1. Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Illinois, 205 N. Mathews Ave., Urbana, IL 61801; formerly, Student Research Assistant, Dept. of Civil Engineering, National Taiwan Univ., No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
2. Assistant Professor, Dept. of Civil Engineering, National Taiwan Univ., No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan (corresponding author).
3. Student Research Assistant, Graduate Institute of Networking and Multimedia, National Taiwan Univ., No. 1, Sec. 4, Roosevelt Rd., Taipei 10617, Taiwan.
4. Professor, Medical School, National Taiwan Univ., No. 7, Zhongshan S. Rd., Taipei 10002, Taiwan.