1. Department
of Materials Science and Engineering, Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro, Nam-gu,
Pohang, Kyungbuk, 790-784, Korea
2. Department
of Mechanical Engineering, Northwestern University, 2145 Sheridan
Road, Evanston, Illinois 60208-3111, United States
3. Department
of Maxillofacial Biomedical Engineering and Institute of Oral Biology, School of Dentistry, Kyung Hee University, Seoul 130-701, Korea
4. Graduate
Institute of Ferrous Technology (GIFT), Pohang University of Science and Technology (POSTECH), 77 Cheongam-ro,
Nam-gu, Pohang, Kyungbuk 790-784, Korea