Pannarat Guayjarernpanishk
Faculty of Applied Science and Engineering, Khon Kaen University, Nong Khai Campus, Nong Khai
Thailand

Tossapol Phoophifa
Department of Mathematics, Faculty of Science, Mahasarakham University, Maha Sarakham
Thailand

Piyapatr Busababodhin
Department of Mathematics, Faculty of Science, Mahasarakham University, Maha Sarakham
Thailand