Affiliation: | (1) Department of Information and Mathematics, Korea University, 208 Seochang-ri, Jochiwon-eup, Yeongi-gun, 339-700 Chungnam, Korea;(2) Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), San 31 Hyoja-dong, Nam-gu, 790-784 Pohang, Korea |