1. Mechanical Engineering, Kobe University, 1-1 Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
2. SCIOCS, 880, Isagozawa-cho, Hitachi-shi, Ibaraki-ken 319-1418, Japan
3. Department of Energy Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
4. PRESTO, Japan Science and Technology Agency, Kawaguchi 332-0012, Japan