Research team on Data & Web Mining


[25/06/2018] Greek Word2Vec (Greek Word Embeddings):
Check our Word2Vec embeddings for the Greek Language, based on a very large recent collection of Greek text (Greek Web). Based on the produced model, several word similarity and analogy tasks can be performed that reveal semantic and syntactic properties of Greek words.
[03/09/2015] Prof Vazirgiannis presents in the European Summer School in Information Retrieval (ESSIR) a tutorial entitled "Graph-of-words: boosting text mining with graphs"
[02/09/2015] Παρουσίαση: Αρχειοθέτηση ιστοπεριεχομένου και διατήρηση ψηφιακής μνήμης: "η εμπειρία του ΟΠΑ"-Μ. Βαζιργιάννης, Επιστημονική Ημερίδα: Η συμβολή των οικονομικών βιβλιοθηκών στην έρευνα και στην ανάπτυξη, Τράπεζα της Ελλάδος, Παρασκευή 6 Μαρτίου 2015, Περισσότερα: εδώ.
[01/09/2015] "Μηχανή Αναζήτησης στο ενοποιημένο εκπαιδευτικό περιεχόμενο Α.Ε.Ι. - Τ.Ε.Ι & περιοδικά ΣΕΑΒ" - στο πλαίσιο της οριζόντιας δράσης Βιβλιοθηκών ΣΕΑΒ.
[08/07/2014] Margarita Karkali defended successfully her PhD thesis “Efficient Novelty Detection in Document Streams” on 7/7/2014.
[14/06/2013] We are pleased to announce that our team (student group from the undergraduate db-net Machine Learning) made it to the best 10 teams of the DMC 2013 competition. More details about the contest you can find here.
To maintain the suspension who the winner is the organisers of DMC 2013 will nominate the first teams within the evening of the first conference day (July 2, 2013) of prudsys User Days.
[16/04/2013] Short paper:
  • Francois Rousseau and M. Vazirgiannis, Composition of TF normalizations: new insights on scoring functions for ad hoc IR
has been accepted in ACM SIGIR Conference.
[16/04/2013] Demo paper:
  • Margarita Karkali, Dimitris Pontikis and M. Vazirgiannis, Match the News: a Firefox Extension for Real-Time News Recommendation
has been accepted in ACM SIGIR Conference.
[20/03/2013] The Matchthenews Plugin is now fully approved by Firefox!
Match-the-News latest version also introduces a new feature. See your history in clouds. See the mozilla entry: or visit the plugin web page at:
[03/07/2012] The Matchthenews Plugin developed by M. Karkali (Ph.D. Student) is approved by Firefox!
MatchtheNews offers the latest news relevant to the web page you are currently browsing capturing your recent interests - using real time feeds in a friendly interface.
The plugin respects privacy! All personal data are stored locally and used ONLY in the favor of the user. See the mozilla entry: or visit the plugin web page at:
[30/08/2011] We are pleased to announce that our team (student group from the postgraduate dbnet Machine Learning) made it to the semi-finals in the Google Online Marketing Challenge 2011!
We had another team participating in the contest (student group from the undergraduate dbnet Data and Web Mining) which also achieved a very good performance and made it to the Strong Campaign Category.
The Google Online Marketing Challenge is a global online marketing student competition open to any higher education institution from anywhere in the world. More details about the contest you can find here:
[01/11/2010] Ph.D. and Post doc positions - Distributed Web Mining
[01/11/2010] Dr. Dimitrios Mavroeidis, recent Ph.D. graduate of the Department of Informatics and member of the DB-NET Research group was awarded the “Best Paper Award" among Data Mining submissions for his paper entitled "Accelerating Spectral Clustering with Partial Supervision" at the "ECML PKDD 2010 European Conference on Machine Learning and Principles and Practice of Knowledge Discovery in Databases" - ECML/PKDD 2010. The conference took place in Barcelona, Spain, in September 2010. ECML/PKDD 2010 is a very competitive conference (~650 submissions, with an acceptance rate < 20%). The conference is the most important event on the fields of Machine Learning and Data Mining in Europe and one of the most important globally, with about 450 participants each year. The next ECML/PKDD 2011 will take place in Athens with the participation of Athens University of Economics and Business as a co organizer. Prof. M. Vazirgiannis serves as PC co-chair. More info
[12/05/2010] ΠΤΥΧΙΑΚΕΣ ΕΡΓΑΣΙΕΣ 2010
[06/12/2009] We announce the X-SDR is a prototype designed specifically for the deployment and assessment of any dimensionality reduction technique. It comprises an integrated environment for dimensionality reduction and knowledge discovery that addresses the whole life cycle of data mining. In the current version, it supports communication with a variety of database management systems and integrates a large number of dimensionality reduction algorithms including the MATLAB toolbox for dimensionality reduction. Additionally, it interacts with Weka thus enabling the exploitation of a large number of knowledge mining algorithms. Finally, X-SDR provides an API that enables the integration and evaluation of any dimensionality reduction algorithm. Through this page you may download the application or retrieve additional information related to this effort. Please visit the .
X-SDR Web page
[01/12/2009] Prof. M. Vazirgiannis, co-organizes and and serves as PC co-chair of the "European Conference on Machine Learning
and Principles and Practice of Knowledge Discovery in Databases" (ECML PKDD) 2011 that will take place in Athens in September 2011. See more details at: ECML/PKDD 2011, Athens
[03/12/2008] - Our ICDM 2008 paper "Enhancing the Stability of Spectral Ordering with Sparsification and Partial Supervision: Application to Paleontological Data", by Dimitrios Mavroeidis and Ella Bingham has been selected as a best paper for possible publication in Knowledge and Information Systems Journal (KAIS,
[20/02/2008] Our group has two papers accepted in ACM/ SIGMOD 2008:
- A. Vlachou, C. Doulkeridis, Y. Kotidis, "Angle-based Space Partitioning for Efficient Parallel Skyline Computation.", In Proceedings of ACM SIGMOD International Conference on Management of Data, Vancouver, Canada, June 2008.
- A. Vlachou, C. Doulkeridis, K. Nørvåg, M. Vazirgiannis, "On Efficient Top-k Query Processing in Highly Distributed Environments", In Proceedings of ACM SIGMOD International Conference on Management of Data, Vancouver, Canada, June 2008.
[07/10/2007] D. Mavroeidis and M. Vazirgiannis receive "Outstanding Contribution Award" for their participation in the ECML/PKDD 2007 Discovery challenge.
[25/08/2007] Our paper "A Clustering Framework based on Subjective and Objective Validity Criteria" authored by M. Halkidi, D. Gunopulos, M. Vazirgiannis and C. Domeniconi was accepted for publication in the ACM Transactions on Knowledge Discovery from Data Journal.
[19/07/2007] Our recent graduate Dr. Magdalini Eirinaki
was hired as Assistant Prof. in San Jose State University, California, USA. Congratulations!!
[31/07/2006] DB-NET participated in the ECML/PKDD 2006 Discovery challenge (Task A: Spam Filtering) achieving the 5th position (out of 21 participants) See further details in:
[17/05/2006] Our invited talk, "Semantic Overlay Networks for P2P Web Search", will be presented in the workshop The Future of Web Search Barcelona - May 19-20, 2006, organized by Yahoo! Research
[13/03/2006] Our tutorial, "From Unsupervised to Semi-supervised Learning: Algorithms and evaluation approaches", will be presented in 2006 SIAM Conference on Data Mining.
[22/01/2006] Our paper, A foundation for representing and querying moving objects is the topTODS journal paper for the decade 1994-2003 with regards to citations. Details.
[03/12/2005] Our research prototype system "Medical Data Mining -
Association Rules" for Mining Medical Epidemiological Data is adopted by the Greek System for Surveillance and Antimicrobial Resistance (member of the World Health Organization initiative Whonet).
[03/06/2004] Προσφερόμενες Διπλωματικες Εργασίες