• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2001년도 학술발표회 논문집(I)
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• pp.25-34
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• 2001

A grid-based KIneMatic wave soil-water EROsion and deposition Model (KIMEROM) that predicts temporal variation and spatial distribution of sediment transport in a watershed was developed. This model uses ASCII-formatted map data supported from the regular gridded map of GRASS (U.S. Army CERL, 1993)-GIS (Geographic Information Systems), and generates the distributed results by ASCIIl-formatted map data. For hydrologic process, the kinematic wave equation and Darcy equation were used to simulate surface and subsurface flow, respectively (Kim, 1798; Kim et al., 1993). For soil erosion process, the physically-based soil erosion concept by Rose and Hairsine (1988) was used to simulate soil-water erosion and deposition. The model adopts sing1e overland flowpath algorithm and simulates surface and subsurface water depth, and sediment concentration at each grid element (or a given time increment. The model was tested to a 162.3 km$^2$ watershed located in the tideland reclaimed area of South Korea. After the hydrologic calibration for two storm events in 1999, the results of sediment transport were presented for the same storm events. The results of temporal variation and spatial distribution of overland flow and sediment areas are shown using GRASS.

• Geomechanics and Engineering
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• 제22권5호
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• pp.375-384
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• 2020

In this study, the application of conventional cubic law to a deep depth condition was experimentally evaluated. Moreover, a modified equation for estimating the rock permeability at a deep depth was suggested using precise hydraulic tests and an effect analysis according to the vertical stress, pore water pressure and fracture roughness. The experimental apparatus which enabled the generation of high pore water pressure (< 10 MPa) and vertical stress (< 20 MPa) was manufactured, and the surface roughness of a cylindrical rock sample was quantitatively analyzed by means of 3D (three-dimensional) laser scanning. Experimental data of the injected pore water pressure and outflow rate obtained through the hydraulic test were applied to the cubic law equation, which was used to estimate the permeability of rock fracture. The rock permeability was estimated under various pressure (vertical stress and pore water pressure) and geometry (roughness) conditions. Finally, an empirical formula was proposed by considering nonlinear flow behavior; the formula can be applied to evaluations of changes of rock permeability levels in deep underground facility such as nuclear waste disposal repository with high vertical stress and pore water pressure levels.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2021년도 학술발표회
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• pp.142-142
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• 2021

An arbitrary representation of an urban drainage sewer system was devised using a geographic information system (GIS) tool in order to calculate the surface and subsurface flow interaction for simulating urban flood. The proposed methodology is a mean to supplement the unavailability of systematized drainage system using high-resolution digital elevation(DEM) data in under-developed countries. A modified DEM was also developed to represent the flood propagation through buildings and road system from digital surface models (DSM) and barely visible streams in digital terrain models (DTM). The manhole, sewer pipe and storm drain parameters are obtained through field validation and followed the guidelines from the Plumbing law of the Philippines. The flow discharge from surface to the devised sewer pipes through the storm drains are calculated. The resulting flood simulation using the modified DEM was validated using the observed flood inundation during a rainfall event. The proposed methodology for constructing a hypothetical drainage system allows parameter adjustments such as size, elevation, location, slope, etc. which permits the flood depth prediction for variable factors the Plumbing law. The research can therefore be employed to simulate urban flood forecasts that can be utilized from traffic advisories to early warning procedures during extreme rainfall events.

• 천문학회지
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• 제54권5호
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• pp.157-170
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• 2021

We investigate flow and magnetic structure of a solar prominence with a focus on how the magnetic field originally determined by subsurface dynamics gives rise to the structure. We perform a magnetohydrodynamic simulation that reproduces the self-consistent evolution of a flow and the magnetic field passing freely through the solar surface. By analyzing Lagrangian displacements of magnetized plasma elements, we demonstrate the flow structure that is naturally incorporated to the magnetic structure of the prominence formed via dynamic interaction between the flow and the magnetic field. Our results explain a diverging flow on a U-loop, a counterclockwise downdraft along a rotating field line, acceleration and deceleration of a downflow along an S-loop, and partial emergence of a W-loop, which may play key roles in determining structural properties of the prominence.

• 한국수자원학회논문집
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• 제50권11호
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• pp.795-802
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• 2017

본 연구는 지하댐에 의한 수자원 개발량을 평가하는 방법론을 제시한다. 연구 대상지역으로 선택한 쌍천 지하댐은 동해안 쌍천유역 하구에 위치하며 비피압 충적 대수층을 형성하고 있다. 동해안에는 지형적으로 유사한 지하댐 후보지가 여러 개 존재한다. 본 연구에서는 대수층의 지하수위를 평면 2차원 FDM 모형으로 산출하였으며, 여기서 유역 유출은 대수층 표면에 침투항으로서 입력된다. 3개의 유역 유출모형의 평균으로서, 기저유량은 $0.5m^3/sec$로 산출되었다. 그리고 이 기저유량 근처의 유입량을 갈수기 유입으로 간주하여, 유입량 및 양수량 변화에 따른 지하수위를 산출하는 방법으로 수자원 개발량을 평가하였다. 구체적으로는 현재 속초시 생활용수를 공급하고 있는 실제 양수량($28,000m^3/day$)을 적용하여, 우물 수위가 대수층 바닥에 도달하거나 지하수위가 대수층 표면을 상회하여 지표수 흐름이 발생하는 유입량을 추정하였다. 또한 수자원 개발량을 증대시키기 위하여 우물의 양수량을 증가시키거나 추가 우물을 설치하는 상황을 재현하고, 극심한 갈수기에 가능한 양수량을 산출하였다.

• Water Engineering Research
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• 제1권1호
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• pp.25-37
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• 2000

This study presents some results of a preliminary study for the coupled precipitation and river flow prediction system. The model system in based on three numerical models, Mesoscale Atmospheric Simulation model for generating atmospheric variables. Soil-Plant-Snow model for computing interactions within soil-canopy-snow system as well as the energy and water exchange between the atmosphere and underlying surfaces, and TOPMODEL for simulating stream flow, subsurface flow, and water tabled depth in an watershed. The selected study area is the 2,703 $\alpha_4$ $\km_2$ Soyang River basin with outlet at Soyang dam site. In addition to providing the results of rainfall and stream flow predictions, some results of DEM and GIS application are presented. It is obvious that the accurate river flow predictions are highly dependant on the accurate predictation predictions.

• 한국해양공학회지
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• 제7권1호
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• pp.81-91
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• 1993

Studies on the flow pattern due to reclamation in the Myunggi-Nocksan region are carried out based on field observations and numerical experiments. Serial time series measurement of current, temperature and salinity were conducted for 1 tidal period at intervals of 1 hour from surface to bottom on station located at 128.deg. 54' 44" E, 35.deg. 01' 04" N in April and June 1992. Surface current opposite to the subsurface current causes turbulent mixing to make homogeneous salinity pattern in vertical section. Reclamation has little effect on the wave pattern and flow patterns are also nearly similar except on the nearby region of reclamation where flow speed somewhat weakened.

• 물과 미래
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• 제12권1호
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• pp.56-59
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• 1979

직접유출 수문곡선의 감수부를 유발하는 지표하류출 과정이 사대종확산모형기법에 의하여 모의되었다. 유출과정은 필시곡선도에 의한 소유역을 대표하는 개급적 선형 수로를 통하여 상류선형수로의 유출과 핵심 소유역의 유효강우량을 추적하여 수행된다. 유출 속도, 확산인자, 침투와 지표하흐름 영역에 관한 매개변수의 산출과정이 기록된다.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2004년도 임시총회 및 추계학술발표회
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• pp.269-272
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• 2004

The use of colloidal gas aphron (CGA), as an external oxygen carrier, provides a promising alternative to promote aerobic bioremediation of BTEX in the subsurface environment. CGA is a stable bubble supported by three surfactant layers and can supply oxygen below the soil surface uniformly due to its plug-flow characteristic. Since CGA has a hydrophobic layer that can act as a partitioning medium for hydrophobic contaminants it is known to facilitate desorption of soil-sorbed contaminants. In addition, bioaugmentation and biostimulation are possibly achieved by using CGA when generated from a solution containing BTEX-degrading microorganisms and appropriate nutrients. In this study, we presented the physico-chemical characteristics of CGA generated from a solution composed of microorganisms and nutrients. The applicability of CGA as an in situ aerobic bioremediation technology of BTEX will be further evaluated.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2011년 춘계학술대회논문집
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• pp.592-595
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• 2011

A numerical investigation on a suction vortices, free vortices and subsurface vortices behavior in the model sump system with multi-intakes is performed A test model sump and piping system were designed based on Froude similitude for the prototype of the recommended structure layout by HI-9.B Standard for Pump Intake Design of the Hydraulic Institute. A numerical analysis of three dimensional multiphase flows through the model sump is performed by using the finite volume method of the CFX code with multi-block structured grid systems. A ${\kappa}-{\omega]$ ShearStressTransportturbulencemodelandthe Rayleigh-Plesset cavitation model are used for solving turbulence cavitating flow. From the numerical analysis, several types of vortices are reproduced and their formation, growing shedding and detailed vortex structures are investigated. To reduce abnormal vortices, an anti-vortex device is considered and its effect is investigated and discussed.