• Journal of Broadcast Engineering
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• v.5 no.2
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• pp.167-175
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• 2000

Compressed bitstreams generated by an MPEG-2 video encoder (or digital TV picture transmission are quite sensitive to channel errors. Due to the coding structure of the MPEG-2 video compression algorithm, a single bit error can affect not only the current Picture frame but also succeeding frames. Error concealment algorithms attempt to repair damaged portions of the picture by exploiting spatial and temporal redundancies in the correctly received and reconstructed video frames. In this paper, we analyze the effect of channel errors in MPEG-2 video bitstreams and estimate lost motion vectors by exploiting temporal redundancies in the video frames. Motion vectors can be estimated from the vertically adjacent extended region of lost macroblocks. Finally, we conceal the damaged macroblocks by compensating the displacement with the estimated motion vectors. Simulation results demonstrate that both the weighted sum algorithm and the extension matching algorithm achieve good performance in terms of PSNR values as well as subjective image quality.

• Korean Journal of Remote Sensing
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• v.35 no.2
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• pp.317-326
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• 2019

Development projects and related environmental impacts take place in space. Therefore, it is important to use spatial information in the environmental impact assessment process. This study proposes to construct spatial information produced by various organizations as an inventory and suggests it to be utilized in environmental impact assessment process. For this purpose, investigate the use of spatial information in the environmental impact assessment process and list of environmental space information provided by public information systems. and applied the methodology derived from previous studies to build an inventory of spatial information using environmental impact assessment. The spatial information utilized in the environmental impact assessment work was 64 items. Based on the data availability, linkage and renewability, the spatial information of the Environment that can be used for the environmental impact assessment was 45 items. Finally 49 items, including 19 new items were presented as an inventory, contributing to the performance of environmental impact assessment based on spatial information.

• Journal of KIISE:Information Networking
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• v.34 no.5
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• pp.305-315
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• 2007

Broadband Convergence Network (BcN) is the network which unifies telephone network, the Internet and broadcasting networks. Threats to each network can bring serious problems in BcN environment since the whole network can be damaged by various types of attack. The purpose of this study is to suggest the prototype of intrusion-tolerant network design of BcN to guarantee the continuous operation of BcN services against malicious attacks. First, BcN service components, selected by analysis of service time and coverage importance, are classified into three groups by their type: server type, gateway type and hybrid type. Second, the necessity of applying intrusion tolerance on BcN services is deduced by possible attack scenarios on BcN. Finally, we suggest the intrusion-tolerant network design suitable to BcN, using hardware redundancy and secure policies. Also, we present that the suggested network design can increase the intrusion tolerance of BcN.

• Proceedings of the Korean Association of Geographic Inforamtion Studies Conference
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• 2004.03a
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• pp.189-194
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• 2004

최근 정보통신기술의 급속한 발전은 Mobile 기반의 GIS 구현 및 활용을 가능하게 하였다. 현재 지자체 상하수도관리업무는 현장작업(외업)과 실내작업(내업)이 혼합되어 있으며, 시설물 관리 및 공사감독 업무의 경우 현장작업과 실내업무가 같은 연장선상에 있어 기존 업무흐름체계로는 업무를 이중으로 처리하여야 하는 문제점이 있다. 이러한 문제점은 데이터의 오류 및 중복업무에 따른 업무가중을 초래하여 업무효율성 제고에 영향을 미친다. 본 연구에서는 이러한 문제점의 해결방안을 찾고자 경기도 고양시를 연구 대상지역으로 하여, Mobile GIS를 기반으로 한 상하수도 관리업무의 효율적인 지원방안을 연구하였고, 그에 따른 효율성을 정량적으로 분석하였다.

• Journal of Information Management
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• v.39 no.2
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• pp.131-161
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• 2008

Recently electronic journal articles prevail throughout researchers because of the development of internet and electronic publishing technology. It is caused by limited collection development budget, lack of physical storage space for printed journals in libraries, and the user convenience of web services. But from the view of ownership, electronic journals can be unfavorable to information users or libraries who cannot have the permanent right to access all the subscribed journals. Actually the libraries only have right to access journals for subscription periods in using electronic journals. So the users and libraries are willing to purchase printed journals in spite of high cost. As an basis for collaborative collection development and sharing preservation of Korean libraries for the foreign journals, the data analysis is carried out for the journals collection in terms of regional distribution, overlapping status, and journal subject. And the considerables are discussed for collaborative strategic collection development, which means the reduction of overlapped subscription and maximization of utilization in a national standpoint.

• The Journal of the Korea Contents Association
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• v.6 no.2
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• pp.105-116
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• 2006

With the development of IT technology, the amount of digital contents used in various environments of wired/wireless networks have been increased hugely and rapidly To protect the loss of the digital contents from the sudden accident, continuous data backup is required. In this paper, we design and implement the backup system that stores digital contents in backup storage by objectifying the contents with a unit of I/O size and giving them the unique E using the properties of digital contents to avoid duplicated store of the same data. The backup system reduces the amount of backup data efficiently by backing up the only one copy of the duplicated data. as a result, the backup system can back up the digital contents more efficiently in a constrained storage space.

• Journal of the Korea Society of Computer and Information
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• v.14 no.8
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• pp.43-50
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• 2009

Text information in a digital video provides crucial information to acquire semantic information of the video. In the proposed method. text candidate regions are extracted from input sequence by using characteristics of stroke and text candidate regions are localized by using projection to produce text bounding boxes. Bounding boxes containing text regions are verified geometrically and each bounding box existing same location is tracked by calculating matching measure. which is defined as the mean of absolute difference between bounding boxes in the current frame and previous frames. Finally. text regions are enhanced using temporal redundancy of bounding boxes to produce final results. Experimental results for various videos show the validity of the proposed method.

• Journal of the Korea Society of Computer and Information
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• v.14 no.11
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• pp.31-40
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• 2009

The most common cleaning methods of cleaning robot can be divided into two categories: the random and the boustrophedon method. A cleaning robot using the random method moves straight until it bumps into an obstacle. If it collides with an obstacle, the cleaning robot turns a specific angle and continues moving straight. Therefore, the random method often tends to clean the already clean area repeatedly. In addition, it takes a long time to complete cleaning. A cleaning robot using the boustrophedon method moves straight until it collides with an obstacle. If it meets an obstacle, the cleaning robot moves to the next uncleaned space through turning and moving ahead. when resuming cleaning from the new region, a cleaning robot moves in the direction opposite to the direction of the previous cleaning. Because the boustrophedon method cleans a cleaning space more densely, its performance is excellent in an obstacle-free space or a small space. However, In a space with obstacles or a complex structure, it takes a long time to complete the cleaning work. Cleaning should be systematically approached with a good understanding of the work area. The virtual map-based cleaning robot proposed in this paper cleaned a work space efficiently. The efficiency of the proposed method was measured through simulation.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.22 no.5
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• pp.182-199
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• 2023

Since 2021, government departments have been promoting Automated Driving Technology Development and Innovation Project as national research and development(R&D) project. The automated vehicles and service technologies developed as part of these projects are planned to be subsequently provided to the public at the selected Living Lab City. Therefore, it is important to determine a spatial area and operation section that enables safe and stable automated driving, depending on the purpose and characteristics of the target service. In this study, the static Operational Design Domain(ODD) elements for Level 4 automated driving services were reclassified by reviewing previously published papers and related literature surveys and investigating field data. Spatial analysis techniques were used to consider the reclassified ODD elements for level 4 in the real area of level 3 automated driving services because it is important to reflect the spatial factors affecting safety related to real automated driving technologies and services. Consequently, a total of six driving mode changes(disengagement) were derived through spatial information analysis techniques, and the factors affecting the safety of automated driving were crosswalk, traffic light, intersection, bicycle road, pocket lane, caution sign, and median strip. This spatial factor analysis method is expected to be useful for determining special areas for the automated driving service.

• Journal of Korea Spatial Information System Society
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• v.2 no.1 s.3
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• pp.91-107
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• 2000

Geographic Information Systems(GISs) generally use a very large amount of spatial data. and are implemented on various software and hardware system. If it is impossible to exchange the spatial data efficiently among the different hardware, software, and operation systems, data sharing will be very difficult and duplicated storage & management of the spatial data will result in a great economic loss. To solve such problems, a national organization established a national standard for GIS and constructed spatial databases at the national level. In Korea, SDTS(Spatial Data Transfer Standard) is selected as a national standard for the common data transfer format. In this paper, we design and implement a SDTS Data Management System which can support display, insertion, update, deletion of SDTS data, extraction and creation of a specified area, error checking and reporting, setting and verification of a SDTS profile through the GUI (Graphic User Interface) environment. Hereafter, as GIS industry is continually activated and a demand for the SDTS data increases, a requirement for analysis and trust of the SDTS data will grow bigger, so the necessity of the SDTS Data Management System developed in this paper will also grow rapidly.