1. School of Mechanical and Automotive Engineering, High Safety Vehicle Core Technology Research Center, Inje University, 607 Obang-dong, Gimhae, Gyeongnam 621-749, Korea
2. School of Mechanical, Aerospace & Systems Engineering, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea
3. Graduate School of Mechanical Engineering, Inje University, 607 Obang-dong, Gimhae, Gyeongnam 621-749, Korea