## 1 Introduction
[9] investigated the optimal vertical placement of isolators in multi-story buildings. The aim of the optimization was the minimization of the maximum floor accelerations, while the constraints were related to interstory drifts, maximum base displacements and the seismic isolation total cost. [PERSON] et al. [10] obtained the optimal friction coefficient by minimizing the sum of squares of structural absolute accelerations. The results revealed that the optimization of friction coefficient depended more on the isolation period than on various other ratios (mass, damping, etc.). The optimization of isolators parameters installed at multi-story buildings via harmony search (HS) was examined by [PERSON] et al. [11]. It was shown that the HS algorithm was an efficient optimization technique considering this application, and it proved its robustness regarding the variation in the ground motion characteristics. [PERSON] and [PERSON] [12] implemented genetic algorithms (GA) to perform optimization of structures isolated with triple friction pendulum bearings (TFFB) under three seismic hazard levels. It was concluded that the outer (i.e., upper and lower) concave sliding surface parameters (curvature radii, friction coefficients, displacement capacities) of TFPB isolators had a more significant effect on the structural response compared to the inner sliding surface properties, while the hazard level had a marginal influence on the optimization results. [PERSON] et al. [13] examined the optimal performance of a base-isolated building considering the limitation on excessive isolator displacements. It was shown that the constrained-optimal isolation system produced significantly different results compared to the unconstrained formulation. [PERSON] and [PERSON] [14] studied the impact of foundation layer characteristics on the dynamic response of buildings isolated with SFPB. Taking into account soil-structure interaction, the optimum SFPB parameters were derived from a wide range of friction bearing properties. [PERSON] et al. [15] presented a performance-based optimization formulation for multi-story buildings isolated with multiple-coupling friction dampers. The performance parameters of the isolation scheme were used as design variables, the displacements and accelerations were chosen as the objectives and the optimization problem was solved via sequential quadratic programming. Recently, [PERSON] and [PERSON] [16] presented a study on sizing optimization of SFPB and TFPB isolators placed at the base of liquid storage tanks, using several nature-inspired optimizers. The minimization of tank base accelerations was the objective of this formulation, while the constraints were related to the vibration period and damping capacity of the isolators. [PERSON] et al. [17] implemented three bio-inspired search methods in order to achieve the optimization of the isolation period and damping ratio of a simple four-story, two-dimensional frame isolated with rubber bearings. The results were compared with those obtained via HS optimizer by [PERSON] et al. [11], while it was reported that the three algorithms converged to similar optimum values. A limited number of far- and near-fault accelerograms were used, and it was found that near-fault records are the most influential ones, resulting in less favorable seismic response parameters during the optimization process. The impact of three control systems, namely tuned viscous mass damper (TVDD), tuned inerter damper (TID) and tuned mass damper (TMD), on improving the seismic response of base isolated structures was compared by [PERSON] et al. [18]. Suitable optimization formulations were applied to optimize the properties of the three control systems. According to the results of this study, all three optimal control systems effectively reduced the dynamic distress of the isolated structure. [PERSON] et al. [19] applied an adaptive harmony search algorithm to optimize the base isolation system of a structure.