Department of Computer Science and Information Engineering, Graduate Institute of Biomedical Electronics and Bioinformatics and Graduate Institute of Networking and Multimedia, National Taiwan University, Taipei, Taiwan.|Department of Computer Science and Information Engineering, Graduate Institute of Biomedical Electronics and Bioinformatics and Graduate Institute of Networking and Multimedia, National Taiwan University, Taipei, Taiwan.|Department of Computer Science and Information Engineering, Graduate Institute of Biomedical Electronics and Bioinformatics and Graduate Institute of Networking and Multimedia, National Taiwan University, Taipei, Taiwan.