• Title/Summary/Keyword: geospatial database

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Landslide Susceptibility Mapping and Verification Using the GIS and Bayesian Probability Model in Boun (지리정보시스템(GIS) 및 베이지안 확률 기법을 이용한 보은지역의 산사태 취약성도 작성 및 검증)

  • Choi, Jae-Won;Lee, Sa-Ro;Min, Kyung-Duk;Woo, Ik
    • Economic and Environmental Geology
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    • v.37 no.2
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    • pp.207-223
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    • 2004
  • The purpose of this study is to reveal spatial relationships between landslide and geospatial data set, to map the landslide susceptibility using the relationship and to verify the landslide susceptibility using the landslide occurrence data in Boun area in 1998. Landslide locations were detected from aerial photography and field survey, and then topography, soil, forest, and land cover data set were constructed as a spatial database using GIS. Various spatial parameters were used as the landslide occurrence factors. They are slope, aspect, curvature and type of topography, texture, material, drainage and effective thickness of soil. type, age, diameter and density of wood, lithology, distance from lineament and land cover. To calculate the relationship between landslides and geospatial database, Bayesian probability methods, weight of evidence. were applied and the contrast value that is >$W^{+}$->$W^{-}$ were calculated. The landslide susceptibility index was calculated by summation of the contrast value and the landslide susceptibility maps were generated using the index. The landslide susceptibility map can be used to reduce associated hazards, and to plan land cover and construction.

Steep Slope Management System integrated with Realtime Monitoring Information into 3D Web GIS (상시계측센서정보와 3차원 Web GIS를 융합한 급경사지관리시스템)

  • Chung, Dong Ki;Sung, Jae Ryeol;Lee, Dong Wook;Chang, Ki Tae;Lee, Jin Duk
    • Journal of Korean Society of Disaster and Security
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    • v.6 no.3
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    • pp.9-17
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    • 2013
  • Geospatial information data came recently in use to build the location-based service in various fields. These data were shown via a 2-D map in the past but now can be viewed as a 3-D map due to the dramatic evolution of IT technology, thus improving efficiency and raising practicality to a greater extent by providing a more realistic visualization of the field. In addition, many previous GIS applications have been provided under desktop environment, limiting access from remote sites and reducing its approachability for less experienced users. The latest trend offers service with web-based environment, providing efficient sharing of data to all users, both unknown and specific internal users. Therefore, real-time information sensors that have been installed on steep slopes are to be integrated with 3-D geospatial information in this study. It is also to be developed with web-based environment to improve usage and access. There are three steps taken to establish this system: firstly, a 3-D GIS database and 3-D terrain with higher resolution aerial photos and DEM (Digital Elevation Model) have been built; secondly, a system architecture was proposed to integrate real-time sensor information data with 3D Web-based GIS; thirdly, the system has been constructed for Gangwon Province as a test bed to verify the applicability.

Availability Analysis on Detection of Small Scale Gas Emission Facilities using Drone Imagery (드론영상을 이용한 소규모 가스 배출시설 탐지 가능성 분석)

  • Shin, Jung-Il;Kim, Ik-Jae;Hwang, Dong-Hyun;Lee, Jong-Min;Lim, Seong-Ha
    • Journal of Cadastre & Land InformatiX
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    • v.47 no.1
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    • pp.213-223
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    • 2017
  • Recently, the air quality of South Korea has deteriorated and public interest has been increasing. Various observation means are used for the monitoring of the atmospheric environment, but it relies on the experience and judgment of the observer in the absence of spatial information on the emission facilities. The purpose of this study was to determine the availability of using drones for monitoring air pollutant emission facilities. A texture transformation method was applied to the drone ortho image to detect the small gas emission facility and the slope data calculated by the digital surface model (DSM) was used to reduce the false alarm ratio. As a result, it shows the possibility of using drones in the detection of small gas emission facilities by showing about 80% of positive detection ratio and 40% of false alarm ratio. In the future, various researches are required to the improve positive detection ratio and the reduction of the false alarm ratio. Based on these results, it is necessary to construct a database including 3D spatial information of air pollutant emission facilities.

Spatial OLAP Implementation for GIS Decision-Making - With emphasis on Urban Planning - (GIS 의사결정을 지원하기 위한 Spatial OLAP 구현 - 도시계획을 중심으로 -)

  • Kyung, Min-Ju;Yom, Jae-Hong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.6
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    • pp.689-698
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    • 2009
  • SOLAP system integrates and complements the functions of both OLAP and GIS systems. This enables users not only to easily access geospatial data but also to analyze and extract information for decision making. In this study a SOLAP system was designed and implemented to provide urban planners with GIS information when making urban planning decisions. Rapid urbanization in Korea has brought about ill-balanced urban structure as the result of development without detailed analysis of urban plans. Systematic urban planning procedures and automated systems are crucial for detail analysis of future development plans. Data regarding the development regulations and current status of land use need to be assessed precisely and instantly. Multi-dimensional aspects of a suggested plan must be formulated instantly and examined thoroughly using 'what if' scenarios to come up with a best possible plan. The SOLAP system presented in this study designed the dimension tables and the fact tables for supplying timely geospatial information to the planners when making decisions regarding urban planning. The database was implemented using open source DBMS and was populated with necessary attribute data which was freely available from the Statistics Korea bureau homepage. It is anticipated the SOLAP system presented in this study will contribute to better urban planning decisions in Korea through more timely and accurate provision of geospatial information.

An Integrated Approach to the GIS Data Reengineering for the New Korea Geodetic Datum (세계측지계 도입에 따른 공간데이터 재정비를 위한 통합모델 연구)

  • Lee Yang-Won;Park Key-Ho
    • Journal of the Korean Geographical Society
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    • v.40 no.2 s.107
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    • pp.153-171
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    • 2005
  • The newly adopted Korea Geodetic Datum (a.k.a. KGD2002) calls for massive reengineering work on geospatial dataset. The main focus of our study is placed on the strategy and system implementations of the required data reengineering with a keen attention to integrated approaches to interoperability, standardization, and database utilization. Our reengineering strategy includes file-to-file, file-to-DB, DB-to-file, and DB-to-DB conversion for the coordinate transformation of KGD2002. In addition to the map formats of existing standards such as DXF and Shapefile, the newly recommended standards such as GML and SVG are also accommodated in our reengineering environment. These four types of standard format may be imported into and exported from spatial database via KGD2002 transformation component. The DB-to-DB conversion, in particular, includes not only intra-database conversion but also inter-database conversion between SDE/Oracle and Oracle Spatial. All these implementations were carried out in multiple computing environments: desktop and the Web. The feasibility test of our system shows that the coordinate differences between Bessel and GRS80 ellipsoid agree with the criteria presented in the existing researches.

A study on the Accuracy Analysis of the World Geodetic System Transformation for GIS Base Map and Database (GIS 기본도 및 DB의 세계측지계 좌표변환 정확도 분석에 관한 연구)

  • Cho, Jae-Kwan;Choi, Yun-Soo;Kwon, Jay-Hyoun;Lee, Bo-Mi
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.3
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    • pp.79-85
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    • 2008
  • This study aims to derive a practical coordinate transformation method for the existing geographic information database. After analyzing the status and problems of existing 1/1,000 digital base map and GIS application database, the transformation parameters are estimated and the accuracy of the transformation is determined based on the transformed coordinates. We analyzed the accuracy of a transformation using the published national transformation coefficients as well as the estimated local transformation coefficients using national and urban control points in a study area. In addition, the 1/1,000 digital base map from aerial triangulation is compared with respect to the coordinates of urban control points. Based on the comparison, the biases on the national control points which were used at the time of digital map generation was analyzed. Then, the accuracy of transformed coordinates based on the world geodetic system using local transformation coefficients estimated from urban control points are determined. We also analyzed the transformation accuracy of underground infrastructure database using the same transformation method as the case of 1/1,000 digital base map. Through this study, it was found that the estimation of transformation coefficients by Molodensky-Badekas using urban control points was suitable for a local government. Furthermore, it was obvious that the accuracy of a 2-dimensional affine transformation was comparable to that of 7 parameter transformation for a local area. Applying the coordinate transformation and bias correction, we could transform GIS application database which was built by an offset surveying based on digital base map within the transformation accuracy of 10 cm. Therefore, it was judged that there will not be a big problem on the transformation of the GIS DB to the world geodetic system.

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Landslide Vulnerability Mapping considering GCI(Geospatial Correlative Integration) and Rainfall Probability In Inje (GCI(Geospatial Correlative Integration) 및 확률강우량을 고려한 인제지역 산사태 취약성도 작성)

  • Lee, Moung-Jin;Lee, Sa-Ro;Jeon, Seong-Woo;Kim, Geun-Han
    • Journal of Environmental Policy
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    • v.12 no.3
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    • pp.21-47
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    • 2013
  • The aim is to analysis landslide vulnerability in Inje, Korea, using GCI(Geospatial Correlative Integration) and probability rainfalls based on geographic information system (GIS). In order to achieve this goal, identified indicators influencing landslides based on literature review. We include indicators of exposure to climate(rainfall probability), sensitivity(slope, aspect, curvature, geology, topography, soil drainage, soil material, soil thickness and soil texture) and adaptive capacity(timber diameter, timber type, timber density and timber age). All data were collected, processed, and compiled in a spatial database using GIS. Karisan-ri that had experienced 470 landslides by Typhoon Ewinia in 2006 was selected for analysis and verification. The 50% of landslide data were randomly selected to use as training data, while the other 50% being used for verification. The probability of landslides for target years (1 year, 3 years, 10 years, 50 years, and 100 years) was calculated assuming that landslides are triggered by 3-day cumulative rainfalls of 449 mm. Results show that number of slope has comparatively strong influence on landslide damage. And inclination of $25{\sim}30^{\circ}C$, the highest correlation landslide. Improved previous landslide vulnerability methodology by adopting GCI. Also, vulnerability map provides meaningful information for decision makers regarding priority areas for implementing landslide mitigation policies.

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A STUDY ON THE ANALYSIS OF DIGITAL AERIAL PHOTO USING IMAGE SEGMENTATION (영상분할기법을 이용한 수치항공영상 해석에 관한 연구)

  • Kwon, Hyun;Lee, Hyun-Jik;Park, Hyo-Keun
    • Journal of Korean Society for Geospatial Information Science
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    • v.2 no.2 s.4
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    • pp.131-142
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    • 1994
  • Generally, there are two methods which generates the base map of Geo-Spatial Information System(GSIS). one is the digitizing of existing map, and the other is the analytical plotting method editing data acquired by sensors using computers. But the analytical plotting method and method of the digitizing of existing map is technically complex and has the disadvantages in the costs and time. The subject region of study(the Kwangyang province), was photographed by aircraft, and photographing scale was 1/6,000. Then this area was divided into two specific regions, the residential area, and the agricultural area. In this study, we developed the algorithm that generated base map of database in GSIS from the aerial photo. This algorithm is as followed. First, the digital aerial photos were generated using these aerial photos. Second, these digital aerial photos were enhanced by implementing the histogram equalization. Third, the objects of the enhanced images were extracted by implementing thresholding and edged detection techiques of image segmentation. Finally, these images could be used to updated the base map of database in GSIS. The result obtained from this study showed that method used by this study were more efficient than existing method in costs and time.

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Development of a Web-based Geovisualization System using Google Earth and Spatial DBMS (구글어스와 공간데이터베이스를 이용한 웹기반 지리정보 표출시스템 개발)

  • Im, Woo-Hyuk;Lee, Yang-Won;Suh, Yong-Cheol
    • Spatial Information Research
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    • v.18 no.4
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    • pp.141-149
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    • 2010
  • One of recent trends in Web-based GIS is the system development using FOSS (Free and Open Source Software). Open Source software is independent from the technologies of commercial software and can increase the reusability and extensibility of existing systems. In this study, we developed a Web-based GIS for interactive visualization of geographic information using Google Earth and spatial DBMS(database management system). Google Earth Plug-in and Google Earth API(application programming interface) were used to embed a geo-browser in the Web browser. In order to integrate the Google Earth with a spatial DBMS, we implemented a KML(Keyhole Markup Language) generator for transmitting server-side data according to user's query and converting the data to a variety of KML for geovisualization on the Web. Our prototype system was tested using time-series of LAI(leaf area index), forest map, and crop yield statistics. The demonstration included the geovisualization of raster and vector data in the form of an animated map and a 3-D choropleth map. We anticipate our KML generator and system framework will be extended to a more comprehensive geospatial analysis system on the Web.

The Quality Assurance and Accuracy Improvement of National Basemap Digital Mapping Database (국가기본도 수치지도제작 데이터베이스의 품질유지 및 정확도 향상)

  • Lee, Hyun-Jik
    • Journal of Korean Society for Geospatial Information Science
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    • v.6 no.2 s.12
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    • pp.91-103
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    • 1998
  • The digital map data of national basemap which will be basic data of the information age is accomplished to produce and are ready to distribute to public. Generally, the quality of digital map is affected to data history, position accuracy, attribute accuracy, logical consistency and completeness. The quality of digital map Is assured to use basic data for the field of various appication. The purpose of this study is to develop automated qualify control program of digital map through analysis type of errors in digital mapping, to determine method of high quality digital mapping. As a results of this study, The automated quality control program of digital map is developed to assure logical consistency and completeness of digital map which is used to principal data in the field of GIS and is determined the process of high quality digital mapping. Also, the results of this study is contributed to quality assrence and accuracy improvement of national basemap digital mapping database.

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