Affiliation: | Bassem Ben Hamed 1 Mohamed Chaabane 2 Walid Kacem 2 1 Higher Institute of Applied Sciences and Technology of Gab`es,Department of Mathematics,Street Amor Ben El Khatab,6029 Gab`es,Tunisia 2 National Engineering School of Sfax,Department of Electrical Engineering,Street Soukra km 3.5,B.P. 1173,3038 Sfax,Tunisia |