• Proceedings of the Korean Geotechical Society Conference
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• 2010.03a
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• pp.755-758
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• 2010

본 연구에서는 토목구조물에 대하여 상사율을 고려한 1g 진동대실험(Shaking Table Test)과 전산해석을 수행하여, 실제 지진하중(단주기, 장주기, 인공지진)에 대한 토목구조물의 안정성을 분석 및 평가 하였다. 상사율에 따른 지표면 가속도 거동을 비교 분석하기 위하여 여러 가지 상사율을 적용한 실험을 수행하여 측정된 결과와 전산해석 결과를 상호 비교 분석하여 상사비에 따른 실험결과의 적절성을 평가하였다. 상사율을 1/50과 1/50보다 크게 조성하여 진동대실험과 전산해석 결과에 의하면, 지표면 가속도의 결과는 모두 유사한 결과를 보였다. 상사율 1:50 이상인 단면의 경우 진동대실험과 전산해석 결과 사이의 유사성이 떨어지는 것으로 볼 때, 1:50 이하인 상사단면이 실제 현장에서의 거동을 모사하는데 더 높은 신뢰성을 제공하는 것으로 판단된다.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.171-171
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• 2010

• Journal of the Korea Society for Simulation
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• v.25 no.3
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• pp.97-105
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• 2016

This paper discusses the effect of numerical reinforcement modeling methods on the penetration performance of a penetrator into a concrete target. AUTODYN-3D has been used to conduct the numerical penetration analyses. In order to validate the computational approach, experimental data of Hanchak have been compared to a computation result and a reasonably good agreement could be obtained. The strength and the diameter of a reinforcement have been changed to find out the effect of reinforcement modeling methods on the penetration performance. The impact locations and velocities of a penetrator are also changed to investigate the effect of reinforcement modeling methods. Residual velocities of a penetrator are quantitatively compared in detail for the evaluation of reinforcement modeling effects on the penetration performance.

• Korean Journal of Optics and Photonics
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• v.26 no.3
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• pp.168-171
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• 2015

The heat flow characteristics of a high-power optical semiconductor source have been analyzed using a 3D CFD commercial tool, and the thermal resistance values for each of the layers revealed the places for thermal bottlenecks to be improved. As the heat source of a LD (Laser Diode) has a small volume and a narrow surface, the effective thermal cross-sectional area near it is also quite small. It was possible to expand the cross-sectional area effectively by using graphene layers on the TIM (Thermal Interface Material) layers of a LD chip. The effective values of heat resistance for the layers are compared to confirm the improvement effect of the graphene layers before and after, which can be considered to expand the thermal cross section of the heat transfer path.

• Journal of IKEEE
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• v.22 no.4
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• pp.1056-1061
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• 2018

In this study, we propose the structure of color glass for BIPV (Building Integrated Photovoltaic System) and develop process technology to realize it. It was verified through computer simulation based on wave optics that two different kinds of metal oxide thin films with different refractive indices could be integrated to realize different colors with good transmittance. To fabricate the structure, we used RF Magnetron deposition method to achieve the target thickness uniformly. The optical analysis of the samples was carried our by comparing with the results of computer simulations and it was found that this technique can be stably implemented on lab scale. The stability test over weeks was confirmed at room temperature. This method is expected to be very useful in BIPV buildings.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.4
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• pp.215-226
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• 2022

Significant efforts have been devoted to developing high-performance composite materials by emulating the structure of biological creatures with superior mechanical characteristics. Nacre has been one of the most sought-after natural structures due to its exceptional fracture toughness compared with the constituent materials. However, the effect of manipulating the nacre-like geometry on the impact performance has not been fully investigated thus far. In this study, composites of randomly manipulated nacreous geometry are numerically developed and the impact performance is analyzed. We develop an algorithm by which the planar area of platelets in the nacre-like design is randomly resized. Thereafter, the numerical models of nonuniform nacre-patterned multi-layer structures are developed and the drop-weight impact simulation is performed. The impact behaviors of the model are evaluated by using the ratio of absorbed energy, the von Mises stress distribution, and the impact force-time curve. Therefore, the effect of the geometric irregularity on the nacre-patterned design is elucidated. This insight can be efficiently utilized in establishing the optimum design of the nacre-patterned structure.

• Journal of the Korean Institute of Gas
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• v.9 no.2 s.27
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• pp.22-27
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• 2005

In this study, we analyze computational simulation of cryogenic distillation process to separate $^{13}CH_4$ and $^{12}CH_4$ from LNG by using the cryogenic energy. Used computational simulation program is made Smoker's equation and FUG(Fenske-Underwood-Gilliland)'s method by short-cut method. Generally speaking, the technology of carbon isotope separation is studied by many methods, especially the separation by cryogenic distillation process is commercialized because of many merits.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2018.10a
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• pp.195-196
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• 2018

We have investigated electrical and optical characteristics of $H_2Pc$ introduced OLED devices. $H_2Pc$ layer acted on tunnel barrier for incident electrons. we have also observed that energy band of the proposed structure was varied as applied electric field by simulation using TCAD program.

• Journal of Radiation Protection and Research
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• v.29 no.4
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• pp.269-273
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• 2004

The hybrid dead time model adopting paralyzable (or extendable) and non-paralyzable (or non-extendable) dead times has been introduced to extend the usable range of G-M counters in high counting rate environment and the relationship between true and observed counting rates is more accurately expressed in the hybrid model. GMSIM, dead time effects simulator, has been developed to analyze the counting statistics of G-M counters using Monte Carlo simulations. GMSIM accurately described the counting statistics of the paralyzable and non-paralyzable models. For G-M counters that follow the hybrid model, the counting statistics behaved in between two idealized models. In the future, GMSIM may be used in predicting counting statistics of three G-M dead time models, which are paralyzable, non-paralyzable and hybrid models.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.145-148
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• 2010

항만 구조물의 건전성 평가 기술의 개발을 위한 기초 연구로서, 강제진동해석을 통하여 케이슨 구조-지반 경계부의 손상에 대한 진동응답을 분석하고자 한다. 이를 위해 세 단계의 연구를 수행하였다. 첫째, 케이슨 구조물의 진동특성 분석을 위해 시간영역기반의 AR(auto-regressive)모델을 선정하였다. 둘째, 모형 케이슨 구조물을 대상으로 진동응답 계측실험을 수행하였으며, AR-모델을 통해 진동특징을 실험적으로 분석하였다. 셋째, 대상 케이슨 시스템의 유한요소모델을 구성하고, 구조-지반 경계부의 손상에 따른 동적응답 특성의 변화를 수치적으로 분석하였다. 이를 위해 강제진동을 모사 하였으며, 구조-지반 경계부의 강성변화에 따른 케이슨 구조물의 진동응답의 변화를 분석하였다.