• Title/Summary/Keyword: 지형 모델

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Application of Passive Sampler in Validation and Calibration of Air Dispersion Model (대기확산모델의 검정 및 보정을 위한 Passive Sampler의 활용)

  • 김선태;김주인;김성근;배장영
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 1999.10a
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    • pp.170-171
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    • 1999
  • 대기 중 오염물질의 확산 및 미래의 예측을 위하여 대기확산모형을 많이 사용하고 있으며, 국내에서 사용하고 있는 대기확산모형의 대부분은 미국 EPA에서 보급하는 것을 사용하고 있다. 이 중에서 최근에 많이 사용하고 있는 단기모형으로는 기간과 지형이 고려되는 ISCST3 모형을 들 수 있다. 국내 모델의 사용에 있어서 가장 중요한 문제점은 모델의 검정과 보정을 위한 data의 부재를 들 수 있다.(중략)

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The Analysis of Building Downwash Effect using ISCST3-PRIME Model (ISCST3-PRIME모델을 이용한 건물 세류현상 해석)

  • 조진식;구윤서;최상민;정은동
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2002.11a
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    • pp.395-396
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    • 2002
  • 국내 지형이 복잡하고, 대단위 배출시설들이 대도시 주변에 많이 위치하고 있기 때문에 굴뚝에서 배출된 오염물질이 주변에 미치는 영향을 정확히 파악하기 위해서는 굴뚝 주변의 건물 세류현상에 대해 세밀한 해석이 요구된다. 현재 국내 환경영향평가에서 건물세류현상을 평가하기 위해서 주로 미국 환경보호청에서 제공하고 있는 ISC3모델을 사용하고 있다(US EPA, 1995). 그러나 이 모델에서는 건물과 굴뚝간의 거리에 따른 연기확산의 차이가 발생하는 것을 고려할 수 없고, 또한 건물 주위에 형성되는 와류(wake)에 의해서 배출된 연기의 중심축이 기울어지는 것 등을 고려 할 수 없다. (중략)

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Generation of Progressively Sampled DTM using Model Key Points Extracted from Contours in Digital Vector Maps (수치지도 등고선의 Model Key Point 추출과 Progressive Sampling에 의한 수치지형모델 생성)

  • Lee, Sun-Geun;Yom, Jae-Hong;Lim, Sae-Bom;Kim, Kye-Lim;Lee, Dong-Cheon
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.25 no.6_2
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    • pp.645-651
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    • 2007
  • In general, contours in digital vector maps, which represent terrain characteristics and shape, are created by 3D digitizing the same height points using aerial photographs on the analytical or digital plotters with stereoscopic viewing. Hence, it requires lots of task, and subjective decision and experience of the operators. DTMs are generated indirectly by using contours since the national digital maps do not include digital terrain model (DTM) data. In this study, model key points which depict the important information about terrain characteristics were extracted from the contours. Further, determination of the efficient and flexible grid sizes were proposed to generate optimal DTM in terms of both quantitative and qualitative aspects. For this purpose, a progressive sampling technique was implemented, i.e., the smaller grid sizes are assigned for the mountainous areas where have large relief while the larger grid sizes are assigned for the relatively flat areas. In consequence, DTMs with multi-grid for difference areas could be generated instead of DTMs with a fixed grid size. The multi-grid DTMs reduce computations for data processing and provide fast display.

Evaluating Suitable Analysis Methods Using Digital Terrain in Viewshed Analysis (수치지형도를 활용한 가시권 분석의 적정 분석방법에 관한 연구)

  • Yeo, Chang-Hwan;Jang, Young-Jin
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.1
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    • pp.40-48
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    • 2011
  • The purpose of this study is to contribute enhancing the accuracy of viewshed analysis through the explanation for an analysis method of viewshed analysis using GIS. According to previous studies, the visible area using digital terrain in viewshed analysis depends on a visible interest area, scale of terrain, spatial resolution and surface data. In this study, we used trend analysis and RMSE analysis in order to find the effect of a visible interest area, scale of terrain, etc in viewshed analysis. Results of this study are as follows. First, the result of viewshed analysis depends on a visible interest area, scale of terrain, spatial resolution, surface data such as previous studies. Second, the results in forest area are reliable than those of flat area in terms of a visible interest area. Third, the results based on raster grid data are stable than those of TIN(triangulated irregular network) in terms of input surface data. Fourth, according to the result of trend and RMSE analysis, the spatial resolution for analysis is differently applied to different scales digital terrain map in viewshed analysis. In detail, it is desirable that the spatial resolution is set less than 10m(in the case of 1/1,000 digital terrain map), 20m(in the case of 1/5,000 map), 30m(1/25,000 map).

Numerical Model for Predicting Sand Bar Formation around River Mouth (하구역의 사주 형성 예측을 위한 수치 모델)

  • Kuroiwa, Masamitsu;Matsubara, Yuhei;Suzuki, Yoko;Kuchiishi, Takayuki
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.26 no.2
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    • pp.96-102
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    • 2014
  • A three-dimensional beach evolution model was presented to predict morphodynamics around a river mouth. The presented model was based on the depth-averaged (2DH) and quasi three-dimensional (Q-3D) nearshore current modules, and the model took into account shoreline changes, the effect of advection diffusion of suspended load and discharged sediments from the river. First, the 3D beach evolution model was applied to the formation of sand spits and terrace at the river mouth in order to investigate the performance of the model. Secondly, the model was applied to the river mouth at the Ara River, facing the Sea of Japan. The formation of sand spit at the Ara River in winter season was reproduced. The computed result showed qualitatively agreement with field site observation.