1. Assistant Professor, Dept. of Civil Engineering, National Taipei Univ. of Technology, No. 1, Section 3, Jungshiau East Rd., Daan Chiu, Taipei 106-08, Taiwan, Republic of China.
2. Associate Professor, Dept. of Civil Engineering, National Taipei Univ. of Technology, Taipei 106, Taiwan, R.O.C.
3. Professor, Dept. of Civil Engineering, National Taiwan Univ., Taipei 106, Taiwan, R.O.C.