## 1 Introduction  
The dynamic test method of earthquake-loaded structural systems has been developed for more accurately assessment. These methods are largely classified into numerical methods and experimental methods. In the numerical method, the structural system can be represented by the discretized motion equations and the solution is obtained to evaluate the dynamic characteristics of the structure. However, there are limitations on the diversity and accuracy of material models for structures, and several types of numerical time integration methods have been developed and used to date. Compared to the numerical method, the experimental methods, such as pseudo-dynamic tests and shaking table tests, can be more direct in evaluating the dynamic elastic properties of structures relatively effectively, but it is expensive and may require huge experimental facilities depending on the experiment [1]. Additionally, it is difficult to repeat the same test using a shake table due to the cost of manufacturing the specimen. To overcome these shortcomings, the real-time hybrid test (RTHT) has been actively studied by many researchers [2; 3; 4; 5; 6; 7; 8; 9; 10; 11; 12; 13; 14; 15; 16; 17; 18; 19; 20; 21; 22; 23; 24; 25; 26; 27]. The real-time hybrid test method is one of the less expensive and more efficient methods compared to the shaking table test and allows you to evaluate the dynamic characteristics of the structure with high accuracy. The early concept of the hybrid testing was initiated from a pseudo-dynamic test simulating seismic loads using one actuator to predict the nonlinear behavior of structures in the 1960s [2,3]. In the 1980s, theoretical studies of the pseudo-dynamic test were established [4,5]. After started by [PERSON] and the real-time hybrid test were developed with special programs such as OpenSees and OpenFresco [6, 7, 8, 9, 10, 11]. As a part of NEES (Network for Earthquake Engineering Simulation) project, [PERSON] et al. tried something new to fix the iteration numbers for the convergence error and designed the optimum algorithm for the real-time hybrid test with \(1\) DOF (Degree of Freedom) and 2-DOF models [12]. [PERSON] also developed the multi-degree of freedom real-time hybrid testing with various numerical scheme [13]. Lately, [PERSON] et al. focused on the quality of the simulation strongly depending on the correct application of the interface boundary conditions between the numerical and the physical subdomains with eight actuators [14]. In order to evaluate the seismic performance for a twelve-story precast reinforced concrete shear-wall structure, [PERSON] et al. employed the full-scale bottom structural model as the physical substructure and the elastic non-linear model as the numerical substructure and used an equivalent force control method [15]. [PERSON] et al. and [PERSON] et al. have conducted the real-time hybrid test for concrete structures after developing Mercury with optimized computer environment for numerical analysis and hardware [16,17]. For the dynamic performance of bridge structures, the hybrid test with seismic proactive system such as viscous damper and isolators has been conducted by many researchers [18, 19, 20, 21]. Recently, mooring system of offshore structure was applied with real-time hybrid test method [22]. [PERSON] et al. developed a robust standardized procedure for hybrid testing of a multi-span bridge through internet between Canada and Taiwan [23]. Recently, [PERSON] et al. tried to carry out hybrid simulations of a three-span reinforced concrete bridge among EU, US, and Canada [24]. The tests involved partners located on both sides of the Atlantic with each one assigned a numerical or a physical module of the substructured bridge. Despite the network latency in linking remote sites, the intercontinental hybrid simulation was accomplished and repeated successfully, highlighting the efficiency, and repetitiveness of the approach.