1. Postdoctoral Research Associate, Dept. of Civil and Natural Resources Engineering, Univ. of Canterbury, Private Box 4800, Christchurch 8140, New Zealand; formerly, Ph.D. Candidate, Univ. of Canterbury.
2. Associate Professor (Reader), Dept. of Civil and Natural Resources Engineering, Univ. of Canterbury, Private Box 4800, Christchurch 8140, New Zealand (corresponding author).