• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2009.01a
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• pp.572-577
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• 2009

This paper proposes a novel reversible image authentication method that requires neither location map nor memorization of parameters. The proposed method detects image tampering and further localizes tampered regions. Though this method once distorts an image to hide data for tamper detection, it recovers the original image from the distorted image unless no tamper is applied to the image. The method extracts hidden data and recovers the original image without memorization of any location map that indicates hiding places and of any parameter used in the algorithm. This feature makes the proposed method practical. Simulation results show the effectiveness of the proposed method.

• Journal of information and communication convergence engineering
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• v.6 no.2
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• pp.187-191
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• 2008

In the mobile environments for the vector map services, a map simplification work through the map generalization steps helps improve the readability of the map on a large scale. The generalization operations are various such as selection, aggregation, simplification, displacement, and so on, the formal operation algorithms have not been built yet. Because the algorithms require deep special knowledge and heuristic, which make it hard to automate the processes. This thesis proposes some map generalization algorithms specialized in mobile vector map services, based on previous works. This thesis will show the detail to adapt the approaches on the mobile environment, to display complex spatial objects efficiently on the mobile devices which have restriction on the resources.

• Journal of the Semiconductor & Display Technology
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• v.15 no.3
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• pp.67-71
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• 2016

This paper addresses a problem of defocus map recovery from single image. We describe a simple effective approach to estimate the spatial value of defocus blur at the edge location of the image. At first, we perform a re-blurring process using Gaussian function with input image, and calculate a gradient magnitude ratio with blurring amount between input image and re-blurred image. Then we get a full defocus map by propagating the blur amount at the edge location. Experimental result reveals that our method outperforms a reliable estimation of depth map, and shows that our algorithm is robust to noise, inaccurate edge location and interferences of neighboring edges within input image.

• Journal of Internet Computing and Services
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• v.6 no.5
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• pp.97-110
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• 2005

Recently, many WMS(Web Map Services) and POI(Point of Interest) services come to be in service on the Internet using Web GIS(Geographic Information System) as Information Technology and computer H/W are evolved faster in its speed, network bandwidth and features. The Web GIS is, however, limited and constrained on the specification of its system configuration, the service class provided and the presentation methodology of a map. As the mobile Internet becomes popular in mobile service, Web GIS service on mobile environment is strongly required and to be provided by location based WMS(Web Map Service) on a mobile client such as PDA with location information of the user. In this paper, we made an effort to design and implement a GIS computing environment by thin client for mobile web map service. For implementing the thin client GIS computing environment. we were using NGII's(National Geographic Information Institute's) DXF map, representing the map by SVG(Scalable Vector Graphics) recommended by OGC(OpenGis Consortium), and adapting standard XML web service to provide the thin client GIS service on PDA by applying the location information of the user in realtime with GPS on mobile environment.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2010.10a
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• pp.672-674
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• 2010

There are various ways for expressing map on android system. The typical method is to use the API provided by Google, called geocoding although simple display of location of GPS is possible, but node expression of road or the detail information on map for various location service are not available. And it is difficult to express a location in shadow area. In this paper, to solve these problems, we propose a map expression method for location service in specific area based on geocoding and apply the method.

• Journal of the Korean Association of Geographic Information Studies
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• v.9 no.1
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• pp.149-157
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• 2006

The purpose of this study is to search for location potential in Busan metropolitan city and to support decision-making in land use policy. As basis work for the analysis of the location potential, we build rank-map database by using the 11 index. And then by using rank-map, we carried out the location potential ($P_i$) analysis. As a result, we found that many commercial use located in Rank 1 to 2. Also, Rank 4-7 must be made an un-commercial use in assignment of land use zone. These data can be effectively used for land use plan in Busan metropolitan city as the basis data.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06c
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• pp.255-257
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• 2011

본 연구에서는 각종 웹사이트와 이메일을 통해 전달되는 회의공지에 포함된 회의장소를 나타내는 문자열로부터 실제 위치를 추정하는 시스템을 설계 및 구현하였다. 직접 구현한 NER과 Relation-type Classification 모듈을 사용하였으며, 장소에 대한 모델은 기존의 지리정보시스템들과의 상호 운용성을 위하여 OpenStreetMap[6]과 Geonames[7]의 데이터 구조를 참조하여 설계되었고, 실제 위치를 구하기 위하여 내부자원 외에도, 각종 오픈API들을 외부자원으로 활용하였다.

• Journal of Digital Contents Society
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• v.19 no.8
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• pp.1617-1623
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• 2018

It is necessary to develop a next generation location referencing method with higher accuracy as advanced technologies such as autonomous vehicles require higher accuracy of location data. Thus, we proposed a framework for a lane-level location referencing method (L-LRM) based on high-precision digital road network map, and developed a tool which is capable of analyzing and evaluating the proposed method. Firstly, the necessity and definition of location referencing method was presented, followed by the proposal of an L-LRM framework with a fundamental structure of high-precision digital road network map for the method. Secondly, an architecture of the analysis and evaluation tool was described and then the Windows application program was developed using C/C++ programming language. Finally, we demonstrated the performance of the proposed framework and the application program using two different high precision digital maps with randomly generated road event data.

• Journal of Korea Multimedia Society
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• v.8 no.8
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• pp.1023-1031
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• 2005

LBS(Location Based Service) and GIS (Geographic Information System) are supporting necessary services for system which provides geographic information using location information based on various platforms. However the mobile computing environments such as PDA system have serious limitations in functional viewpoints compare of general computing environments, it has problems for developing GIS system which is providing various information. In this paper, we suggest the reduced methods of digital map and format of web-linked digital mao in order to fit in mobile environment. As a result of map generation, the total capacity of the supported digital map was diminished about $99.34\%$ than the original map.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.10 no.11
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• pp.5547-5562
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• 2016

JPEG-LS is an international standard for lossless or near-lossless image-compression algorithms. In this paper, a simple method is proposed to improve the performance of the lossless JPEG-LS algorithm. With respect to JPEG-LS and its supplementary explanation, Golomb-Rice (GR) coding is mainly used for entropy coding, but it is not used for long codewords. The proposed method replaces a set of long codewords with a set of shorter location map information. This paper shows how efficiently the location map guarantees reversibility and enhances the compression rate in terms of performance. Experiments have also been conducted to verify the efficiency of the proposed method.