I am a professor in the Department of Mathematics at the George Washington University (GW), Washington, DC.

I am also the Associate Dean for Undergraduate Studies in the Columbian College of Arts and Sciences, the school of liberal arts at GW.

I can be reached

- in person at my office, Phillips Hall, room 107;
- by telephone at (202) 994-6343;
- by e-mail at dullman@gwu.edu;
- by fax at (202) 994-0854; or
- by snail mail at

The Columbian College of Arts and Sciences

801 22nd Street NW, Room 107

The George Washington University

Washington, DC 20052

My research interests are in the area of graph theory and combinatorics, particularly in the chromatic theory of graphs, combinatorial game theory, and the theory of fractional graph invariants. In 2010, Chapman and Hall published "A Mathematical Look at Politics", written jointly by me and Robbie Robinson. In 1997, John Wiley and Sons published " Fractional Graph Theory ", written jointly by me and Ed Scheinerman.

I have taught combinatorics and analysis courses at all levels. In addition, I designed and taught a course called "Mathematics and Politics'' and a seminar for freshmen on Gödel, Escher, Bach. I have taught calculus at all levels, linear algebra, abstract algebra, number theory, graph theory, differential geometry, real analysis, measure theory, and ergodic theory, among other subjects.

In addition to my research and teaching, I was the lead editor of the Problems Section of the American Mathematical Monthly from 1997 to 2002. I also was the DC Director of the 2001 International Mathematical Olympiad (IMO), which took place in Washington DC in July. I was the deputy leader of the US delegation to the IMO in 1991 in Stockholm and in 1992 in Moscow. These evidence my long-standing interest in problems and contests.

I am an Associate Editor of the American Mathematical Monthly.

From 2007 to 2010, I directed the DC Math Circle, an enrichment program for talented and motivated 8th grade students from the District of Columbia.

I am the principal investigator of a math-science partnership grant to provide in-service professional development to middle school and high school mathematics teachers. This program, which goes by the acronym DC FAME (District of Columbia Fellows Advancing Mathematics Education) supports DC teachers through a 33-credit-hour master's degree in middle-school mathematics, through GW's College of Professional Studies.

During the 2006--2007 academic year, I was on leave from GW and serving as the AMS/AAAS Congressional Fellow, working on Capitol Hill.

I was chair of the Department of Mathematics from 2001 to 2006.

My hobbies include playing piano (mostly Chopin and jazz), playing racquet sports (racquetball), playing Scrabble (I once got TRIOXIDE), cooking (chocolate mousse), going to the theatre (Sondheim), soccer (player, fan, coach, and mom), gardening (not much time for this) and juggling (lacrosse balls). My favorite punchlines include "No, of course I don't believe in that stuff, but I hear it works even if you don't believe in it." and "Really? Come over to my house. I've got closets full of them." Another hobby is composing sentences that seem to be self-referential but actually aren't.

I claim to be the founder and president of NAPAN, the National Association for the Promotion and Advancement of NAPAN.