1. Department of Aerospace Engineering, Pusan National University, Gumjung-ku, Busan 609-735, Republic of Korea
2. Industrial Liaison Innovation Center, Pusan National University, Gumjung-ku, Busan 609-735, Republic of Korea
3. ERC/ITAF, Pusan National University, Gumjung-ku, Busan 609-735, Republic of Korea