I have paid long term visits as invited researcher to the University of Patras, Rio, and University of Athens, Athens, Greece; ENS (Ecole Normale Superieure), Paris, France; ETH (Eidgenoessische Technische Hochschule), Zurich, Switzerland; Universite de Paris Sud a Orsay, France; University of Liverpool, Liverpool, UK; UNAM (Universidad Nacional Autonoma de Mexico; Mexico City, Mexico, SFU (Simon Fraser University), Vancouver, Canada.
I have published in the analysis of algorithms, bioinformatics, communication and data (ad hoc and wireless) networks, computational and combinatorial geometry, distributed computing, and network security. I am the author of Primality and Cryptography (Wiley-Teubner series in Computer Science, 1986), and co-author of Boolean Functions and Computation Models with Peter Clote (Springer Verlag Texts in Theoretical Computer Science, 2002) and Principles of Ad Hoc Networking with Michel Barbeau (Wiley, 2007).
Editorial activities include Associate Editor of International Journal of Computer Science & Applications (IJCSA), Editorial Board of Algorithms , Editorial Board of Discrete Mathematics, Algorithms and Applications, Editorial Board of Electronic Proceedings in Theoretical Computer Science (EPTCS)
I was director of the School of Computer Science from 1994 to 2000. I received the Carleton Research Achievement award in 2000. I have been in the RMC (Research Management Committee) of MITACS (Mathematics of Information Technology and Complex Systems) since 1998. I was IT (Information Technology) Theme Leader from 1998 to 2004 and CNS (Communication, Networks, and Security) Theme Leader from 2004 to 2010 in the MITACS NCE (Networks of Centers of Excellence). I served in the NSERC Grant Selection Committee for the years 2008, 2009, and 2010. I became Carleton University Chancellor's Professor in 2006.