• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.3
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• pp.1-15
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• 2007

In this paper, the return link of interactive GEO satellite network providing multimedia services is considered. First, we classify data by delay characteristics, and analyze the numbers of expected lost packets and expected delay packets for each data class of each terminal. Next we mathematically formulate optimal rate scheduling model to minimize the weighted sum of the numbers of expected lost packets and expected delay packets considering priority of each data class. We also suggest a dynamic rate scheduling scheme based on Lagrangean relaxation technique and subgradient technique to solve the proposed model in a fast time. Extensive experiments show that the proposed scheme provides encouraging results.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.235-237
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• 2003

GIS became increasingly important in information-oriented society as social indirect capital and many GIS data are developed. To use these data effectively standard format that enables easy to transport and store is needed. For this purpose, OGC developed GML based on XML as web standard format of geographical information. In this study, web based mapping with respect to digital geologic map and gravity anomaly map was accomplished using GML. While, styling methods were implemented in XSLT to make the visualizing suitable for the character of each layer, so it is possible to make dynamic maps in the SVG. GML-base map produced in this study can be transferred and represented without loss of the meaning and degrading on the web.

• Journal of Astronomy and Space Sciences
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• v.36 no.3
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• pp.169-180
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• 2019

In this study, a batch least square estimator that utilizes optical observation data is developed and utilized to determine geostationary orbits (GEO). Through numerical simulations, the effects of error sources, such as clock errors, measurement noise, and the a priori state error, are analyzed. The actual optical tracking data of a GEO satellite, the Communication, Ocean and Meteorological Satellite (COMS), provided by the optical wide-field patrol network (OWL-Net) is used with the developed batch filter for orbit determination. The accuracy of the determined orbit is evaluated by comparison with two-line elements (TLE) and confirmed as proper for the continuous monitoring of GEO objects. Also, the measurement residuals are converged to several arcseconds, corresponding to the OWL-Net performance. Based on these analyses, it is verified that the independent operation of electro-optic space surveillance systems is possible, and the ephemerides of space objects can be obtained.

• Proceedings of the KSRS Conference
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• 2003.11a
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• pp.162-164
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• 2003

The multi-disciplinary research project Strengthening Local Authorities in Risk Management (SLARIM), initiated by ITC, includes three case study cities in Asia. An important question is: what are the essential data for risk management and how to access such data. The role of common sources (e.g. census data), data derived from remote sensing (high-resolution satellite imagery, aerial photos), and data from close sensing (field observation, including mobile GIS) to acquire essential risk management data will be discussed. Special attention is given to the question of the minimum area and to disaggregating population data. A few examples are given of Kathmandu / Lalitpur, Nepal.

• Journal of the Semiconductor & Display Technology
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• v.7 no.3
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• pp.59-63
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• 2008

Geo-coding refers to the process of associating data with location information, and the system deals with geographic identifiers expressed as latitude and longitude or street addresses. Although many services have been launched, there still remains a problem for users to create geo-coded photo with manually labeling GPS(Global Positioning System) coordinate or synchronizing with separate devices. In this paper, we design and implement a geo-coding system which utilizes the time and location information embedded in digital photographs in order to automatically categorize a personal photo collection. An included GPS receiver labels a photograph with its corresponding GPS coordinates, and the position of the camera is automatically recorded into the photo image header at the moment of capture. The place and time where the photo was taken allows us to provide context metadata on the management and retrieval of information.

• Proceedings of the Korea Contents Association Conference
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• 2006.05a
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• pp.71-74
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• 2006

By the progress of Information Technology, spatial data have been recognizes as one of essential infrastructure. Now for the near future needs of urban simulation, management, u-City construction, etc. MOCT(Ministry Of Construction & Transportation) have been driving to construct the 3D Geo-spatial Data as one of National Spatial Data Information on a base of 2D GIS(Geographic Information System). In this study we tried to analysis the demands and the optimum implementation method of 3D Geo-spatial Data in local governments. As the result of study, the plan to utilize 3D Geo-spatial Data and to carry out its utilization, and the advanced vision of 3D GIS in for the public affairs of Local Governments and private business scope were proposed.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.26 no.4
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• pp.387-396
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• 2008

An integration between construction CAD data and GIS data needs geo-referencing processes of construction CAD data whose coordinate systems are their own native or even unknown. Generally, these processes are based on manually detected conjugate-vertices. In this study, we proposed an semi-automated conjugate -vertices detection method for building features between construction CAD data and a digital map using a vertex attributed string matching algorithm. A geo-referencing function for construction CAD data based on the similarity transform could be derived with those conjugate-vertices. Using our proposed method, we overlaid geo-referenced CAD data to a digital map of the College of Engineering, Seoul National University and evaluated our method.

• Proceedings of the KSRS Conference
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• v.1
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• pp.508-511
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• 2006

Generally, stereo pair images are necessary for 3D viewing. In the absence of quality stereo-pair images, it is possible to synthesize a stereo-mate suitable for 3D viewing with a single image and a depth-map. In remote sensing, DEM is usually used as a depth-map. In this paper, LiDAR data was used instead of DEM to make a stereo pair from a single aerial photo. Each LiDAR point was assigned a brightness value from the original single image by registration of the image and LiDAR data. And then, imaginary exposure station and image plane were assumed. Finally, LiDAR points with already-assigned brightness values were back-projected to the imaginary plane for synthesis of a stereo-mate. The imaginary exposure station and image plane were determined to have only a horizontal shift from the original image's exposure station and plane. As a result, the stereo-mate synthesized in this paper fulfilled epipolar geometry and yielded easily-perceivable 3D viewing effect together with the original image. The 3D viewing effect was tested with anaglyph at the end.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.12
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• pp.5877-5897
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• 2018

With the popularity of mobile networks and smartphones, geo-textual publish/subscribe messaging has attracted wide attention. Different from the traditional publish/subscribe format, geo-textual data is published and subscribed in the form of dynamic data flow in the mobile network. The difference creates more requirements for efficiency and flexibility. However, most of the existing Top-k geo-textual publish/subscribe schemes have the following deficiencies: (1) All publications have to be scored for each subscription, which is not efficient enough. (2) A user should take time to set a threshold for each subscription, which is not flexible enough. Therefore, we propose an efficient and flexible Top-k geo-textual publish/subscribe scheme. First, our scheme groups publish and subscribe based on text classification. Thus, only a few parts of related publications should be scored for each subscription, which significantly enhances efficiency. Second, our scheme proposes an adaptive publish/subscribe matching algorithm. The algorithm does not require the user to set a threshold. It can adaptively return Top-k results to the user for each subscription, which significantly enhances flexibility. Finally, theoretical analysis and experimental evaluation verify the efficiency and effectiveness of our scheme.

• The KIPS Transactions:PartD
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• v.8D no.5
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• pp.516-572
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• 2001

Geographic Information System(CIS) deal with data which can potentially be useful for a wide range of applications. The information needed by each application can be vary, specially in resolution, detail level, application view, and representation style, as defined in the modeling phase of the geographic database design. To be able to deal with such diverse needs, GIS must offer features that allow multiple representation for each geographic entity of phenomenon. This paper addresses on the problem of formal definition of the objects and their relationships on the geographical information systems. The geographical data is divided into two main classes : geo-objects and geo-fields, which describe discrete and continuous representations of spatial reality. I studied the attributes and the relationship roles over geo-object and nongeo-object. Therefore, this paper contributed on the efficient design of geographical class hierarchy schema by means of formalizing attribute-domains of classes.