1. Department of Mechanical Engineering, Saitama Institute of Technology, 1690 Fusaiji, Fukayashi, Saitama 369-0293, Japan
2. Steel Division of Topy Industries Co., Ltd., Meikai Town, Toyohashi, Aichi 441-8510, Japan
3. Meiji Institute for Advanced Study, of Mathematical Sciences, Meiji University, 4-21-1 Nakano, Nakano-Ku, Tokyo 164-8525, Japan