1. Postdoctoral Research Associate, Dept. of Civil Engineering and Engineering Mechanics, Univ. of Arizona, Tucson, AZ 85721.
2. Assistant Professor, Dept. of Civil Engineering, Kyung Hee Univ., 446-701, 1 Seocheon-Dong, Giheung-Gu, Yongin-Si, Kyunggi-do, South Korea.
3. Professor, School of Civil, Environmental and Architectural Engineering, Korea Univ., 136-713, Anam-ro 145, Seongbuk-gu, Seoul, South Korea.
4. Professor, Dept. of Civil Engineering and Engineering Mechanics, Univ. of Arizona, Tucson, AZ 85721 (corresponding author).