1. School of Information Technology Engineering Mathematics and Physics, University of the South Pacific Mechanical Engineering Division, , Private Mail Bag, Suva , Fiji
2. School of Information Technology Engineering Mathematics and Physics, University of the South Pacific Electrical Engineering Division, , Suva , Fiji
3. Univ Lyon, INSA Lyon, Université Claude Bernard Lyon 1, Ecole Centrale de Lyon, CNRS, Ampère, UMR5505 , Villeurbanne 69621 , France