• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.2
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• pp.207-215
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• 2010

There are two methods to survey the natural cave. One is plane table surveying and the other is recording chart surveying. The drawing maps drawn by these methods are 2D. Furthermore, it is difficult to figure out the accurate dimension about full sections and whole interior products because of use of plane table and recording chart. Accordingly, in this study, the 3D spatial information about Dangcheomuldonggul was constructed by the Terrestrial LiDAR and high resolution digital camera where is belong to Jeju Volcanic Island and Lava Tubes as the first World Natural Heritage of the Republic of Korea. Also, the utilization possibility of 3D spatial information was suggested to the basic data of deformation and change detection through structure analysis, section analysis, shape analysis, and interior products analysis.

• Spatial Information Research
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• v.9 no.2
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• pp.325-340
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• 2001

This research is to construct more useful Geo-spatial data by building spatial data to three dimensional and utilize the database effectively for development of application, maintenance and management program, and application technology, which is on going based on “Haeundae three dimensional database construction project”. Furthermore, the acquisition of geographic information data and the technological improvement of effective construction would be the important factors to judge the qualitative reputation of GIS. Above all, studies to create accurate data and overcome the error limitation are much more important than any other thing. Final form of Spatial Data to materialize efficient GIS(Geographic Information System) must be three dimensional spatial data which has attribute data, actual concept and numerical value of real world. In connection to that, development is on the move to improve building technique of useful spatial data and digitalize the entire country in cryberspace. $\ulcorner the cyber country lrcorner$is designed to mange the entire country systematically. This simulation would be able to cover administration of government institution, public service, corporate business and even the public life in the cyeberspace though the computer. Materialization of efficient GIS and establishment of condition as technically strong nation through the early realization of $\ulcorner the cyber country lrcorner$will provide a great opportunity to open up the global market with exportation of advanced technology.

• Spatial Information Research
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• v.15 no.2
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• pp.95-109
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• 2007

Recently people have been offered location based services on road networks. The navigation system, one of applications, serves to find the nearest gas station or guide divers to the shortest path based 2D map. However 3D map is more important media than 2D map to make sense friendly for the real. Although 3D map's data size is huge, portable devices' storage space is small. In this paper, we define continuous perspective queries to support 3D map to mobile user on road networks and propose this queries processing method.

• Journal of Korean Society of Forest Science
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• v.88 no.3
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• pp.389-399
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• 1999

This study was conducted to develop an application software, SIDAS3D(Stand Inventory Data Analysis System for 3 Dimensional Representation), of which the purpose of development is to make it easier to analyze and display the 3D spatial structure of a forest stand, based on the data such as tree position, species, DBH, height, clear length of individual trees, and crown width. This program has a statistical analysis function for stand attributes per hectare and displays simple graphs of stand statistics such as the distribution of diameters, heights, and volumes. It also has two additional functions, of which one is to display the 3D image of stand structure and the other is to display the image of crown projection. In addition, this program provides an imaginary treatment simulation function, which can visually confirm the suitability of silvicultural treatments on computers. To test the precision and reliability of SIDAS3D, data obtained by the precision forest inventory method were used. Statistical analysis ability of SIDAS3D was compared with that of SAS. And its representational ability was compared with that of TreeDraw. According to the verification, SIDAS3D was superior to SAS and TreeDraw in both the data processing time and the interpretative ability of results. It was concluded that SIDAS3D could be used to help users efficiently make decisions for appropriate silvicultural treatments and rational management plans because it has analysis functions providing various valuable information.

• Journal of the Ergonomics Society of Korea
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• v.23 no.1
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• pp.13-22
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• 2004

Due to economical or technological reasons. humans are responsible for inspection functions in many cases. Humans. however. are rarely perfect. thus allowing non-confirming parts to be processed. As the attributes of interest or the variety of products increases. the inspection system becomes less effective because of the sensory and cognitive limitations of human inspectors. Any means that can support or aid the human inspectors is necessary to compensate for inspection difficulty. Augmented reality (AR) offers a new approach in designing an inspection system as a means to augment the cognitive capability of inspectors by providing the 3D spatial proximity between two information channels. The experimental results suggest that AR might be an effective tool that reduces inspection time without sacrificing the measuring accuracy.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.27 no.6
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• pp.741-747
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• 2009

For construction of 3D virtual city models, airborne digital cameras, laser scanners, multi-oblique photograph systems and other devices are currently being used. With such advanced techniques, precise 3D spatial information can be collected and high quality 3D city models can be built in a considerably large area. The 3D spatial information to be built has to provide the latest information that quickly reflects the causes of any change due to urban development. In this study, a UAV photogrammetric method using low cost UAV and digital camera was proposed to acquire and update 3D spatial information effectively on small areas where information continuously change. In the proposed UAV photogrammetric method, the elements of interior orientation were acquired through camera calibration and the vertical and oblique photographs were taken at 9 points and the 3D drawing of ground control points and buildings was performed using 20 images among the pictured images. This study also analyzed the accuracy of the proposed method comparing with ground survey data and digital map in order to examine whether the method can be used in on-demand 3D spatial information update on relatively small areas.

• Journal of Korea Spatial Information System Society
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• v.11 no.1
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• pp.63-70
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• 2009

3D GIS(Geographic Information System) processes, analyzes and presents various real-world 3D phenomena by building 3D spatial information of real-world terrain, facilities, etc., and working with visualization technique such as VR(Virtual Reality). It can be applied to such areas as urban management system, traffic information system, environment management system, disaster management system, ocean management system, etc,. In this paper, we propose video visualization technology based on 3D geographic information to provide effectively real-time information in 3D geographic information system and also present methods for establishing 3D building information data. The proposed video visualization system can provide real-time video information based on 3D geographic information by projecting real-time video stream from network video camera onto 3D geographic objects and applying texture-mapping of video frames onto terrain, facilities, etc.. In this paper, we developed sem i-automatic DBM(Digital Building Model) building technique using both aerial im age and LiDAR data for 3D Projective Texture Mapping. 3D geographic information system currently provide static visualization information and the proposed method can replace previous static visualization information with real video information. The proposed method can be used in location-based decision-making system by providing real-time visualization information, and moreover, it can be used to provide intelligent context-aware service based on geographic information.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.427-439
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• 2019

Purpose: We generated geospatial information of unmanned aerial vehicle based on various SW and analyzed the location accuracy of orthoimage and DSM and texture mapping of 3D mesh. Method: The same unmanned aerial image data is processed using two different SW, and spatial information is generated. Among the generated spatial information, the orthoimage and DSM were compared with the spatial information generation results of the unmanned aerial photogrammetry SW by performing quantitative analysis by calculating RMSE of horizontal position and vertical position error and performing qualitative analysis. Results: There were no significant differences in the positional accuracy of the orthoimage and DSM generated by each SW, and differences in texture mapping in 3D mesh. The creation of the 3D mesh indicated the impact of the Unmanned Aerial Photogrammetry SW. Conclusion: It is shown that there is no effect of SW on the creation of orthoimage and DSM for geospatial analysis based on unmanned aerial vehicle. However, when 3D visualization is performed, texture mapping results are different depending on SW.

• Current Optics and Photonics
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• v.5 no.4
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• pp.409-420
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• 2021

We propose a method to synthesize a color non-hogel-based computer-generated-hologram (CGH) from light field data of a three-dimensional scene with a hologram pixel pitch shared for all color channels. The non-hogel-based CGH technique generates a continuous wavefront with arbitrary carrier wave from given light field data by interpreting the ray angle in the light field to the spatial frequency of the plane wavefront. The relation between ray angle and spatial frequency is, however, dependent on the wavelength, which leads to different spatial frequency sampling grid in the light field data, resulting in color aberrations in the hologram reconstruction. The proposed method sets a hologram pixel pitch common to all color channels such that the smallest blue diffraction angle covers the field of view of the light field. Then a spatial frequency sampling grid common to all color channels is established by interpolating the light field with the spatial frequency range of the blue wavelength and the sampling interval of the red wavelength. The common hologram pixel pitch and light field spatial frequency sampling grid ensure the synthesis of a color hologram without any color aberrations in the hologram reconstructions, or any loss of information contained in the light field. The proposed method is successfully verified using color light field data of various test or natural 3D scenes.

• Journal of the Korean housing association
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• v.12 no.3
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• pp.85-95
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• 2001

This study was conducted to develop the Apartment Information System. This integrated information system is designed to provide a large number of users with the convenient, economical, and safe life in the apartment complex. The characteristics of this system are as follows; 1) The system was developed by CAD technology using 2D and 3D methods with Web base. 2) This system has 2-Tire structures which are able to embody the geographic information on the Web base without special Spatial Engine. 3) Since the spatial data applied to this system is a vector file format, the speed of electrical transmission is fast and it makes possible to search spatially for the client method. The results of this study may contribute to make use of the information system for apartment complex as follows; 1) This system can be used together by the communities of apartment residence, maintenance company and construction company. 2) Also this system can help residence to communicate sharing information and can support the apartment management with open information and clarity. Expecially, the practical data gathering was made for this study only.