1. Dept. of Computer Science and Information Engineering, National Cheng Kung University Tainan, Taiwan
2. Dept. of Computer Science and Information Engineering, National Cheng Kung University, Tainan, Taiwan
3. Dept. of General Medicine and Health Science, Nippon Medical School, Tokyo, Japan
4. Research Institute for Electronic Science, Hokkaido University, Sapporo, Hokkaido, Japan