• Proceedings of the KAIS Fall Conference
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• 2010.11a
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• pp.32-35
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• 2010

바람직한 도시의 건설계획을 위해 2차원 적인 도면의 활용은 한계가 있다. 지방자치단체의 도시계획심의와 민원의 처리에도 3차원 도시모델을 활용하는 추세에 있다. 현장에 가지 않고 사무실에서 업무를 처리하기 위해서는 정밀한 3차원 지형모델이 구축되어야 한다. 또한 건물의 3차원모델링도 신속하고 편리한 방법을 이용해야만 실무에 활용이 가능하다. 본 연구에서는 이를 위해 고해상 고정밀 3차원 지형모델링은 물론 스케치업을 이용한 효율적인 건물모델링방법 강구하여 실무에 적용가능성을 제시하였다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.14 no.2
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• pp.151-157
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• 1996

This study, experimentally, aims at presenting the methodology to construct an efficient digital terrain by com-paring and analyzing the accuracy among the existing Digital Terrain Models, develope 3-D fractal terrain model-ling program by applying digital algorithm of fractal geometry and using turbo pascal, and lastly perform basic research on constructing GSIS-based 3-D fractal terrain modelling system by integrating a PC-based GSIS Pack-age and the 3-D fractal terrain modelling program developed by this paper. The results are as follows -First, the method to produce TIN(Triangulated Irregular Network) by the combination of point data and line data was showed as an alternative to construct efficient Digital Terrain Model. Second, developing GSIS-based 3-D fractal terrain modelling system, applying fractal geometry is the basic research in developing the new terrain modelling method. also, this study presented the possibility of 3-D terrain modelling with the use of fractal.

• The Journal of the Korea Contents Association
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• v.7 no.9
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• pp.204-211
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• 2007

In this study 3D topographic modeling was made by using aerial photography and digital terrain map, through this we did visibility analysis and implemented Web GIS of Dong-A university. Studying area was Busan Saha-gu Hadan-dong, we used aerial photography on a scale of 1:20,000 and digital terrain map on a scale of 1:5,000. Ortho correction image was made by aerial photography through selecting GCP, image matching, image resampling and precise differential rectification. And DEM on digital map was created using ArcView program, making 3D topographic modeling by road layer and building layer and implementing Web GIS about Dong-A university.

• 한국공간정보시스템학회:학술대회논문집
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• 2005.05a
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• pp.319-325
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• 2005

지리정보데이터는 공간개념을 가지고 있음에도 불구하고 대부분 2차원 평면 위주의 공간 자료로 이루어져 왔다. 그러나 GIS 데이터는 2차원 평면위주의 공간자료보다 3차원 공간자료를 기반으로 한 시각화를 통하여 다차원적인 분석이 가능해지고 있다. 최근 인터넷 환경에서 구동되는 3D GIS의 중요성이 인식되기 시작하였고, 3D GIS는 초기에는 지형을 단순히 3차원 가시화 하는 기능 위주에서 최근 3차원 지형분석, 3차원 도시, 3차원 시설물 등의 현실감 있는 모델링과 분석기능을 제공하는 단계는 물론, 가상현실 기능이 강조된 3D GIS까지 등장하는 단계에 이르렀다. 본 연구에서는 GIS 툴(ArcView)을 사용하여 대학캠퍼스의 부지, 구조물 및 시설물의 3D GIS를 구축할 수 있었으며 3D 모델링을 통해 다양한 각도에서의 조감도 작정과 경관분석을 행하였고 향후 시설물 확충에 따른 공간활용계획의 기본 자료로서 그 활용성을 검토하고자 하였다 이것은 GIS의 가장 발전적 형태인 Web GIS구축을 위한 인터넷 데이터베이스로서 정보 공유와 조회는 물론 사용자 측면의 분석까지 가능하도록 이용할 수 있다. 따라서 본 연구에서는 추후 웹 GIS 기법을 적용하여 캠퍼스의 3차원 관리를 위해 웹서버를 구축하고 2D를 기반으로 한 인터넷 맵의 한계를 벗어나 3D 모델링으로 웹상에서 사용자에게 다각도의 3차원 공간을 구현함으로써 2차원 데이터와 더불어 3차원 공간영상의 공유가 가능하도록 시도하고자 한다.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.77-85
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• 1997

Researches in the field of Computer Graphics and Geographical Information Systems(GIS) have extensively studied the method of photo-realistic landscape modelling, because it have become a commom requirement in applications such as flight simulators, mission rehearsal, and construction planning. A common approach to the display of terrain uses a Digital Elevation Model(DEM). DEM is an evenly spaced array of the terrain elevation data and can be obtained from stereo satellite data. With the DEM data, the process of 3D terrain modelling consists of three steps. The first step is to extract the meaningful data (such as peak, pit, passes...) from DEM data based on LOD(Level Of Detail) criteria. The second is to construct the 3D surface by TIN, which represents a surface as a set of non-overlapping continuous triangular facets of irregular size and shape. The third is a rendering of 3D terrain model. The goal of this research is a construction of 3D terrain with TIN. To do this, we are going to app]y Radial Sweep Algorithm. Radial Sweep Algorithm for generating TIN works quickly and efficiently. However, it does not solve the problem caused by the approximated nature of triangulated surface. To solve this problem, this research derive improved radial sweep algorithms with the optimal triangle definition.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.2 s.4
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• pp.99-108
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• 1994

In this thesis, we propose the 3D terrain modelling method for the better understanding of the geographic information. The process of 3D terrain medelling consists of three steps. The first step is to obtain real-world data from satellite images and stored in the form of DEM(Digital Elevation Model). The second one is to extract the meaningful data from DEM data based on LOD(Level Of Detail). And the third is to construct the 3D surface by TIN(Triangulated Irregular Network) with the extracted meaingful data. The proposed dynamic TIN reconstruction algorithm locally reconstruct the existed TIN model with the additional a new point. In this way, we can construct the TIN with the reduced time and can simulated 3D terrain model in real time.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.2
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• pp.207-213
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• 1997

The purpose of this study is to aim at presenting efficient technique of 3-D Terrain Modelling through multilateral approach methods and to compare with raw data, using low-densed randomly located point data. The subject religion of this study are selected two sites and take into consideration for degree of freedom about low-densed randomly located point data. The result of this study by precision analysis of digital cartographic map-ping using low-densed randomly located point data bave shown that . First, making digital cartographic map, the technique of making it using low-desned randomly located point data by TIN-based results to good and fast run-time in A and B sites all together. Second, the visualization analysis results of digital cartographic map using TIN and GRID-based terrain modeling techniqus similar exacts A and B sites, but the terrain modeling techniqus by TIN-based are small data size than GRID-based with the data with the data size of saving with DXF files. Third, making digital catographic map using terrain modeling techniques by Grid-based, the standard errors of low-densed randomly located point data and interpolated data using gridding method have more good results by radial basis function interpolation techniques at A and B sites all together.

• Geophysics and Geophysical Exploration
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• v.27 no.1
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• pp.37-50
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• 2024

The magnetotelluric (MT) survey can be affected by external environmental factors. In particular, when acquiring MT data in islands, it is essential to consider the combined effect of topography and sea to understand the results and make accurate interpretations. To analyze the MT response (apparent resistivity, phase) with consideration of the effect of topography and sea, a small cone-shaped island model surrounded by deep sea was created. Two-dimensional (2-D) and three-dimensional (3-D) forward modeling were performed on the terrain model considering topography and the island model considering both topography and sea. The 2-D MT response did not reflect the topographic and sea effect of the direction orthogonal to the 2-D profile. The 3-D MT response included topographic and sea effects in all directions. The XY and YX components of the apparent resistivity were separated on undulating topography, such as a hill. A conductor at 1 km below sea level could be distinguished from topographic and sea effects in the MT response, and low resistivity anomaly was attenuated at greater depths. This study will facilitate understanding of field data measured on small islands.

• Journal of the Korean Geophysical Society
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• v.9 no.4
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• pp.371-376
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• 2006

Digital high resolution cameras are widely available, and are increasingly use in digital close-range photogrammetry. And photogrammetry instruments are developing rapidly and the precision is improving continuously. The building of 3D terrains of high precision are possible and the calculation of the areas or the earthwork volumes have high precision due to the development of the technique of the spatial information system using computer. Using the digital camera which has capacity of keeping numerical value by itself and easy carrying, we analyze the positioning error according to various change of photographing condition. Also we try to find a effective method of acquiring basis data for 3D modeling of high-accuracy in pixel degree through digital close-range photogrammetry with bundle adjustment for digital elevation model generation.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.04a
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• pp.550-555
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• 2003

최근에 Lidar 데이터를 이용한 3차원 위치 정보와 지표면 속성 정보를 취득하는 연구가 많이 진행되고 있다. 높은 위치 정확도, 3차원 데이터 동시 취득, 기존 측정 방식에 비하여 점 데이터 취득의 자동화, 데이터 정확도의 안정성 등으로 인하여 복잡한 지형 및 인공구조물이 존재하는 지역에서 Lidar 데이터의 응용 사례가 많이 나타나고 있으며, 특히 건물 모델링에서 반자동 방식의 디지털 사진측량에 비하여 자동 모델링의 가능성을 보여주고 있다. 일반적으로 Lidar 데이터의 점밀도는 1점/㎡이내이며, 촬영된 스트립을 중복시켜 점밀도를 높이기도 한다. 건물은 크기와 형태가 다양하기 때문에 모델링에 필요한 점밀도를 제시하기는 어렵지만 5점 내외에서 모델링이 가능하다고 알려져 있으며 건물이외에 다른 지형지물에 대한 모델링 연구는 거의 이루어지지 않고 있다. 따라서 본 논문에서는 Lidar 데이터의 점밀도에 따라 지물의 모델링 가능성을 평가하고 효율적인 데이터 취득 방안을 제시하고자 한다.