• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.199-208
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• 2012

To develop site characterization technologies for a radioactive waste disposal research in KAERI, the geological and hydrogeological investigations have been carried out since 1997. In 2006, the KURT (KAERI Underground Research Tunnel) was constructed to study a solute migration, a microbiology and an engineered barrier system as well as deeply to understand geological environments in in-situ condition. This study is performed as one of the site characterization works around KURT. Several investigations such as a lineament analysis, a borehole/tunnel survey, a geophyscial survey and logging in borehole, were used to construct the geological model. As a result, the geological model is constructed, which includes the lithological model and geo-structural model in this study. Moreover, from the results of the in-situ hydraulic tests, the hydrogeological properties of elements in geological model were evaluated.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.6
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• pp.626-633
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• 2006

Bucheon city has been rapidly urbanized and steadily enlarged. Also, the city depends on groundwater as an alternative water resource. The objective of this study is to characterize the hydrogeology in this city including the recharge of groundwater and hydraulic property of an aquifer in order to investigate the chemical characteristics and contamination of groundwater in the Bucheon area. Eleven groundwater wells in the Bucheon area were selected for applying certain hydraulic tests, such as pumping and recovery tests. Theis method and Theis recovery method were used to obtain hydraulic parameters, such as hydraulic conductivity, transmissivity by applying recovery tests. The playground of school and uncovered areas layed a major function of recharging areas. The groundwater well in these areas showed high recharge, transmissivity, and hydraulic conductivity. In a downtown area, groundwaier wells showed low pumping capacity and hydraulic parameters. Groundwater samples were collected from 48 different locations in the Bucheon area and that showed very various chemical composition in groundwater Their electrical conductivity showed various ranges from 70.4 to $1,287{\mu}S/cm$. The composition more significantly affected the groundwater due to the land use and urbanization than that of the aquifer rock type.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.18 no.2
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• pp.133-141
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• 2020

A geological repository comprises a natural barrier and an engineered barrier system. Its design components consist of canisters, buffers, backfill, and near-field rock. Among the engineered barrier system components, bentonite buffers minimize the groundwater flow from near-field rock and prevent the release of nuclide. Investigation of the hydraulic conductivity of the buffer to groundwater flow is an important factor in the performance evaluation of the stability and integrity of the engineered barrier of the repository. In this study, saturated hydraulic conductivity tests were performed using Gyeongju bentonite at various dry densities and temperatures, and a hydraulic conductivity prediction model was developed through multiple regression analysis using the 120 result sets of hydraulic conductivity. The test results showed that the hydraulic conductivity tends to decrease as the dry density increases. In addition, the hydraulic conductivity increased with increasing temperature. The multiple regression analysis results showed that the coefficient of determination (R²) of the hydraulic conductivity prediction equation was as high as 0.93. The hydraulic conductivity prediction equation presented in this study could be used for the design of engineered barrier systems.

• Journal of the Korea Society for Simulation
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• v.21 no.3
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• pp.79-88
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• 2012

Recently, the study in efficient operation, maintenance, and equipment-design have been growing rapidly in military industry to meet the required missions. Through out these studies, the importance of Concurrent Spare Parts(CSP) are emphasized. The CSP, which is critical to the operation and maintenance to enhance the availability, is offered together when a equipment is delivered. Despite its significance, th responsibility for determining the range and depth of CSP are done from administrative decision rather than engineering analysis. The purpose of the paper is to optimize the number of CSP per item using simulation and multiple regression. First, the result, as the change of operational availability, was gained from changing the number of change in simulation model. Second, mathematical regression was computed from the input and output data, and the number of CSP was optimized by multiple regression and linear programming; the constraint condition is the cost for optimization. The advantage of this study is to respond with the transition of constraint condition quickly. The cost per item is consistently altered in the development state of equipment. The speed of analysis, that simulation method is continuously performed whenever constraint condition is repeatedly altered, would be down. Therefore, this study is suitable for real development environment. In the future, the study based on the above concept improves the accuracy of optimization by the technical progress of multiple regression.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.2
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• pp.189-194
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• 2016

This paper deals with the economic effects for the Surion(KUH-1) research and development program. The economic effects was measured by Inter-industry analysis method for production-inducing effects, value-added inducement effects, and job-creation effects and by estimating actual domestic input cost. In addition, technical riffle effects was analyzed for aerospace industry, defense industry and commercial industry market through similarity and contribution of technology.

• Journal of Bio-Environment Control
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• v.9 no.4
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• pp.185-192
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• 2000

This study was conducted to develop mathematical model of respiration rate of cucumber plant under varying environmental conditions. 8.55% of gross photosynthesis of individual cucumber plant was used as respiration. Growth respiration coefficient was estimated as 0.0935. Maintenance respiration rate was estimated as 0.00158g CH$_2$g$^{-1}$ .h$^{-1}$ at 24$^{\circ}C$ of air temperature and it increased exponentially as air temperature became higher. Respiration rate decreased poportionally as content of storage carbohydrate became lower. Ion uptake respiration rate of roots was estimated as 0.6648g C$H_2O$.(gN)$^{-1}$ .

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2010.06a
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• pp.306-311
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• 2010

수질모의에는 유속, 유량, 저수량, 체류시간의 자료를 비롯한 수심, 하폭, 유하거리, 수표면적과 등 다양한 수리학적 정보를 필요로 하며, 이러한 자료들은 수질모의의 기초자료로서 그 중요도와 활용도가 높게 나타나고 있다. 하지만 기초자료의 구축 방안 및 기준이 표준화되지 않아 각 기관별로 상이한 데이터를 보유하고 있으며, 기초자료의 선정에 따라 연구 결과가 달라지는 동 관련 연구의 신뢰도와 정확도에까지 영향을 미치고 있다. 이에 본 연구에서는 수질모의에 주로 쓰이는 1차원 수질모의에 필요한 수리학적 기초자료의 체계화된 구축방안을 마련하고, 이를 GIS 데이터로 정의한 한국형 Stream Reach File의 구축방안을 제시하고자 한다. 우선 기존에 구축된 미국 EPA Reach File 구축사례를 기초로 하여 관련 자료의 분석과 속성 내역을 파악하고 국내 실정에 적합한 방안을 제시하였다. 본 설계안에 사용되는 기초자료는 기존에 구축된 자료를 최대한 활용하였으며, 필요에 따라 데이터 편집 과정을 수행토록 하였다. 본 연구 결과를 따라 실제 Stream Reach File을 구축할 수 있으며, 이를 통해 관련 연구의 체계화된 기초자료의 제공이 가능할 것이다. 또한, 향후 오염원데이터와 연계하여 수질오염총량관리제를 지원할 수 있으며, 다양한 정보와 결합하여 다차원적인 수질모의도 가능할 것이다 나아가 Reach File에 대한 지속적인 연구를 통해 개선사항 및 보완점을 도출하여 보다 발전되고 완성된 한국형 수리기초자료를 구축하여야 할 것이다.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.420-424
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• 2005

K시 강변여과수 개발 지역에서 적정 채수량 산정 및 지표수 연계 특성을 파악하기 위한 적절한 현장 시험 세부계획 수립과 그 근거를 마련하였다. 일반적으로 단계양수시험을 통하여 적정 채수량 산정 후, 산정된 적정 채수량으로 장기양수 시험을 통하여 주변 수리권에 미치는 지하수위 변화와 강변여과수의 수질변화를 관찰하여 지표수와 연계한 변동특성을 파악하는 일련의 과정을 생각할 수 있다. 그러나 K시 강변여과수 개발 지역과 같은 연약 지반에서는 단계 양수시험시의 높은 양수량에 인한 지반 침하의 우려로 인해 이에 대한 공정의 변화가 불가피하였다. 따라서 현장 시험 공정 순서를 바꾸어서 장기 양수 시험 후 단계양수시험을 수행하는 새로운 대안을 모색하였고 이를 뒷받침 해주는 근거를 제시하고자 한다. 뿐만 아니라 단계양수시험의 단계별 적절한 양수시간을 합리적, 효율적으로 결정하여 경제적이면서 가급적 빠른 시간 내에 단계양수시험을 완료 가능하게 만들고, 가능한 한 더 오랜 기간동안 장기 양수 시험을 가능하게 함으로써 제한된 시간내에 많은 수리지질학 및 화학적인 정보를 얻을 수 있도록 하였다.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.6 no.4
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• pp.397-403
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• 1994

The seepage flow has been investigated conducting laboratory experiments mainly in order to determine the relation of seepage flow friction factor against Reynolds number. The apparatus of seepage flow measurements has the water flow almost horizontaly. Several sets of experiments were carried out, and various flow conditions were obtained in each set of flow. To cover wide range of flow conditions, used were various materials of different measurement sizes and various stages of water discharge in the seepage flow tests. Shape factor equation was developed using existing data, and based on the present laboratory data, an explicit equation was developed for the estimation of friction factor of seepage flow in the range of Reynolds number from about 1 to about 600. The same equation is expected for the flow condition of Reynolds number over 600, considering the trend of friction factor distribution.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.365-369
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• 2006

MODSIM 모형은 하천유역 네트워크 모형으로 최신의 네트워크 최적화 알고리즘을 적용함으로써 유역내에서 물리적 수문학적으로 그리고 수리권과 같은 제도적인 면을 동시에 고려한 물 배분이 가능하며, 네트워크 흐름 최적화 기법은 복잡한 유역 시스템의 모의 능력을 증대시켜 준다. 모형을 이용하여 링크와 노드 및 우선순위를 토대로 금강유역을 대상으로 3개의 저류노드, 57개의 비저류노드, 72개의 수요노드 및 127개의 링크로 구성된 네트워크를 구축하였다. 개발된 네트워크 모형의 적용성 평가를 위해 충청지역의 행정중심복합도시 건설전 후의 용수수급에 대해서 분석하였으며, 네트워크 설계, 우선순위의 설정, 모의운영의 시나리오 분석 등에 있어서 만족할만한 성과를 도출하였다.