1. Korea Atomic Energy Research Institute, MMIS Team, 150, Duckjin-dong Yuseong-gu, Daejeon 305-353, Korea
2. Korea Advanced Institute of Science and Technology Computer Science Division, EECS Department and Advanced Information Technology Research Center (AITrc) 373-1, Kusong-dong, Yuseong-gu, Daejeon 305-701, Korea