1. Graduate Student, National Taiwan Univ., Dept. of Civil Engineering, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.
2. Postdoctoral Fellow, National Taiwan Univ., Dept. of Civil Engineering, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan.
3. Associate Professor, National Taiwan Univ., Dept. of Civil Engineering, No. 1, Sec. 4, Roosevelt Road, Taipei, 10617, Taiwan (corresponding author).