Giorgos was born in Athens, Greece on the 5th of July, 1985 and raised in Lixouri, Kefalonia, Greece. He received his diploma in Electrical and Computer Engineering from the Democritus University of Thrace, Greece in 2011. In addition, he received his Master's degree in the Democritus University of Thrace under the advisory of Assistant Prof. Pavlos Efraimidis. His scientific interests include design and analysis of algorithms, algorithmic game theory, distributed computing and social networks.

Website: http://james.gr/
Phone: 697 6 452133
Email: [email protected]


Athena Research and Innovation CenterJanuary 2012 - December 2014

Researcher on funded project ATLAS (Advanced Tourism pLAnning System, GSRT/CO-OPERATION/11SYN-10-1730)

ATLAS seeks to create a step change in tourism services by advancing the state-of-the-art of the algorithms for fast geo‐aware social media tagging and annotation and geo‐aware multimedia information retrieval and recommendation. In particular, ATLAS aims at an innovative breakthrough in combining the just mentioned technologies for practical tourism services at a quality level that meets the expectations of the users.


Democritus University of ThraceMarch 2012 - July 2014

M.Sc., Algorithmic Game Theory
  • Thesis: Algorithmic Techniques for Influence Dynamics in Social Networks
  • Advisor: Pavlos S. Efraimidis

In this thesis, a non-cooperative, zero-sum game of influence between two firms on a social network is defined and examined. The social network is represented with a directed graph of n individual agents with an initial opinion on a particular subject. The DeGroot model defines the opinion dynamics and the rules of social interaction, according to which the belief of each individual is influenced by the opinions of their neighbors. The players of the game are two external entities who have diametrically opposed opinions. Each player tries to manipulate the community in their own opinion’s favor, by actively interfering with the social graph structure. We investigate possible equilibria, identify basic principles for a successful strategy and compare the performance of several algorithms implementing player strategies.

Democritus University of ThraceFebruary 2011

Diploma, Computer Security
  • Thesis: Distributed Search among Agents with Enhanced Privacy
  • Advisor: Pavlos S. Efraimidis


DUTH at TREC 2013 Contextual Suggestion TrackNovember 2013

Published by George Drosatos, Giorgos Stamatelatos, Avi Arampatzis and Pavlos S. Efraimidis

In this report we give an overview of our participation in the TREC 2013 Contextual Suggestion Track. We present an approach for context processing that comprises a newly designed and fine-tuned POI (Point Of Interest) data collection technique, a crowdsourcing approach to speed up data collection and two radically different approaches for suggestion processing (a k-NN based and a Rocchio-like). In the context processing, we collect POIs from three popular place search engines, Google Places, Foursquare and Yelp. The collected POIs are enriched by adding snippets from the Google and Bing search engines using crowdsourcing techniques. In the suggestion processing, we propose two methods. The first submits each candidate place as a query to an index of a user’s rated examples and scores it based on the top-k results. The second method is based on Rocchio’s algorithm and uses the rated examples per user profile to generate a personal query which is then submitted to an index of all candidate places. The track evaluation shows that both approaches are working well; especially the Rocchio-like approach is the most promising since it scores almost firmly above the median system and achieves the best system result in almost half of the judged contextprofile pairs. In the final TREC system rankings, we are the 2nd best group in MRR and TBG, and 3rd best group in [email protected], out of 15 groups in the category we participated.

Controlled Access in Enclosed Building using a ComputerApril 2012

Published by Giorgos Stamatelatos and George Drosatos

Στα πλαίσια αυτής της δουλειάς υλοποιήσαμε μία πλατφόρμα για το άνοιγμα μιας πόρτας χρησιμοποιώντας σύγχρονες τεχνολογίες, όπως αναγνώριση δακτυλικού αποτυπώματος και δικτυακής διαχείρισης. Εξηγούμε τον τρόπο με τον οποίο το πετύχαμε καθώς και τα εργαλεία που χρησιμοποιήσαμε τόσο σε επίπεδο υλικού όσο και λογισμικού.

Quantum: A Peer-to-Peer Network for Distributed Computations with Enhanced PrivacySeptember 2009

Published by G. Stamatelatos, G. Drosatos, P.S. Efraimidis

In this paper Quantum is being presented. Quantum is a peer-to-peer network used for distributing computations among independent agents. The main feature of Quantum is the privacy of the peers which participate in each distributed computation. Furthermore, Quantum supports infrastructures which are formed by a mass of agents communicating over the Internet, and is tolerant of adding/removing peers. In the proposed solution we have chosen a decentralized network architecture and exploited peer-to-peer network technologies.


  • Programming Languages and Tools

    • C, C++ (incl. Win32 and Boost)
    • C#, Java (incl. several Apache Commons libraries)
    • Python and other scripting tools
    • GNU Make, UNIX Shell Scripting
    • CUDA, OpenCL
    • MATLAB
  • Web Development

    • Experience with HTML5 advances
    • JavaScript (AJAX, jQuery)
    • Server-side tools (PHP, MySQL, PostgreSQL)
    • Front-end Frameworks (Bootstrap, Foundation)
    • Familiar with popular CMSs
  • Operating Systems

    • Microsoft Windows Family
    • Linux and other UNIX variants
    • Experience in installation and administration of RAID, Web Servers, various SQL Servers, BIND9 DNS Server, Postfix Mail Server, Remote Administration
  • Productivity Applications

    • Eclipse, NetBeans, Visual Studio
    • LaTeX, Vim
    • DVCS (Git, Mercurial), VCS (CVS, SVN)
    • Most common productivity packages for Windows and Linux platforms


  • Greek Native speaker

  • English Fluent