1. Postdoctoral Research Associate, Dept. of Electrical Engineering and Electronics, The Manchester Centre for Electrical Energy, UMIST, P.O. Box 88, Manchester M60 1QD, U.K.
2. Lecturer, Centre for Operational Research and Applied Statistics, Univ. of Salford, Greater Manchester M5 4WT, U.K.
3. Senior Research Scientist, EA Technology, Capenhurst, Chester CH1 6ES, U.K.