1. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801 (corresponding author).
2. Structural Engineer, Samsung C&T, 1321-20 Seocho2-dong, Seocho-gu, Seoul 137-857, Korea.
3. Professor, Dept. of Safety Engineering, Pukyong National University, Busan 608-739, Korea.
4. Professor, Dept. of Civil and Environmental Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, Korea.
5. Professor, School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Korea.
6. Professor, Dept. of Civil and Environmental Engineering, Northeastern Univ., Boston, MA 02115.