1. Reader, Applied Mechanics Dept., M.N.N.I.T., Allahabad-04, India.
2. Professor, Applied Mechanics Dept., Indian Institute of Technology, Delhi-16, India.
3. Professor, TUHH, Meerestechnik II, Essendorfer Str. 42, 21073 Hamburg, Germany.
4. Graduate Student, Applied Mechanics Dept. Indian Institute of Technology, Delhi-16, India.