1. Dept. of Statistics, Bharathiar Univ., Coimbatore 641046, IN, e-mail: rvijayrn@yahoo.com
2. Dept. of Statistics, Manonmaniam Sundaranar Univ., Tirunelveli 627012, IN, e-mail: aln_24@rediffmail.com
3. Dept. of Science and Humanities, PSN Engineering College, Tirunelveli 627152, IN, e-mail: raji_dl@yahoo.co.in