1. Department of Physics, Faculty of Science, Yamagata University, Kojirakawa, Yamagata 990-8560
2. Department of Material and Biological Chemistry, Faculty of Science, Yamagata University, Kojirakawa, Yamagata 990-8560
3. Department of Polymer Science & Engineering, Yamagata University, Jonan, Yonezawa, Yamagata 992-8510