1. Assistant Professor, Dept. of Civil Engineering, Delft Univ. of Technology, P.O. Box 5048, 2600 GA Delft, The Netherlands.
2. MASc. Candidate, Dept. of Civil Engineering, Univ. of British Columbia, 17 Tovey Cres, Victoria BC, Canada V9B 1A4.
3. Associate Professor, Dept. of Civil Engineering, Univ. of British Columbia, 4026-2424 Mail Mall, Vancouver BC, Canada V6T 1Z4.
4. Professor, Dept. of Forestry, Univ. of British Columbia, 4026-2424 Mail Mall, Vancouver BC, Canada V6T 1Z4.