1. Graduate Research Assistant, Dept. of Civil & Environmental Engineering, Yonsei Univ., Seoul 120-749, Republic of Korea.
2. Director, Provincial Office of Jeollabuk-do, Jeonju, Jeollabuk-do 560-761, Republic of Korea.
3. Associate Professor, Dept. of Civil & Environmental Engineering, Yonsei Univ., Seoul 120-749, Republic of Korea (corresponding author).