###### Abstract
[PERSON] [29] developed a DRF model as a function of the damping ratios, natural periods, magnitude, and distance using 2229 vertical strong ground motion records of shallow crustal earthquakes in active tectonic regions from the Next Generation Attenuation-West2 database. [PERSON] et al. [30] presented a damping model for scaling 5%-damped vertical spectral ordinates, and the model was based on a ground motion prediction equation for a vertical-to-horizontal spectral ratio [31] model developed for shallow active crustal regions in Europe and the Middle East. [PERSON] and [PERSON] [32] considered the DRF for the absolute acceleration spectrum to be more susceptible to ground motion characteristics than the DRF for the pseudo-acceleration spectrum and presented a complex DRF model for the different acceleration spectra for different damping ratios and periods using 3198 vertical strong motion records on subduction earthquakes recorded by K-NET and KiK-net in Japan. Using 6466 vertical strong motion records on shallow crustal and upper-mantle earthquakes recorded by the Kyoshin network (K-NET) and the Kiban-Kyoshin network (KiK-net), [PERSON] et al. [33] and [PERSON] and [PERSON] [34] proposed site-related DRF models for the displacement spectra and the acceleration spectra, respectively. They concluded that magnitude and distance have a significant impact on the DRF according to their residual analysis. [PERSON] [35] studied the influence of the closest distance, site conditions, earthquake magnitude, peak ground acceleration (PGA), and damping ratios on DRFs using 195 real vertical ground motion earthquakes selected from the PEER strong motion database. He indicated that the moment magnitude of an earthquake has a significant impact on DRFs, but the effect of the soil type, distance, and PGA is negligible. In addition, he developed simplified empirical formulations to compute the DRF for the vertical component. [PERSON] et al. [36] employed 892 offshore and 4033 onshore ground motion records from the Kyoshin network to exhibit the differences in the DRFs of offshore and onshore ground motions. They stressed that the influence of the site conditions on offshore DRFs is extremely minor. They proposed offshore DRF models for horizontal and vertical acceleration spectra from Japan's Sagami Bay region based on 34 spectral periods and 10 damping ratios, where only the spectral periods and damping ratios were taken into account as variables. The uncertainty in the DRF model mainly depends on the path and site effects, and the standard deviations of the DRFs for the vertical component were slightly less than those for the horizontal component. Recently, [PERSON] and [PERSON] [37] presented the variation in the DRFa, DRFd, and DRFv in relation to the viscous damping ratio. The DRFs were computed by considering the displacement (Sd), pseudo-velocity (PSV), and pseudo-acceleration (PSa) response spectra. The mean DRF variations for a total of 20 real earthquake ground motions recorded in soft soil (180 \(<\) V\({}_{\text{S30}}\)\(\leq\) 360 m/s) according to the Turkish Building Earthquake Code [15] were considered, and the records were selected from the NGA-West2 strong ground motion database. The authors found that for longer natural vibration periods (especially T \(>\) 1.0 s), the mean DRFs of the selected earthquake ground motions were nearly constant but fluctuated for T \(<\) 0.3 s. They ascertained that the mean DRF variations with respect to the viscous damping ratios were compatible with the code-based DRF relations for selected records. [PERSON] and [PERSON] [38] used a set of 5962 records from the PEER NGA-West2 database. They explored the DRFv at 1%, 2%, 8% and 10% damping ratios with respect to 5% for a period range of 0-4.0 s. They stated that magnitude, epicentral distance, and soil type parameters are less practical and important to the DRFv. They proposed using a simplified relation as a function of the period to compute the DRFv regardless of the seismological parameters.