1. Department of Mathematics, Shanghai Normal University, Shanghai 200234, China
2. Department of Healthcare Administration and Medical Informatics, and Research Center of Nonlinear Analysis and Optimization, Kaohsiung Medical University, and Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung 807, Taiwan
3. Research Center for Interneural Computing, China Medical University Hospital, China Medical University, Taichung 40402, Taiwan