• Journal of Korean Society for Geospatial Information Science
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• v.7 no.1 s.13
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• pp.75-86
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• 1999

Three dimensional city model is composed of man-made and natural features, among these, most of man-made features are buildings. Therefore, it is very important to extract the building informations accurately and promptly to update the existing database. To achieve this, DTM can be reconstructed using building Information which is extracted from DTM, then this can be used as three dimensional city model. Thus, this paper aims to extract building boundaries and heights from high resolution DTM and edge informations of aerial photograph using mathematical morphology and image segmentation. We found that it is possible to extract buildings using opening operation in mathematical morphology and to improve the accuracy of building extraction using edge informations from aerial photograph.

• Journal of Korean Society for Geospatial Information Science
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• v.7 no.2 s.14
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• pp.57-68
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• 1999

In case of topographic information construction it is most important as basemap determines the success or failure of GIS It is argument that digitizing works of basemap are divided by NGIS and PBLIS. So, it have to accompany the combination and application of cadastral information for constructing a usful basemap. In this study, we generated ortho image map using 1:5,000 aerial-photography image, present the comparative analysis for the overlay accuracy and map revision of topographic and cadastral information using ortho image map to base map. So, we present application schemes for land use, environment, and city planning field as well as union database by overlaying of image map and cadastral information.

• Journal of Korean Society for Geospatial Information Science
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• v.7 no.2 s.14
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• pp.69-80
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• 1999

The purpose of this study is to develop a Bridge Disaster Management System for bridge safety control using Geographic Information Systems(GIS). The constructed database includes several graphic layers such as basemap, road, bridge location, etc. and has related text attributes for 32 bridges and its facilities in Chinju City. Using the language of Visual Basic 5.0, personal computer based Bridge Disaster Management System which has several functions for bridge safety analysis was developed. The developed GIS based Bridge Disaster Management System has the functions of fast and efficient data searching, file management, searching and management of bridge characteristics, bridge related map viewing, searching and management of traffic survey, bridge inspection and repair work results, and evaluating the bridge safety grades, etc..

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.65-75
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• 1997

Nowadays, digital map plays a role as a container of spatial database.'there have been many researches concerning the improvements of the digital map accuracy. From the user's viewpoint, however, the quality level of digital nap is as important as its accuracy, because fitness-for-use is considered the most important factor to the users. This study aims to find the methodology for determining the grade nか digital map. To accomplish this, we propose two major stages. First, weight factors of the layers are given according to the importance of the functions which must be considered in digital map generation. Scond, weight factors of the components to evaluate the accuracy of the digital map are presented By scoring the components and by summing the scores, the method for determining fitness-for-use is developed.

• Journal of Korean Society for Geospatial Information Science
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• v.5 no.2 s.10
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• pp.193-205
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• 1997

It is required for multi-users to share massive mapping data effectively that distributed data model in the Client-Server environment is developed for the replication consistency. The existing model is not effective to the long transaction just like a mapping system, since it does not account lot consistency between GUI screen and database replications even though it emphasizes on the replication consistency. The performance of concurrency control is very important for those long transactions, especially the mapping systems. This model is to support consistency between GUI screen and replicas using display locks. It suggests consistency model improving process performance by modifying memory consistency model and optimistic concurrency control for mapping data's characteristics.

• Journal of Korean Society for Geospatial Information Science
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• v.13 no.1 s.31
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• pp.71-80
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• 2005

Recently, water quality problems are emerging as important social issues since water quality in rivers and lakes are significantly deteriorated. Thus, an accurate prediction system on reservoir water quality is required, as well as an integrated system which can provide a solution for taking away contaminated materials. This research aims to develop an intelligent decision support system, which uses a GIS enabling management and spatial analysis. The developed system is a prototype that can be applied into real spot. This research area includes the following main subjects; system analysis and design, geometry data collection and database implementation, data acquisition and analysis on reservoir water quality, interface design and development GIS, and development of an expert system for water quality forecasting by WASPS.

• Journal of Korean Society for Geospatial Information Science
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• v.6 no.1 s.11
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• pp.27-34
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• 1998

A Unique Feature Identifier(UFID) is a way of referring to a feature, generally representing a tangible feature in the real world. In other words, a UFID uniquely identifies the related feature in the database and is normally used to link two or more databases together. This paper presents a UFID system aiming at the internal uses for National Geography Institute(NGI) as well as external uses for National Geographic Information System(NGIS) generally to link datasets together. The advantage of the proposed type of UFID lies in the meaningful nature of the identifier in providing a direct spatial index - administrative area and feature code. The checksum character proposed in this research is designed to remove any uncertainty about the number being corrupt. It will account lot digit transposition during manual input as well as corruption in transfer or processing.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.4
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• pp.1-9
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• 2008

It is restricted on CPU ability, memory, display size and networking to process GIS data on ubiquitous-based terminal. For that reason, we tried to improve the cadastral electronic file to solve these problems in this paper. The format of old cadastral electronic files is not efficient because it is made of file structure. So, it has inconvenience to let us read whole file, displaying on the screen and connecting to geographic objects by adding index file like database for connecting to geographic object and displaying on the screen. The file size was decreased to 27.6% of original file size through converting format.

• Korean Journal of Geomatics
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• v.2 no.2
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• pp.131-137
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• 2002

The digital photogrammetric products have been increasingly used as an accurate foundation for representing information associated with infrastructure management. The technological advances in merging raster and vector data within the framework of GIS have allowed for the inclusion of DTMs and digital orthophotos with vector data and its associated attributes. This study addresses not only generating DEMs and digital orthophotos but producing three dimensional building models from aerial photos of an urban area by employing the digital photogrammetric technology. DEMs and digital orthophotos were automatically generated through the process of orientations, image matching and so on, and then the practical problems, which must be solved especially in applying to urban areas, were considered. The accuracy of produced digital orthophotos was derived by using check points. Also three dimensional visualization imagery, which is useful in the landform analysis, and 3D building models were produced. Digital photogrammetric products would be used widely not only as GIS framework data layers by using the GIS link function which links attribute and image information in the database for applying to infrastructure management and but as geospatial data for especially 3D GIS in urban areas.

• Journal of Korean Society for Geospatial Information Science
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• v.1 no.2 s.2
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• pp.105-112
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• 1993

The conventional method for solving transportation problems were mainly based on numerical methods, where the understanding of outputs is not easy. Some difficulties come from the seperation of three key steps-the preparation of input for transportation traffic simulation, and model output interpretation. GSIS can help to eliminate some of thoses difficulties by combining graphics, database, and transportation plaining models. As pilot study, this study shows an application of Geovision GSIS to TRANPLAN transportation planning model that is based on four-step travel demand forecasting procedure. Accrued benefits and procedure are presented.