1. Department of Aerospace Engineering, Nagoya University, Nagoya, Aichi 464-8603, Japan
2. Mitsubishi Heavy Industry ltd., 16-5 Konan 2-chome, Minato-ku, Tokyo 108-8215, Japan
3. Department of Engineering Mechanics and Energy, University of Tsukuba, 1-1-1 Tennodai Tsukuba, Ibaraki 305-8573, Japan