1. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801 (corresponding author).
3. Executive Vice President, Geotechnical Dept., Dasan Engineering Co., Ltd., Seoul, Korea 151–055.
4. Professor, Dept. of Civil and Environmental Engineering, Seoul National Univ., Seoul, Korea 151–744.