1. Department of Mechanical and Intellectual Systems Engineering Faculty of EngineeringUniversity of Toyama, Gofuku 3190, Toyama 930-8555, Japan
2. YSK Co., Ltd., 3103-6 Kitanokawachi-otsu Nishimatsuura-gun Arita-cho Saga 849-4166, Japan
3. Yoshinori industry Co., Ltd., 1-1-7 Fukumachi, Nishiyodogawa, Osaka 555-0034, Japan