TAN YiDalian University of Technology, Dalian, ChinaSHINODA THitachi Research Laboratory, Hitachi Ltd. 391-12 Hitachi, JapanMISHIMA YTokyo Institute of Technology, Nagatuta. Midori-Ku, Yokohama 227, JapanSUZUKI TDepartment of Metallurgical Engineering, Tokyo Institute of Technology. Ookayama, Meguro-Ku, Tokyo 152, Japan