1. Division of Mechanical and Automotive Engineering, College of Engineering, Wonkwang University,460 Iksandae-ro, Iksan, Jeonbuk, 570-749, Republic of Korea
2. Department of Orthopedics, Daejeon St. Mary’s Hospital, Catholic University of Korea, 64, Daeheung-ro, Jung-gu, Daejeon, 301-723, Republic of Korea