1. Professor, Univ. of Michigan, Ann Arbor, MI 48109 (corresponding author).
2. Associate Professor, Univ. of Pittsburgh, Pittsburgh, PA 15261.
3. Chief Engineer, Cives Steel Company, Dayton, OH 45469.
4. Professor, Univ. of Cincinnati, Cincinnati, OH 45221.
5. Associate Professor, Univ. of Notre Dame, Notre Dame, IN 46556.