• Proceedings of the Korean Information Science Society Conference
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• 1999.10a
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• pp.326-328
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• 1999

지리정보시스템(GIS) 클라이언트는 Open API를 이용한 개방형 구조를 지향하고 있다. OLE DB는 OLE/COM을 기반으로 다양한 데이터 소스에 대한 표준 인터페이스를 제공하기 때문에 서로 다른 데이터 소스에 대한 상호운용성을 지원하는 것이 용이하다. 그러나 OLE DB를 이용하여 공간 데이터를 수정하는 경우에 Two-Phase Locking 방식으로 인한 긴 대기시간(Long Wait)과 set 단위의 locking을 지원하지 않는 문제가 발생한다. 본 논문은 OLE DB를 이용한 공간데이터의 수정을 위하여 Row 단위의 잠금이 아닌 Rowset 단위의 영역잠금을 위한 잠금 모드와 인터페이스를 정의한다. 그리고 긴 대기시간을 해결하고 동시성을 높이기 위해 동시수정 트랜잭션 인터페이스를 정의하고 프로토콜을 제시한다.

• Journal of the Korean Association of Geographic Information Studies
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• v.11 no.1
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• pp.31-44
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• 2008

The 1st phase framework data implementation of National Geographic Information Systems (NGIS) used 1:5,000 digital map with 5 years updating period which is lacking in the latest information. This is a significant factor which hinders the use of framework data. This study proposed the efficient technical method of a location based object data management and system implementation for updating framework data. First, we did an object-oriented data modeling and database design using a location based features identifier(UFID: Unique Feature IDentifier). The second, we developed the system with various functions such as a location based UFID creation, input and output, a spatial and attribute data editing, an object based data processing using UML(Unified Modeling Language). Finally, we applied the system to the study area and got high quality data of 99% accuracy and 35% benefit effect of personnel expenses compare to the previous method. We expect that this study can contribute to the maintenance of national framework data as well as the revitalization of various GIS markets by providing user the latest framework data and that we can develop the methods of a feature-change modeling and monitoring using an object based data management.

• Spatial Information Research
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• v.17 no.2
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• pp.231-241
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• 2009

Recently, The importance of a quality control for implementing 3D geospatial database has being emphasized to build a 21st century knowledge society and an ubiquitous land. The improvement of 3D geospatial database quality control through establishing an integrated quality control makes data suppliers update data efficiently and users get high quality data. The purpose of this study was to derive the improvement plan of 3D geospatial database quality control through the analyses of the existing 3D geospatial database quality control and case studies. The results of this study are as follows. Firstly, we defined the concept of 3D geospatial database quality control. Secondly, we set the boundary, factors and process of 3D geospatial database quality control through classifying it in detail. Lastly, we drew improvement contents such as the quality control checklist by implementation process according to the improvement plan of 3D geospatial database implementation.

• Journal of Astronomy and Space Sciences
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• v.19 no.4
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• pp.351-366
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• 2002

In this study, we developed low cost INS and (D)GPS integration for continuous attitude and position and utilized it for the determination of exterior orientation parameters of image sensors which are equipped in 4S-Van. During initial alignment process, the heading information was extracted from twin GPS and fine alignment with Kalman filter was performed for the determination of roll and pitch. Simulation and van test were performed for the performance analysis. Based on simulation result, roll and pitch error is around 0.01-0.03 degrees and yaw error around 0.1 degrees. Based on van test, position error in linear road is around 10 cm and curve around 1 m. Using direct georeferencing method, the image sensor's orientation and position information can be acquired directly from (D)GPS/INS integration. 4S-Van achieved 3D spatial data using (D)GPS/INS and image data can be applied to the spatial data integration and application such as contemporary digital map update, road facility management and Video GIS DB.

• Asian Journal of Atmospheric Environment
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• v.10 no.1
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• pp.42-50
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• 2016

This study presents a performance evaluation of four different land surface models (LSM) available in Weather Forecast Research (WRF). The research site was located in Haean Basin in South Korea. The basin is very unique by its geomorphology and topography. For a better representation of the complex terrain in the mesoscale model were used a high resolution topography data with a spatial resolution of 30 meters. Additionally, land-use layer was corrected by ground mapping data-sets. The observation equipments used in the study were an ultrasonic anemometer with a gas analyzer, an automatic weather station and a tethered balloon sonde. The model simulation covers a four-day period during autumn. The result shows significant impact of LSM on meteorological simulation. The best agreement between observation and simulation was found in the case of WRF with Noah LSM (WRF-Noah). The WRF with Rapid Update Cycle LSM (WRF-RUC) has a very good agreement with temperature profiles due to successfully predicted fog which appeared during measurements and affected the radiation budget at the basin floor. The WRF with Pleim and Xiu LSM (WRF-PX) and WRF with Thermal Diffusion LSM (WRF-TD) performed insufficiently for simulation of heat fluxes. Both overestimated the sensible and underestimated the latent heat fluxes during the daytime.

• The KIPS Transactions:PartA
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• v.13A no.3 s.100
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• pp.241-252
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• 2006

In cluster file systems, the availability of files has been supported by replicating entire files or generating parities on parity servers. However, those methods require very large temporal and spatial cost, and cannot handle massive failures situation on the file system. So we propose HA-PVFS, a cluster file system supporting high data availability adaptive to temporal locality. HA-PVFS restricts replication or parity generation to some important files, for that it employs an efficient algorithm to estimate file access patterns from limited information. Moreover, in order to minimize the performance degradation of the file system, it uses delayed update method and relay replication.

• Journal of Korean Society for Geospatial Information Science
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• v.16 no.3
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• pp.35-41
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• 2008

Recently needs for the convergence of CAD and GIS data are increasing, and many studies on converting two systems to each other are being carried out. In this study, to revise and update the building data of digital map using CAD data for construction, the outline of building is abstracted from the CAD data and the outline is generalized to the same level of detail with the building data of digital map. Several line simplification algorithms to generalize the outline are adopted and compared, especially at the view of satisfaction to the drawing rule for digital map. Douglas-Peucker algorithm, Lang's algorithm, Reumann-Witkam algorithm, and Opheim algorithm are applied as the line simplification method. To evaluate the results of these algorithms, visual assessment and variation ratio of the number of points, total length of lines, the area of polygon, and satisfaction ratio to the drawing rule of digital map are analyzed. The result of Lang algorithm and Douglas-Peucker algorithm show superior satisfaction ratio. But general satisfaction ratio is 50~60% for all algorithm. Therefore there seems to be a limit to use these algorithms for the simplification method to update the building data in digital map and it is necessary to develop line simplification algorithm which satisfy the drawing rule well.

• Korean Journal of Construction Engineering and Management
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• v.10 no.5
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• pp.148-157
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• 2009

When an emergency situation happens in buildings, the top priority is to ensure the occupant from danger as soon as possible. Achieving that goal is a multifaceted and difficult task. However, current evacuation systems have many deficiencies in dealing with the emergency in multi-level structures. The shortage of abilities to continuously update database, predict the future situation and provide the information to users with contextual information is the limit in current systems. Thus, it is very crucial to introduce Evacuation Information System (EIS), which is able to respond quickly to the emergency, and transfer the information to both the administrator and the occupant. The main purpose of this paper is to build EIS on the basis of the indoor Geographical Information System (GIS). When the emergency happens, EIS gives the instruction to Emergency Response Model (ERM) at once. ERM carries out the order and calculates the optimal evacuation routes, then sends the result to EIS. At last, EIS transmits evacuation messages to the occupant who implements evacuation plan. This paper highlights the benefits of EIS in two aspects. One is that EIS can update the data continuously to support evacuation strategy-making. The other is that it can transmit evacuation messages to both the administrator and the occupant.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.96-100
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• 2004

In the ship building industry various problems of erection is counterfeited due to formation of bottle necks in the block erection flow pattern This kind of problems cause accumulated problems in real-time erection right on the floor, When such a problem is approached, a support data of the entire erection sequence should be available, Here planning is done by reasoning about the future events in order to verify the existence of a reasonable series of actions to accomplish a goal. This technique helps in achieving benefits like handling search complications, in resolving goal conflicts and anticipation of bottleneck formation well in advance to take necessary countermeasures and boosts the decision support system, The data is being evaluated and an anticipatory function is to be developed This function is quite relevant in day to day planning operation. The system updates database with rearrangement of off-critical blocks in the erection sequence diagram, As a result of such a system, planners can foresee months ahead and can effectively make decisions regarding the control of loads on the man, machine and work flow pattern, culminating to an efficient load management. Such a foreseeing concept helps us in eliminating backtracking related adjustment which is less efficient compared to the look-ahead concept. An attempt is made to develop a computer program to update the database of block arrangement pattern based on heuristic formulation.

• Spatial Information Research
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• v.13 no.4 s.35
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• pp.373-380
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• 2005

Mobile Mapping Systems are effective systems to acquire the position and image data using vehicle equipped with the GPS (Global Positioning System), IMU (Inertial Measurement Unit), and CCD camera. They are used in various fields of road facility management, map update, and etc. In the general photogrammetry such as aerial photogrammetry, GCP (Ground Control Point)s are needed to compute the image exterior orientation elements (the position and attitude of camera). These points are measured by field survey at the time of data acquisition. But it costs much time and money. Moreover, it is not possible to make sufficient GCP as much as we want. However Mobile Mapping Systems are more efficient both in time and money because they can obtain the position and attitude of camera at the time of photographing. That is, Image Orientation Technique must use GCP to compute the image exterior orientation elements, but on the other hand Direct Georeferencing can directly compute the image exterior orientation elements by GPS/INS. In this paper, we analyze about the positional accuracy comparison of ground point using the Image Orientation Technique and Direct Georeferencing Technique.