1. Postdoctoral Researcher, National Technical Univ. of Athens, Institute of Structural Analysis and Seismic Research, Zografou Campus, Iroon Polytexneiou 9, 15780 Athens, Greece.
2. Postdoctoral Researcher, National Technical Univ. of Athens, Institute of Structural Analysis and Seismic Research, Zografou Campus, Iroon Polytexneiou 9, 15780 Athens, Greece (corresponding author).