1. Prof., Civ. Engrg. and Mechanics Dept., The Catholic Univ. of America, Washington, D.C.
2. Assoc. Prof., Civ. Engrg. and Mechanics Dept., The Catholic Univ. of America, Washington, D.C.
3. Wright and Mok, Consult. Engrs., Silver Spring, Md.
4. Visiting Assoc. Prof., National Taiwan Univ., Taipei, Taiwan, China