1. Research Structural Engineer, Building and Fire Research Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8611.
2. Professor, Dept. of Civil and Environmental Engineering, Univ. of Michigan, Ann Arbor, MI 48109.
3. Senior Research Structural Engineer, Building and Fire Research Laboratory, National Institute of Standards and Technology, Gaithersburg, MD 20899-8611.