1. Department of Applied Mathematics, Chung Yuan Christian University, Chung Li, Taiwan, Republic of China
2. Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
3. Department of Applied Mathematics, National Chung Hsing University, Taichung City, Taiwan, Republic of China
4. Center for Fundamental Science, Kaohsiung Medical University, Kaohsiung, Taiwan, Republic of China