[1] Hindustan Inst Technol & Sci, Dept Math, Chennai 603103, Tamil Nadu, India
[2] Univ Hassan 2, Fac Sci Ben MSik, Lab Informat Proc, BP 7955, Casablanca, Morocco
[3] Univ Tun Hussein Onn, Fac Appl Sci & Technol, Dept Math & Stat, Parit Raja, Johor, Malaysia