1. Department of Materials Processing, Graduate School of Engineering Tohoku University, Aoba-yama 6-6-02, Sendai 980-8579, Japan,
2. Department of Materials Processing, Graduate School of Engineering Tohoku University, Aoba-yama 6-6-02, Sendai 980-8579, Japan
3. Faculty of Engineering, Department of Mechanical Systems Engineering Toyama Prefectural University, 5180 Kurokawa, Imizu, Toyama 939-0398, Japan