1. Hokkaido Research Organization, Kita 19 Nishi 11, Kita-ku, Sapporo, Hokkaido, Japan.
2. Maebashi Institute of Technology, 460-1 Kamisadorimachi, Maebashi, Gunma Prefecture, Japan.
3. Muroran Institute of Technology, 27-1 Mizumotocho, Muroran, Hokkaido, Japan.