• Journal of the Korean Association of Geographic Information Studies
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• v.17 no.2
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• pp.95-106
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• 2014

In this study, the applicability of a standard vector model was evaluated using RIMGIS vector data and a portal based river-geospatial information web service system was developed using XML and JSON based data linkage between the server and the client. The RIMGIS vector data including points, lines, and polygons were converted to the Geospatial Data Model(GDM) developed in this study and were validated by layers. After the conversion, it was identified that the attribute data of a shape file remained without loss. The GeoServer GDB(GeoDataBase) that manages a DB in the portal was developed as a management module. The XML-based Geography Markup Language(GML) standards of OGC was used for accessing to and managing vector layers and encoding spatial data. The separation of data content and expression in the GML allowed the different expressions of the same data, convenient data revision and update, and enhancing the expandability. In the future, it is necessary to improve the access, exchange, and storage of river-geospatial information through the user's customized services and Internet accessibility.

• The Transactions of the Korea Information Processing Society
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• v.1 no.3
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• pp.279-289
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• 1994

A Geographic Database System is a database system which supports map-formed output and allows users to store, retrieve, manage and analyze spatial and aspatial data. Because of large data amount, takes too much time to input spatial data into a Geographic Database System and too much storage. Therefore, an efficient spatial data collecting system is highly required for a Geographic Database System to reduce the input processing time and to use the storage efficiently. In this paper, we analyze conventional vectorizing methods and suggest a different approach. Our approach vectorizes specific geographic data when the users input its aspatial data, instead of vectorizing all the map data. And also, we propose optimized vector data format using tag bit to use the storage that collected data efficiently.

• Korean Journal of Remote Sensing
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• v.9 no.1
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• pp.51-78
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• 1993

The main purpose of this paper is to design and implement an integrated geigraphic information system. To this end, careful examinations of various existing GIS packages based on vector and raster type model were performed. A vector type INTGIS which is operating in MS-Windows environment was developed. INTGIS is composed of many modules creating various menus which are able to facilitate user interface with the system. The function and utility of INTGIS was tested using real data. We found INTGIS is reliable and useful for extensive spatial analysis and mapping activity. Further development of INTGIS will be carried on in order to integrate vector and raster data, and to manipulate three dimensional data.

• Journal of the Korean Association of Geographic Information Studies
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• v.2 no.1
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• pp.54-62
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• 1999

Vectorizing for input processing of map is the most time and cost consuming task, and the quality of vector data depends on that processing result. Therefore, it is an important task to develop a good vectorizing system in the GIS. Thinning algorithm is the most important technology for deciding the quality of vector data in the vectorizing system. In this paper, as a suitable algorithm for map vectorizing we considered several algorithms that preserve topological and geometric characteristics, and have no distortion of the contour line. As a results, we implemented WPTA4 and well known thinning algorithm, and compared WPTA4 execution results with the others.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.9 no.1
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• pp.97-107
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• 1991

This paper was suggested the detailed methods on the integration of Remote Sensing and GIS for various application of two functions at the one system with making the most use of respective merits rather than make use of independent systems. It developed of algorithm about simultaneous overlay of raster and vector data for remote sensing and GIS for these objects. For test application on integration of remote sensing and GIS, it used of remote sensing data of satellite and used to topographic map of the same area for vector data acquisition of GIS application. For the practical application, it proved of effective value of integration of raster and vector data by present of useful technique with multilateral approach method through data conversion about thematic application for major application fields of remote sensing and GIS and it suggested that new application technique for integrated application of remote sensing GIS through synthetic situation analysis.

• Journal of Korean Society for Geospatial Information Science
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• v.2 no.1 s.3
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• pp.99-106
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• 1994

Raster data mode and Vector data are the two major model in geographic information systems. These two data models are difficult to be intergrated because of their differences in structures and properties. Almost all of the current GIS systems process in one data model by converting one data type to another type. So. the loss and change of information caused by data conversiion degrades the accuracy of data. In this paper, we propose a new data model which can process two data models without conversion. We use quadtree for raster data and topological vector model for vector data. The output is formed as raster data model of quadtree. We can get more accurate overay output, and this intergrated model is more suitable for data like forest, landuses, soils that consist of classes which have small distribution changes.

• Spatial Information Research
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• v.15 no.3
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• pp.323-333
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• 2007

Recently, the South and North Korea have collaborated in the economic cooperation. Success for the cooperation of the South and North Korea has supported the basic and fundamental GIS data building for geographic information (GI) and the land-use of the North Korea. This North Korea GIS project is also vital to facilitate rebuilding and reconnecting socio-economic infrastructures such as reconnecting road and railway networks between the South and North Korea. Thus, this paper emphasizes on the fundamental issues of GIS data building in North Korea area and suggests GI and data establishment methods of the North Korea regions which has not been achieved in GIS research activities in Korea. As the basic GI and data in the North Korea, topographical maps, satellite imageries, and thematic maps were collected and used for surveying of territorial areas of the North Korea. The database of those dataset were built by scanning, image processing, and classifying land-use types. In addition, this paper exacted vector data from the database and included the vector data into the database as other basic GI dataset that enable to analyze quantitative and qualitative territorial land use and development in the North Korea.

• Journal of Positioning, Navigation, and Timing
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• v.11 no.4
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• pp.287-295
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• 2022

The GNSS coordinate time series is used as important data for geophysical analysis such as terrestrial reference frame establishment, crustal deformation, Earth orientation parameter estimation, etc. However, various factors may cause discontinuity in the coordinate time series, which may lead to errors in the interpretation. In this paper, we describe the discontinuity in the coordinate time series due to the equipment replacement for domestic GNSS stations and discuss the change in movement magnitude and velocity vector difference in each direction before and after discontinuity correction. To do this, we used three years (2017-2019) of data from 40 GNSS stations. The average magnitude of the velocity vector in the north-south, east-west, and vertical directions before correction is -12.9±1.5, 28.0±1.9, and 4.2±7.6 mm/yr, respectively. After correction, the average moving speed in each direction was -13.0±1.0, 28.2±0.8, and 0.7±2.1 mm/yr, respectively. The average magnitudes of the horizontal GNSS velocity vectors before and after discontinuous correction was similar, but the deviation in movement size of stations decreased after correction. After equipment replacement, the change in the vertical movement occurred more than the horizontal movement variation. Moreover, the change in the magnitude of movement in each direction may also cause a change in the velocity vector, which may lead to errors in geophysical analysis.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.18 no.2
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• pp.89-104
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• 2015

In order to effectively manage forested areas in South Korea on a national scale, using remotely sensed data is considered most suitable. In this study, utilizing Land coverage maps and Forest type maps of national geographic information instead of collecting field data was tested for conducting supervised classification on SPOT-5 and KOMPSAT-2 imagery focusing on forested areas. Supervised classification were conducted in two ways: analysing a whole area around the study site and/or only forested areas around the study site, using Support Vector Machine. The overall accuracy for the classification on the whole area ranged from 54.9% to 68.9% with kappa coefficients of over 0.4, which meant the supervised classification was in general considered moderate because of sub-classifying forested areas into three categories (i.e. hardwood, conifer, mixed forests). Compared to this, the overall accuracy for forested areas were better for sub-classification of forested areas probably due to less distraction in the classification. To further improve the overall accuracy, it is needed to gain individual imagery rather than mosaic imagery to use more spetral bands and select more suitable conditions such as seasonal timing. It is also necessary to obtain precise and accurate training data for sub-classifying forested areas. This new approach can be considered as a basis of developing an excellent analysis manner for understanding and managing forest landscape.

• Journal of Korea Spatial Information System Society
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• v.1 no.2 s.2
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• pp.127-135
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• 1999

Currently, many geographic information systems deal with only vector data. Therefore, handling raster data for various types of information is greatly needed. In this paper, we design and implement a raster processor which handles spatial information in a spatial object management system called Object Management system for Geospatial Application (OMEGA). We define the data structure of the raster information to be stored in the spatial object management system and implement it to a class library in order for use in making an application program. Furthermore, a query operation and related module is implemented to extract raster information. They are then imbedded in the query executer to process a query of the raster information. Simulation results are given.