1. Division of Mechanical and Aerospace Engineering, Faculty of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, 060-8628 Sapporo, Hokkaido, Japan
2. Division of Mechanical and Space Engineering, Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, 060-8628 Sapporo, Hokkaido, Japan