• 한국물환경학회지
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• 제31권4호
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• pp.407-417
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• 2015

Soil loss is one of the significant disasters which have threatened human community and ecosystem. Particularly, Korea has high vulnerability of soil loss because rainfall is concentrated during summer and mountainous regions take more than 70% of total land resources. Accordingly, the sediment control management plan are required to prevent the loss of soil resources and to improve water quality in the receiving waterbodies. In this regard, the objectives of this study are 1) to quantify the effect of the Vegetative Filter Strip (VFS) on sediment runoff reduction and 2) to analyze the relationship of rainfall intensity and sediment runoff. For this, SATEEC and VFSMOD were used to estimate sediment runoff according to rainfall intensity and to quantify the effect of VFS on sediment runoff reduction, respectively. In this study, the VFS has higher impact on sediment reduction for lower maximum rainfall intensity, which means that the maximum rainfall intensity is one of significant factors to control sediment runoff. Also, the sediment with VFS considered was highly correlated with maximum rainfall intensity. For these results, this study will contribute to extend the applicability of VFS in establishing eco-friendly sediment control plans.

• Spatial Information Research
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• 제15권3호
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• pp.291-299
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• 2007

강원도 지역은 매년 다양한 재해를 반복적으로 겪고 있으며 이러한 재해는 이 지역의 지속적인 발전에 장애요인이 되고 있다. 특히 2002년 태풍 루사에 의한 집중호우는 막대한 피해와 더불어 우리사회의 많은 교훈을 남겼다. 본 연구에서는 홍수 유출량을 경제적 관점에서 평가함으로써 수자원 관리의 중요성을 부각하고자 하였다. 그 결과 2002년 루사 당시 삼척시 오십천의 홍수유출에 따른 수자원의 경제적 손실은 약 5천 5백만원이 유실된 것으로 분석되었다.

• 상하수도학회지
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• 제35권6호
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• pp.517-531
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• 2021

The water supply facilities of Korea have achieved a rapid growth, along with the other social infrastructures consisting a city, due to the phenomenon of urbanization according to economic development. Meanwhile, the level of water supply service demanded by consumer is also steadily getting higher in keeping with economic growth. However, as an adverse effect of rapid growth, the quantity of aged water supply pipes are increasing rapidly, Bursts caused by pipe aging brought about an enormous economic loss of about 6,161 billion won as of 2019. These problems are not only worsening water supply management, also increasing the regional gap in water supply services. The purpose of this study is to classify hazard evaluation indicators and to rank the water distribution network hazard by cluster using the TOPSIS method. In conclusion, in this study, the entropy-based multi-criteria decision-making methods was applied to rank the hazard management of the water distribution network, and the hazard management ranking for each cluster according to the water supply conditions of the county-level municipalities was determined according to the evaluation indicators of water outage, water leakage, and pipe aging. As such, the hazard ranking method proposed in this study can consider various factors that can impede the tap water supply service in the water distribution network from a macroscopic point of view, and it can be reflected in evaluating the degree of hazard management of the water distribution network from a preventive point of view. Also, it can be utilized in the implementation of the maintenance plan and water distribution network management project considering the equity of water supply service and the stability of service supply.

• Tribology and Lubricants
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• 제28권1호
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• pp.33-37
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• 2012

Automotive wheel bearing grease helps to reduce stresses and prevent wear of wheel bearings. But it is easily contaminated by water and other contaminants. Previously, our research group reported the change of grease physical properties such as dropping point, work penetration and oxidation work stability, water washout characteristics, leakage tendency, oil separation, evaporation loss and rust protection by water contamination. In this paper, we analyzed the physical characteristics of grease such as lubricity, viscosity and total acid number to investigate the mechanism of thickener decomposition. In water contaminated grease, the total acid number and wear scar were increased, the viscosity was decreased due to the decomposition of lithium complex thickener.

• 한국수자원학회논문집
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• 제45권6호
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• pp.617-629
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• 2012

본 연구에서는 낙동강유역을 대상으로 토양 침식 및 유실의 위험성을 분석 및 평가하기 위해 토지이용도를 세부적으로 분석하여 유역별 토양침식 발생의 위험성을 순위화하였다. 또한, 토양침식량을 RUSLE 모형을 이용하여 산정하였고 토지이용도 분석 결과와 함께 토양침식 위험성이 높은 유역을 평가하였다. 최종적으로 해당 유역에 산사태 위험지도와의 비교를 통해 유역내 토양유실 대책 수립을 위한 자료의 활용 방안을 분석하였다. 분석 결과, 전체 낙동강유역내 토양침식 위험성이 높은 것으로 선정된 유역은 내성천유역으로 토지이용도 분석결과와 RUSLE 모형의 결과에서 모두 토양유실 측면에서 위험성이 높은 것으로 나타났다. RUSLE 모형 결과에서 토양침식량이 높은 것으로 나타난 지역과 산사태 위험지역의 분포는 유사한 것으로 나타났으나, 하천 주변의 토지이용에 따른 토양유실의 위험성은 RUSLE를 이용한 산정 결과에서만 확인할 수 있었다.

• 한국콘텐츠학회:학술대회논문집
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• 한국콘텐츠학회 2006년도 추계 종합학술대회 논문집
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• pp.413-416
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• 2006

본 연구에서는 효과적인 토양보존 및 관리에 필요한 전략적 접근 방법을 제시하였다. 이를 위해 탁수발생이 뚜렷이 구분되는 안동호와 임하호 유역을 선정하였으며, 탁수발생 원인인 토사유실을 평가하기 위해 RUSLE 토사유실모델을 이용하였다. 토사유실 가능성이 높은 지역들은 GIS에 의한 지형특성을 기초로 분석되어질 수 있으며, 특히 상하류 유역이나 인간의 활동영역인 하천주변 특성들을 이용하여 검토할 수 있다. 본 연구에서 제안된 모델링 결과는 토양보존 및 관리를 위해 검토되어지는 토사유실 원인지역을 선정하기 위한 가이드라인으로 활용될 수 있다. 또한 이러한 접근방법은 상대적으로 간편하며, 실질적으로 널리 활용될 수 있다.

• 한국환경농학회지
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• 제27권4호
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• pp.314-320
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• 2008

During the summer season, more than half of the annual precipitation in Korea occurs during the summer season due to the geographical location in the Asian monsoon belt. So, this causes severe soil erosion from croplands, which is directly linked to the deterioration of crop/land productivity and surface water quality. Therefore, much attention has been given to develop accurate estimation tools of soil erosion. The aim of this study is to assess the performance of using the empirical Universal Soil Loss Equation (USLE) and the physical-based model of the Water Erosion Prediction Project (WEPP) to quantify eroded amount of soil from agricultural fields. Input data files, including climate, soil, slope, and cropping management, were modified to fit into Korean conditions. Chuncheon (forest) and Jeonju (level-plain) were selected as two Korean cities with different topographic characteristics for model analysis. The results of this current study indicated that better soil erosion prediction can be achieved using the WEPP model since it has better power to illustrate a higher degree of spatial variability than USLE in topography, precipitation, soils, and crop management practices. These present findings are expected to contribute to the development of the environmental assessment program as well as the conservation of the agricultural environment in Korea.

• 한국수소및신에너지학회논문집
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• 제21권3호
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• pp.184-192
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• 2010

PEM fuel cell produces electric power, water and heat by the electrochemical reaction of hydrogen and oxygen. The heating value is dependent on the molar enthalpy of vaporization of product water and the performance loss. In this paper, the heating value of fuel cell stack has been studied under various stack operating temperatures to achieve more efficient heat management. A technology using the molar enthalpy of vaporization of product water is suggested to reduce heat-up time during start-up of a fuel cell vehicle.

• 환경영향평가
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• 제18권4호
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• pp.235-243
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• 2009

Wetlands considered to be an important natural resources because they provide biodiversity and habitat for species to breed and survive. In this regard, many countries in the world provide wetlands and have policies and laws to protect them. In Korea we hosted RAMSAR COP-10 at Changwon in 2008 representing Korea's endeavor to wetland protection. But, in the process of development Wetlands are easy target to be lost due its easy access and the laws and regulations to protect them are relatively weak. Thus, this research focused on the introduction of No Wetland Loss(NWL) and we can achieve wetland protection in the economy market ways. Thus, NWL should consider 1) a clear definition of NWL and harmony and consensus of introduction of NWL, 2) considering most wetlands be private we need a financial support for securing wetlands, 3) inventories for wetlands in Korea, draw a line of demarcation, technic to evaluate wetlands, 4) wetland restoration considering function of ecosystem not total amount of wetlands. Wetland protection should be a part of Basic Law of Water Management which in its progress and we need further studies on wetland protection because of watershed management, deserted agricultural paddies, etc.

• Nuclear Engineering and Technology
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• 제53권2호
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• pp.484-497
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• 2021

This paper proposes an extended time uncertainty analysis approach in Level 2 human reliability analysis (HRA) considering severe accident management (SAM) strategies. The method is a time-based model that classifies two time distribution functions-time required and time available-to calculate human failure probabilities from delayed action when implementing SAM strategies. The time required function can be obtained by the combination of four time factors: 1) time for diagnosis and decision by the technical support center (TSC) for a given strategy, 2) time for strategy implementation mainly by the local emergency response organization (ERO), 3) time to verify the effectiveness of the strategy and 4) time for portable equipment transport and installation. This function can vary depending on the given scenario and includes a summation of lognormal distributions and a choice regarding shifting the distribution. The time available function can be obtained via thermal-hydraulic code simulation (MAAP 5.03). The proposed approach was applied to assess SAM strategies that use portable equipment and safety depressurization system valves in a total loss of component cooling water event that could cause reactor vessel failure. The results from the proposed method are more realistic (i.e., not conservative) than other existing methods in evaluating SAM strategies involving the use of portable equipment.