1. Professor, Dept. of Industrial Engineering and Management, National Chin-Yi Univ. of Technology, Taichung City 41170, Taiwan (corresponding author).
2. Professor, Dept. of Industrial Engineering and Management, National Chin-Yi Univ. of Technology, Taichung City 41170, Taiwan.
3. M.S. Student, Dept. of Industrial Engineering and Management, National Chin-Yi Univ. of Technology, Taichung City 41170, Taiwan.