1. Department of Mathematics, Faculty of Science, King Mongkut’s University of Technology Thonburi 1 , Bangkok 10140, Thailand
2. Department of Mathematics and Statistics, University of Swat 2 , Swat 19120, Khyber Pakhtunkhwa, Pakistan
3. Department of Mathematics, School of Science, King Mongkut’s Institute of Technology Ladkrabang 3 , Bangkok 10520, Thailand