• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.609-619
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• 2016

RHadoop is a collection of R packages that allow users to manage and analyze data with Hadoop. In this paper, we implement K-Means algorithm based on MapReduce framework with RHadoop to make the clustering method applicable to large scale data. The main idea introduces a combiner as a function of our map output to decrease the amount of data needed to be processed by reducers. We showed that our K-Means algorithm using RHadoop with combiner was faster than regular algorithm without combiner as the size of data set increases. We also implemented Elbow method with MapReduce for finding the optimum number of clusters for K-Means clustering on large dataset. Comparison with our MapReduce implementation of Elbow method and classical kmeans() in R with small data showed similar results.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.12
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• pp.1053-1060
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• 2016

As location recognition for autonomous vehicles develops, the need for a precise map for autonomous driving has increased. A precise map must be built based upon accurate position. Recent studies have accelerated research in this area by using various sensors that calculate the accurate position by comparing and recognizing objects around the roads. However, application of such methods is limited because these studies only take objects with significant verticality into consideration. Thus, new research is needed to overcome the limitations: a method that is not constrained by the existence of certain types of surrounding objects shall be proposed. Most roads contain road marking information, such as lanes, direction signs, and pedestrian crossings. Such information on the road surface is a valuable resource for building a precise map. This paper proposes a method of building a precise map by using road marking information.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2022.10a
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• pp.75-76
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• 2022

WPS is a system that finds the location of a current moving object through information of a wireless AP. The current location is determined by utilizing the outdoor and indoor AP signal strength characteristics. Even if the map is configured for the first service, the map information of the DB built by the variability of the AP signal cannot be 100% reliable in the case of outdoor. Therefore, various algorithms are needed to increase the accuracy of WPS. This paper proposes a system to increase positioning accuracy by applying various methods to determine the current position of a moving object.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2003.11a
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• pp.15-20
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• 2003

As an emerging technology in Computer graphics areas, SVG(Scalable Vector Graphic) makes it possible to make use of Vector graphics for servicing maps in basic internet browsing environment. SVG based thematic map Internet GIS system implemented by this research is free of special server side GIS mapping system and client side extra technology. It provides high-quality vector map which can interact with the user, template map which can be used for other purpose, glance the future map based on Webservices technologies. Many good characteristics of SVG in mapping at computer screen and reusability of SVG document provide new era of visualzation of geographic information.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.26 no.6B
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• pp.856-866
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• 2001

본 논문에서는 radix-4 방식을 이용한 고속 터보 MAP 복호 알고리즘을 제안하고 이를 설계하기 위해 VHDL 모델링 하였다. VHDL 시뮬레이션을 하기 위해 radix-4 방식의 터보 MAP 복호기의 구조를 설계하였으며, 복호속도 효율성을 분석하기 위해 기존의 Radix-2 방식의 복호기도 VHDL 시뮬레이션 하였다. 구현 결과, 약 2.4배의 복호속도 향상을 알 수 있었다.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.43 no.2 s.344
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• pp.16-21
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• 2006

Internet Engineering Task Force(IETF) proposed the Hierarchical Mobile IPv6(HMIPv6) to support mobility efficiently. The HMIPv6 was developed to reduce the signaling overhead and delay concerned with Binding Update in Mobile IPv6. However, the HMIPv6 still need a further enhancement for supporting the real-time application because HMIPv6 only concerns with the latency resulted within a MAP For providing seemless handoff we propose a scheme that can reduce latency when Mobile Node changes a MAP. Also we compare the HMIPv6 with the proposed scheme through a analysis model.

• Spatial Information Research
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• v.15 no.1
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• pp.15-23
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• 2007

Recently, Korea became the first country which started Terrestrial-DMB service. The DMB service is still at a very early stage throughout the world. At this stage, it is an important issue to develop DMB contents which distinguish DMB from traditional broadcasting by utilizing DMB's mobility. In this paper, we will propose outline of map service through DMB along with related services such as traffic and location information. This outline includes the map service protocol and map data structure for DMB. There is little research at the moment related to it, and this preliminary research enables map service through DMB. A map service would bring DMB a distinct advantage over traditional broadcasting. Moreover, further services based on broadcasting network and mobility would contribute to rapid growth of DMB.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.12C
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• pp.1194-1200
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• 2006

In this paper, we propose an adaptive MAP (Maximum A Posteriori) high-resolution image reconstruction algorithm using local statistics. In order to preserve the edge information of an original high-resolution image, a visibility function defined by local statistics of the low-resolution image is incorporated into MAP estimation process, so that the local smoothness is adaptively controlled. The weighted non-quadratic convex functional is defined to obtain the optimal solution that is as close as possible to the original high-resolution image. An iterative algorithm is utilized for obtaining the solution, and the smoothing parameter is updated at each iteration step from the partially reconstructed high-resolution image is required. Experimental results demonstrate the capability of the proposed algorithm.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.19 no.1
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• pp.85-93
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• 2001

Digital mapping project of topographic map was conducted according to the master plan for the development of the National Geographic Information System, to manage national geo-spatial information efficiently in rapidly changing information technology society. It needed to correct and supplement digital map because of time pressure, sudden urbanization and users'need. In this study, after the framework data of thematic map was given a definition based on data model of National Base Map, data model of topographic-cadastral map was presented. Also data format and meta data suited to presented data model of topographic-cadastral map were presented so that they could be used in various fields.

• KIISE Transactions on Computing Practices
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• v.21 no.4
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• pp.299-307
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• 2015

Currently, many kinds of World Wide Web contents are produced by an individual journalism. Users who simply obtain information by surfing the web becomes the producer, and many contents created by these users reflect on their own interesting topics and social issues. Among these issues, the environmental contents are considered in this study, which we proposed as EcoMap, a media service platform for such contents. In terms of EcoMap, a way of thinking about our own environment would be affected, and the environmental information will be produced and shared more effectively by the users on the web.