1. Institute of Industrial Science, University of Tokyo, 7-22-1, Roppongi, Minato-ku, Tokyo, 106, Japan
2. Department of Mechanical Engineering, Queen's University, Kingston, Ontario, K7L 3N6, Canada
3. Rolling Stock Department, Conventional Lines Operation Division, Central Japan Railway Company, 1-3-4, Meieki, Nakamura-ku, Nagoya, 450, Japan