[1] Faculty of Engineering, Kyushu University, 744, Motooka, Nishi-ku, Fukuoka-shi, Fukuoka 819-0395, Japan
[2] Basic Technology Research Center, Corporate Research and Development Center, NSK Ltd., 5-50, Kugenuma Shinmei 1-chome, Fujisawa-shi, Kanagawa 251-8501, Japan
[3] Graduate School of Engineering, Tohoku University, 6-6-01, Aramaki-aza-aoba, Aoba-ku, Sendaishi, Miyagi 980-8579, Japan