Meetings

IPCO 1990, Waterloo (Local organizing committee)
Fourteenth Math Programming Symposium, Amsterdam 1991 (Organizing Committee)
First DONET Meeting, London, 1995 (Principal Organizer)
BelAirs Workshops on Combinatorial Optimization, Holetown, Barbados,

        1993 with W. Pulleyblank
        1995 with A.M.H. Gerards
        2007 with Sylvia Boyd
        2008 with B. Cook and F. Eisenbrand
        2009 with Adrian Vetta

Graphs and Matroids Cluster, ISMP Atlanta, 2000
IMA Workshop on Network Management and Design, Minneapolis, 2003 (with D. Bienstock, T. Carpenter, D. Johnson, C. Monma)
Telecommunication and Network Design Cluster, ISMP 2006, Rio

Program Committees: CO 1996; ESA 1999; SODA 2002; IPCO 2005; SODA 2005; SIAM Discrete 2008; INOC 2008, APPROX 2009, IPCO 2010 (chair).