Tin-Chih Toly Chen1, W Art Chaovalitwongse2, Michael J O'grady3, Katsuhiro Honda4. 1. Department of Industrial Engineering and Management, National Chiao Tung University, 1001, University Rd., Hsinchu City, Taiwan. tolychen@ms37.hinet.net. 2. Industrial Engineering, University of Arkansas, Fayetteville, AR, USA. 3. UCD School of Computer Science & Informatics, University College Dublin, Belfield, Dublin 4, Ireland. 4. Human Information System Laboratory, Graduate School of Engineering, Osaka Prefecture University, Gakuencho 1-1, Nakaku, Sakai, Osaka, 599-8531, Japan.