1. Department of Materials Science and Engineering; Yonsei University; Seoul 120-749 Republic of Korea
2. Division of Advanced Materials Science; Pohang University of Science and Technology (POSTECH); Pohang Gyungbuk Korea
3. The 4th R&D Institute; Agency for Defense Development; P.O.Box 35-4 Yuseong-gu Daejeon 305-600 Korea