Affiliation: | (1) Department of Mathematical Sciences, University of Bath, Bath, BA2 7AY, United Kingdom;(2) Department of Mechanical Engineering, University of Bath, United Kingdom;(3) Departments of Mathematical Sciences and Mechanical Engineering, University of Bath, United Kingdom;(4) Present address: Centrum voor Wiskunde en Informatica (CWI), P. O. Box 94079, 1090 GB Amsterdam |