1. Flight Safety Technology Division, Korea Aerospace Research Institute, 169-84 Gwahangno, Yuseong-gu, Daejeon 305-806, Republic of Korea
2. Department of Sensor Systems, Hanwha Corporation R&D Center, 52-1 Oesam-dong, Yuseong-gu, Daejeon 305-106, Republic of Korea
3. Department of Information and Statistics, Research Institute of Natural Science, Gyeongsang National University, 501 Jinjudaero, Jinju, Gyeongsangnam-do 660-701, Republic of Korea