Discrete and Computational Geometry

This volume consists of those papers presented at the Japan Conference on Discrete and Computational Geometry 98. The conference was held 9-12 - cember 1998 at Tokai University in Tokyo. Close to a hundred participants from 10 countries participated. Interest in Computational Geometry surfaced among engineers in Japan - out twenty years ago, while interest in Discrete Geometry arose as a natural extension of the research of a group of graph theorists more recently. One of the goals of the conference was to bring together these two groups and to put them in contact with experts in these ?elds from abroad. This is the second conference in the series. The plan is to hold one every year and to publish the papers of the conferences every two years. The organizers thank the sponsors of the conference, namely, The Institute of Educational Development of Tokai University, Grant-in-Aid of the Ministry of Education of Japan (A.Saito;(A)10304008), Mitsubishi Research Institute, Sanada Institute of System Development, Japan Process, and Upward. They also thank especially T. Asano, D. Avis, V. Chv atal, H. Imai, J. Pach, D. R- paport, M. Ruiz, J. O Rourke, K. Sugihara, T. Tokuyama, and J. Urrutia for their interest and support.