1. Department of Systems Integration, Yokohama National University, Yokohama 240-8501, Japan
2. Department of Aeronautics and Astronautics, The University of Tokyo, Bunkyo, Tokyo 113-8656, Japan
3. Department of Advanced Energy, The University of Tokyo, Kashiwa, Chiba 277-8561, Japan
4. Division of Systems Research, Yokohama National University, Yokohama 240-8501, Japan