1. Struct. Research Engr., Center for Building Tech., National Bureau of Standards, Washington, D.C.
2. Ingenieur en Chef des Pon ts et Chaussees, Centre Scientifique et Technique du Batiment, Etablissement de Nantes, Nantes, France
3. Mathematical Statistician, Statistical Engrg. Lab., National Bureau of Standards, Washington, D.C.