1. Tsuruoka National College of Technology, Inooka Sawada 104, Tsuruoka 997-8511
2. Institute for Materials Research, Tohoku University, Katahira 2-1-1, Aoba-ku, Sendai 980-8577
3. Faculty of Engineering, Yamagata University, Jonan 4-3-16, Yonezawa 992-8510