Institution: | 1. Division of Mathematical Science, Department of Social Medicine, Faculty of Medicine, University of Miyazaki, Kihara 5200, Kiyotake-cho, Miyazaki, 889-1692, Japan;2. Department of Physics and Astronomy, University of Lethbridge, Lethbridge, AB T1K 3M4, Canada;3. Department of Physics, Ehime university, 2-5 Bunkyo-cho, Matsuyama, 790-8577, Japan |