- 2021 - 2022: I spent my sabbatical leave visiting the University of Ioannina in Greece, Aix-Marseille University in France (financially supported by Aix-Marseille University) and Ca’ Foscari University of Venice in Italy (financially supported by Ca’ Foscari University of Venice).
- 2014: Grant (10,000 euros) from the Hellenic Academic Libraries Link for co-authoring (in greek) the book ‘Algorithmic Theory of Distributed Computing’, together with Evangelos Kranakis (Carleton Univ., Canada), Aris Pagourtzis (NTUA, Greece) and Danny Krizanc (Wesleyan Univ., USA).
- 2011: Maître de conferences invité at École Centrale de Marseille, Marseille, France.
- 2011: Research grant for visiting the Slovakian Academy of Sciences offered by the Ministries of Education of Greece and Slovakia (Bilateral Exchange Programme for Researchers).
- 2006 - 2007: Post-doctoral researcher at the McMaster School of Computational Engineering and Science, McMaster University, Hamilton, Ontario, Canada. Supervisor: Assist. Prof. George Karakostas (see my oldweb page).
- 2006: Post-doctoral researcher at the Laboratoire Bordelais de Recherche en Informatique (LaBRI), Bordeaux, France. Supervisors: Dr. Ralf Klasing, Prof. Andre Raspaud.
- 2004 – 2006: Post-doctoral researcher at the Department of Informatics and Telecommunications, National and Kapodistrian University of Athens, Athens, Greece. Supervisor: Prof. Ioannis Emiris.
- 2003 – 2004: Post-doctoral researcher at the Research Chair in Distributed Computing, Département d'informatique et d'ingénierie, Université du Québec en Outaouais, Gatineau, Québec, Canada. Supervisors: Prof. Andrzej Pelc, Prof. Jurek Czyzowicz.