• Journal of the Korean Association of Geographic Information Studies
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• v.1 no.1
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• pp.3-7
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• 1998

The issue of data accuracy brings a different perspective to the issue of GIS modeling, calls into a question the usefulness of data models such as DEM. Accuracy can be determined by randomly checking positional and attribute accuracy within a GIS data layer. With the increasing availability of DEM and the software capable of processing them, it is worthwhile to call attention for data accuracy and error analysis as GIS application depends on the priori established spatial data. The purpose of this paper was to investigate methods for data accuracy measurement and error detection methodology with two types of DEM's: 1 to 24,000 and 1 to 250,000 DEM released by U.S. Geological Survey. Another emphasis was given to the development of methodology for processing DEM's to create Arc/Info and GRASS layers. Data accuracy analysis with DEM was applied to a 250 sq.km area and an error was detected at a scale of 1:24,000 DEM. There were two possible reasons for this error: gross errors and blunders.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.6
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• pp.363-369
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• 2021

High-definition road maps are used as the basic infrastructure for autonomous vehicles, so the latest road information must be quickly reflected. However, the current drawing and structural editing process of high-definition road maps are manually performed. In addition, it takes the longest time to generate road lanes, which are the main construction targets. In this study, the point cloud of the road lane markings, in which color types(white, blue, and yellow) were predicted through the PointNet model pre-trained in previous studies, were used as input data. Based on the point cloud, this study proposed a methodology for automatically drawing and structural editing of the layer of road lane markings. To verify the usability of the 3D vector data constructed through the proposed methodology, the accuracy was analyzed according to the quality inspection criteria of high-definition road maps. In the positional accuracy test of the vector data, the RMSE (Root Mean Square Error) for horizontal and vertical errors were within 0.1m to verify suitability. In the structural editing accuracy test of the vector data, the structural editing accuracy of the road lane markings type and kind were 88.235%, respectively, and the usability was verified. Therefore, it was found that the methodology proposed in this study can efficiently construct vector data of road lanes for high-definition road maps.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.200-215
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• 2023

With the rapid advance of autonomous driving technology, the related vehicle market is experiencing explosive growth, and it is anticipated that the era of fully autonomous vehicles will arrive in the near future. However, along with the development of autonomous driving technology, questions regarding its safety and reliability continue to be raised. Concerns among technology adopters are increasing due to media reports of accidents involving autonomous vehicles. To promote the improvement of the safety of autonomous vehicles, it is essential to analyze previous accident cases and identify their causes. Therefore, in this study, we aimed to analyze the factors influencing the severity of autonomous vehicle accidents using previous accident cases and related data. The data used for this research primarily comprised autonomous vehicle accident reports collected and distributed by the California Department of Motor Vehicles (CA DMV). Spatial information on accident locations and additional traffic data were also collected and utilized. Given that the primary data used in this study were accident reports, a Poisson regression analysis was conducted to model the expected number of accidents. The research results indicated that the severity of autonomous vehicle accidents increases in areas with low lighting, the presence of bicycle or bus-exclusive lanes, and a history of pedestrian and bicycle accidents. These findings are expected to serve as foundational data for the development of algorithms to enhance the safety of autonomous vehicles and promote the installation of related transportation infrastructure.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.2
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• pp.165-173
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• 2008

This study aims at generating automatically three dimensional geometric models of roads using LIDAR data and a digital map. The main processes in the proposed method are (1) generating a polygon encompassing a road region using a road layer from the digital map, (2) extracting LIDAR points within the road region using the polygon, (3) organizing the points into surface patches and grouping the patches into surface clusters, (4) searching the road surface clusters and generating the surface model from the points linked to the clusters, (5) refining the boundary using a digital map. By applying the proposed method to real data, we successfully generated the linear and surface information of the roads.

• Journal of the Korean Society for Library and Information Science
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• v.41 no.1
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• pp.185-214
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• 2007

This study intends to design the bibliographic framework based on IFLA-FRBR model for television program materials and to evaluate this in terms of effectiveness of retrieval and usability of the system. The FRBR model supplies mote suitable bibliographic framework of audio-visual material which has a sufficient hierarchical relations and relative bibliographical records. The followings are research methods designed by this study; (1) The experimental metadata system named it FbCS based on FRBR was developed by using the entity-related database and composed of multi-layed and hierarchy. FbCS is developed through benchmarking of a case study for iMMix model in Netherlands based on FRBR. (2) To evaluate effectiveness of retrieval and usability of FbCS, this study made a experiment and survey by user groups of professionals.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.81-89
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• 2017

Autofocus(AF) Method is essential to overcome the performance degradation due to motion measurement errors under airborne SAR environment. In this paper, back-projection algorithm(BPA) is applied to SAR raw data acquired under the squinted mode, and preprocessing algorithm of AF for BPA is investigated. To apply AF to SAR image effectively, image backplane rotation method and doppler location alignment function for BPA are proposed. The proposed method is applied to SAR raw data acquired in a flight test and shows excellent performance improvement in real data.

• Proceedings of the Korea Water Resources Association Conference
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• 2021.06a
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• pp.484-484
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• 2021

본 연구를 통해 개발된 웹기반 가뭄아틀라스에 탑재되는 가뭄인벤토리 지도서비스 모듈은 GIS기반 가뭄상황관리를 위해 일정 수준의 가공이 필요한 다양한 GIS 가뭄분석정보를 제공하여 가뭄 대응 업무 담당자가 공간에 기반한 가뭄분석 업무에 사용함을 주목적으로 해당 서비스 모듈을 개발하였다. 본 연구를 통해 개발된 지도서비스 모듈은 JAVA 언어로 개발되었으며, 오픈소스 기반의 Geosever와 Openlayer를 적용하여 167개 시군을 대상으로 가뭄 관련 분석지도를 제공하는 서비스 모듈이다. 지도 레이어별 가시화를 통한 중첩분석이 가능하며, 사용자 필요 시 해당 분석지도를 다운로드 받을 수 있도록 개발을 진행하였다. 상세 제공 정보로는 가뭄 분석을 위한 면적정보와 통계정보로 이원화하여 서비스를 제공하며, 개별 가뭄인벤토리 지도는 지역별 차트정보와 속성DB 테이블을 같이 지도화면에 표출한다. 주요기능으로는 가뭄인벤토리 지도서비스 창을 활성화하여 사용자가 필요한 가뭄인벤토리 지도를 체크하면 가뭄아틀라스 지도화면에 가시화된다. 체크된 가뭄인벤토리 지도는 테이블정보 표출과 자료 다운로드 기능을 제공한다. 해당 서비스 모듈의 관리 및 사용 방법으로는 가뭄인벤토리 지도데이터를 GIS 데이터셋화하여 Geoserver에 로딩하며, 로딩된 지도데이터는 WMS(web tilemap service) 포맷으로 변환한 뒤, 각각의 분석지도가 가지고 있는 속성DB정보를 고려해 지도 스타일을 적용하였다. 웹 브라우저 표출방법으로는 Openlayer 기반으로 GeoWebCache를 생성해 가뭄인벤토리 지도를 웹기반 가뭄아틀라스 상에 표출한다.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.3
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• pp.311-320
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• 2008

A LIDAR can rapidly generate 3D points by densely sampling the surfaces of targets using laser pulses, which has been efficiently utilized to reconstruct 3D models of the targets automatically. Due to this advantage, LIDARs are increasingly applied to the fields of Defense and Security, for examples, being employed to intelligently guided missiles and manned/unmanned reconnaissance planes. For the prior verification of the LIDAR applicability, this study aims at generating simulated LIDAR data. Here, we derived the sensor equation by modelling the geometric relationships between the LIDAR sub-modules, such as GPS, IMU, LS and the systematic errors associated with them. Based on this equation, we developed a program to generate simulated data with the system parameters, the systematic errors, the flight trajectories and attitudes, and the reference terrain model given. This program had been applied to generating simulated LIDAR data for urban areas. By analyzing these simulated data, we verified the accuracy and usefulness of the simulation. The simulator developed in this study will provide economically various test data required for the development of application algorithms and contribute to the optimal establishment of the flight and system parameters.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.4
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• pp.131-139
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• 2010

Recent spread of GIS and the increasing demand of spatial data have brought about the development of web GIS. In addition to sharing and mapping spatial data, web GIS is also required to provide spatial analytic functions on the web. The FOSS(free and open source software) can play an important role in developing such a system for web GIS. In this paper, we proposed a web-based system for raster data analysis using map algebra. We employed GRASS as an open source software and implemented the GRASS functionalities on the web using java methods for invocation of server-side commands. Map algebra and AHP were combined for the raster data analysis in our system. For a feasibility test, the landslide susceptibility in South Korea was calculated using rainfall, elevation, slope angle, slope aspect, and soil layers. It is anticipated that our system will be extensible to other web GIS for raster data analysis with GRASS.

• Journal of the Korean Association of Geographic Information Studies
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• v.12 no.1
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• pp.1-11
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• 2009

Rapid visualization of flood area of downstream according to the dam effluent in flood season is very important in dam management works. Overlay zone of river bight should be removed to represent flood area efficiently based on flood stage which was modeled in river channels. This study applied drainage enforcement algorithm to visualize flood area considering river bight by coupling Coordinate Operation System for Flood control In Multi-reservoir (COSFIM) and Flood Wave routing model (FLDWAV). The drainage enforcement algorithm is a kind of interpolation which gives to advantage into hydrological process studies by removing spurious sinks of terrain in automatic drainage algorithm. This study presented mapping technique of flood area layer considering river bight in Namgang-Dam downstream, and developed system based on Arcobject component to execute this process automatically. Automatic extraction system of flood area layer could save time-consuming efficiently in flood inundation visualization work which was propelled based on large volume data. Also, flood area layer by coupling with IKONOS satellite image presented real information in flood disaster works.