• International Journal of Contents
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• 제18권1호
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• pp.76-84
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• 2022

Tidal power generation plays a critical role in reducing greenhouse gas emissions. It uses a tidal force generated by gravitational force between the moon, the earth, and the sun. The change of seawater height generates the tide-generating force, and the magnitude of the change is the tide level. The tide level change has the same period as the tide-generating force twice a day, every 29.5 days, every year, and every 18.6 years. Sihwa Lake Tidal Power Station is Korea's first tidal power plant that began commercial power generation in August 2011 and has been accumulating a large volume of data on electricity production, power generation sales, sluice displacement, and tide levels. The purpose of this paper was to analyze the impact of the inefficiency factors affecting production and the tidal level change on tidal power generation and their characteristics using Sihwa Lake Tidal Power's operational performance data. Throughout this paper we show that tidal power generating operation is accurately predicting the trends of magnitude of tidal force to be periodical for each day. determining the drop to initiate the water turbine generator factoring the constraints on the operation of Sihwa Lake, and reflecting the water discharge through the floodgate and water turbine during the standby mode in the power generation plan to be in the optimal condition until the initiation of the next power generation can maximize power generation.

• 분석과학
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• 제14권1호
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• pp.34-43
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• 2001

수소화물생성법-유도결합플라스마-원자방출분광법으로 게르마늄을 분석할 때 보조산으로 phosphoric acid의 사용은 nitric acid, hydrochloric acid, sulfuric acid, perchloric acid, boric acid, tartaric acid, malic acid, oxalic acid, acetic acid, tannic acid, citric acid의 사용보다 높은 수소화물 생성효율을 보였고, 같은 pH영역이라도 phosphate ion이 존재하는 buffer의 사용이 더 높은 생성효율을 보였다. 또한, 2.5M phosphoric acid를 이용한 결과, 시료용액 내에 잔류하는 산이나 공존원소의 영향이 감소하였다. 환원제와 안정제의 농도가 증가할수록 수소화물 생성효율은 증가되었으며, 최대방출세기를 나타내는 산의 세기는 높은 쪽으로 이동했고 농도영역은 넓어졌다. 인산 존재 하에서의 게르마늄의 검출한계는 $0.03{\mu}g/L$이었다.

• Nuclear Engineering and Technology
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• 제54권1호
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• pp.110-116
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• 2022

Human failure event (HFE) dependency analysis is a part of human reliability analysis (HRA). For efficient HFE dependency analysis, a maximum number of minimal cut sets (MCSs) that have HFE combinations are generated from the fault trees for the probabilistic safety assessment (PSA) of nuclear power plants (NPPs). After collecting potential HFE combinations, dependency levels of subsequent HFEs on the preceding HFEs in each MCS are analyzed and assigned as conditional probabilities. Then, HFE recovery is performed to reflect these conditional probabilities in MCSs by modifying MCSs. Inappropriate HFE dependency analysis and HFE recovery might lead to an inaccurate core damage frequency (CDF). Using the above process, HFE recovery is performed on MCSs that are generated with a non-zero truncation limit, where many MCSs that have HFE combinations are truncated. As a result, the resultant CDF might be underestimated. In this paper, a new method is suggested to incorporate HFE recovery into the MCS generation stage. Compared to the current approach with a separate HFE recovery after MCS generation, this new method can (1) reduce the total time and burden for MCS generation and HFE recovery, (2) prevent the truncation of MCSs that have dependent HFEs, and (3) avoid CDF underestimation. This new method is a simple but very effective means of performing MCS generation and HFE recovery simultaneously and improving CDF accuracy. The effectiveness and strength of the new method are clearly demonstrated and discussed with fault trees and HFE combinations that have joint probabilities.

• 한국수소및신에너지학회논문집
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• 제33권6호
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• pp.643-659
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• 2022

For the economic analysis of fuel cells, levelized cost of electricity was calculated according to the type, capacity, and annual production of the fuel cells. The cost of every component was calculated through the system component breakdown. The direct cost of the system included stack cost, component cost, assembly, test, and conditioning cost, and profit markup cost were added. The effect of capacity and annual production was analyzed by fuel cell type. Sensitivity analysis was performed according to stack life, capital cost, project period, and fuel cost. As a result, it was derived how much the economic efficiency of the fuel cell improves as the capacity increases and the annual production increases.

• 가족자원경영과 정책
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• 제25권4호
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• pp.71-86
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• 2021

본 연구는 기혼 남성의 가사노동참여 양상의 변화를 파악하기 위해 남성의 가사노동시간의 영향 요인을 세대별로 파악하는 목적으로 한다. 이를 위해 기혼남성을 베이비붐세대, X세대, Y세대로 구분하고, 각 세대별 가사노동참여 요인을 가사노동 참여가설을 적용시켜 분석해 보았다. 자료는 통계청 '2019년 생활시간조사' 원자료를 사용하였다. 기혼남성의 가사노동시간에 영향을 미치는 요인을 분석하기 위해 다항로지스틱 분석을 실시하였다. 분석결과 베이비붐세대 기혼남성의 가사노동시간은 경제적 효율성가설과 성역할태도가설, 요구반응가능성가설에 의해 설명이 가능하고, X세대 기혼남성의 가사노동시간은 경제적 효율성가설, 성역할태도가설, 시간가용성가설, 요구반응가능성가설 모두에 의해 설명이 가능하였다. 반면, Y세대 기혼남성의 가사노동시간은 시간가용성가설과 요구반응가능성가설에 의해서만 설명이 가능하였다. 세대별로 가사노동참여의 동인이 다르다는 사실은 남성 대상 일가정양립지원 정책수립에 있어 세대별 특성을 고려해야 한다는 점을 시사해준다.

• Wind and Structures
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• 제21권1호
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• pp.63-84
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• 2015

The shape of a tall building has significant impact on wind force generation and wind-induced dynamic response. To study the effect of recessed cavities, wind excitations on a wind-tunnel model of an H-section tall building were compared with those on a square-section building model. Characteristics of the fluctuating wind pressures on the side faces of the two tall buildings and their role in the generation of crosswind forces on the buildings were investigated with the space-time statistical tool of proper orthogonal decomposition (POD). This paper also compares the use of different pressure data sets for POD analysis in situations where pressures on two different surfaces are responsible for the generation of a wind force. The first POD mode is found to dominate the generation of crosswind excitation on the buildings.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.355-357
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• 2006

A study of the photovoltaic generation system tend to concentrate its importance on specific filed such as analysis of photovoltaic characteristic, improvement of a inverter, and controller. In this paper, a practical facility of the photovoltaic generation system and connection of its organization are presnted with process of 1.2kW prototype. From the results of monitoring system which is for reliability and analysis of the photovoltaic generation system, stability of the system was confirmed.

• 대한가정학회지
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• 제37권4호
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• pp.111-124
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• 1999

The purpose of this study was to investigate the effect of generation on consciousness toward wedding ritual and to compare the difference in their consciousness between the young and the old. Data were obtained from 489 individuals living in Seoul. OLS regression analysis was used to identify the effect of generation on consciousness toward wedding ritual. The effect of generation was significant in the consciousness of wedding procedures, while it was not significant in the consciousness of wedding expenditures, holding other factors constant. [t was also found that procedure-important style was associated with more expenditures on wedding. The findings of this study suggested that the materialism had an important effect on the consciousness of wedding procedures for both generations. Understanding these factors is useful for family resource management professionals and educators who develop educational programs to build desirable wedding culture in Korea.

• 한국가스학회지
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• 제10권4호
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• pp.11-16
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• 2006

본 논문에서는 현재 국제에너지기구에서 국가 에너지시스템분석에 공식적으로 사용되고 있는 시장분배모형(MARKAL: MARKet ALlocation) 모형을 이용하여 국내 발전부문의 온실가스 배출감축 잠재량평가를 위한 분석을 실시하였다. 모형 운영에 필요한 입력자료를 구축하고 4개의 시나리오를 설계하여 2040년까지의 발전기술의 구성, 특히 가스발전의 온실가스 감축에 대한 역할을 다양하게 분석하였다.

• 대한기계학회논문집A
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• 제20권2호
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• pp.553-563
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• 1996

An algorithm for automatic mesh generation of two-dimensional arbitrary planar domain is proposed by using Delaunay triangulation algorithm. An efficient algorithm is proposed for the construction of Delaunay triangulation algorithm over convex planar domain. From the definition of boundary, boundary nodes are first defined and then interior nodes are generated ensuring the Delaunay property. These interior nodes and the boundary nodes are then linked up together to produce a valid triangular mesh for any finite element analysis. Through the various example, it is found that high-quality triangular element meshes are obtained by Delaunay algorithm, showing the robustness of the current method. The proposed mesh generation scheme has been extended to automatic remeshing, which is applicable to FE analysis including large deformation and large distortion of elements.