1. Department of Mechanical Engineering, Seoul National University, Seoul 08826, Republic of Korea
2. Mechatronics R&D Center, Samsung Electronics, Suwon 18448, Republic of Korea
3. Department of Mechanical Engineering, Dankook University, Yongin, Gyeonggi-do 16890, Republic of Korea
4. Institute of Advanced Machines and Design, Seoul National University, Seoul 08826, Republic of Korea