1. Department of Aerospace Engineering and LANL-CBNU Engineering Institute Korea, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonbuk, Jeonju 561-756, Republic of Korea
2. Structures and Materials Department, Korea Aerospace Research Institute, Daejeon 305-333, Republic of Korea
3. X-NDT Inc., #304, Building of Engineering Institute Korea, 567 Baekje-daero, Deokjin-gu, Jeonbuk, Jeonju 561-756, Republic of Korea