1. Department of Systems Integration, Yokohama National University, Yokohama 240-8501, Japan
2. Department of Advanced Energy, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
3. Department of Engineering, Tokyo Metropolitan College of Industrial Technology, 8-17-1, Minami-senjyu, Arakawa-ku, Tokyo 113-0852, Japan
4. Division of Systems Research, Yokohama National University, Yokohama 240-8501, Japan