• 한국전산구조공학회논문집
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• 제37권3호
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• pp.205-216
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• 2024

최근 원자력 지진 PSA(Probabilistic Safety Assessment)를 토대로 산업시설물의 지진 PSA를 수행하는 연구가 진행되었다. 해당 연구는 원자력 발전소와 산업시설물의 차이를 파악하고, 최종적으로 운영정지를 목표로 하는 고장수목(Fault Tree)를 구축한 후 시각적 확률도구인 베이지안 네트워크(Bayesian Network, BN)으로 변환하였다. 본 연구는 선행연구를 기반으로 지진으로 유발된 구조손상으로 인해 발생 가능한 화재･폭발에 대해 PSA를 수행하고자 하였다. 이를 위해 화재･폭발을 사건수목(Event Tree)으로 표현하고, BN으로 변환하였다. 변환된 BN은 화재･폭발 모듈로서 선행연구에서 제시된 고장수목 기반 BN과 연계되어 최종적으로 지진 유발 화재･폭발 PSA를 수행할 수 있는 BN 기반 방법론이 개발되었다. 개발된 BN을 검증하기위해 수치예제로서 가상의 가스플랜트 Plot Plan을 생성하였고, 가스플랜트의 설비 종류가 구체적으로 반영된 대규모 BN을 구축하였다. 해당 BN을 이용하여 지진 규모에 따른 전체시스템의 운영정지 확률 및 하위시스템들의 고장확률 산정과 더불어 역으로 전체시스템이 운영 정지되었을 때 하위시스템들의 영향도 분석과 화재･폭발 가능성을 산정하여 다양한 의사결정을 수행할 수 있음을 제시함으로써 그 우수성을 확인하였다.

• Journal of Platform Technology
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• 제6권3호
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• pp.38-46
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• 2018

스마트 그리드는 전력 생산자와 소비자 간의 양방향 통신을 통해 효율적으로 전력을 생산 및 소비하기 위한 지능형 전력망이다. 신재생 에너지가 발전하면서 신재생 에너지가 스마트 그리드에서 차지하는 비율이 점점 높아지고 있다. 신재생 에너지는 발전량이 실시간으로 변하기 때문에 발전량의 예측 및 조절이 가능한 기존의 발전 방식과는 다른 문제점이 있다. 스마트 그리드에 자가 적응 프레임워크를 적용하는 것은 실시간으로 변하는 신재생 에너지의 발전량에 적응함으로써 스마트 그리드의 효율적인 운영을 가능케 할 것이다. 본 논문에서는 태양광 발전 시설이 설치된 스마트 마을을 가정하고 이에 자가 적응 프레임워크인 AiTES 를 적용 하여 자가 적응 프레임워크를 통해 스마트 그리드의 효율적인 운영이 가능함을 보였다.

• 한국CDE학회논문집
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• 제21권3호
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• pp.341-352
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• 2016

Manual 3D pipeline modeling from LiDAR scanned point cloud data is laborious and time-consuming process. This paper presents a method to extract the pipe, elbow and branch information which is essential to the automatic modeling of the pipeline connection. The pipe geometry is estimated from the point cloud data through the Hough transform and the elbow position is calculated by the medial axis intersection for assembling the nearest pair of pipes. The branch is also created for a pair of pipe segments by estimating the virtual points on one pipe segment and checking for any feasible intersection with the other pipe's endpoint within the pre-defined range of distance. As a result of the automatic modeling, a complete 3D pipeline model is generated by connecting the extracted information of pipes, elbows and branches.

• 복식
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• 제58권6호
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• pp.42-53
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• 2008

This study is about the development of Fashion Design using of Korean Motive applied Digital Medium. With rapid change during the 21st century, digital media has emerged as the most important communication tool to facilitate speedy and interactive conversation. The recent emergence of 'Mass Customization' is a good reflection of digital transition's interactive features, realizing product variation and customization through flexibility and immediate responsiveness. In this so-called digital era, fashion is a tool that facilitates the use of digital media, while acting as the object, or the purpose, where digital media can be applied. This study looked at the development situations and future utilization method regarding digital fashion, which was recreated through digital media. In this study, a new design process was developed through digital media and actually manufactured Korean image clothing to reflect the motif of plant found in Korean folk paintings. Three-Dimensional(3D) digital shape was dressed in virtual clothing for comparison, thereby adding some features of textile design to three-Dimensional(3D) shape. Through the process, the study can provide various potential accesses to future development of fashion design utilizing digital media.

• 전기학회논문지
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• 제61권9호
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• pp.1260-1268
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• 2012

Recently, lack of power reserve margin was observed quite often. In this paper, we studied the method to secure power source for a short time, to cut the utility power peak load, and to reduce the users electricity bills. Emergency diesel generator of an office building is to be converted into a dual-fuel engine generator which is responsible for a portion of the peak load. Compared to the conventional diesel fuel generator, the proposed dual-fuel engine is able to reduce the generation power cost by dual-fuel combustion, and it also mitigates the building's utility power peak load by charging the building's peak load. If the dead resources (a group of emergency dual-fuel engine generators), as a Virtual Power Plant, are operating in peak time, we can significantly reduce future large power development costs. We investigated the current general purpose electricity bills as well as the records of the building electric power usage, and calculated diesel engine generator renovation costs, generation fuel costs, driving conditions, and savings in electricity bills. The proposed dual-fuel engine generation method reduces 18.1% of utility power peak load, and turned out to be highly attractive investment alternative which shows more than 27% of IRR, 76 million won of NPV, and 20~53 months of payback periods. The results of this study are expected to be useful to developing the policy & strategy of the energy department.

• Nuclear Engineering and Technology
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• 제51권4호
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• pp.1008-1016
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• 2019

In the SG (steam generator) of PWR (pressurized water reactor) for a nuclear plant, hundreds of U-shaped tubes are used for the heat exchanger system. They interact with primary pressurized cooling water flow, generating flow-induced vibration in the secondary flow region. A simplified U-tube model is proposed in this study to apply for experiment and its counterpart computation. Using the commercial code, ANSYS-CFX, we first verified the Moody chart, comparing the straight pipe theory with the results derived from CFD (computational fluid dynamics) analysis. Considering the virtual mass of fluid, we computed the major modes with the low natural frequencies through the comparison with impact hammer test, and then investigated the effect of pump flow in the frequency domain using FFT (fast Fourier transform) analysis of the experimental data. Using two-way fluid-structure interaction module in the CFD code, we studied the influence on mean flow rate to generate the displacement data. A feasible CFD method has been setup in this research that could be applied potentially in the field of nuclear thermal-hydraulics.

• 신재생에너지
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• 제18권3호
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• pp.32-42
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• 2022

Rapid spread of intermittent renewable energy has amplified the instability and uncertainty of power systems. The Korea Power Exchange (KPX) promoted efficient management by opening the power brokerage market in 2019. By combining small-scale intermittent renewable energy with a flexible facility through the power brokerage market, the KPX aims to develop a virtual power plant system that will allow the conversion of existing intermittent renewable energy into collective power plants. However, the participation rate of renewable power owners in the power brokerage market is relatively low because other markets such as the small solar power contract market or the Korea Electric Power Corporation power purchase agreement are more profitable. In this study, we used a choice experiment to determine the attributes affecting the participation rate in the power brokerage market for 113 renewable power owners and estimate the value of the power brokerage market. According to the estimation results, a low smart meter installation cost, low profit variations, long contract periods, and few clearances increased the probability of participation. Moreover, the average value of the power brokerage market was estimated to be 2.63 million KRW per power owner.

• Genomics & Informatics
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• 제19권1호
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• pp.7.1-7.13
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• 2021

Levodopa (L-DOPA) therapy is normally practised to treat motor pattern associated with Parkinson disease (PD). Additionally, several inhibitory drugs such as Entacapone and Opicapone are also cosupplemented to protect peripheral inactivation of exogenous L-DOPA (~80%) that occurs due to metabolic activity of the enzyme catechol-O-methyltransferase (COMT). Although, both Entacapone and Opicapone have U.S. Food and Drug Administration approval but regular use of these drugs is associated with high risk of side effects. Thus, authors have focused on in silico discovery of phytochemicals and evaluation of their effectiveness against human soluble COMT using virtual screening, molecular docking, drug-like property prediction, generation of pharmacophoric property, and molecular dynamics simulation. Overall, study proposed, nine phytochemicals (withaphysalin D, withaphysalin N, withaferin A, withacnistin, withaphysalin C, withaphysalin O, withanolide B, withasomnine, and withaphysalin F) of plant Withania somnifera have strong binding efficiency against human COMT in comparison to both of the drugs i.e., Opicapone and Entacapone, thus may be used as putative bioenhancer in L-DOPA therapy. The present study needs further experimental validation to be used as an adjuvant in PD treatment.

• 아태비즈니스연구
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• 제13권1호
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• pp.213-230
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• 2022

Purpose - The purpose of this study is to find out any potential factors for explanatory variables when calculating the virtual successful bid rate in case of no collusion. Design/methodology/approach - An empirical analysis was conducted in this study with a regression analysis that included 725 bid samples under the public construction technical type bidding. Findings - The result of the basic analysis showed that there are several factors affecting the successful bid rate. First, collusion variable; second, government variable; third, successful bidder design score variable and the number of bidder variable among bidding features; fourth, turnkey variable based on the alternative method; fifth, civil works variable and plant works variable based on building work; sixth, asset variable and the fourth-quarter performance difference variable. However, the technical proposal method variable among bidding features was found to be statistically insignificant in column(4). Research implications or Originality - The significance of this research is that new variable such as the government variable and the fourth-quarter performance difference variable were added in the regression model, which showed statistically significant research results.

• 한국표면공학회지
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• 제56권1호
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• pp.84-93
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• 2023

The spent nuclear fuel is burned during the planned cycle in the plant and then generates elements such as actinide series, fission products, and plutonium with a long half-life. An 'interim storage' step is needed to manage the high radioactivity and heat emitted by nuclides until permanent-disposal. In the case of Korea, there is no space to dispose of high-level radioactive waste after use, so there is a need for a period of time using interim storage. Therefore, the intensity of neutrons and gamma-ray must be determined to ensure the integrity of spent nuclear fuel during interim storage. In particular, the most important thing in spent nuclear fuel is burnup evaluation, estimation of the source term of neutrons and gamma-ray is regarded as a reference measurement of the burnup evaluation. In this study, an analysis of spent nuclear fuel was conducted by setting up a virtual fuel burnup case based on CE16×16 fuel to check the total amount and spectrum of neutron, gamma radiation produced. The correlation between BU (burnup), IE (enrichment), and CT (cooling time) will be identified through spent nuclear fuel burnup calculation. In addition, the composition of nuclide inventory, actinide and fission products can be identified.