• Title/Summary/Keyword: 3차원 지형모델

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Estimation of Optimal Weight in Tidal Modeling with the Adjoint Method (조석 모델링에서 adjoint 방법 적용시 적정 가중치 산정)

  • Lee, Jae-Hak;Park, Kyeong;Song, Yong-Sik
    • The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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    • v.5 no.3
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    • pp.177-185
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    • 2000
  • The adjoint method is a method of data assimilation to improve the model results by seeking for model parameters that minimize the cost function and satisfy the governing equations of a model simultaneously. An adjoint package was set up for the two-dimensional linear tidal model and was applied to an idealized domain for an optimal estimation of the open boundary conditions. The assimilating data were selected from the results of forward modeling. Attention is paid on the response of the adjoint package to weighting parameters, the importance of initial estimates of model parameters and the applicability of the adjoint package to the case with varying depth. A procedure to determine optimal weight is presented based on the relationships between weights and other factors.

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Analysis on the Oceanic Circulation and Pollutant Transport near a Wolsung Nuclear Power Plant (월성원전주변의 해수유동 및 오염물 이동해석)

  • Park, Geon-Hyeong;Kim, Ki-Chul;Lee, Jung-Lyul;Suh, Kyung-Suk
    • Proceedings of the Korea Water Resources Association Conference
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    • 2011.05a
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    • pp.250-250
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    • 2011
  • 지정학적으로 3면이 바다로 접하고 있는 우리나라 해안가 주변의 원자력발전소는 관류형 냉각 방식(Once-through cooling System)을 채택하고 있기에, 이 계통을 통과한 냉각수는 주변해역으로 흘러들어가 주변 환경에 영향을 줄 수 있다. 또한 동해 주변 인접국들의 활발한 원자력 이용과 방사능 물질의 수송 등으로 인해 방사능 사고 위험이 증대됨에 따라 동해 원전 주변의 해양방사성물질 거동에 대한 필요성이 제기되고 있다. 이에 따라 동해의 해양환경을 조사 분석하여 해역에서의 오염 물질의 거동 파악이 중요하고, 산업시설 주변 연안의 오염물 이동 및 해석을 위해 오염물의 시 공간적으로 농도를 추정하는 것이 중요한 사항이다. 따라서 본 연구에서 수직 수평적으로 2차원 및 3차원화가 용이한 EFDC 모델을 사용하였다. 국립해양조사원에서 발간하는 DC103의 수치해도를 이용하여 모델영역은 동서방향으로 171km, 남북방향으로 235km로 설정하고, 격자간격은 $1km{\times}1km$의 정방향 격자를 사용하여 동해 월성 주변의 조위 시계열 검증 및 조화분석을 통한 검증을 실시한 결과 관측한 결과와 양호한 재현성을 나타내었다. 또한 국립수산과학원에서 제공되고 있는 년별 수온, 염분 자료 등의 해양환경과 지형적 특성을 고려하여 오염 물질의 이동 경로를 파악함으로써 사고시 피해를 줄이고자 한다.

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Experimental Study for Beach Process by Construction of Offshore Structure (외해구조물 건설에 따른 해빈 변형에 관한 실험적 연구)

  • 이중우
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.12 no.2
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    • pp.96-106
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    • 2000
  • Though the recent years, large scale structures have been built on offshore for utilization of coastal ocean space as offshore airport and marine terminals. Sometimes, those big scale structures, however, happened to act as significant barriers against waves and severe beach erosion would take place on the coast. The present study deals nearshore topography changes affected by construction of an offshore structure with different distance from the shore. The series of three dimensional movable bed experiments have been examined in detail. Moreover, in order to make clear the relation of nearshore currents and local erosions behind offshore structure, the nearshore currents are calculated by Boussinesq equation model and compared with the same scale condition of the physical model experiments.

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Microcellular Propagation Loss Prediction Using Neural Networks and 3-D Digital Terrain Maps (신경회로망과 3차원 지형데이터를 이용한 마이크로셀 전파손실 예측)

  • 양서민;이혁준
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.10 no.3
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    • pp.419-429
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    • 1999
  • Identifying the boundary of the effective receiving power of waves is one of the most important factors for cell optimization. In this paper, we introduce a propagation loss prediction model which yields highly accurate prediction in very complex areas as Seoul where a mixture of many large buildings, small buildings, broad streets, narrow alleys, rivers and forests co-exist in an irregular arrangement. This prediction model is based on neural networks trained on field measurement data collected in the past. Using these data along with 3-D digital elevation maps and vector data for building structures, we extract the parameter values which mainly affect the amount of propagation loss. These parameter values are then used as the inputs to the neural network. Trained neural network becomes the approximated function of the propagation loss model which generalizes very well and can predict accurately in the regions not included in training the neural network. The experimental results show a superior performance over the other models in the cells operating in the city of Seoul.

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Analysis of Surface Runoff and Pollutant Transport Characteristics of Juam Control Dam Basin using HSPF (HSPF 모델을 이용한 주암조절지댐 유역의 강우 및 오염물질 부하 유출특성 분석)

  • Goh, Nayeon;Kim, Jaeyoung;Seo, Dongil
    • Proceedings of the Korea Water Resources Association Conference
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    • 2022.05a
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    • pp.405-405
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    • 2022
  • 본 연구는 주암조절지댐 유역의 강우 빛 비강우시츨 포함한 장기간의 유역유출 및 지하수 이동에 따른 유량분석과 오염물질 부하 유입특성을 분석함으로써 유역의 오염물질을 선제적으로 관리하고 조절지댐내의 수질을 효과적으로 관리하기 위해서 수행되었다. Hydrological Simulation Program - Fortran (HSPF) 모델을 적용하기 위하여 주암조절지댐 유역의 복잡한 지형과 기상조건 및 오염원 자료를 반영하고 수질관리 대책을 수립하는 데 적용하고자 하였다. 주암조절지댐 유역은 환경부의 소유역 구분을 고려하여 28개의 유역으로 세분화하고 티센망도를 고려해 3개의 그룹으로 재차 분류하였다. 기상 자료는 연구대상지역의 직접측정자료의 한계로 여수와 광양 기상청의 자료를 사용하였으며, 강우 자료 또한 소유역 그룹에 맞춰 입력 자료로 사용하였다. HSPF 모델의 보정은 유량 및 수질 (총질소 및 총인)에 대하여 2017 ~ 2021년의 모니터링 실측자료를 대상으로 수행되었다. 보정 결과는 R2, RMSE로 평가하였고, 보정된 HSPF 모델을 바탕으로 유역별 유량 및 수질에 영향을 미치는 주요 인자를 분석하였다. 본 연구의 결과는 주암조절지댐의 수질을 예측할 수 있는 3차원 수리-수질 모델의 입력자료로 활용될 예정이며, 추후 기후변화 영향을 고려한 상류 유역의 수질관리 계획 수립에 기여할 것으로 기대된다.

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Urban Flood Simulation Considering Building and Sewer Lines (건물 및 우수 배제를 고려한 시가지 범람해석)

  • Kang, Sang-Hyeok
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.29 no.3B
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    • pp.213-219
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    • 2009
  • In densely urban areas, features such as the sewer system, buildings and river banks have an effect on flow dynamics and flood propagation, and will therefore be accounted for in the model set-up. While two-dimensional (2D) flood models of urban areas are at the forefront of current research into flood inundation mechanisms, they are however constrained by inadequate parameters of topography, and insufficient and inaccurate data. In this study, an urban flood model (overland flow, 2D urban flood flow and sewer flow) was combined and applied at Samcheok city which was damaged by inundation in 2002, in order to simulate inundation depth. The influence of buildings and pumping capacity was also analyzed to estimate the inundated depth in the study area. As a result, it was found that urban inundated depth are affected by pumping capacity directly and it increased about 20-30 cm on most of the modeled area with a building share rate of 0.2-0.6 per unit grid.

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.

A Geographic Modeling System Using GIS and Real Images (GIS와 실영상을 이용한 지리 모델링 시스템)

  • 안현식
    • Spatial Information Research
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    • v.12 no.2
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    • pp.137-149
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    • 2004
  • For 3D modelling artificial objects with computers, we have to draw frames and paint the facet images on each side. In this paper, a geographic modelling system building automatically 3D geographic spaces using GIS data and real images of buildings is proposed. First, the 3D model of terrain is constructed by using TIN and DEM algorithms. The images of buildings are acquired with a camera and its position is estimated using vertical lines of the image and the GIS data. The height of the building is computed with the image and the position of the camera, which used for making up the frames of buildings. The 3D model of the building is obtained by detecting the facet iamges of the building and texture mapping them on the 3D frame. The proposed geographical modeling system is applied to real area and shows its effectiveness.

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Two-Dimensional Resistivity Modeling by Finite Element Method (유한요소법에 의한 2차원 비저항 모델링)

  • Kim, Hee Joon
    • Economic and Environmental Geology
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    • v.19 no.4
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    • pp.283-292
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    • 1986
  • Finite element method with linear triangular and bilinear rectangular elements is applied to solve the three-dimensional potential distribution due to a point source of current located in or on the surface of the earth containing arbitrary two-dimensional resistivity distribution. The modeling technique developed in this paper is flexible to model conductive inhomogeneity and surface topographies, and more accurate to evaluate surface potentials than the conventional techniques using finite difference method. Since it is possible to reduce nodal points with acceptable accuracy, this modeling technique is very efficient and economic in terms of execution time and core space. A few geologic structures adequate to demonstrate above features are simulated in this paper.

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Development of Three Dimensional Animal's Habitat Map by GIS (GIS에 의한 3차원 동물서식도 제작)

  • Park, Joon-Kyu;Kim, Min-Gyu
    • Journal of the Korean Association of Geographic Information Studies
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    • v.14 no.4
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    • pp.54-62
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    • 2011
  • At present, about 1.6 million bio-species have been discovered in the world. Approximately 30 thousand indigenes have been recorded in Korea and about fifteen thousand species of biology inhabit in Korea national park. Korea national park where has been lived 133 species at 60 percent of endangered species is a very important wildlife protection area. The construction of database about substantive distribution and habitat of wildlife is urgently needed to protect and manage endangered species. In this study, main habitats about animals were registered using GIS program in Jirisan National Park and 3 dimensional habitat map was produced. Also, new plan was suggested to preserve and manage animals in national parks by producing 3 dimensional habitat map. The habitat map was produced using coordinate file of animals, polygon file about boundary of national park, and ASTER GDEM. New conceptional animal habitat map will be used by means of the valuable information when the plans for preservation/management and habitat protection about animals are designed.