1. Prof., Inst. of Struct. Anal. and Aseismic Res., Nat. Tech. Univ. of Athens, Zografou Campus, GR-15773, Athens, Greece.
2. Res. Asst., Inst. of Struct. Anal. and Aseismic Res., Nat. Tech. Univ. of Athens, Zografou Campus, GR-15773, Athens, Greece.