1. Graduate Student, Dept. of Aerospace Engineering, Pusan National Univ., Busan 46241, Republic of Korea.
2. Research Engineer, School of Aerospace Engineering, Georgia Institute of Technology, 275 Ferst Dr., Atlanta, GA 30332.
3. Assistant Professor, Dept. of Aerospace Engineering, Pusan National Univ., Busan 46241, Republic of Korea (corresponding author).