• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.3
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• pp.116-131
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• 2014

In this study, sunshine environment in an urban area is analyzed using a numerical model which considers sunshine-duration blocking by topography and buildings. The numerical model used in this study has an improvement in the algorithm detecting sunshine duration in the model domain. The main improvement in the algorithm is to detect sunshine duration using all the surfaces of any grid cell(the previous model uses the center of any grid cell). The improvement in the algorithm gives more accurate evaluation of sunshine duration at corner surfaces of buildings. Using the improvement model and geographic information system(GIS) data, sunshine environment is analysed at an building-congested area in Busan for a week in four seasons. The results show that sunshine duration can be much changed by apartment complexes, high-rise buildings, topography in the model domain.

• Journal of Korean Society for Geospatial Information Science
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• v.18 no.1
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• pp.63-72
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• 2010

In this study, an earth work design program which will improve the efficiency of earth work and enable to carry out the design using 3D Geospace-based earth work modelling in design stage was developed. Estimate of accurate earth work volume is achievable using 3D grid DEM, and based on this, a mass calculation chart was developed for movement of earth and equipment. In consideration for the resources for various construction equipments needed for civil engineering works, soil conversion and the passage is displayed. In addition, the result is restored in the form of open API-based KLM to make it possible for the users to identify the progress of the construction, thereby enhancing the intuitive understanding of three-dimensional visualization and making it easier to share the result of the analysis.

• Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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• 2004.11a
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• pp.153-159
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• 2004

Recently remote sensing technology is applied for digital and photographical data acquisition by use of satellites sensors. And It used for images restoration of vanished spatial information at the same sites according to changed of time and spaces. In this study, it applied for the 3-dimensional images generation and fly simulation to possibility for various application. As a results of its applied, it gained the results not only improvement of present methods but also real various application possibilities for 3 dimensional Image restoration.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.21 no.2
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• pp.165-172
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• 2003

IKONOS satellite images are particularly well suited for stereo feature extraction. But, because IKONOS doesn't offer information about the satellite ephemeris and attitude, we have to use IKONOS RPC(Rational Polynomial Coefficients) data for 3-D feature extraction. In this study, it was intended to increase the accuracy and the efficiency in application of high resolution satellite images. Therefore, this study develop the program to extract 3-D feature information and have analyzed the geometric accuracy of the IKONOS satellite images by means of the change with the number, distribution and height of GCPs. This study will provide basic information for luther studies of the accuracy correction in IKONOS and high resolution satellite images.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.5
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• pp.1463-1476
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• 2014

In order to understand hydrodynamic and morphodynamic characteristics under wave-current interactions in an estuary, a coupled model for two-way analysis between existing 3-d numerical wave tank and newly-developed 3-d morphodynamic model has been suggested. Comparing to existing experimental results it is revealed that computed results of the newly-suggested model are in good agreement with each laboratory test result for wave height distribution, vertical flow profile and topographical change around ocean floor pipeline in wave-current coexisting field. Also the numerical result for suspended sediment concentration is verified in comparison with experimental result in solitary wave field. Finally, it is shown that the 3-D coupled Hydro-Morphodynamic model suggested in this study is applicable to morphological change under wave-current interaction in an estuary.

• Spatial Information Research
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• v.15 no.4
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• pp.363-370
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• 2007

This study has been carried for the development of the basic algorithm of helicopter navigation system based on TRN (Terrain Referenced Navigation) with information input from the GPS. The helicopter determines flight path due to Origination-Destination analysis on the Cartesian coordinate system of 3-D DTM. This system shows 3-D mesh map and the O-D flight path profile for the pilot's acknowledgement of the terrain, at first. The system builds TCF (terrain clearance floor) far the buffer zone upon the surface of ground relief to avid the ground collision. If the helicopter enters to the buffer zone during navigation, the real-time warning message which commands to raise the body pops up using Matlab menu. While departing or landing, control of the height of the body is possible. At present, the information (x, y, z coordinates) from the GPS is assumed to be input into the system every 92.8 m of horizontal distance while navigating along flight path. DTM of 3" interval has been adopted from that which was provided by ChumSungDae Co., Ltd..

• Journal of the Korean association of regional geographers
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• v.9 no.2
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• pp.203-216
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• 2003

The process of constructing coastal digital elevation model(DEM), for the 3 dimensional analysis, is composed by abstracting land layers for land elevation and water depth, reprojecting UTM, relocating geographical grid, and interpolating works. The geomorphic set of shallow sea, including tidal current, tidal zone deposition, and water depth distribution, was analyzed by eye search of Landsat TM image, masking of land zone, band combination and regression analysis. Some horizontal differences, between combined DEM and surveyed data of shallow sea, was corrected for analysis. Analyzed geomorphic elements are stream channel, alluvial fan, coastal terrace, tidal current. and shallow sea bank. Results of analysis present that transported fluvial materials influence tidal sedimentation, especially from Gahwacheon river, for the role of artificial draining flooding waters from Jinyang Reservoir, almost in the summer season. In the coastal area with less tidal current, more fine materials are deposited. The influence of currental deposition are higher on small pockets with west coast of well developed terraces. The lower skirt of alluvial fans developed into the tidal zone of shallow sea. Small pocket type bays are closed by coastal current, and less influenced from tidal deposition. The bank of Jinju Bay are developed originally from submerging of remnant erosional mountain ranges, and play on the role of trapping fine materials.

• 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.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.6
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• pp.591-598
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• 2008

Recently, the government has improvement projects of dangerous road for the site that has very high accident rate due to bad geometric structures of the road. Although, route selecting of the road is a basic and important process, but the process of route selecting must consider the technical, safety and environment factor together. Also, the technology for the 3-dimensional terrain model can be used as an important factor in planning and designing for selecting alternative route projects. In the course of experimenting with the 3-dimensional topography generated by the combination of the digital map and drawing of route, the technology as been developed to offer the multi-dimensional access to the potential construction sites from the nearby main roads. This 3-dimensional digital elevation model has made it possible to make various terrain analysis base on GIS, which provides real-time virtual access to the designated construction sites for development planning and construction projects. Therefore, this study presents a reasonable plan for route selecting from some alternative routes through subjective evaluation and classify the methods linked basic design of road construction.

• Journal of Korean Society for Geospatial Information Science
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• v.21 no.4
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• pp.135-142
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• 2013

This study aims to seek adequate and optimized method of applying high quality three-dimensional spatial data created via high-resolution digital aerial photograph image and aerial LiDAR data onto three-dimensional planning of environmentally friendly, ecological restoration of rivers in accordance with irrigation and flood control objectives of urban rivers. Through three-dimensional modeling of before and after the restoration, the research also offers basic information regarding restorations of rivers. Also the transition from the conventional two-dimensional planning into three-dimensional planning environment using smart spatial information acquire accuracy of river analysis, analyze possible civil complaints and suggest solutions to potential problems.