RUEY-LIANG MA AND CHUNG-PING CHUNG*
Computer & Communications Research Laboratories, ITRI
Hsinchu County, Taiwan 310, R.O.C.
E-mail: rlma@ozu.ccl.itri.org.tw
*Institute of Computer Science and Information Engineering
National Chiao Tung University Hsinchu,
Taiwan 300, R.O.C.