Katsuhito NAKAZAWA*, Keiichi KATAYAMA, Hiroyasu SAKAMURA† and Itaru YASUI†
Graduate School of Engineering, Tokai University; 1117, Kitakaname, Hiratsuka-shi 259-1292 Japan † Institute of Industrial Science, The University of Tokyo; 7-22-1, Roppongi, Minato-ku, Tokyo 106-8558 Japan