1. Department of Applied Mathematics, I-Shou University, Kaohsiung 84001, Taiwan
2. Department of Leisure and Recreation Management, Ph.D. Program in Engineering Science, Chung Hua University, Hsinchu 30012, Taiwan
3. Department of Applied Mathematics, National Sun Yat-sen University, Kaohsiung 80424, Taiwan
4. Department of Computer Science and Engineering, National Sun Yat-sen University, Kaohsiung 80424, Taiwan