1. Osaka University, Faculty of Engineering 2-1 Yamada-oka, Suit a, Osaka, Japan
2. Mitsubishi Electric Corporation 2-2-3 Marunouchi, Chiyodaku, Tokyo, Japan
3. Mitsubishi Electric Corporation 8-1-1 Tsukaguchi-honmachi, Amagasaki, Japan
4. Osaka University, Faculty of Engineering 2-1 Yamada-oka, Suita, Osaka, Japan