Referee for

Editorial Board,
(2011Present)

Editorial Board,
(1997Present)

Editorial Board,
Journal of Discrete Mathematics
(20112016)

Organizer,
(2016)

Organizing Committee,
Computers in Scientific Discovery 7 (2015)

Organizing Committee,
(2015)

Organizer,
(2015)

Advisory Council,
(20042014)

Organizer,
Minisymposium on Graph Pebbling
(2012)

Organizer,
Minicourse on Linear Optimization
(2011)

Organizer,
Minisymposium on Graph Pebbling
(2009)

Program Committee,
Jubilee Conference on Discrete Mathematics
(2009)

Organizer,
(2008)

Organizer,
Minisymposium on Graph Pebbling
(2004)

Director,
(2004)

Program Director,
,
(20002002)

CoDirector,
Summer Teacher's Institute in Mathematics
(2001)

Organizing Committee,
(2001)

Member,
Arizona Mathematics Education Panel of Experts
(20002001)

Editor,
Electronic Newsletter
(19971999)

Education Director,
,
(1998)

Steering Committee,
,
(19961998)
