[1] King Mongkuts Univ Technol Thonburi, Dept Math, Bangkok 10140, Thailand
[2] Usmanu Danfodiyo Univ, Dept Math, Sokoto 840004, Nigeria
[3] King Mongkuts Univ Technol Thonburi KMUTT, Ctr Excellence Theoret & Computat Sci TaCS CoE, Fac Sci, Sci Lab Bldg,126 Pracha Uthit Rd, Bangkok 10140, Thailand
[4] China Med Univ Hosp, China Med Univ, Dept Med Res, Taichung 40402, Taiwan
[5] Rambhai Barni Rajabhat Univ, Fac Sci & Technol, Dept Math, Chanthaburi 22000, Thailand