1. The Yokohama Rubber Co., Ltd., 2-1 Oiwake, Hiratsuka, Kanagawa 254-8601, Japan
2. Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577, Japan
3. Metrology and Analysis Systems Product Division, Hitachi High-technologies Corporation, 1040 Ichige, Hitachinaka, Ibaraki 312-0033, Japan