Affiliation: | a Research Institute for Applied Mechanics, Kyushu University, 6-1 Kasuga-Koen, Kasuga-city, Fukuoka 816-8580, Japan b Department of Aeronautics and Astronautics, Graduate School of Engineering, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan |