• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.330-333
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• 2015

충적하천에서 발생하는 하천의 침식과 퇴적은 흐름을 통해 발생하는 자연적인 현상이다. 침식 및 퇴적에 대한 수치모형을 이용한 분석은 하천에 존재하는 보와 같은 수리구조물들의 유사이송에 대한 영향을 연구하는데 효과적인 방법이다. 본 연구에서는 낙동강에 위치한 강정고령보에서 달성보 구간을 대상으로 보 건설 후 다기능보 운영을 통해 발생되는 하상변동에 대해 다양한 유사량 산정 공식별 대상구간에 대한 하상변동양상을 파악하고 실측자료와의 비교를 통해 실제 한천에서의 수리구조물 영향을 고려한 하상변동 예측에 대한 HEC-RAS 모형의 적용성을 평가하였다.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.280-280
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• 2020

지구 온난화 현상 및 이상기후로 지구환경 변화는 물환경 변화에 많은 영향을 미치고 있다. 특히, 지표수에 의존도가 높은 국내의 수자원 공급시스템은 지구환경 변화에 의한 강우 분포의 시간적, 공간적 불균질성에 대한 취약성이 높으며, 이에 기후변화에 따른 상대적 변동성이 적은 지하수자원의 활용 가능성이 높아지고 있다. 지하수 인공함양 기술은 강우, 지하수 및 하수 처리수 등의 잉여 수자원을 관정, 수로, 인공함양 분지 및 습지, 지하댐 등의 인공시설물을 활용하여 지하 대수층에 주입시킨 후 양질의 수자원을 확보하는 기술이다. 이번 연구에서는 수치해석을 활용하여 함양지역의 유역형상 및 지층경사, 대수층 두께, 체류시간, 수리상수 등 수리지질 인자를 고려한 인공함양 방식별 인공함양 효율성을 평가하고자 한다. 인공함양 방식은 수직관정 및 수로(Ditch)를 적용하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.20 no.1
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• pp.11-17
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• 2014

In this study, a hydraulic model experiment under wave conditions was carried out to investigate the gap/distance between two near-unit farm lines that affects the rope kink and shape variation of a seaweed farm during mooring block movement. As a result, rope kink occurred during the low wave height condition as the gap/distance between the two near-unit farm lines decreased. The seaweed farm maintained a stable shape in the higher wave height conditions as the gap/distance between the two near-unit farm lines increased. This result indicates that rope kink is sensitively affected by the gap/distance between the two near-unit farm lines. A tendency to increase the critical wave height was observed when mooring block movement occurred, and as the mooring block weight and wave period increased. From the experimental results in which incident wave conditions and the mooring block weight changed, as the front side mooring block weight increased from 3.0 to 8.0 tons, the seaweed farm was stable, and rear side mooring block movement hardly occurred. The observed tension of the seaside mooring line was a maximum at about 3.0 ton/m.

• Korean Journal of Soil Science and Fertilizer
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• v.36 no.4
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• pp.181-192
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• 2003

We developed a mathematical simulation model to portray the vertical distribution of soil water from the measured weather data and the known soil hydraulic properties, and then compared simulation results with the periodically measured soil water profiles obtained on Jungdong sandy loam to verify the model, In this model, we solved potential-based Richards' equation by the implicit finite difference method superimposed on the predictor-corrector scheme. We presumed that: soil hydraulic properties are homogeneous; soil water flows isothermally; hysteresis is not considered; no vapor flows; no heat transfers into the soil profiles; and water added to soil surface is distributed along the soil profile following partial displacement principle. The input data were broadly classified into two groups: (1) daily weather data such as rainfall, maximum and minimum air temperatures, relative humidity and solar radiation and (2) soil hydraulic data to approximate unsaturated hydraulic conductivity and water retention. Each hydraulic polynomial function approximated using the Chebyshev polynomial and least square difference technique in tandem showed a fairly good fit of the given set of data. Vertical distribution of soil water as approximations to the Richards' equation subject to changing surface and phreatic boundaries was solved numerically during 53 days with a comparatively large time increment, and this pattern agreed well with field neutron scattering data, except for the surface 0.1 m slab.

• Journal of Korea Water Resources Association
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• v.33 no.2
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• pp.237-245
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• 2000

Sihwa seadike is originally designed to control the water level In lake Sihwa. However the sluice gate is being operated everyday to preserve the water quality of lake. Due to the frequent operation of gates the bottom of drainage canal which is composed of weathered rock and soft rock is being scoured. Recently the bottom in the front area of apron was protected by putting underwater concrete. This study is carried out to understand the hydraulic situation for protection, and to estimate the trend of scouring by comparing between energy dissipation and registance of bottom rock. Annandale(1995) introduced the erodibility index theory, and suggested a criteria to judge the erodibility of rock through the relation between the erodibility index and energy dissipation. Determenation of erodibility index of rock is based on the results of sample core analysis, and the energy dissipation of flow is calculated from the estimation of total head on the scale model. These two values are plotted on the criteria, and the erodibility of rock is determined.

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.613-619
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• 2009

과거의 용수개발은 단위시설 또는 단위사업별 중심의 양적 확대개발 위주로 추진하여 수리시설간 수자원을 효율적으로 활용할 수 있는 용수공급체계가 미흡하였다. 수리시설의 양적 확대개발 위주의 추진결과 '03년도 총 수리시설수인 68,018개소 중 관개면적 50ha이상의 주 수원공은 1,888개소로서 전체수리시설의 2.8%를 차지하여 비합리적인 공급불균형 현상이 발생하여 체계적인 급수관리가 이루어지지 못하는 문제가 발생하였다. 또한 기존의 공급체계는 논 용수중심에서 식생활 변화로 인한 밭작물 수요증가로 용수이용 패턴이 변하고 있다. 더욱이 농촌지역의 생활환경 개선이 요구됨에 따라 생활용수, 공업용수, 환경용수 등 농촌지역에 과거와는 다른 형태의 용수수요가 발생하고 있다. 하지만 농촌지역의 수자원은 한정되어 있고 환경파괴 및 적지부족 등의 이유로 신규 수자원개발이 불가능한 사회여건이 지속되어 있어 많은 문제점이 나타나고 있어 균형적인 농촌발전과 건전한 농촌지역조성을 위해서는 새로운 대안이 제시되어야 하는 시점이다. 본 연구에서는 그 대안으로 부각되고 있는 농업용저수지 재개발에 대하여 사업의 우선순위를 합리적으로 결정할 수 있는 의사결정시스템의 개발을 목적으로 하고 있다. 기존 문헌을 고찰하면 개발우선순위는 과학적 논리보다는 정치적, 사회적 논리가 의사결정에 중요한 역할을 하였으나 의사결정시스템의 제공을 통해 정책결정자가 과학적이고 합리적인 논리에 따라 사업개발의 우선순위를 결정할 수 있을 것으로 기대한다. 본 연구에서는 재개발 의사결정에 필요한 지형적, 사회적, 환경적 요인을 지수화 하는 방법을 고찰하였고, 우선순위를 산정에 필요한 수치지도, 저수지 관련 자료의 작성과 지형정보(GIS)를 구축하였다. 우선순위 대상저수지의 선정은 기존문헌과 수계 및 용량 등을 고찰하여 79개로 우선 선별하였다.

• Tunnel and Underground Space
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• v.12 no.4
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• pp.312-320
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• 2002

It is well-known that when single rock fractures undergo shear displacement, they are influenced by the boundary conditions and fracture roughness. In this case, aperture geometry will change by means of dilation due to the shear displacement. As fractures become the flow paths, fluid flow through rock fractures is affected by the void geometry. In this study, therefore, the influence of roughness on shear behavior of fractures has been investigated, and the resulting hydraulic behavior has been analyzed. In order for this study, a statistical method has been used to generate rough fractures, and they have been adopted into new conceptual models fur fracture shearing and flow calculations. The main contributions of this study are as follows: firstly, fracture shear behavior becomes less brittle with decreasing fracture roughness and increasing normal stress. Then, the characteristics of aperture distribution becomes those of roughness of fractures indicating its hydraulic significance. Finally, it is observed that with decreasing fracture roughness the breakdown of channel flow occurs more slowly.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.537-554
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• 2006

Water levels of thermal groundwater ($>30^{\circ}C$) were recorded from March 2002 to June 2006 at several monitoring wells within the Yuseong spa area. Using these data, we elucidated the long-term cyclic fluctuations of thermal groundwater levels with 1 year period. We also observed a noticeable water level variation with periods of 0.5, 1 and 7 days in most monitoring wells, which indicates relatively good hydraulic connectivity within the main hotspring area. By comparing water level variations among several wells, we found out that E-W and N-S trending geological structures should be an important control factor for emplacement and flow of thermal groundwater in the study area. It may be also inferred that geothermal source is highly associated with the hydraulic connectivity of aquifers at the Yuseong spa area.

• School Mathematics
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• v.11 no.3
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• pp.513-526
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• 2009

The purpose of this paper intuitively shows the exact and logical explanation of Independent Event and Dependent Event. In actual classrooms, teachers have difficulty in describing the connection between those events and real life. Some teachers have wrong perceptions on the definition of those events. For example, they may not realize exactly what P(B A)=P(B) means and may not explain intuitively the original meaning of why it is independent event. Also they believe that Independent Event and Dependent Event do not always match with real life. This paper, therefore, tries to prove intuitively the exact meanings of those events in the Verbal Form with some examples and it proves that those events exactly match with real life. It is expected that this paper will greatly contribute to the improvement of probability education.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.18 no.1
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• pp.67-73
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• 2000

The water quality of inland stream is polluting with industrialization and urbanization, and with that water quality of lake also deteriorated, to manage water quality pollution problem of lake, new water quality management method is needed. As a pilot study of the method that manage water quality of lake using GSIS(Geo-Spatial Information System), we study the method which automatically extract the hydraulic characteristic informations of lake in GSIS environment. Also, as an example of practical use of the extracted hydraulic characteristic information of lake, we carry out the characteristic analysis of waterbody flow using finite different method. With the automation the extraction procedure of hydraulics characteristic information needed in characteristic analysis of waterbody flow, we carried out the analysis efficiently. Particularly, with the extraction of section information on lake not in layout form, in analyzable form, we make the analysis that section information of lake was indispenably required(e.g. stratification analysis) possible in GSIS environment.