1. Visiting Scholar, Division of Construction Engineering and Management, Purdue Univ., West Lafayette, IN.
2. Professor, Division of Construction Engineering and Management, Purdue Univ., West Lafayette, IN.
3. Research Professor, Dept. of Environmental Engineering, Univ. of Seoul, Seoul, Republic of Korea.
4. Professor, Dept. of Engineering Technology, IUPUI, Indianapolis, IN.
5. Professor, Dept. of Environmental Engineering, Univ. of Seoul, Seoul, Republic of Korea.