Being in a stable continental region (SCR) with a limited history of instrumentation, South Korea has not collected sufficient instrumental data for data-driven ground motion models. To address this limitation, we investigated the suitability of the hybrid ground motion simulation method that Graves and Pitarka (2010, 2015) proposed for simulating earthquake ground motions in South Korea. The hybrid ground motion simulation method used in this study relies on region-specific parameters to accurately model phenomena associated with the seismic source and the wave propagation. We initially employed relevant models and parameters available in the literature as a practical approach. We incorporated a three-dimensional velocity model developed by Kim et al. (2017) and a one-dimensional velocity model presented by Kim et al. (2011) to account for the crustal velocity structure of the Korean peninsula. To represent the earthquake source, we utilized Graves and Pitarka’s rupture generator algorithm along with a magnitude-area scaling relationship developed for SCR by Leonard (2014). Additionally, we assumed the stress and attenuation parameters based on studies of regional seismicity. Using the implemented platform, we simulated the 2016 Mw5.57 Gyeongju earthquake and the 2017 Mw5.4 Pohang earthquake. Subsequently, we compared results with recorded accelerations and an empirical ground motion prediction equation at strong motion stations. Our simulations had an overall satisfactory agreement with the recorded ground motions and demonstrated the potential of broadband hybrid ground motion simulation for engineering applications in South Korea. However, limitations remain, such as the underestimation of long-period ground motions during the 2017 Pohang earthquake and the lack of a model to predict the ground motion amplification associated with the near-surface site response accurately. These limitations underscore the importance of careful validation and refinement of region-specific models and parameters for practically implementing the simulation method.

In stable continental regions, selecting appropriate ground motions for seismic design and dynamic response analysis presents significant challenges. This study evaluates the liquefaction potential of the Nakdonggang delta region, South Korea, by generating synthetic ground motion scenarios and applying a scenario-based liquefaction assessment approach. We utilized a hybrid broadband ground motion simulation method proposed by Graves and Pitarka (2010, 2015) to create bedrock ground motions for three hypothetical earthquakes (Mw 6.2 and 6.0) occurring along the Dongrae and Miryang faults. The generated synthetic ground motions were used as input for onedimensional nonlinear site response analyses, incorporating shear wave velocity profiles derived from surface wave inversion. The simulated ground motions demonstrated higher responses at short periods and relatively weaker responses at long periods compared to the Korean design spectra. This amplification of long-period components was attributed to the dynamic response of deep sedimentary layers, while high-frequency components were generally deamplified due to damping effects in shallow silty layers. Liquefaction susceptibility was assessed using surface ground motions derived from the site response analyses, following the SPT-based simplified method proposed by Idriss and Boulanger (2008). Results indicated high liquefaction potential across most sites for the Dongrae earthquake scenario, while liquefaction was unlikely for all sites under the Miryang-1 scenario. For the Miryang-2 scenario, liquefaction was predicted at some sites. Overall, liquefaction is expected at PGA values of approximately 0.13 g or higher, with sites exhibiting lower shear wave velocities being more vulnerable to liquefaction

The damage to structures during an earthquake can be varied depending on the frequency characteristics of seismic waves and the geological properties of the ground. Therefore, considering such attributes in the design ground motions is crucial. The Korean seismic design standard (KDS 17 10 00) provides design response spectra for various ground classifications. If required for time-domain analysis, ground motion time series can be either selected and adjusted from motions recorded at rock sites in intraplate regions or artificially synthesized. Ground motion time series at soil sites should be obtained from site response analysis. However, in practice, selecting suitable ground motion records is challenging due to the overall lack of large earthquakes in intraplate regions, and artificially synthesized time series often leads to unrealistic responses of structures. As an alternative approach, this study provides a case study of generating ground motion time series based on the hybrid broadband ground motion simulation of selected scenario earthquakes at sites in the Nakdonggang delta region. This research is significant as it provides a novel method for generating ground motion time series that can be used in seismic design and response analysis. For large-magnitude earthquake scenarios close to the epicenter, the simulated response spectra surpassed the 1000-year design response spectra in some specific frequency ranges. Subsequently, the acceleration time series at each location were used as input motions to perform nonlinear 1D site response analysis through the PySeismoSoil Package to account for the site response characteristics at each location. The results of the study revealed a tendency to amplify ground motion in the mid to long-period range in most places within the study area. Additionally, significant amplification in the short-period range was observed in some locations characterized by a thin soil layer and relatively high shear wave velocity soil near the upper bedrock.

A demand for bio-diesel oil increases as one of solution for exhaustion of fossil fuel and reduction of CO2 emission, and research on bio-diesel is being carried out. Bio-diesel oil is mainly esterified from vegetable oil with methanol in order to use for fuel on diesel engine and has demerit that costs are increased as compared with directly using like non-esterified one. Bio-diesel oil within 3% mixed with gas oil is used at present, proportion of bio-diesel oil will be increase by 5% in future. We judged that wasted soybean oil non-esterified could be used on diesel engine with an electronic fuel injection according to previous researches with a mechanical fuel injection. A performance test using only gas oil, gas oil with esterified bio-diesel oil 5% and wasted soybean oil non-esterified 5% on diesel engine with the electronic fuel injection were carried out. It is noticed that gas oil with wasted soybean oil non-esterified 5% has more similar characteristics to gas oil than gas oil with esterified bio-diesel oil 5%.

There are increased in using the bio-ethanol, as the carbon neutral attracts many researchers due to a reduction in carbon dioxide spotted as the global warming gas. A gasoline engine with 100% of the bioethanol was developed and used in Brazil already, but researches of using the bio-ethanol in diesel engines are lack. In this study, combustion tests with blend fuel of the gas oil and bio ethanol by 50% maximally due to a low cetane number of bio-ethanol were accomplished as a basic study of introduction of using the bioethanol in diesel engines. The result was that smoke emission was decreased with increase in proportion of the bio-ethanol, due to the increase of a amount of pre-mixed combustion with ignition delay. Although the amount of CO2 is reduced according as the bio-ethanol is used(carbon neutral), the emission of CO2 with increase in the proportion of the bio-ethanol was more increased due to lower a heat value of bio-ethanol than gas oil.

시대적 변화에 따라 디지털 시대가 열리며 생활 속 많은 부분이 편리해졌다. 이러한 편리한 삶에 의해 사람들의 비만율이 점차 증가하고 있으며, 운동의 필요성이 대두되고 있다. 하지만 많은 사람들이 운동을 하지 않거나 운동을 하더라도 3～6개월 사이에 중단한다는 사실이 여러 연구사례를 통해 증명되었다. 본 논문에서는 이러한 사실들을 검증하기 위해 운동에 대한 이론적 배경과 선행연구사례를 바탕으로 헬스케어 체감형 AR게임인 “Walking Pet” Prototype을 설계하고 개발하였다. 개발한 “Walking Pet”은 운동에 대한 동기부여를 위해 운동 데이터를 제공하며, 운동을 자발적으로 즐겁게 할 수 있도록 펫 시스템을 적용하였다. 본 논문에서 개발한 “Walking Pet” Prototype의 효율성을 검증하기 위해 헬스케어 어플리케이션을 필요로 하는 남녀 100명을 대상으로 순기능적인면의 만족도에 대한 설문통계를 하였다.

온라인 게임의 역사는 다른 게임들에 비해 짧은 역사를 가지고 있는데 반해 많은 성장과 결과를 보였다. 그 중 캐릭터 커스터마이징 시스템은 온라인 게임을 이루고 있는 다른 요소들에 비해 상대적으로 많은 발전을 이루지는 못했다. 커스터마이징 시스템이 상대적으로 많은 발전을 이루지 못한 데에는 당시의 그래픽 기술력문제가 큰 영향을 주었다. 하지만 그래픽의 발전과 함께 사용자들의 풍부한 표정에 대한 욕구 수요가 가능해 졌으며, 캐릭터 얼굴 변환 아이템이 새로운 수익을 창출할 정도로 근래에 나오는 커스터마이징 시스템은 자유도 높은 시스템으로 만들어지고 있다. 본 논문에서는 높아진 자유도만큼 개성 있는 캐릭터들이 다양하게 만들어 질 수 있도록 사람의 인상을 연구하고 분석하는 학문인 관상학을 근거로 아이온 커스터마이징 시스템을 분석하여 발전적인 캐릭터 커스터마이징 시스템 구성을 하였다.