• 한국전산구조공학회논문집
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• 제27권5호
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• pp.437-450
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• 2014

원전의 항공기 충돌 리스크 평가에 사용되는 대표매개변수를 선정하기 위한 방법론을 개발하였다. 대상 원전은 국내의 대표적인 경수로형 원전 중 하나로 선정하여 3차원 유한요소 해석 모델을 구축하였다. 콘크리트 재료모델에는 소성손상모델이 적용되었으며, 강재는 다중선형곡선거동을 가지는 것으로 모델링하였다. 운동에너지, 전체 충격량, 최대 충격량, 최대 하중등 4종의 대표매개변수 후보군을 선정하였다. 각각의 매개변수 후보군은 모두 충돌 속도와 질량의 함수로 표현되므로, 충돌속도 50~200m/s, 항공유량 30~90%의 범위에 대하여 매개변수값을 도출하고 충돌 해석을 수행하여, 충돌 시의 구조 응답과의 상관관계를 분석하였다. 모든 해석에서 항공기의 기종은 보잉767 기종으로 선정하였다. 충돌해석에는 Riera의 하중-시간 이력 함수를 이용한 해석기법을 적용하였다. 매개변수와 충돌 시 응답의 상관관계 적합성은 결정계수값을 이용하여 분석하였다. 4 종의 대표매개변수 후보군 중 최대 하중값이 가장 직관적일 뿐만 아니라 본 연구에서의 해석 케이스에서는 응답과의 상관성도 가장 뛰어난 것으로 나타남에 따라, 항공기충돌 리스크 평가를 위하여 가장 적합한 매개변수라 할 수 있을 것으로 판단되었다.

• 환경영향평가
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• 제6권2호
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• pp.35-59
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• 1997

In this study, for the effective environmental investigation at the level of planning, environmental assessment model to be integrated with urban comprehensive plans was developed. This model was applied to the Suwon City urban comprehensive plan and was tested to derive the future application program and the adaptability to the current research issues. The results of this study can be summarized as follows: First, we defined basic items for environmental assessment as to be used in the developed SEA model. We also defined three ranges and twelve items for the environmental assessments, which can be used in the assessment of the urban comprehensive plan through the expert advices. Second, we performed the case study by applying the developed SEA model to the Suwon City urban comprehensive assessment, and investigated the environmental impacts through an expert inquiry at the "phase 5" of the model. The results of the case study showed that Suwon City urban comprehensive plan contained partially discrepancies at the goal of the planning. The spatial strategy for leisure, park and open space, and green belt was analysed not to be effective in energy use. The case study also indicated that the environments of Suwon City are expected to be much worse in each sectional plan, if the City was to implement the present five sectional plans for life boundary and distribution of population, land use plan, transportation plan, industrial development plan, and life environmental plan. Third, according to the result of the case study, an mitigation plan for urban comprehensive plan of Suwon City was proposed as the following four stages; modification of planning goal, modification of site alternatives, modification of planning contents, and proposal of mitigation measures.

• 자원ㆍ환경경제연구
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• 제25권4호
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• pp.565-590
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• 2016

전 세계는 온실가스 배출량을 저감하기 위한 방안을 제시하고 있다. 우리나라는 2030년 전망치 대비 국내에서 25.7%, 전체로는 37%의 국가 자발적 감축목표를 제출하였다. 본 연구에서는 기술평가를 위한 통합평가모형인 GCAM(Global Change Assessment Model)을 이용하여 국가 자발적 감축목표에서 제시한 감축목표 25.7%가 우리나라 에너지시스템에 미치는 영향을 평가한다. 분석결과, 석탄, 가스를 사용하는 발전기술은 각각 28%, 13.5% 발전량이 줄어드는 것으로 나타나지만, 바이오매스, 풍력, 태양에너지는 각각 47.6%, 22.0% 그리고 45.4% 증가하는 것으로 나타났다. 주목할 점은 신기술로 분류되는 USC(초초임계발전) 등 화석연료 발전기술들이 온실가스 감축목표달성에 전혀 또는 거의 기여하지 못하는 결과를 보인다는 점에서 향후 신기술을 선정할 때 정량적 평가 등 세심한 주의가 필요함을 보여준다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2023년도 학술발표회
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• pp.287-287
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• 2023

Surface water-groundwater interaction (SWGI) is an important hydrological process that influences both the quantity and quality of water resources. However, regional scale SWGI model calibration and uncertainty analysis have been a challenge because integrated models inherently carry a vast number of parameters, modeling assumptions, and inputs, potentially leaving little time and budget to explore questions related to model performance and forecasting. In this study, we have proposed the application of iterative ensemble smoother (IES) for uncertainty analysis and calibration of the widely used integrated surface-subsurface model, SWAT-MODFLOW. SWAT-MODFLOW integrates Soil and Water Assessment Tool (SWAT) and a three-dimensional finite difference model (MODFLOW). The model was calibrated using a parameter estimation tool (PEST). The major advantage of the employed IES is that the number of model runs required for the calibration of an ensemble is independent of the number of adjustable parameters. The pilot point approach was followed to calibrate the aquifer parameters, namely hydraulic conductivity, specific storage, and specific yield. The parameter estimation process for the SWAT model focused primarily on surface-related parameters. The uncertainties both in the streamflow and groundwater level were assessed. The work presented provides valuable insights for future endeavors in coupled surface-subsurface modeling, data collection, model development, and informed decision-making.

• The Korean Journal of Ecology
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• 제7권3호
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• pp.109-118
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• 1983

Near future dynamics of water qualities (nutrient concentration) of the Han River was predicted, based on a mathematical model representing the relationship between the nutrient concentration in th river wagter and environmental factors (population density, land-use types, rock compositions and nutrient accumulation) in the basin. The population density and land-use types were forecasted to change distinctly in the downstream area, especially in Seoul City area in 1985~1990 whereas any environmental factor was not expected to change its level significantly in both upstream and middle reaches areas. It was indicated by the model that the nutrients concentration in the up- and mid-streams would keep its level in future as it was, but it would increase drastially in the downstream area. For the preservation of the water qualities in the downstream at least to keep its level as it was in 1980, practical countermeasures were proposed, based on the assessment of the contribution of each environmental factor to the water qualities.

• Nuclear Engineering and Technology
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• 제51권2호
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• pp.561-572
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• 2019

In the design criterion for the nuclear power plant piping system, the limit state of the piping against an earthquake is assumed to be plastic collapse. The failure of a common piping system, however, means the leakage caused by the cracks. Therefore, for the seismic fragility analysis of a nuclear power plant, a method capable of quantitatively expressing the failure of an actual piping system is required. In this study, it was conducted to propose a quantitative failure criterion for piping system, which is required for the seismic fragility analysis of nuclear power plants against critical accidents. The in-plane cyclic loading test was conducted to propose a quantitative failure criterion for steel pipe elbows in the nuclear power plant piping system. Nonlinear analysis was conducted using a finite element model, and the results were compared with the test results to verify the effectiveness of the finite element model. The collapse load point derived from the experiment and analysis results and the damage index based on the stress-strain relationship were defined as failure criteria, and seismic fragility analysis was conducted for the piping system of the BNL (Brookhaven National Laboratory) - NRC (Nuclear Regulatory Commission) benchmark model.

• 환경영향평가
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• 제7권2호
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• pp.65-70
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• 1998

ArcView와 FEMWASP 모형을 이용하여 영월유역의 현재 및 장래의 환경질을 해석하기 위한 통합적인 환경영향평가 도구를 개발하였다. 모든 입력자료와 계산 결과는 ArcView상에서 준비되어 도시되었다. ArcView내의 Avenue의 "system.execute" 명령어를 사용하여 FEMWASP과 ArcView를 통합하였다. 모델링 결과에 의하면 장래 영월호의 수질은 부영양화 상태에 이를 것으로 판단되었다. 개발된 시스템은 상수원수의 수질관리 분야의 정책의 계획이나 규제 방안을 결정하는 데 적용될 수 있을 것이다.

• 한국방재학회:학술대회논문집
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• 한국방재학회 2007년도 정기총회 및 학술발표대회
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• pp.376-379
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• 2007

In recent years, the natural damage associated with flood disaster has been dramatically increased. However, there is no rational method which reflects urban characteristics to estimate the regional safety assessment for flood disaster. The purpose of this study is to develop the regional safety assesment model for urban flood. Flood risk and reduction assesment were estimated by using the linear sum of the Z score of the assessment factors and the weight value of each factor from the expert survey data. And then the regional safety assessment was estimated by subtracting reduction factor value from risk factor value. GIS tool was used to estimate the factor assesment and integrated regional safety. This study can be used to determine the priority of flood protection project, execute the flood insurance and establish the urban plans and the flood mitigate plan.

• 환경영향평가
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• 제20권3호
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• pp.337-348
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• 2011

Urban environmental problem became one of major issues during its urbanization processes. Environmental impacts are assessed during recent urban planning and development. Though the environmental impact assessment considers meteorological impact as a minor component, changes in wind environment during development can largely affect the distribution pattern of air temperature, humidity, and pollutants. Impact assessment of local wind is, therefore, a major element for impact assessment prior to any other meteorological impact assessment. Computational Fluid Dynamics (CFD) models are utilized in various fields such as in wind field assessment during a construction of a new building and in post analysis of a fire event over a mountain. CFD models require specially formatted input data and produce specific output files, which can be analyzed using special programs. CFD's huge requirement in computing power is another hurdle in practical use. In this study, a CFD model and related software processors were automated and integrated as a microscale wind environmental impact assessment system. A supercomputer system was used to reduce the running hours of the model. Input data processor ingests development plans in CAD or GIS formatted files and produces input data files for the CFD model. Output data processor produces various analytical graphs upon user requests. The system was used in assessing the impacts of a new building near an observatory on wind fields and showed the changes by the construction visually and quantitatively. The microscale wind assessment system will evolve, of course, incorporating new improvement of the models and processors. Nevertheless the framework suggested here can be utilized as a basic system for the assessment.

• 한국농공학회:학술대회논문집
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• 한국농공학회 2005년도 학술발표논문집
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• pp.502-508
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• 2005

In order to assess the environmental risk of pesticides, information is usually required on the likelihood of exposure of organisms to the constituents of pesticides, expressed as a predicted environmental concentrations (PECs) and the likely effects of the constituents of pesticides on aquatic and terrestrial organisms, expressed as a predicted no-effect concentrations (PNECs). In this paper, the pesticide fate model, RICEWQ alone and coupled with the pesticide movement model, RIVWQ was used to simulate the potential for predicting the environmental concentrations of pesticides in paddy fields and adjacent surface water systems. The RICEWQ model was successfully calibrated against field data in poinding depth for paddy field. For the assessment of importance for water and pesticide management conditions and field scales, the integrated RICEWQ-RIVWQ model was simulated by the scenario analysis. The results of this study can be used as a basic information for assessing the environmental risk of pesticides.