1. Associate Professor, Dept. of Construction Engineering, National Yunlin Univ. of Science and Technology, No. 123, Section 3, University Rd., Touliu, Taiwan 640, Republic of China.
2. Postdoctoral Research Associate, Dept. of Construction Engineering, National Yunlin Univ. of Science and Technology, No. 123, Section 3, University Rd., Touliu, Taiwan 640, Republic of China (corresponding author).