1. Postdoctoral Research Assistant, Dept. of Civil Engineering, Univ. of Dundee, Dundee DD1 4HN, U.K.
2. Lecturer, School of Mechanical, Aerospace and Civil Engineering, Univ. of Manchester, P.O. Box 88, Manchester M60 1QD, U.K.
3. Professor, Dept. of Civil Engineering, Univ. of Dundee, Dundee DD1 4HN, U.K.
4. Postdoctoral Research Assistant, School of Mechanical, Aerospace and Civil Engineering, Univ. of Manchester, P.O. Box 88, Manchester M60 1QD, U.K.
5. Professor, School of Mechanical, Aerospace and Civil Engineering, Univ. of Manchester, P.O. Box 88, Manchester M60 1QD, U.K.