1. Assistant Professor, Dept. of Civil Engineering, Boazç Univ., Bebek, 80815 Istanbul, Turkey.
2. Assistant Professor, Dip. Ingegneria Strutturale e Geotecnica, Univ., di Roma “La Sapienza,” Rome, Italy.
3. Professor, Dept. of Civil Engineering and Engineering Mechanics, Columbia Univ., 610 S.W. Mudd Building, Mail Code 4709, 500 West 120th St., New York, 10027.
4. Professor, Dept. of Mechanical Engineering, Columbia Univ., 610 S.W. Mudd Building, Mail Code 4709, 500 West 120th St., New York, 10027.