Scientific Activities：
Chairman of the 2nd Hellenic Conference on Artificial Intelligence, 2002
Co-Chair of the 2nd International Summer School on AI Planning, 2002
Guest Editor of the Special issue on Knowledge Discovery from Distributed Information Sources, Journal of Information Sciences, 2003
Member of the editorial board of the International Journal on Artificial Intelligence Tools (IJAIT)
Program Chair, 2nd ADBIS Workshop on Data Mining and Knowledge Discovery, ADMKD’2006
Workshop co-chair, European Conference on Artificial Intelligence 2008 (ECAI’08)
Chairman of the 1st Hellenic Artificial Intelligence Summer school (HAISS09 ),August 2009
Workshop co-chair of the 19th International Conference on Automated Planning and Scheduling, ICAPS 2009
General Co-chair, 5th IFIP International Conference on Artificial Intelligence Applications and Innovations (AIAI’2009)
Organizing chair, International Conference on Artificial Neural Networks (ICANN 2010)
Guest Editor, special issue on “Artificial Intelligence Techniques for Pervasive Computing“, International Journal on AI Tools (IJAIT), World Scientific, 2010
General Chair of 24th IEEE International Conference on Tools with AΙ, November 2012
General co-Chair of 17th Panhellenic Conference on Informatics , PCI 2013
General co-Chair of 9th Hellenic Conference on Artificial Intelligence, SETN 2016