1. Assistant Professor, Dept. of Mining and Geological Engineering, Univ. of Alaska, Fairbanks, P.O. Box 755800, Fairbanks, AK 99775-5800.
2. Professor, Dept. of Mining and Geological Engineering, Univ. of Alaska, Fairbanks, P.O. Box 755800, Fairbanks, AK 99775-5800.
3. Professor, Dept. of Civil and Environmental Engineering, Univ. of Alaska, Fairbanks, P.O. Box 755900, Fairbanks, AK 99775-5900.
4. Professor, Graduate School of Engineering, Hokkaido Univ., Sapporo, Hokkaido 060-8628, Japan.