1. School of Integrated Design Engineering, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan
2. Toshiba Machine Co., Ltd, 2068-3 Oooka, Numazushi, Sizuoka, Japan
3. Fujikura Kasei Co., Ltd, 2-6-15 Shibakouen, Minato-ku, Tokyo, Japan