1. Division of Electrical Engineering, Kanazawa Institute of Technology, Nonoichi, Ishikawa 921-8501, Japan
2. R & D Department, Fujikura-kasei Co., Ltd., 13-1, Sakurada 5, Washimiya, Kitakatsushika, Saitama 340-0203, Japan
3. Silicones Division, Nippon Unicar Co., Ltd., 6-1, Ohte 2, Chiyoda, Tokyo 100-0004, Japan