1. Senior Environmental Specialist, Office of Secretary General, Environmental Protection Administration, 41, Sec. 1, Chung-Hwa Rd., Taipei, Taiwan.
2. Professor, Dept. of Civil Engineering, National Taiwan Univ. 1, Sec. 4, Roosevelt Rd., Taipei, Taiwan.
3. Professor, Dept. of Civil and Environmental Engineering, Northern Arizona Univ., Flagstaff, AZ 86011.