1. Department of System Design Engineering, Keio University 3-14-1 Hiyoshi, Kouhoku-ku, Yokohama 223-8522, Japan
2. ULVAC Inc., 2500 Hagisono, Chigasakishi, Kanagawa 253-8543, Japan
3. Fujikura Kasei Co., Ltd, 2-6-15, Shibakouen, Minato-ku, Tokyo 105-0011, Japan