1. Department of Materials Science and Engineering; Seoul National University; Seoul 151-742 Korea
2. Department of Mechanical Engineering; University of Colorado at Boulder; Boulder CO 80309 USA
3. MK electron; 316-2 Geumeo-ri, Pogok-myeon Yongin-si Gyeong gi-do 449-810 Korea
4. Samsung SDI Co. Ltd.; Giheung-gu, Yongin-si Gyeonggi-do 446-577 Korea