1. Mem. ASME
2. Graduate School of Information Science and Technology, Hokkaido University, Kita-14, Nishi-9, Kita-ku, Sapporo 060-0814, Japan
3. Hitachi, Mechanical Engineering Research Laboratory, 832-2, Horiguchi, Hitachinaka 312-0034, Japan
4. Hitachi Information Systems, 2-1-20 Jyonan, Mito 310-0803, Japan