Preface: Volume 11

The Ninth Quadrennial International Conference on Graph Theory, Combinatorics, Algorithms and Applications was held June 4-9, 2000 at Western Michigan University. This conference has been held every four years since 1968, hosted by the Department of Mathematics and Statistics at Western Michigan University. The 1996 Conference attracted nearly 300 participants from all over the world (including Canada, China, Denmark, England, France, Hungary, India, Israel, Italy, Japan, Korea, Germany, the Netherlands, Puerto Rico, Saudi Arabia, Scotland, South Africa, and Spain) and included five days of principal, invited and contributed presentations by approximately 200 speakers. ledgments cellent support of Western Michigan University, Dr. Elson S. Floyd, President Dr. Diether H. Haenicke, Past President (with his generous support of the Sixth, Seventh, Eighth, and the Ninth International Conferences) ntinued support of the Division of Research and Sponsored Programs, Dr. Donald E. Thompson, Vice President ne support of the College of Arts and Sciences, Dr. Elise Jorgens, Dean erall support of the Department of Mathematics and Statistics, Dr. John Petro, past Chair Dr. Jay Wood, Chair ne financial support of the Number Theory Foundation, Dr. Carl Pomerance, Director Ms. Ethel Rathburn, Secretary ecial assistance of our friends and co-directors, Dr. Ronald L. Graham, Dr. John Petro and Dr. Allen J. Schwenk and associate directors Jiuqiang Liu, Michael Raines, and Ping Zhang. pport and assistance of our graph theory colleagues, Professors Arthur White and Gary Chartrand. ne assistance of colleagues around the world who assisted with refereeing of the manuscripts. ecial administrative assistance of Cheryl Peters and the fine secretarial assistance of Maryann Bovo and Margo Chapman. dicated work of our conference assistants, Vince Castellana, Linda Eroh, Raluca Muntean and Wendy Weaver. itors apologize in advance for any oversight in the acknowledgments and any errors in the manuscripts. tion many years and after many conferences, when leaving Kalamazoo, boarding the airplane, Paul Erdös would say “Maybe you can hold the next Conference in my memory.” Upon his passing shortly after the 8th Kalamazoo Conference, the decision to proceed with a 9th Conference in memory of Paul Erdös was easy and direct. Thus the Erdös 2000 Conference was held during June 4-9, 2000 in Kalamazoo. So it is with special devotion and honor that we dedicate these Proceedings to him. r special friend and teacher of many colleagues here was the late Edward A. Nordhaus, to whom these special proceedings are also dedicated.