}, volume={2}, pages={822--827}, year={2015}, organization={IEEE} }
- A preliminary version of this work appeared as
- Antonios Dimitriadis, Pavlos S. Efraimidis and Vasilios Katos, Malevolent App Pairs: An Android Permission Overpassing Scheme, accepted in 1st International Workshop for Malicious Software and Hardware in Internet of Things (MAL-IoT 2016), in proceedings of the ACM International Conference on Computing Frontiers (pp. 431-436).
- George Drosatos, Pavlos S. Efraimidis, Garrath Williams and Eleni Kaldoudi,”Towards Privacy by Design in Personal e-Health Systems.” Proc. of the 9th International Conference on Health Informatics (HealthInf 2016), part of BIOSTEC, pp. 472-477, 2016.
- Aimilia Tasidou, Pavlos S. Efraimidis, Yannis Soupionis, Lilian Mitrou, Vasilios Katos,”Privacy-preserving, user-centric VoIP CAPTCHA challenges: An integrated solution in the SIP environment.” Information & Computer Security 24.1 (2016): 2-19.
- Efraimidis, Pavlos S. “Weighted random sampling over data streams.” Algorithms, Probability, Networks, and Games. Springer, LNCS, volume 9295, 2015. 183-195.
- P.S. Efraimidis. Weighted Random Sampling over Data Streams, Technical Report LPDP-2010-03, Dept. Electrical and Computer Engineering, Democritus University of Thrace (http://arxiv.org/abs/1012.0256).
- Antonios Chatzitoulousis, Pavlos S. Efraimidis, and Ioannis N. Athanasiadis, Interoperable multimedia annotation and retrieval for the tourism sector, 9th Metadata and Semantics Research Conference (MTSR 2015), pp. 65-76, CCIS 544, Springer.
@inproceedings{karagiannis2015social, title={Social network analysis of public lists of POIs}, author={Karagiannis, Ioannis and Arampatzis, Avi and Efraimidis, Pavlos S and Stamatelatos, Giorgos}, booktitle={Proceedings of the 19th Panhellenic Conference on Informatics}, pages={61--62}, year={2015}, organization={ACM}, doi={10.1145/2801948.2802031}, url={https://doi.org/10.1145/2801948.2802031} } - Arampatzis, Avi, George Drosatos, and Pavlos S. Efraimidis. “Versatile Query Scrambling for Private Web Search.” Information Retrieval Journal 18.4 (2015): 331-358.
- M. Tsavli, P.S. Efraimidis, V. Katos, L. Mitrou, Reengineering the user: Privacy concerns about personal data on smartphones, Information Management and Computer Security, 23(4), 394-405, Emerald, 2015.
- Preliminary results presented in: M. Tsavli, P.S. Efraimidis, V. Katos, Reengineering the user: Privacy concerns about personal data on smartphones, 8th International Symposium on Human Aspects of Information Security & Assurance (HAISA 2014).
- I.Refanidis, Ch.Emmanouilidis, I.Sakellariou, A.Alexiadis, R.A.Koutsiamanis, K.Agnantis, A.Tasidou, F.Kokkoras and P.S.Efraimidis, myVisitPlannerGR: Personalized Itinerary Planning System for Tourism, accepted in the 8th Hellenic Conference on Artificial Intelligence (SETN 2014).
- Ioannis Psaroudakis, Vasilios Katos, and Pavlos S. Efraimidis, A novel mechanism for anonymizing GSM calls using a resource based SIP community network, accepted in Security and Communication Networks, Wiley, 2014.
- Preliminary results presented in SEC 2012: Ioannis Psaroudakis, Vasilios Katos, and Pavlos S. Efraimidis, A framework for anonymizing GSM calls over a smartphone VoIP network, In proceedings of the 27th IFIP International Information Security and Privacy Conference (SEC 2012), Volume 376, 2012, pp 543-548, June 4-6, 2012. (PDF)
- George Drosatos, Pavlos S. Efraimidis, User-Centric Privacy-Preserving Statistical Analysis of Ubiquitous Health Monitoring Data, accepted in Computer Science and Information Systems, 2014.
- George Drosatos, Pavlos S. Efraimidis, Ioannis N. Athanasiadis, Ellie D’Hondt and Matthias Stevens, Privacy-Preserving Computation of Participatory Noise Maps in the Cloud, Journal of Systems and Software, Volume 92, Pages 170–183, Elsevier, June 2014.
- Preliminary results presented in COMPSAC 2012:
@inproceedings{NoiseTubePrime, author={George Drosatos and Pavlos S. Efraimidis and Ioannis N. Athanasiadis and Ellie D'Hondt and Matthias Stevens}, booktitle={36th Annual IEEE Computer Software and Applications Conference (COMPSAC 2012)}, title={A privacy-preserving cloud computing system for creating participatory noise maps}, year={2012}, month={july}, isbn = {978-0-7695-4736-7}, location = {Izmir, Turkey}, pages = {581-586}, publisher = {IEEE Computer Society} }
- Preliminary results presented in COMPSAC 2012:
- Yannis Soupionis, Remous-Aris Koutsiamanis, Pavlos S. Efraimidis, Dimitrios Gritzalis, A game-theoretic analysis of preventing spam over Internet Telephony via audio CAPTCHA-based authentication, accepted in Journal of Computer Security, IOS Press, 2014.
- TREC 2013 – Contextual Suggestion track: Award winning algorithms for contextual recommendation in the Text Retrieval Conference (TREC) Contextual Suggestion track, November 2013. (Poster Slides BibTex)
- Pavlos S. Efraimidis and Remous-Aris Koutsiamanis. “Money-based coordination of network packets.” International Conference on Algorithms and Complexity. Springer Berlin Heidelberg, 2013. (PDF)
- Pavlos S. Efraimidis and Remous-Aris Koutsiamanis. On Money as a Means of Coordination between Network Packets, Technical Report available at http://arxiv.org/abs/1208.3747.
- Avi Arampatzis, George Drosatos and Pavlos S. Efraimidis. A Versatile Tool for Privacy-Enhanced Web Search, Proceedings of the 35th European Conference on Information Retrieval (ECIR 2013), Moscow, LNCS 7814, pp. 368-379, Springer, 2013. (PDF)
- Remous-Aris Koutsiamanis and Pavlos S. Efraimidis. A heaviest hitters limiting mechanism with O(1) time complexity for sliding-window data streams, Journal of Internet Technology, Issue Number (ISSN): 1607-9264, 14(1), January 2013, DOI: 10.6138/JIT.2013.14.1.12. (PDF)
- Avi Arampatzis, Pavlos S. Efraimidis and George Drosatos. A Query Scrambler for Search Privacy on the Internet. Information Retrieval, 16(6): 657-679, Springer, 2013, http://dx.doi.org/10.1007/s10791-012-9212-1, 2012, [IF: 0.914, SJR: 0.053]. (PDF BibTex)
- George Drosatos and Pavlos S. Efraimidis. An efficient privacy-preserving solution for finding the nearest doctor. Personal and Ubiquitous Computing: Special Issue on Assistive Environments for the Disabled and the Senior Citizens, 2012, in press, [IF: 0.938, SJR: 0.047]. (PDF BibTex)
- Aimilia Tasidou, Pavlos S. Efraimidis, Yannis Soupionis, Lilian Mitrou, Vasilios Katos, User-centric, Privacy-Preserving Adaptation for VoIP CAPTCHA Challenges, to appear in the 6th International Symposium on Human Aspects of Information Security & Assurance (HAISA 2012).
- George Drosatos, Aimilia Tasidou and Pavlos Efraimidis. Privacy-Preserving Television Audience Measurement using Smart TVs. In proceedings of the 27th IFIP International Information Security and Privacy Conference (SEC 2012), Volume 376, 2012, pp 223-234, June 4-6, 2012, [Acceptance rate: 25%]. (PDF BibTex)
- Avi Arampatzis, Pavlos Efraimidis and George Drosatos. Enhancing Deniability against Query-logs. In proceedings of 33rd European Conference on Information Retrieval (ECIR 2011), pp. 117-128, Apr. 2011, [Acceptance rate: 20%]. (PDF BibTex)
- Lazaros Tsavlidis, Pavlos S. Efraimidis, Remous-Aris Koutsiamanis, Prince: an effective router mechanism for active queue management, to appear in Journal of Internet Engineering, Vol 6, No 1, ISSN 1791-177X. (PDF)
- Aimilia Tasidou and Pavlos S. Efraimidis, Using Personal Portfolios to Manage Customer Data, 6th DPM International Workshop on Data Privacy Management (DPM 2011), LNCS, Volume 7122, 2012, Pages 141-154.
- George Drosatos and Pavlos Efraimidis. Privacy-Preserving Statistical Analysis on Ubiquitous Health Data. In proceedings of the 8th international conference on Trust, privacy and security in digital business (TrustBus 2011), LNCS, Volume 6863, 2011, Pages 24-36. (PDF BibTex)
- Remous-Aris Koutsiamanis, Pavlos S. Efraimidis, An exact and O(1) time heaviest and lightest hitters algorithm for sliding-window data streams, Proceedings of the 5th FTRA International Conference on Multimedia and Ubiquitous Engineering (MUE 2011), IEEE Computer Society, June 28-30, 2011, Pages 89-94. Technical Report available at http://arxiv.org/abs/1103.0116.
- George Drosatos and Pavlos Efraimidis. Privacy-Enhanced Management of Ubiquitous Health Monitoring Data. In proceedings of 4rd ACM International Conference on PErvasive Technologies Related to Assistive Environments (PETRA 2011), May 25-27, 2011. (PDF BibTex).
- Grigorios Anagnostopoulos and Pavlos S. Efraimidis. Bayesian Games on a Maxmin Network Router, In Proceedings of Mini-conference on Applied Theoretical Computer Science (MATCOS-10), student session, Koper, Slovenia, October 13th and 14th, 2010, pp. 29-34. (PDF, Proceedings of MATCOS-10)
- P.S. Efraimidis. (alpha, beta) Fibonacci Search, Technical Report LPDP-2010-02, Dept. Electrical and Computer Engineering, Democritus University of Thrace (http://arxiv.org/abs/1012.0259).
- P.S. Efraimidis, L. Tsavlidis and G. Mertzios, Window-Games between TCP flows, Theoretical Computer Science (TCS), 411:31-33, pp. 2798-2817, 2010, doi:10.1016/j.tcs.2010.03.031 (Technical Report LPDP-2008-01).
- Preliminary results presented in SAGT 2008: P.S. Efraimidis, L. Tsavlidis, Lecture Notes in Computer Science (LNCS) 4997, Springer, pages 95-108, 2008. (report, conf version)
- G. Drosatos and P.S. Efraimidis. A privacy-preserving protocol for finding the nearest doctor in an emergency, 3rd ACM International Conference on PErvasive Technologies Related to Assistive Environments, PETRA 2010, pp. 18:1—8, 2010. (PDF BibTex).
- Aimilia Tasidou, Pavlos S. Efraimidis and Vasilis Katos, Economics of Personal Data Management: Fair Personal Information Trades, 3rd international conference on e-Democracy (eDemocracy 2009), Lecture Notes of ICST (LNICST), Springer-ICST, Volume 26, 2010, pp 151-160.
@inproceedings{stamatelatos2009quantum, AUTHOR = {Georgios Stamatelatos and Georgios Drosatos and Pavlos S. Efraimidis}, TITLE = {Quantum: A Peer-to-Peer Network for Distributed Computations with Enhanced Privacy}, BOOKTITLE = {EYRHKA 2009 Conference Proceedings}, PAGES = {201-210}, ORGANIZATION = {3rd Pan-hellenic Scientific Student Conference on Informatics}, MONTH = {September}, YEAR = {2009} } - P.S. Efraimidis, G Drosatos, F. Nalbadis and A. Tasidou, Towards Privacy in Personal Data Management. Information Management & Computer Security (IMCS), Volume 17, Issue 4, pp. 311-329, Emerald, 2009.
- Pavlos S. Efraimidis and Vasilis Katos, “Probability and Information Theory”, Chapter in the volume “Modern Cryptography: Theory and Applications”, Edited by M. Burmester, S. Gritzalis, S. Katsikas and V. Chrissikopoulos, Publisher: Papasotiriou, Papasotiriou Editions, 2011 (in greek).
- Dimitrios Kikidis and Pavlos S. Efraimidis, “Privacy issues of the usage of Web Search Engines”, 3rd Conference SFHMMY (Students of Electrical and Computer Engineering Departments conference), 10-11 April 2009, Thessaloniki (conf version in greek). The FireFox AddOn Random Search Engine described in the paper.
- Sotirios-Aggelos Lenas, Pavlos S. Efraimidis and Vasilis Katos, “Database Forensics”, Technical Report LPDP-2009-2 (in greek). (pdf)
- Vasilis Katos and Pavlos S. Efraimidis, “Identity Assurance in the Surveillance Society”, chapter in the volume “Privacy Protection in Information and Communication Technologies: Technical and Legal Issues”, Edited by K. Lambrinoudakis, L. Mitrou, S. Gritzalis and S. Katsikas, ISBN 9789607182708, Papasotirou Editions, 2010 (in greek).
- P.S. Efraimidis, The Complexity of Linear Programming in (\gamma,\kappa)-form, Information Processing Letters, Volume 105, Issue 5, 29 February 2008, Pages 199-201 (report, journal version) .
- P.S. Efraimidis and P. Spirakis, Weighted Random Sampling, Chapter in Encyclopaedia of Algorithms, Springer 2008 (chapter).
- G. Papaschinopoulos, G. Stefanidou and P.S. Efraimidis, Existence, uniqueness and asymptotic behavior of the solutions of a fuzzy differential equation with piecewise constant argument, Information Sciences 177 (2007), pp 3855-3870 (journal version).
- G. Drosatos, P.S. Efraimidis and A. Karakos, Secure Mobile Database Applications: A Case Study, Technical Report LPDP-2007-01 (PDF BibTex).
- P.S. Efraimidis and P. Spirakis. Approximation schemes for scheduling and covering on unrelated machines, Theoretical Computer Science 359 (1), pp 400-417, 2006 (report, journal version).
- P.S. Efraimidis and P. Spirakis. Weighted Random Sampling with a Reservoir, Information Processing Letters 97 (5), pp 181-185, 2005 (report, journal version).
- P.S. Efraimidis and P. Spirakis. Efficient Approximation Algorithms for Scheduling Unrelated Parallel Machines, 1st Balkan Conference in Informatics, pp 122-132, Thessaloniki, Greece, 2003.
- K. Siozios, P.S. Efraimidis and A. Karakos. Design and implementation of a Secure Mobile IP Architecture, 9th Panhellenic Conference on Informatics, pp 269-279, Thessaloniki, Greece, 2003.
- P.S. Efraimidis and P. Spirakis. Positive Linear Programming extensions: Parallel Complexity and Applications. Proc. EuroPAR 2000, August 30 – September 1, 2000, Technical University of Munich, Germany, Lecture Notes in Computer Science 1900: pp. 456-460, Springer 2000, ISBN 3-540-67956-1.
- P.S. Efraimidis and P. Spirakis. The Lagrangian Search Method (LSM): Applying Lagrangian relaxation to approximately solved restricted linear programs. Chapter in Advances in Convex Analysis and Global Optimization: Honoring the Memory of C. Caratheodory (1873-1950), N. Hadjisavvas and P. Pardalos (eds.), Dordrecht, Kluwer Academic Publishers, Aug. 2001.
- P.S. Efraimidis and P. Spirakis. Combinatorial Randomized Rounding: Boosting Randomized Rounding with Combinatorial Arguments, Chapter in the Book “Stochastic optimization: algorithms and applications”, (Gainesville, FL, 2000), S. Uryasev and P. Pardalos (eds.), pp. 31-53, Kluwer Academic Publishers, Dordrecht, 2001.
- P.S. Efraimidis and P. Spirakis. Randomized Approximation Schemes for Scheduling Unrelated Parallel Machines. Electronic Colloquium on Computational Complexity (ECCC), TR 00-007, 2000.
- P.S. Efraimidis, C. Glymidakis, B. Mamalis, P. Spirakis, and B. Tampakas. Parallel Text Retrieval on a High Performance Super Computer Using the Vector Space Model. ACM SIGIR 1995: 58-66, Seattle, WA.
- S. Walter, S. Volmer and P.S. Efraimidis: Parallel Rendering of 3D Ultrasound at Interactive Rates. Proc. 1st EUROGRAPHICS Workshop for Parallel Graphics and Visualization, pp. 189-202, Bristol, September 1996.
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