Shih-Hsu Chang, Fang-Hsuan Cheng and Wen-Hsing Hsu
Department of Computer Science and Information Engineering
Da-Yeh University
Changhwa, Taiwan 515, R.O.C.
*Department of Computer Science
Chung-Hua University
Hsinchu, Taiwan 300, R.O.C.
+Department of Electrical Engineering
National Tsing Hua University
Hinchu, Taiwan 300, R.O.C.
++Institute of Information Science
Academia Sinica
Taipei, Taiwan 115, R.O.C.