H. Kubota

Faculty of Education, Gifu University, Gifu, Japan

S. Demura

Graduate School of Natural Science & Technology, Kanazawa University, Kakuma, Kanazawa, Ishikawa, Japan

M. Uchiyama

Research and Education Center for Comprehensive Science, Akita Prefectural University, Kaidobata-Nishi, Shimoshinjo-Nakano, Akita, Japan