1. Research Unit on Renewable Energies and Electric Vehicles University of Sfax, Sfax Engineering School B.P. W, 3038 Sfax, Tunisia. Tel.: +216 74 274 088; Fax: +216 74 275 595; E-mail: a.masmoudi@enis.rnu.tn
2. Allison Transmission Division of General Motors P.O. Box 502650, Indianapolis, IN, USA. Tel.: +317 915 2721; Fax: +317 915 2703; E-mail: ahmed.el-antably@gm.com