1. Department of Mathematics and Statistics, Faculty of Science, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
2. Faculty of Science, Guangxi University of Technology and Science, Liuzhou 545000, China
3. Laboratory of Computational Statistics and Operations Research, Institute for Mathematical Research, Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia
4. Faculty of Arts and Social Sciences, Nottingham University Business School, University of Nottingham Malaysia, Semenyih 43500, Selangor, Malaysia