1. Department of Civil and Environmental Engineering, KAIST, 373-1, Guseong-dong, Yuseong-gu, Daejeon 305-701, Korea E-mail: simonchoi@kaist.ac.kr; hpark57@kaist.edu
2. Department of Civil Engineering, Hanyang University, 1271, Sa-1 dong, Sangnok-gu, Ansan, Gyeonggi-do 425-791, Korea E-mail: moonilkim@hanyang.ac.kr
3. Department of Urban Engineering, Chungbuk National University, 12, Gaeshin-dong, Heungduk-gu, Cheongju, Chungbuk 361-763, Korea E-mail: paullee@chungbuk.ac.kr