• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.1
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• pp.19-30
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• 2007

Modeling 3D buildings is an essential process to revive the real world into a computer. There are two ways to create a 3D building model. The first method is to use the building layer of 1:1000 digital maps based on high density point data gained from airborne laser surveying. The second method is to use LiDAR point data with digital images achieved with LiDAR. In this research we tested one sheet area of 1:1000 digital map with both methods to process a 3D building model. We have developed a process, analyzed quantitatively and evaluated the efficiency, accuracy, and reality. The resulted differed depending on the buildings shape. The first method was effective on simple buildings, and the second method was effective on complicated buildings. Also, we evaluated the accuracy of the produced model. Comparing the 3D building based on LiDAR data and digital image with digital maps, the horizontal accuracy was within ${\pm}50cm$. From the above we derived a conclusion that 3D building modeling is more effective when it is based on LiDAR data and digital maps. Using produced 3D building modeling data, we will be utilized as digital contents in various fields like 3D GIS, U-City, telematics, navigation, virtual reality and games etc.

• Journal of the HCI Society of Korea
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• v.1 no.2
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• pp.51-58
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• 2006

Information visualization, generally speaking, consists of three steps: transform from raw data to data model, visual mapping from data model to visual structure, and transform from visual structure to information model. In this paper, we propose a visual mapping method from spatiotemporal table information, which is related to events in large-scale building, to 3D map metaphor. The process has also three steps as follows. First, after analyzing the table attributes, we carefully define a context to fully represent the table-information. Second, we choose meaningful attribute sets from the context. Third, each meaningful attribute set is mapped to one well defined visual structure. Our method has several advantages. First, users can intuitively achieve non-spatial information through the 3D map which is a powerful spatial metaphor. Second, this system shows various visual mapping method applicable to other data models in the form of table, especially GIS. After describing the whole concept of our visual mapping, we will show the results of implementation for several requests.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.723-731
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• 2009

Recently, it has been strangely increasing rainfall and rainfall meter by global warming. so flood damage is being increase. It has happened there are so many damaged by influence by backwater of dam. However, the alleviative solutions of flood damages are focused on the lower river basin where the density of population is higher than upper river basin. This research proceeds based on design and build 3D topography model and reflects the topographical factors of upper river basin. It also simulated the circumstances of flooding by investigation of factors of outflow, hence, as a result, we would find out the vulnerable area for flooding and scale of damages effectively. This research suggests the solution and method of flooding for vulnerable area of the flooding to reduce the damages by predicting flooding. Thus, the suggestion may support to make a decision efficiently to prevent the damage of flooding.

• Proceedings of the KSRS Conference
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• v.1
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• pp.417-420
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• 2006

In these days, mobile application dealing with information contents on mobile or handheld devices such as mobile communicator, PDA or WAP device face the most important industrial needs. The motivation of this study is the design and implementation of mobile application using high resolution satellite imagery, large-sized image data set. Although major advantages of mobile devices are portability and mobility to users, limited system resources such as small-sized memory, slow CPU, low power and small screen size are the main obstacles to developers who should handle a large volume of geo-based 3D model. Related to this, the previous works have been concentrated on GIS-based location awareness services on mobile; however, the mobile 3D terrain model, which aims at this study, with the source data of DEM (Digital Elevation Model) and high resolution satellite imagery is not considered yet, in the other mobile systems. The main functions of 3D graphic processing or pixel pipeline in this prototype are implemented with OpenGL|ES (Embedded System) standard API (Application Programming Interface) released by Khronos group. In the developing stage, experiments to investigate optimal operation environment and good performance are carried out: TIN-based vertex generation with regular elevation data, image tiling, and image-vertex texturing, text processing of Unicode type and ASCII type.

• Spatial Information Research
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• v.16 no.4
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• pp.441-453
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• 2008

With the rapid progress of location based services, GIS, and ubiquitous computing technologies, the space that we are dealing with is no longer limited to outdoor space but being extended to indoor space. Indoor space has some differences from outdoor space, therefore to provide integrated spaces and seamless services, it is required to establish new theories, data models, and systems. For this reason, ambitious project has been launched last year to establish a theoretical background, develop a core technologies and systems, and provide services of indoor spatial awareness. In this paper, we present an overall sketch on the project and major research topics. First, we present the ISA (indoor spatial awareness) project with its goal and research topics. Second, a simplified 3D spatial model, called prism model, is proposed as a basic data types and operators of indoor spatial DBMS. Third, a indoor feature data model, developed T. Kolbe et al. who is a member of this project team, is introduced in this paper. This model provides a basis for the integration of different spaces.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.31-37
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• 2004

GIS 분야에서 다루는 공간 데이터는 대부분 2차원의 데이터이다. 현실 공간에 존재하는 3차원 객체의 2차원 정보만을 취하거나 혹은 2차원 공간으로 투영하는 등의 방법으로 데이터를 저장한다. 이러한 방법은 정보의 손실로 인한 데이터 활용범위가 축소되고, 현실 공간을 정확하게 반영하지 못하는 문제가 있다. 최근 3차원 공간 데이터를 저장, 관리 가능한 DBMS가 개발되고, 3차원 데이터에 대한 관심과 요구가 높아가고 있다. 하지만 3차원 데이터를 단순 저장만 가능할 뿐 공간 연산에 대한 연구가 미흡한 실정이다. 본 연구에서는 3차원 공간 모델을 이용하여 공간 데이터베이스 표준에서 정의하고 있는 공간 관계 연산을 설계하였다. 공간 데이터 모델로는 OGC에서 제시한 GML3에서 정의하는 모델을 사용하였고, 공간 관계 연산에 대한 설계 도구로는 공간 관계를 연산하는데 가장 좋은 방법으로 알려진 DE-9IM을 이용하였다.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.11 s.176
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• pp.104-110
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• 2005

GIS(Gas Insulated Switchgear) is used in electric power system, to insure non conductivity, breaking capacity and operating reliability. The commercial dynamic analysis code COSMOS MOTION and 3-D modeling program SOLID WORKS were used to simulate dynamic analysis of the closing resistors of the GIS in this paper. To reduce chatter vibration of closing resistors, the motion of moving and fixed parts of closing resistors were simulated by varying the spring constant, the damping coefficient and the mass of moving and fixed parts. The simulated results were compared with experimental results. As a result, chatter vibration of closing resistors of the GIS could be reduced by using the results. These data can be used to determine the spring constant, the damping coefficient and mass of a moving part to reduce chatter vibration when the next model is developed.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.10a
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• pp.13-18
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• 2004

In this study, a new method is proposed generating 3D wire-frames of building using the lowest level topology, points, which are input by human operators. Through the procedure, it is possible to make prediction occlusion points and generate the topology automatically among points, lines, surfaces from buildings. In order to adjust the error of initial values which are input manually, the least squares adjustment for model-image fitting is carried out using the edge information of aerial imagery. And also, model fitting procedure is done making all surfaces plane of buildings by the least squares adjustment. As a result of those procedure, 3D building models are refined similar to real figures of buildings.

• Proceedings of the Korea Water Resources Association Conference
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• 2007.05a
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• pp.1125-1129
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• 2007

본 연구는 하천에 대한 효율적 관리를 위하여 하천계획, 설계, 관리 등 하천업무에 필요한 3차원하천정보 기본계획을 바탕으로 GIS, RS 등의 신기술을 접목함으로써 현장에 방문하는 것과 유사한 하천현황을 한눈에 파악할 수 있는 3차원 하천지형정보시스템을 안양천 32.5km 구간을 시범적으로 구축하였다. 구축된 시범시스템을 통해 다양한 속성 및 대장정보의 제공이 가능하고 사실적인 하천현장의 3차원 구현으로 신속하고 효율적인 정보 획득이 용이하다. 이는 지속적이고 체계적인 하천정보의 활용을 극대화할 수 있을 뿐만 아니라 다양한 하천관리업무 및 중요한 의사결정에 이바지할 수 있을 것으로 사료된다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.38 no.2
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• pp.141-151
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• 2020

Since it was first studied in 1980, solar energy analysis model for geographic information systems has been used to determine the approximate spatial distribution of terrain. However, the spatial pattern was not able to be grasped in 3D (three-dimensional) space with low accuracy due to the limitation of input data. Because of computational efficiency, using a constant value for the brightness of the sky caused the simulation results to be less reliable especially when the slope is high or buildings are crowded around. For the above reasons, this study proposed a model that predicts solar energy of vertical surfaces of buildings with four stages below. Firstly, CIE (Commission Internationale de l'Eclairage) luminance distribution model was used to calculate the brightness distribution of the sky using NREL (National Renewable Energy Laboratory) solar tracking algorithm. Secondly, we suggested a method of calculating the shadow effect using ray tracing. Thirdly, LOD (Level of Detail) 3 of 3D spatial data was used as input data for analysis. Lastly, the accuracy was evaluated based on the atmospheric radiation data collected through the ground observation equipment in Daejeon, South Korea. As a result of evaluating the accuracy, NMBE was 5.14%, RMSE 11.12, and CVRMSE 7.09%.