1. Senior Engineer, Geotechnical Engineering Dept., Yooshin Engineering Corporation, 832-40 Yoksam-Dong, Seoul, Gangnam-Gu 135-936, Korea.
2. Assistant Professor, South Dakota School of Mines and Technology, 501 E. St. Joseph St., Rapid City, SD 57701.
3. Professor, Civil, Environmental and Architectural Engineering Dept., Univ. of Kansas, 1530 W. 15th St., Lawrence, KS 66045 (corresponding author).