• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.179-182
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• 2008

This study simulated the flood inundations of the Nakdong River catchment running through Yangsan, a small city located in the south eastern area of Korea by using the depth averaged two-dimensional hydrodynamic numerical model. The numerical model employs the staggered grid system including moving boundary and a finite different method to solve the Saint-Venant equations. A second order upwind scheme is used to discretize the nonlinear convection terms of the momentum equations, whereas linear terms are discretized by a first order leap-frog scheme(Cho and Yoon, 1998). The numerical model was applied to a real topography to simulate the flood inundation of the Yangsan basin. The numerical results for urban district are visualized in three dimension. These results can be essentially utilized to construct the three dimensional inundation map after building the GIS-based database in local public organizations in order to protect the life and property safely.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.35 no.6
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• pp.609-616
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• 2017

National Geographic Information Institute has established a plan that preoccupies UCPs (Unified Control Points) at 2~3km intervals in urban areas by considering the distance between existing UCPs by satellite images and aerial photographs in 2015. In this study, we discussed the method of selecting the locations of optimal UCPs by simulating GPS reception environment in candidate sites for UCPs using GIS. For this purpose, we selected new candidate sites for installing UCPs using satellite images and aerial photographs, and analyzed the GPS reception environment by calculating the visibility distance from buildings around UCPs using GIS skyline analysis. The number of and the arrangement of visible satellites that are capable of GPS satellite reception from the viewpoint of sky view were showed by GIS skyline analysis. Quality evaluation results of GPS observation data were compared with average PDOP calculated from hourly PDOP and TEQC in two points of Sungkyunkwan University during 8 hours. As a result of GPS reception environment using GIS, if the PDOP increases, the data acquisition rate is lowed, and the multipath error and the cycle slip are increased. Thus, this study verified that the quality of GPS observation data can be secured by constructing three-dimensional spatial information and simulating PDOP when preoccupying multiple UCPs using GIS.

• 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 the Korean Association of Geographic Information Studies
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• v.8 no.2
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• pp.55-67
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• 2005

This study presented the route location method by applying AHP and evaluating quantitatively. This study developed the program that can be easily applied to this kind of road design, and built the decision support system for route location. The study results are summarized as follows ; We could quantitatively evaluate the appropriateness of exiting routes by applying the AHP based on GIS. If we apply this to the roads that will be newly constructed, we can make the objective and reliable route location when making road plans and basic designs. We improved the technique of route location by applying the decision support system with third-dimensional data, which considers even the vertical alignment plan, to the existing decision support system with second-dimensional data. And, since we can set those data such as vertical slope, earth-volume, structure size, location and construction cost to independent variables, we can make road designs more scientifically and reasonably.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.117-128
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• 2005

This study presented the route location method by applying AHP and evaluating quantitatively. This study developed the program that can be easily applied to this kind of road design, and built the decision support system fur route location. The study results are summarized as follows : We could quantitatively evaluate the appropriateness of exiting routes by applying the AHP based on GIS. If we apply this to the roads that will be newly constructed, we can make the objective and reliable route location when making road plans and basic designs. We improved the technique of route location by applying the decision support system with third-dimensional data, which considers even the vertical alignment plan, to the existing decision support system with second-dimensional data. had, since we call set those data such as vertical slope, earth-volume, structure size, location and construction cost to independent variables, we can make road designs more scientifically and reasonably.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.25 no.2
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• pp.99-105
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• 2007

This research is about applying aerial photos to three-dimensional simulation of road design. Instead of existing road design approach using digital map, which inexactly represent some part of topography and landmarks, digital aerial photos are applied to three-dimensional road design to address such inexactness of the map. First of all, ortho-photos are made using aerial photos, and a digital elevation model is created by extracting DEM. Then, by applying the coordinates practically using in planar design to three-dimensional approach, this model will be much helpful in the analyses of road route and viewscape. In addition, through the use of Virtual GIS, many evaluation factors such as urban design, flora, soil, water channel or road shape, flood plan are used for examination, and the effectiveness of applying three-dimensional simulation based on such route design standard is to be reviewed. In this paper, a basic research about three-dimensional design of structures is performed, and through the three-dimensional design, some effective determination to decision-making was carried out. Hereafter, it appears some research regarding environment-friendly construction and design should be followed.

• Spatial Information Research
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• v.19 no.1
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• pp.93-105
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• 2011

In recent years, large and complex three-dimensional building has been constructed by the development of building technology and advanced IT skills, and people have lived there and spent a considerable time so far. Accordingly. in this sophisticatcd three-dimensional space, emergencies services or convenient information services have been in demand. In order to provide these services efficiently, understanding of topological relationships among the complex space should be supported naturally. Not on1y each method of understanding the topological relationships but also its efficiency can be different depending on different topological data models. B-rep based data model is the most widely used for storaging and representing of topological relationships. And from early 2000s, many researches on a network based topological data model have been conducted. The purpose of this study is to verify the efficiency of performance on spatial queries. As a result, Network-based topological data model is more efficient than B-rep based data model for determining the spatial relationship.

• Journal of Korean Society for Geospatial Information Science
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• v.24 no.3
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• pp.67-73
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• 2016

The present study evaluated the blocking effect of natural and artificial topography on sunshine duration in the southern coastal area of Haui-do. The geospatial data for the target area was constructed by geographic information system(GIS) data. Three-dimensional modeling based on solar azimuth and altitude angles was conducted for the assessment of sunshine environment. The sunshine area was evaluated over 80~90% of the target area in the daytime, especially in summer. The blocking effect of mountainous terrain on sunshine duration was presented at the northern residential area in the late afternoon. There was also the effect of artificial topography by construction of fill-up bank on sunshine environment at the southern residential area early in the morning and the south-western part of salt field in the late afternoon.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.28 no.3
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• pp.385-392
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• 2010

A LiDAR technique has the merits that survey engineers can get a large number of measurements with high precision quickly. Aerial photos and satellite sensor images are used for generating 3D spatial images which are matched with the map coordinates and elevation data from digital topographic files. Also, those images are used for matching with 3D spatial image contents through perspective view condition composed along to the designated roads until arrival the corresponding location. Recently, 3D aviation image could be generated by various digital data. The advanced geographical methods for guidance of the destination road are experimented under the GIS environments. More information and access designated are guided by the multimedia contents on internet or from the public tour information desk using the simulation images. The height data based on LiDAR is transformed into DEM, and the real time unification of the vector via digital image mapping and raster via extract evaluation are transformed to trace the generated model of 3-dimensional downtown building along to the long distance for 3D tract model generation.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.15 no.1
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• pp.29-39
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• 1997

The need of transformation parameters from local geodetic datums to a geocentric coordinate system is becoming more common, with the increasing application of satellite positioning techniques to LIS/GIS survey with cadastral management. In this paper, the national transformation parameters between the Korean geodetic coordinates which is based on the Bessel 1841 ellipsoid and the WGS84 ellipsoid are determined by the least square methods with weighted parameter constraints. Three-dimensional geocentric coordinates are based on GPS observation at 31 stations in the geodetic network, the datum parameters are computed within a standard deviation of less than 1 meter. In South Korea, the national transformation parameters with Bessel geoid-heights are useful for GPS baseline processing and for middle-scale map/database transformation.