1. Department of Mathematics, The College of William & Mary, Williamsburg, VA, USA
2. General Education Center, National Taipei University of Technology, Taipei, Taiwan
3. Department of Applied Mathematics, National Chung Hsing University, Taichung, Taiwan
4. Department of Applied Mathematics, National Sun Yat-sen University, Kaohsiung, Taiwan
5. Department of Healthcare Administration and Medical Information, and Center of Fundamental Science, Kaohsiung Medical University, Kaohsiung, Taiwan