ELA, Volume 14, p. 1, January 2005.
     
                         PREFACE

The workshop "Directions in Combinatorial Matrix Theory" 
was held May 7-8, 2004 at the Banff International Research 
Station (BIRS) in Banff, Alberta, Canada. Supported by 
BIRS and the International Linear Algebra Society (ILAS), 
the workshop provided researchers working in combinatorial
matrix theory with an opportunity to present accounts of 
their current research, to identify challenges for the 
discipline to undertake, and to suggest new approaches 
to explore.  

The workshop's organizing committee consisted of Shaun 
Fallat (University of Regina), Hadi Kharaghani (University 
of Lethbridge), Steve Kirkland (University of Regina), 
Bryan Shader (University of Wyoming), Michael Tsatsomeros 
(Washington State University), and Pauline van den Driessche 
(University of Victoria). The intent of the organizers 
was that the meeting would serve to establish connections 
between both individual researchers and between research 
areas, and would promote collaboration and new research.  

"Directions in Combinatorial Matrix Theory" attracted 29
faculty (10 from Canada, 15 from the U.S., and 4 from abroad),
2 post-doctoral fellows, and 6 graduate students. The workshop 
included 15 talks and two open problem sessions, and a lecture 
by Miroslav Fiedler (Czech Academy of Sciences), who was the 
distinguished ILAS speaker. The presentations focused on 
current developments in the following emerging themes in 
Combinatorial Matrix Theory:  Spectral properties of families
of matrices associated with graphs; Matrix theory and graph 
theory in the service of Euclidean geometry; Algebraic tools 
for combinatorial problems; and Spectral properties of classes
of matrices. See  

    http://www.pims.math.ca/birs/workshops/2004/04w2525/ 

for more details of the objectives, titles and abstracts for 
talks and open problems presented.

Each of the papers in this volume of The Electronic Journal 
of Linear Algebra is related to a talk given at the workshop, 
and has been refereed according to the journal's usual high 
standards. It is our hope that this volume will serve  not 
only as a lasting document of the workshop itself, but also 
as a tool for motivating future research in combinatorial 
matrix theory. 

Steve Kirkland, Bryan L. Shader and Pauline van den Driessche
Special Issue Editors