• Journal of Korean Society for Geospatial Information Science
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• v.17 no.3
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• pp.13-21
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• 2009

Digital map should have the up-to-dateness as well as the accuracy to perform a role as the national spatial data. As digital mapping process require aerial photograph, surveying, and field working, it consumes a lot of time and cost. So there is a limit to maintain the up-to-dateness. If we updates the digital map frequently by using the as-built drawings, we can prevent the waste of national budget by reuse of existing drawings and make accuracy updates from existing survey results. In spite of this advantages, due to insufficiency of CAD drawing standard, inconsistency of file types of as-built drawings and digital maps, and topology relations between input features and original features, so the frequent updates using the as-built drawings is on the difficult situation to perform. In this research, first, CAD features extracted from as-built drawings land the new/update whether original features exist or not and generate topology from spatial relation of features. Second, suggest the efficient partial-update-plan performing integrity test. As a result, guarantee the accuracy and the up-to-dateness of digital map.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.33 no.5
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• pp.397-405
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• 2015

Currently, Korea's digital maps are being produced through traditional aerial photogrammetry methods. Aerial photogrammetry is the most economical way to produce a map of a wide area. However, timely survey is not allowed depends on weather condition and it is inefficient for small area surveying in economic point of view. Therefore, it costs too much and needs long time to produce a map for various small areas where are terrestrial changes for updating the map. In contrast, UAV photogrammetry is possible to work even in cloudy weather because of shooting at low altitude below the clouds. It also has excellent mobility and shoot quickly and well suited for small-scale mapping in several places by low cost. In this study, we produced an ortho-photo and digital map with the UAV photogrammetry method using SIFT and SfM algorithm and verified its accuracy to evaluate the applicability for future digital map updates. The accuracy was verified by comparing the results of the ground survey for check points selected on the digital map. Test results show small errors at ±2.6cm in X coordinates, ±2.8cm in Y coordinates and ±5.8cm in height and we could find a possibility that UAV photogrammetry would be fully applicable for digital map updating.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.4
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• pp.3-11
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• 2014

Recently, rapid urbanization has necessitated continuous updates in digital map to provide the latest and accurate information for users. However, conventional aerial photogrammetry has some restrictions on periodic updates of small areas due to high cost, and as-built drawing also brings some problems with maintaining quality. Alternatively, this paper proposes a scheme for efficient and accurate update of digital map using point cloud data acquired by Terrestrial Laser Scanner (TLS). Initially, from the whole point cloud data, the building sides are extracted and projected onto a 2D image to trace out the 2D building footprints. In order to register the footprint extractions on the digital map, 2D Affine model is used. For Affine parameter estimation, the centroids of each footprint groups are randomly chosen and matched by means of a modified RANSAC algorithm. Based on proposed algorithm, the experimental results showed that it is possible to renew digital map using building footprint extracted from TLS data.

• Journal of Korea Multimedia Society
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• v.25 no.8
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• pp.1007-1021
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• 2022

Autonomous driving of unmanned aerial vehicles may have to pay expensive cost to create and switch new routes if unexpected obstacles exist or local map updates occured by the control system due to incorrect route information. Integrating digital twins into the path-following process requires more computing resources to quickly switch the wrong path to an alternative path, but it can quickly update the path during flight. In this study, we design a DEVS-based simulation environment which can modify optimized paths through short-term simulation of multi-virtual UAVs for applying digital twin concepts to path follow. Through simulation, we confirmed the possibility of increasing the mission stability of UAV.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.13-27
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• 1997

For the National Geo-Spatial Information System the development of the National Digital Basemap database is actively underway in Korea. For the National Digital Basemap database to be truly useful for various applications development it is essential to maintain its reliability. To maintain the reliability of the database it is necessary to understand the nature and the frequency of the errors in it. In general, a data inspection under the standardized quality control process is required to maintain the quality of a large database. In addition, it is important to maintain complete and detailed records of the inspection results so as to understand the relationship between the m and other factors causing errors. These records can be used as a reference for map updates and future application development. The goal of this study is to count the frequency of errors based on the typology of errors found in the digitized map inspection process and to analyze the correlation between errors and topographic composite quotient This study also provides guidelines for the inspection process regarding the error-prone cartographic elements in the digital map generation process.

• Journal of Korea Spatial Information System Society
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• v.10 no.4
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• pp.37-45
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• 2008

Increased demand for the latest spatial information, it is necessary to study the complement current map updating systems for responding the diverse environment of the national territory information. This study suggests the way to update 1/5,000 digital maps with the application of as-built drawings based on current systems. This study compares current as-built drawings with digital maps, and consider intra and international related cases and regulations. This study also selects case areas based on different types of as-built drawings and updates digital maps with the application of as-built drawings. After the consideration of systems and regulations related to as-built drawings, the research results, including the improvement and the application of as-built drawings, are presented. It is expected that the foundation to provide more rapid and accurate geographic information can be achieved from the research result.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.32 no.1
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• pp.29-38
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• 2014

UAV(Unmanned Aerial vehicle) could be effectively applied in a field of land monitoring for analyzing disaster area and mapping, because it can quickly acquire image data at low costs. For this reason, we reviewed the legal system related to mapping, and proposed suggestions for improving in legal system, due to introducing the UAV to Korean land-monitoring through this paper. Also, we evaluated spatial and time accuracy of the digital map, which are generated from UAV images that were taken for occasional map updates and disaster detections. As a result, the mean error is about 10m if only GPS/INS data used, while using GCP(Ground Control Points) it is about 10cm. Therefore, we conclude that the UAV could be effective method in korea land-monitoring field.

• Journal of Korean Society for Geospatial Information Science
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• v.22 no.3
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• pp.3-10
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• 2014

Digital maps are made by experts who digitize the data from aerial image and field survey. And the digital maps are updated every 2 years in National Geographic Information Institute. Conventional Digitizing methods take a lot of time and cost. And geographic information needs to be modified and updated appropriately as geographical features are changing rapidly. Therefore in this paper, we modify the digital map updates the road information for rapid high-resolution aerial orthophoto taken at different times were performed HSI color conversion. Road area of the cassification was performed the region growing methods. In addition, changes in the target area for analysis by applying the CVA technique to compare the changed road area by analyzing the accuracy of the proposed extraction.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.3
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• pp.97-104
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• 2010

The important factors in a flood simulation are hydrologic data (such as the rainfall and intensity), a threedimensional terrain model, and the hydrologic inundation calculation matrix. Should any of these factors lack accuracy, flood prediction data becomes unreliable and imprecise. The three-dimensional terrain model is constructed based on existing digital maps, current map updates, and airborne LiDAR data. This research analyzes and offers ways to improve the model's accuracy by comparing flood weakness areas selected according to the existing data on flood locations and design frequency.

• Imaging Science in Dentistry
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• v.30 no.1
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• pp.55-62
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• 2000

Purpose: This study was performed to develop the electronic textbook (CD-rom title) about preclinical practice of oral and maxillofacial radiology, using multimedia technology with interactive environment. Materials and Methods: After comparing the three authoring methods of multimedia, i.e. programming language, multimedia authoring tool and web authoring tool, we determined the web authoring tool as an authoring method of our electronic textbook. Intel Pentium II 350 MHz IBM-compatible personal computer with 128 Megabyte RAM, Umax Powerlook flatbed scanner with transparency unit, Olympus Camedia l400L digital camera, ESS 1686 sound card, Sony 8 mm Handycam, PC Vision 97 pro capture board, Namo web editor 3.0, Photoshop 3.0, ThumbNailer, RealPlayer 7 basic and RealProducer G2 were used for creating the text document, diagram, figure, X-ray image, video and sound files. We made use of javascripts for tree menu structure, moving text bar, link button and spread list menu and image map etc. After creating all files and hyperlinking them, we burned out the CD-rom title with all of the above multimedia data, Netscape communicator and plug in program as a prototype. Results and Conclusions : We developed the dental radiology electronic textbook which has 9 chapters and consists of 155 text documents, 26 figures, 150 X-ray image files, 20 video files, 20 sound files and 50 questions with answers. We expect that this CD-rom title can be used at the intranet and internet environments and continuous updates will be performed easily.