1. Department of Statistics and Operations Research, College of Science, King Saud University , P.O. Box 2455, Riyadh 11451 , Saudi Arabia
2. ENSIIE, University of Evry-Val-d’Essonne , 1 square de la Résistance 91000 Évry-Courcouronnes cedex , France
3. Department of Mathematics, Faculty of sciences of Sfax, University of Sfax , Tunisia