1. Ph.D. Student, Institute of Structural Analysis and Aseismic Research, Dept. of Civil Engineering, National Technical Univ. of Athens, Zografou Campus, Athens 157-80, Greece.
2. Associate Professor, Institute of Structural Analysis and Aseismic Research, Dept. of Civil Engineering, National Technical Univ. of Athens, Zografou Campus, Athens 157-80, Greece.