• KIEE International Transactions on Power Engineering
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• v.3A no.4
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• pp.214-221
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• 2003

In view of the fact that gas insulated switchgear (GIS) is an important piece of equipment in a substation, it is highly desirable to continuously monitor the state of equipment by measuring the partial discharge (PD) activity in a GIS, as PD is a symptom of an insulation weakness/breakdown. However, since the PD signal is relatively weak and the external noise makes detection of the PD signal difficult, it therefore requires careful attention in its detection. In this paper, the algorithm for detection of PD in the GIS using the wavelet transform (WT) is proposed. The WT provides a direct quantitative measure of the spectral content and dynamic spectrum in the time-frequency domain. The most appropriate mother wavelet for this application is the Daubechies 4 (db4) wavelet. 'db4', the most commonly applied mother wavelet in the power quality analysis, is very well suited to detecting high frequency signals of very short duration, such as those associated with the PD phenomenon. The proposed algorithm is based on utilizing the absolute sum value of coefficients, which are a combination of D1 (Detail 1) and D2 (Detail 2) in multiresolution signal decomposition (MSD) based on WT after noise elimination and normalization.

• Journal of Korean Society for Geospatial Information Science
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• v.17 no.4
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• pp.31-38
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• 2009

Most 3D models found in the literature focus on theoretical topology for exterior 3D volumes. Although there are a few indoor models such as CityGML or IFC, implementing a full topology for the indoor spaces is either less practical due to the complexity or not even necessary in some application domains. Moreover, current spatial DBMSs do not support functionalities explicitly for 3D topological relations. In this study, an alternative method to build a 3D indoor model with less complexity ernativespatial DBMS is suggested. Focusnation the fact that semantic attributes can be storedion the floor surface, we suggestivemulti-layered 3D model for indoor spaces. We show the process to build the proposed model in the PostGIS, a spatial DBMS. And, then, as an example application, we illustrate the process to build and run a campus building information system.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.4D
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• pp.695-702
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• 2006

In GIS-based Spatial Decision-making Support System (SDSS), the Boolean logic by conventional simple overlay method contains two problems. One is losing lots of information in analysis process, the other is unable to reflect of weighting values between evaluated items. Therefore, evaluation system as Analytic Hierarchy Process (AHP) needs to improve these problems effectively. The purpose of this study is to provide the benefit of AHP method and GIS spatial analysis in site analysis for crop cultivation. First, the weighting value of AHP for topography, distribution grade of water, property of soil and slope items are evaluated throughout survey to experts of soil, crop and agricultural management fields. On the basis of these weighting value of AHP by items, site suitability analysis for black raspberry cultivation is performed. To estimate the benefit of AHP method, the current cultivating map of black raspberry is constructed in Ssangchi-myeon district. In comparison with site analysis of Boolean logic, site analysis of AHP method shows more realistic.

• Proceedings of the KSRS Conference
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• 2002.10a
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• pp.169-174
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• 2002

In this paper, we suggest a new spatial information system called video GIS where video is used for spatial data construction and is integrated with map. We develop a prototype system of video GIS and apply it to roadside facility management. The main functions supported by the suggested system are data collection, coordinate calculation and conversion, data construction, analysis, searching, and browsing. The stereo images and corresponding position data are collected by a vehicle named 4S-Van that has GPS, IMU, and cameras. The 3-D coordinates of the objects in the images, such as road sign, signal lamp, and building, can be calculated and constructed from the collected data. The spatial objects are displayed on both image and map, and can be searched and browsed, which enables visual and realistic browsing and management of spatial objects. Compared to conventional field survey used in roadside facility management, the method enables faster, easier, and more efficient construction of spatial data. The suggested video GIS can be applied not only to roadside facility management but also to many similar projects of central or local governments that are related to GIS.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.80-83
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• 1999

An efficient modeling and management of a large amount of surface data for a wide rage of geographic information play an important role in determining the functionality of 3D geographic information system. It has been put many efforts to design and manage an effective way to enhence the manipulation of the data by considering geometry type and data structures. Recently, DEM(Data Elevation Model) and TIN(Triangulated Irregular Network) are used for representing surface data. In this paper, we propose a 3D data processing method. The method utilizes the major properties of DEM and TIN, respectively. Furthermore, by approximating DEM with a TIN of an appropriate resolution, we can support a fast and realistic surface modeling. We implement the structure with the following 4 level stages. The first is an optimal resolution of DEM which represent all of wide range of geographic data. The second is the full resolution DEM which is a subarea of original data generated by user's selection in our implemeatation. The third is the TIN approximation of this data with a proper resolution determined by the relative position with the camera. And the last step is multi-resolution TIN data whose resolution is dynamically decided by considering which direction user take notice currently. Specially, the TIN of the last step is designed for realtime camera navigation. By using the structure we implemented realtime surface clipping, efficient approximation of height field and the locally detailed surface LOD(Level of Detail). We used the initial 10-meter sampling DEM data of Seoul, KOREA and implement the structure to the 3D Virtual GIS based on the Internet.

• Proceedings of the Korea Information Processing Society Conference
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• 2000.10b
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• pp.1309-1312
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• 2000

컴포넌트를 기반으로 하는 소프트웨어 개발 방법론은 시스템의 규모가 크고 구성이 복잡한 지리정보 시스템에 효율적으로 적응될 수 있다. 이것은 특히 개방형 GIS를 위한 설계와 구현 방법에도 이용되고 있다. 본 논문에서는 복합 피쳐를 지원하는 3차원 지리정보시스템의 컴포넌트 기반 설계 사례에 대해 설명한다. 본 논문에서 제안한 시스템은 OpenGIS 규격과의 호환성을 고려하고 복합 피쳐 및 복합 지리요소를 지원하며 객체 지향 분석 설계 방법론을 이용하여 설계되었다. 본 시스템은 3차원 지리요소의 모델링, 가시화, 공간분석 기능과 4차원 공간 데이터에 대한 질의 기능을 포함하고 있다. 향 후 복잡한 도심 건물 지역을 대상으로 층별 시공간 관리 분석 시스템 등으로 응용될 전망이다.

• Journal of the Korean Association of Geographic Information Studies
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• v.24 no.4
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• pp.82-98
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• 2021

In recent years, as the number of ground subsidence has increased nationwide, the latest and usefulness of underground information for underground space development and underground safety management has become more important than ever. However, the 3D Underground Geospatial Map project, which started in 2015, has a problem with the manual-based long-term update system. This research paper overcomes these limitations and automatically updates the 3D CAD/GIS-based integrated management of underground structures that can be managed automatically from a full-cycle perspective of underground structure data management such as processing, transformation, updating, management, and visualization of 2D/3D underground structure data. If this technology is applied, it is possible to integrate processing and update management of the existing complex 3D construction logic of underground structures in one system, and it is expected that it can be used for underground space development and underground safety management as a foundation technology for automatic update of underground structures data.

• Geophysics and Geophysical Exploration
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• v.4 no.4
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• pp.101-109
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• 2001

In order to develop a spatial information system that can efficiently manage various subsurface data and produce information in a proper form for a user, we established a database of the well cores and built 3-D shapes that visualize the subsurface objects such as wells, ore bodies, tunnels, and mine cavities. We also made analysis tools available for three-dimensional ore bodies constructed here, such as vertical cross-section generator and mass computing tool. This system was developed by coding Avenue, a scripting language incorporated in ArcView, which is a commercial GIS software. Using the system, it is expected that users can make fast and accurate analysis and interpretation through real-time queries and by contemplating various objects in 3-D perspective.

• The KIPS Transactions:PartD
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• v.9D no.4
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• pp.543-554
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• 2002

GIS (Geographic Information Systems) need faster access and better visualization. For faster access and better visualization in GIS, map generalization and levels of detail are needed. Existing spatial indexing methods do not support map generalization. Also, a few existing spatial indexing methods supporting map generalization do not support ail map generalization operations. We propose a new index structure, i.e. the LR-tree, supporting ail map generalization operations. This paper presents algorithms for the searching and updating the LR-tree and the results of performance evaluation. Our index structure works better than other spatial indexing methods for map generalization.

• Journal of Korean Society of Rural Planning
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• v.3 no.1
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• pp.96-104
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• 1997

The purpose of this study is to develop a dynamic DSS (Decision Support System) interfaced with GIS (Geographic Information System) and agriculture information network, In this study, DSS was developed to assist services which required tremendous and real time data in national scale. The data transmitte'd from the local area by the agriculture network were stored in DBMS (Data Base Management System) and analyzed by GIS. GIS and database tools used in this study were ARC/INFO 7.1.1 and INFORMIX 4.0. ACSAS (Agriculture Calamity Service Asist System) by the system prototype was constructed to solve the problem about the drought counterplan service which was to take the responsibility in the Ministry of Agriculture. It was easy to transfer, process, and analyze the information using the system. Specially, the meteological, the reservoir storage rate and the drought counterplan information were spatially analyzed by the functions of GIS.