1. Applied Mathematics Program, Faculty of Science and Technology, Valaya Alongkorn Rajabhat University under the Royal Patronage (VRU), 1 Moo 20 Phaholyothin Road, Klong Neung , Klong Luang , Pathumthani 13180 , Thailand
2. Department of Mathematics, Faculty of Science and Technology, Phetchabun Rajabhat University , Phetchabun 67000 , Thailand
3. School of Science, University of Phayao , Phayao 56000 , Thailand