[1] Behbahan Khatam Alanbia Univ Technol, Dept Math, Behbahan 4718963616, Iran
[2] Grad Univ Adv Technol, Dept Math, Kerman 33131, Iran
[3] Islamic Azad Univ, Dept Math, Shiraz Branch, Shiraz 74731, Iran
[4] Univ Basque Country UPV EHU, Inst Res & Dev Proc, Fac Sci & Technol, Dept Elect & Elect, Leioa 48940, Spain