1. Department of Mechanical Systems Engineering, Tohoku University, 6-6-01 Aramaki Aza Aoba, Aoba-ku, Sendai 980-8579, Japan
2. Industrial Technology Institute, Miyagi Prefectural Government, 2-2 Akedohri, Izumi-ku, Sendai 981-3206, Japan
3. Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan