[1] Acad Romanian Scientists, Sect Math, Bucharest 050094, Romania
[2] Int Islamic Univ, Fac Basic & Appl Sci, Dept Math & Stat, Islamabad 44000, Pakistan
[3] Univ Calif Riverside, Dept Mech Engn, Riverside, CA 92521 USA
[4] King Fahd Univ Petr & Minerals, Ctr Commun & IT Res, Res Inst, Dhahran 31261, Saudi Arabia