• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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• pp.64-64
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• 2003

The aim of this study is to apply and verify of logistic regression at Janghung, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the study area from interpretation of IRS satellite images, field surveys, and maps of the topography, soil type, forest cover, geology and land use were constructed to spatial database. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography were calculated from the topographic database.13${\times}$1ure, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter and density of forest were extracted from the forest database. Land use was classified from the Landsat TM image satellite image. As each factor's ratings, the logistic regression coefficient were overlaid for landslide susceptibility mapping. Then the landslide susceptibility map was verified and compared using the existing landslide location. The results can be used to reduce hazards associated with landslides management and to plan land use and construction.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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• pp.65-70
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• 2003

The weight-of-evidence model one of the Bayesian probability model was applied to the task of evaluating landslide susceptibility using GIS. Using the location of the landslides and spatial database such as topography, soil, forest, geology, land use and lineament, the weight-of-evidence model was applied to calculate each factor's rating at Boun area in Korea where suffered substantial landslide damage fellowing heavy rain in 1998, The factors are slope, aspect and curvature from the topographic database, soil texture, soil material, soil drainage, soil effective thickness, and topographic type from the soil database, forest type, timber diameter, timber age and forest density from the forest map, lithology from the geological database, land use from Landsat TM satellite image and lineament from IRS satellite image. Tests of conditional independence were performed for the selection of the factors, allowing the 43 combinations of factors to be analyzed. For the analysis, the contrast value, W$\^$＋/and W$\^$-/, as each factor's rating, were overlaid to map laudslide susceptibility. The results of the analysis were validated using the observed landslide locations, and among the combinations, the combination of slope, curvature, topographic, timber diameter, geology and lineament show the best results. The results can be used for hazard prevention and planning land use and construction

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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• pp.100-100
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• 2003

The purpose of this study is to reveals spatial relationships between landslides and geospatial data set, map the landslide susceptibility using the relationships and verify the landslide susceptibility using the landslide occurrence data in Bosun area in 1998. Landslide locations were detected from aerial photography and field survey and topography, soil, forest, and land use data sets were constructed as a spatial database using GIS. As the landslide occurrence factors, slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil, type, age, diameter and density of wood and land use were used. Is extract the relationship between landslides and geospatial database, Bayesian probability methods, likelihood ratio and weight of evidence, were applied and the ratio and contrast value that is W$\^$＋/- W$\^$-/ were calculated. The landslide susceptibility index was calculated by summation of the likelihood ratio and contrast value and the landslide susceptibility maps were generated using the index. As a result, it is expected that spatial relationships between landslides and geospatial database is helpful to explain the characteristics of landslide and the landslide susceptibility map is used to reduce associated hazards, and to plan land use and construction.

• 한국GIS학회:학술대회논문집
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• 한국GIS학회 2003년도 공동 춘계학술대회 논문집
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• pp.63-63
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• 2003

The aim of this study is to apply and verify of Bayesian probability model, the likelihood ratio and statistical model, at Janghung, Korea, using a Geographic Information System (GIS). Landslide locations were identified in the study area from interpretation of IRS satellite images, field surveys, and maps of the topography, soil type, forest cover, geology and land use were constructed to spatial database. The factors that influence landslide occurrence, such as slope, aspect and curvature of topography were calculated from the topographic database. Texture, material, drainage and effective soil thickness were extracted from the soil database, and type, diameter and density of forest were extracted from the forest database. Land use was classified from the Landsat TM image satellite image. As each factor's ratings, the likelihood ratio coefficient were overlaid for landslide susceptibility mapping, Then the landslide susceptibility map was verified and compared using the existing landslide location. The results can be used to reduce hazards associated with landslides management and to plan land use and construction.

• Spatial Information Research
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• 제18권1호
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• pp.49-56
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• 2010

시가지 범람 문제를 고려할 경우 침수심의 정량적인 수치계산에 의한 재해 위험을 평가하는 것이 중요하다. 본 연구에서는 2002년 막대한 시가지 침수 피해를 경험한 바 있는 삼척시를 대상으로 범람 모의 계산에 의한 시가지 침수피해 평가를 수행하였다, 입력자료의 변환과정에서 생길 수 있는 에러를 줄이기 위해 시가지 조도계수, 표고, 건물의 점유율 등은 ArcGIS에서 바로 전산화하여 시가지 범람모형을 구축하였으며 계산된 침수심을 토대로 격자별로 피해액을 산정하였다 본 연구를 통하여 강우유출, 침수심 모의 계산, 피해액의 정량적 산정이라는 일연의 과정이 통합적으로 수행되어 향후 시가지 배수계획에 기여할 것으로 기대된다.

• 대한공간정보학회지
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• 제16권3호
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• pp.59-64
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• 2008

토양침식은 산악지역에서 산림조성에 중요한 문제를 일으키며 비옥한 토양을 침식시켜 식생의 성장을 저해시키며 인도에서 수집한 자료와 GIS를 이용하여 인도의 서부산맥 모야유역의 토양침식을 분석하였다. 주제도의 레이어로 산림, 지형경사, 배수 등에 대한 자료가 사용되었으며 토양침식 지도분석에서 48%의 지역이 중간정도의 침식을 보였다. 또한 35%지역은 높은 침식을 보였으며 가장 높은 침식은 식생지역의 7%를 차지하였다. 이러한 토양침식 분석도는 유역에서의 토양침식을 방지하기 위한 대책을 수립하는데 주요한 자료가 될 것으로 판단된다.

• 펄프종이기술
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• 제33권3호
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• pp.9-17
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• 2001

The floc characteristics of base paper stock for coating by the retention aid system consisting of polyacrylamide (high molecular weight low charge density, HMLC) and PEI without and with anionic inorganic oxide (IO) were investigated under various shear conditions of MDDA (modified dynamic drainage analyzer). The floc size was increased with cationic electrolytes dosage whatever inorganic oxide is applied or not. The effect of inorganic oxide on the floc size showed the different result between PAM and PEI. The smaller floc was obtained by PAM without inorganic oxide, but larger floc was obtained by PAM with inorganic oxide. However, the effect of shear force was not observed. Floc formation index was decreased by the addition of cationic electrolytes with or without inorganic oxide. Floc formation index had better correlation format formation index than floc size. The relationships between wet web permeability and mat air permeability showed the significant linear correlation ($R^2$=0.97~0.98) for HML PAM and PEI. Floc formation index gave more useful information than the retention measurement when the performance of retention aids is evaluated at the laboratory before applying at the paper mill.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 2018년도 학술발표회
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• pp.379-379
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• 2018

기후변화와 지구온난화로 인하여 전 세계적으로 폭우발생 빈도 및 강도가 증가하고 있다. 특히 유역 차원에서 도시화와 산업 개발로 인한 불투수면적 증가는 내수침수 증가로 이어지고 있다. 불투수면적이 높고 인구와 건물이 밀집되어있는 도시유역에서의 내수침수는 막대한 재산피해와 인명피해를 야기한다. 도시유역의 불투수층에 내린 강우는 지표면을 따라 흐르다가 대부분 우수관으로 유입되어 유역에서 배출된다. 그러므로 도시 우수관의 설계빈도를 결정하고 설계홍수량을 결정하는 일은 도시 홍수 저감을 위한 구조적인 대책 중 가장 우선적으로 고려되어야 하고, 또 가장 중요한 대책이기도 하다. 본 연구에서는 과거 홍수피해가 빈번히 발생했던 도시유역들 중 유역면적과 우수관망의 구조가 다른 7개의 도시를 선정하여 다양한 강우사상에 따른 유출해석을 실시하였다. 서울과 부산 기상관측소에서 관측된 1975년부터 2015년까지의 강우자료에 대한 EPA-SWMM 모형에서의 유출해석 결과 첨두강우량의 변화에 따른 첨두유출량의 변화를 선형회귀모형으로 분석하였다. 회귀모형의 결정계수와 95% 신뢰구간, 변동계수를 비교하였고, 수계밀도개념을 적용하여 첨두유출량의 변화를 해석한 결과, 우수관망이 조밀하게 건설되어 배수밀도가 높을수록 증가된 첨두강우량에 따라 함께 증가하는 첨두유출량의 예측이 상대적으로 정확하게 가능함을 확인하였다. 우수관의 구조적인 특성에 따른 유출 응답 속도를 고려하여 우수관을 설계한다면, 보다 효율적인 우수관 설계가 가능할 것으로 판단된다.

• Geomechanics and Engineering
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• 제29권5호
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• pp.497-508
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• 2022

Tailings fluidization (i.e., tailings behave as being fluidized) under cyclic loading is one concern during the construction of tailings dams, especially in the shallow tailings layers. The primary goal of this study is to evaluate the responses of tailings under cyclic loadings and the tailings potential for fluidization. A series of cyclic triaxial undrained and drained tests were performed on medium and dense tailings samples under various cyclic stress ratios (CSR). The results indicated that axial strain and excess pore water pressure accumulated over time due to cyclic loading. However, the accumulations were dependent on CSR values, densities, and drainage conditions. The fluidization potential analysis in this study was then evaluated based on the obtained cyclic axial strain and excess pore water pressure. As a result, tailings samples were stable (unfluidized) under small CSR values, and the critical CSR values, where the tailings fluidized, varied depending on the density of tailings samples. Tailings fluidization is triggered as cyclic stress ratios reach critical values. In this study, the critical CSR values were found to be 0.15 and 0.40 for medium and dense samples, respectively.

• Journal of Electrochemical Science and Technology
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• 제14권4호
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• pp.333-348
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• 2023

In this study, a 3D model of the proton exchange membrane fuel cell is established, and a new 3D baffle structure is designed, which is combined with the parallel flow field and then optimized by numerical simulation methods. The number of baffles and the cross-sectional trapezoidal base angle are taken as the main variables, and their impacts on the performance indexes of the cathode side are analyzed. The results show that the 3D baffle can facilitate the convection and diffusion mass transfer of reactants, improve the uniformity of oxygen distribution, enhance the drainage capacity, and make the cell performance superior; however, too small angle will lead to excessive local convective mass flux, resulting in the decrease of the overall uniformity of oxygen distribution and lowering the cell performance. Among them, the optimal number of baffles and angle are 9 and 58°, respectively, which improves the net output power density by 10.8% than conventional flow field.