1. Graduate School of Engineering, Yokohama National University, Tokiwadai 79-5, Hodogaya-ku, Yokohama 240-8501, Japan, Basic Research Laboratory, Noevir Co., Ltd., Okada-cho 112-1, Youkaichi 527-0057, Japan, and Dow Corning Toray Silicone Co., Ltd., Chigusa-Kaigan 2-2, Ichihara 299-01, Japan