1. Research Assistant, Dept. of Engineering, Univ. of Aberdeen, Fraser Noble Building, Aberdeen AB24 3UE, U.K.
2. Reader, Dept. of Engineering, Univ. of Aberdeen, Fraser Noble Building, Aberdeen AB24 3UE, U.K.
3. Principal Scientist, Freshwater Hydrodynamics, National Institute of Water and Atmospheric Research, P.O. Box 8602, Christchurch, New Zealand.
4. Lecturer, Dept. of Engineering, Univ. of Aberdeen, Fraser Noble Building, Aberdeen AB24 3UE, U.K.
5. Dept. of Engineering, Univ. of Aberdeen, Aberdeen AB24 3UE, U.K.; formerly, Research Assistant