1. College of Engineering, Nihon University, Naka-gawara, Tokusada, Tamura-machi, Koriyama-shi, Fukushima 963-8642, Japan
2. Faculty of Engineering, Tamagawa University, 6-1-1 Tamagawa-gakuen, Machida-shi, Tokyo 194-8610, Japan
3. Graduate School of Science and Technology, Niigata University, 8050 Ikarashi 2-no-cho, Nishi-ku, Niigata 950-2181, Japan