Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.|Department of Computer Science and Information Engineering, National Taiwan University and Institute of Information Science, Academia Sinica, Taipei, Taiwan.