1. Associate Professor, Engineering, Architecture, and Aerospace Technology, Univ. of the District of Columbia, 4200 Connecticut Ave., NW, Washington, DC 20008.
2. Dept. of Civil Engineering, Univ. of Toronto, Toronto, ON, Canada M5S 1A4.
3. Dept. of Civil Engineering, Ryerson Univ., Toronto, ON, Canada M5B 2K3.