• Journal of Korea Spatial Information System Society
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• v.11 no.2
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• pp.151-161
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• 2009

In Location-Based Services (LBSs), users requesting a location-based query send their exact location to a database server and thus the location information of the users can be misused by adversaries. Therefore, a privacy protection method is required for using LBS in a safe way. In this paper, we propose a new cloaking region generation algorithm using grids for privacy protection in LBSs. The proposed algorithm creates a m inimum cloaking region by finding L buildings and then performs K-anonymity to search K users. For this, we make use of not only a grid-based index structure, but also an efficient pruning techniques. Finally, we show from a performance analysis that our cloaking region generation algorithm outperforms the existing algorithm in term of the size of cloaking region.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.17 no.5
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• pp.160-172
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• 2018

The method of estimating a position using a GPS has been applied to various fields including a navigation system of an automobile. However, since it is difficult to measure GPS signals indoors, it is difficult to locate specific objects indoors such as a building or factory. To overcome these limitations, this study proposes a system for object location estimation based on Bluetooth5 for the management of materials in factories. The object position estimation system consists of a Bluetooth signal generator, a receiver, and a database server. A signal generator based on Bluetooth Low Energy(BLE) is attached to the material and a receiver is appropriately arranged inside the factory. In this study, we propose "Diagonal Survey Method", a 4 - axis survey algorithm using four receivers to reduce the error of existing trilateration method. The proposed algorithm showed good performance compared to the conventional trilateration and we verified the effectiveness of the proposed system and algorithm by performing the experiment by installing the system in the factory.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.4
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• pp.41-48
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• 2008

Currently used 3D models, which are mostly focused on visualization of 3D objects and lack topological structure, have limitation in being used for 3D spatial analyses and applications. However, implementing a full topology for the indoor spatial objects is less practical due to the increase of complexity and computation time. This study suggests an alternative method to build a 3D indoor model with less complexity using a spatial DBMS. Storing spatial and nonspatial information of indoor spaces in DB tables enables faster queries, computation and analyses. Also it is possible to display them in 2D or 3D using the queried information. This study suggests a 2D-3D hybrid data model, which combines the 2D topology constructed from CAD floor plans and stored in a spatial DBMS and the 3D visualization functionality. This study showed the process to build the proposed model in a spatial DBMS and use spatial functions and queries to visualize in 2D and 3D. And, then, as an example application, it illustrated the process to build an indoor evacuation simulator.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.22 no.2
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• pp.161-170
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• 2004

This study is to standardize framework data model in facility area. This study focuses on standization of application oriented data model in facility management and other facility applications. In order to outline the framework data model in facility area, building and cultural sub-themes which have been proposed in a previously conducted research have initially been considered. Also various international and domestic standards in framework data for facility area have been analyzed to identify appropriate feature classes and types. In order to avoid future conflicts, many facilities experts from various facility areas including facility database and facility manarement have provided their inputs in this study based on their viewpoints and prospects. As a results of this study, we are developed to features and data model or framework data in facility area.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.2
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• pp.57-65
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• 2008

The improvement of the performance in laser radar simulation requires fast retrievals of the spatial locations and attributes of objects in response to the laser signals of the simulators. Since the data used in simulation are complex 3D objects such as terrain, buildings and vehicles, and are of large sizes, commonly used 3D modeling tools are not suitable for this use. We proposed a method to store such 3D objects in a database, perform required queries and integrate with visualization tools. We showed the processes for the data modeling based on 3D topological concepts and then building a spatial DBMS. Also, we illustrated the process for accessing and visualizing the stored data using VRML and performed test computations using some laser signal data. With further enhancement on data modeling and LOD problems in visualization, the proposed method will be practically applied in different situations including laser simulation.

• Journal of the Korean Geographical Society
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• v.45 no.6
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• pp.788-805
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• 2010

The present USN (Ubiquitous Sensor Networks) node deployment practices have many limitations in terms of positional connectivity. The aim of this research was to minimize a redundancy of USN route nodes, by integrating spatially weighted parameters such as visibility, proximity to cell center, road density, building density and cell overlapping ratio into a comprehensive GIS database. This spatially weighted approach made it possible to reduce the number of route nodes (11) required in the study site as compared to that of the grid network method (24). The field test for RSSI (Received Signal Strength Indicator) indicates that the spatially weighted deployment could comply with the quality assurance standard for node connectivity, and that reduced route nodes do not show a significant degree of signal fluctuation for different site conditions. This study demonstrated that the spatially weighted deployment can be used to minimize a redundancy of USN route nodes in a routine manner, and the quantitative evidence removing a redundancy of USN route nodes could be utilized as major tools to ensure the strong signal in the USN, that is frequently encountered in real applications.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2007.10a
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• pp.169-175
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• 2007

고리, 월성, 울진, 영광 등4개 원전부지와 하나로 연구용 원자로 부지에 대해 방사성물질의 대기 중 누출사고 발생 시 대축척 전자지도와 연계한 사고정보 파악, 예상피해분석, 방재시설 및 소개정보 활용 등을 통해 중앙정부 및 지방자치단체가 방사능 물질 피해지역관리 및 신속하고 효율적인 주민대응조치 수립을 위한 의사 결정 지원할 수 있는 방사능방재 지리정보시스템 구축이 필요하다. 본 연구에서는 고리, 월성, 울진, 영광, 대전지역의 원자력 발전소 및 연구용 원자로 반경 40km이내 지역의 행정경계, 도로, 등고, 수계, 건물 등의 일반지형지물정보와, 비상계획구역 내 마을의 상세정보, 집결지, 대피소, 교통통제소, 환경방사능감시기, TLD등의 방재시설물 위치 및 관련 상세정보, 관공서, 경찰서, 소방서, 보건소, 학교, 병원 등의 방재관련 지형지물 위치 및 관련 상세정보, 원전부지 내 인구분포, 보유 차량 분포, 농작물 재배 현황, 축산물 재배현황 등의 방재관련 사회통계정보를 포함하는 공간 및 속성 데이터베이스는 구축하였다. 이를 기반으로 방사선 피폭영향 평가시스템(FADAS)의 예상평가결과를 전자지도 상에 표출하고, 이에 근거한 예상피해를 분석하며, 소개단계 대상 마을 검색 및 바람장 분석을 활용한 소개경로 제시 등을 통해 주민보호조치 의사결정을 지원하며, 사고대응 및 소개현황 정보를 관리하는 웹 기반의 원자력방재 지리정보시스템을 확대 개발하였다. 방재시설물 및 방재관련 지형지물, 방재관련 사회통계자료의 검색기능 및 실시간 원전 바람장 정보조회, 실시간 ERMS 수집정보 조회, 수치예보 정보 조회, 온라인DB관리 등의 확대 구현을 통해 사고대응조치 및 피해분석업무를 지원하였다. 본 연구를 통한 원자력방재 지리정보시스템 완성을 통해 방사능 비상시 중앙본부와 지역본부 및 유관기관 간에 지리정보와 연계한 정확한 사고정보 및 방재정보의 신속한 공유를 제공하고, 적절한 비상대응조치 의사결정 및 주민보조조치 수행을 지원하여 효율적인 사고지역 관리 및 인적 물적 자원의 피해를 최소화하는데 기여할 것으로 기대된다.

• Journal of the Korean Association of Geographic Information Studies
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• v.10 no.2
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• pp.172-183
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• 2007

Recently geospatial information has used widely in many areas such as effective use and management of national land, establishment of city planning, managements of environments and disasters, etc. But present digital map is not suitable for nowadays because of delay of information renewal and changes of topography. In this study, GIS DB construction method was researched through the process of extracting main vector layers such as buildings, roads, contours, etc. from LiDAR data. In order to analyze accuracies of constructed data, the digital topographic maps of 1:1000 scale which were produced by Korea National Geographic Information Institute(NGI) and results of GPS survey were used. Effective DB construction method was suggested through comparing with existing GIS DB construction methods.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.20 no.2
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• pp.119-126
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• 2002

Recently, as advancing the technologies for Web 3D and Virtual Reality, the studies have been progressed actively to provide three dimensional information on the web. Especially, the various applications for providing urban information in 3D space have been developed using EAI(External Authoring Interface) that serves an interface between VRML(Virtual Reality Modeling Language), standard language for embodying virtual reality, and JAVA applet in HTML. In this study, as constructing 3D virtual city information using Digital Map, IKONOS satellite image, VRML and so on, we could provide users which need several information with building location and various urban living information. In addition, applying 3D skills such as texturing, panorama and navigation, users were enabled to perform various route searching and scenery analysis. Finally, to serve urban living information in real time, we designed to search information faster through interfacing database and to update data using ASP(Active Server Page) on web.

• Korean Journal of Construction Engineering and Management
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• v.9 no.4
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• pp.182-192
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• 2008

The purpose of this research is to identify problems and solutions of domestic Life Cycle Cost analysis in BTL(Build-Transfer-Lease), a PFI(Private Finance Initiatives) project. It is expected BTL would be quite effective delivery method for public construction introducing the private's major capital investments and technologies, and obviously LCC analysis is becoming more important factor for success of BTL projects. Nevertheless, there are still some complicated issues in LCC analysis, a technique for selecting the optimal VE(Value Engineering) proposals and estimating OM&R (Operation, Maintenance, & Repair) cost of the buildings, and has been applied limitedly. This research mainly focuses on educational facility, as most frequently delivered by BTL currently, especially with two levels (Alternative LCC and Building LCC) , which is occupied main potion in BTL project. In addition, it identifies four main problems and suggests their solutions through case studies focusing six major factors (WBS, Repair Information, Life Cycle, Time value of money, Repair Information Database, LCC Model) from three projects. Advanced development of this research requires closer partnership between the private / public sectors, and their long term strategies.