• Research Interests:
    • Distributed Computer Systems.
    • Peer-to-Peer Systems.
      • Auditing/Accounting.
      • Complex Query Processing and Optimization.
      • Load Balancing.
      • Routing Overlays.
      • Security.
      • Ubiquitous Computing Devices as Peers.
    • Internet Content Integration & Dissemination.
      • Mediators / Wrappers.
      • Query Result Caching (Active / Semantic Caching).
    • [DBLP] [entry].



  • Journal Publications:
    1. S. Karavarsamis, N. Ntarmos, K. Blekas, and I. Pitas. "Detecting Pornographic Images by Localizing Skin ROIs." International Journal of Digital Crime and Forensics (IJDCF), Volume 5, Number 1, September 2013. [N/A]

    2. T. Pitoura, N. Ntarmos, and P. Triantafillou. "Saturn: Range Queries, Load Balancing and Fault Tolerance in DHT Data Systems." Transactions on Knowledge and Data Engineering (TKDE), Volume 24, Number 7, July 2012 (accepted: 23 December 2010). [N/A]

    3. N. Ntarmos, P. Triantafillou, and G. Weikum. "Statistical Structures for Internet-Scale Data Management." VLDB Journal (VLDBJ), Volume 18, Number 6, December 2009. [N/A]

    4. N. Ntarmos, P. Triantafillou, and G. Weikum. "Distributed Hash Sketches: Scalable, Efficient, and Accurate Cardinality Estimation for Distributed Multisets." ACM Transactions on Computer Systems (TOCS), Volume 27, Issue 1, February 2009. [N/A]

    5. P. Triantafillou, N. Ntarmos, and J. Yannakopoulos. "D.I.C.E.: A Cache Engine for e-Content Integration." IEEE Internet Computing, March/April 2004. [pdf]

  • Conference Publications:
    1. G. Sfakianakis, I. Patlakas, N. Ntarmos, and P. Triantafillou, "Interval Indexing and Querying on Key-Value Cloud Stores." Proceedings of the 29th IEEE International Conference on Data Engineering (ICDE), April 2013 (to appear). [N/A]

    2. S. Karavarsamis, I. Pitas, and N. Ntarmos, "Recognizing Pornographic Images." Proceedings of the 14th ACM Workshop on Multimedia and Security (MMSec), September 2012. [N/A]

    3. G. Koloniari, N. Ntarmos, E. Pitoura, and D. Souravlias, "One is Enough: Distributed Filtering for Duplicate Elimination" Proceedings of the 20th ACM Conference on Information and Knowledge Management (CIKM), October 2011. [N/A]

    4. S. Karavarsamis, N. Ntarmos, and K. Blekas, "InFeRno: An Intelligent Framework for Recognizing Pornographic Web Pages." Proceedings of the European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases (ECML-PKDD) -- demo paper, September 2011. [N/A]

    5. C. Kaidos, A. Pasiopoulos, N. Ntarmos, and P. Triantafillou, "Design and Implementation of the Social Network File System." Proceedings of the 4th Workshop on Social Network Systems (SNS), April 2011. [N/A]

    6. G. Weikum, N. Ntarmos, M. Spaniol, P. Triantafillou, A. Benczur, S. Kirkpatrick, J. Masanes, and M. Williamson. "Longitudinal Analytics on Web Archive Data: It's About Time!" Proceedings of the 5th Biennial Conference on Innovative Data Systems Research (CIDR), January 2011. [N/A]

    7. A. Loupasakis, N. Ntarmos, and P. Triantafillou. "eXO: Decentralized Autonomous Scalable Social Networking." Proceedings of the 5th Biennial Conference on Innovative Data Systems Research (CIDR), January 2011. [N/A]

    8. M. Bender, S. Michel, N. Ntarmos, P. Triantafillou, G. Weikum, and C. Zimmer. "Discovering and Exploiting Keyword and Attribute-Value Co-occurrences to Improve P2P Routing Indices." Proceedings of the 15th ACM Conference on Information and Knowledge Management (CIKM), November 2006. (Best Interdisciplinary Paper Award) [pdf] (*)

    9. N. Ntarmos, P. Triantafillou, and G. Weikum. "Counting at large: Efficient cardinality estimation in Internet-scale data networks." Proceedings of the 22nd International Conference on Data Engineering (ICDE), April 2006. [pdf] (*)

    10. T. Pitoura, N. Ntarmos, and P. Triantafillou. "Replication, Load Balancing, and Efficient Range Query processing in DHT Data Networks." Proceedings of the 10th International Conference on Extending Database Technology (EDBT), March 2006. [pdf] (*)

    11. N. Ntarmos, T. Pitoura, and P. Triantafillou. "Range query optimization leveraging peer heterogeneity in DHT data networks." Proceedings of the 3rd International Workshop on Databases, Information Systems, and Peer-to-Peer Computing (DBISP2P), August 2005. [pdf] (*)

    12. N. Ntarmos and P. Triantafillou. "AESOP: Altruism-Endowed Self-Organizing Peers." Proceedings of the 2nd International Workshop on Databases, Information Systems, and Peer-to-Peer Computing (DBISP2P), August 2004. [pdf] (*)

    13. N. Ntarmos and P. Triantafillou. "SeAl: Managing Accesses and Data in Peer-to-Peer Sharing Networks." Proceedings of the 4th IEEE International Conference on Peer-to-Peer Computing (P2P), August 2004. [pdf] (*)

    14. P. Triantafillou, N. Ntarmos, and J. Yannakopoulos. "D.I.C.E. and Co.In.S.: A Data Integration Cache Engine for a Content Integration System." Proceedings of the 4th IEEE International Conference on Web Information Systems Engineering (WISE) -- short paper, December 2003. [pdf]

    15. P. Triantafillou, N. Ntarmos, and J. Yannakopoulos. "The HyperHotel Application Built over D.I.C.E. and Co.In.S." Proceedings of the 4th IEEE International Conference on Web Information Systems Engineering (WISE) -- demo paper, December 2003. [pdf]

    16. P. Triantafillou, N. Ntarmos, S. Nikoletseas, and P. Spirakis. "Nanopeer Networks and Peer-to-Peer Worlds." Proceedings of the 3rd IEEE International Conference on Peer-to-Peer Computing (P2P), September 2003. [pdf]

    17. P. Triantafillou, C. Xiruhaki, M. Koubarakis, and N. Ntarmos. "Towards High Performance Peer-to-Peer Content and Resource Sharing Systems." In Proceedings of the 1st ACM SIGMOD/VLDB Conference on Innovative Data Systems Research (CIDR), January 2003. [pdf]

  • Informal Conference Publications:
    1. N. Ntarmos and G. Weikum. "Distributed Hash Sketches: Estimating the Cardinality of Large Multisets in Internet-Scale Data Networks." Proceedings of the 5th Hellenic Data Management Symposium (HDMS), September 2006. [N/A] (*)

    2. T. Pitoura, N. Ntarmos, and P. Triantafillou. "Replication, Load Balancing, and Efficient Range Query Processing in DHTs." Proceedings of the 4th Hellenic Data Management Symposium (HDMS), August 2005. [N/A] (*)

    3. N. Ntarmos and P. Triantafillou. "SeAl: Managing Accesses and Data in Peer-to-Peer Sharing Networks." Proceedings of the 3rd Hellenic Data Management Symposium (HDMS), June 2004. [N/A] (*)

    4. P. Triantafillou, N. Ntarmos, and T. Pitoura. "The RangeGuard: Range Query Optimization in Peer-to-Peer Data Networks." Proceedings of the 3rd Hellenic Data Management Symposium (HDMS), June 2004. [N/A] (*)

  • Technical Reports:
    1. G. Sfakianakis, I. Patlakas, N. Ntarmos, and P. Triantafillou. "Interval Indexing and Querying on Key-Value Cloud Stores." TR WP3-7-21.09.2012, Longitudinal Analytics of Web Archive Data (LAWA) Project, September 2012. [N/A]

    2. N. Ntarmos, I. Patlakas, G. Sfakianakis, and P. Triantafillou. "Rank Join Queries in Cloud Stores." TR WP3-6-21.09.2012, Longitudinal Analytics of Web Archive Data (LAWA) Project, September 2012. [N/A]

    3. A. Altanis, I. Patlakas, N. Ntarmos, and P. Triantafillou. "Joins and Selects on Clouds." TR WP3-3-22.09.2011, Longitudinal Analytics of Web Archive Data (LAWA) Project, September 2011. [N/A]

    4. G. Sfakianakis, I. Patlakas, N. Ntarmos, and P. Triantafillou. "Interval Queries on the Cloud." TR WP3-2-22.09.2011, Longitudinal Analytics of Web Archive Data (LAWA) Project, September 2011. [N/A]

    5. N. Ntarmos, I. Patlakas, and P. Triantafillou. "Decentralized Rank Join Queries." TR WP3-1-22.09.2011, Longitudinal Analytics of Web Archive Data (LAWA) Project, September 2011. [N/A]

    6. N. Ntarmos and P. Triantafillou. "Statistical Structures for Internet-Scale Query Optimization." TR 2006/06/01, R.A. Computer Technology Institute, June 2006. [N/A]

    7. N. Ntarmos and P. Triantafillou. "sizeof() in P2P Networks: Hash Sketches over DHTs." TR 2004/12/06, R.A. Computer Technology Institute, December 2004. [N/A]

    8. T. Pitoura, N. Ntarmos, and P. Triantafillou. "HotRoD: Load Balancing and Efficient Range Query Processing in Peer-to-Peer Data Networks." TR 2004/12/05, R.A. Computer Technology Institute, December 2004. [N/A]

    9. N. Ntarmos, T. Pitoura, and P. Triantafillou. "The RangeGuard: Range Query Optimization in Peer-to-Peer Data Networks." TR 2004/12/04, R.A. Computer Technology Institute, December 2004. [N/A]

  • Book Chapters:
    1. I. Aekaterinidis, N. Ntarmos, T. Pitoura, and P. Triantafillou. "Towards Efficient Complex Data Management Services in Peer-to-Peer Networks." R. Baldoni, G. Cortese, and F. Davide, editors, Global Data Management, volume 8 of Emerging Communication: Studies in New Technologies and Practices in Communication. IOS Press, July 2006. [N/A]

  • Theses/Dissertations:
    1. N. Ntarmos. "Development and Utilization of Novel Systems for Auditing, Accounting, and Computing of Global Characteristics and Properties of the Entities in Peer-to-Peer Networks." PhD Thesis, Dept. of Computer Engineering & Informatics, University of Patras, Greece, February 2008. [N/A] (*)

    2. N. Ntarmos. "A Behavior Monitoring and Auditing System for Peer-to-Peer Networks." MEng Thesis, Dept. of Computer Engineering & Informatics, University of Patras, Greece, May 2004. [pdf]

    3. N. Ntarmos. "An Internet Content Integration System: The Mediator and Wrappers." Diploma Thesis, Dept. of Electronic & Computer Engineering, Technical University of Crete, Greece, April 2002. [pdf]




  • Research Projects:
    • LAWA: Longitudinal Analytics of Web Archive Data, ICT-2009.1.6, 2010. [link]

    • Inno-Utilities: Innovation-friendly Public Procurement and Fight Against Telecommunications Fraud and Security Threads, IPS-2001-42014, 2005. [link]

    • DELIS: Dynamically Evolving Large-scale Information Systems, IST-2002-001907, 2004. [link]

    • DBGlobe: A Data-centric approach to Globale Computing, IST-2001-32645, 2002 - 2003. [link]

    • DIET: Decentralized Information Ecosystem Technologies, IST-1999-10088, 2002 - 2003. [link]

    • CRESCCO: Critical Resource Sharing for Cooperation in Complex Systems, IST-2001-33135, 2002. [link]

    • FLAGS: Foundational Aspects of Global Computing Systems, IST-2001-33116, 2002. [link]


(*) This work was co-financed by E.U.-European Social Fund (75%) and the Greek Ministry of Development-GSRT (25%).