• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2008.02a
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• pp.13-16
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• 2008

패치 분배 시스템은 중앙 집중 방식의 구조를 가지고 있다. 이런 중앙 집중 방식의 구조는 많은 사용자가 존재할 경우 영향력이 서버에 집중된다. 따라서 한 노드로 미치는 영향을 최소화하기 위해서 본 논문에서는 P2P 통신 구조의 유연함과 분산적인 성격을 이용한 패치 분배 시스템 구조를 제시한다. 또한 패치 파일이 정상적으로 안전하게 전송 하도록 P2P 프레임 워크를 제안 한다. 이 프레임 워크는 파일에 대한 내용변조에 민감하게 반응 하도록 설계 되었다. 그러므로 우리는 웜, 바이러스, 그리고 해킹에 입구가 되는 취약점을 없애기 위한 패치 파일을 빠른 속도로 네트워크의 구성원에 전파 할 수 있게 된다.

• IEMEK Journal of Embedded Systems and Applications
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• v.10 no.6
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• pp.345-352
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• 2015

Recently, by developing many training systems in battle field, the demand for interconnecting and internetworking between Live, Virtual, Constructive training systems has been increased to support efficient data distribution and system control. But, there are lots of problems for them to interwork, because the existing researches only support L-L, V-V, C-C Interoperability. Therefore, we propose L-V-C gateway to provide interoperable simulation environment based on HLA and DDS between them. First, we illustrate FOM Management that parses RPR-FOM XML file to acquire Data information to be shared between them, and generates common data structure and source code used for L-V-C Gateway. L-V-C Gateway created from FOM Management supports Data Conversion and Quality of Service between HLA and DDS. HLA Federate and DDS Domainparticipant in L-V-C Gateway play a role of logical communication channel and relay data from HLA Federation to DDS Domain and vice versa.

• Genomics & Informatics
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• v.4 no.4
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• pp.173-181
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• 2006

Pattern finding is one of the important tasks in a protein or DNA sequence analysis. Alignment is the widely used technique for finding patterns in sequence analysis. BLAST (Basic Local Alignment Search Tool) is one of the most popularly used tools in bio-informatics to explore available DNA or protein sequence databases. BLAST may generate a huge output for a large sequence data that contains various sequence patterns. However, BLAST does not provide a tool to summarize and analyze the patterns or matched alignments in the BLAST output file. BLAST lacks of general and robust parsing tools to extract the essential information out from its output. This paper presents a pattern summary system which is a powerful and comprehensive tool for discovering pattern structures in huge amount of sequence data in the BLAST. The pattern summary system can identify clusters of patterns, extract the cluster pattern sequences from the subject database of BLAST, and display the clusters graphically to show the distribution of clusters in the subject database.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.9
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• pp.3539-3558
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• 2015

This paper investigates and analyzes the default block placement strategy of HDFS. HDFS is a typical representative distributed file system to stream vast amount of data effectively at high bandwidth to user applications. However, the default HDFS block placement policy assumes that all nodes in the cluster are homogeneous, and places blocks with a simple RoundRobin strategy without considering any nodes' resource characteristics, which decreases self-adaptability of the system. The primary contribution of this paper is the proposition of a network load sensitive block placement strategy. We have implemented our algorithm and justify it through extensive simulations and comparison with similar existing studies. The results indicate that our work not only performs much better in the data distribution but also improves write performance more significantly than the others.

• Proceedings of the Korean Information Science Society Conference
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• 2011.06d
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• pp.163-166
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• 2011

클라우드 컴퓨팅이란 인터넷 기술을 활용하여 모든 인프라 자원(소프트웨어, 서버, 스토리지, 네트워크 등)을 서비스화(as a Service)하여, 언제, 어디서든, 장치에 독립적으로 네트워크를 통해 사용하고, 사용한 만큼 비용을 지불하는 컴퓨팅으로써, 대표적인 서비스 업체로는 구글과 아마존이 있다. 최근 아파치 재단에서는 구글의 GFS와 동일 또는 유사한 시스템을 만들기 위해 HDFS 오픈소스 프로젝트를 진행하고 있다. HDFS는 빈번한 하드웨어 고장에도 원본 데이터를 복구할 수 있는 가용성을 보장하기 위해 파일 데이터를 블록 단위로 나누어, 다시 datanode에 복제하여 저장한다. 이 기법은 복제가 많아 질수록 가용성은 높아지나 스토리지가 증가한다는 단점을 가지고 있다. 따라서 본 논문에서는 이러한 문제점을 해결하기 위해 행렬의 특성을 이용한 새로운 분산 저장 기법을 제안한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.3
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• pp.575-580
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• 2017

In these days, the big-size and high resolution multimedia file is widely used through networks. To transfer and service effectively, the internet network technology is necessary to substitute broadcasting. Normally Content Delivery Network(CDN) is widely used in conventional internet for multimedia services. But it has a small bandwidth to service. So to solve this problems, many researchers have suggest the protocol for download, content distribution/saving, server synchronization, caching, pushing rate, and streaming etc. But all of these has some defects like low resolution, packets loss and delay, real application implementations etc. So, this paper suggests a new method of network protocol based on P2P collaboration and user's content using information. And it evaluated the performance of suggested method. As the results, it showed the effectiveness of 4 performances indices : download speed, decreasing rate of connected user in same time, adaptive hit ratio, traffic decreasing rate.

• Bulletin of the Korean Chemical Society
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• v.20 no.5
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• pp.517-524
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• 1999

By heating the magnesiumsilicate (Mg2SiO4:forsterite) xerogel in carbon dioxide, carbonaceous component was intentionally introduced into the amorphous solid precursor. Carbon was introduced homogeneously as unidentate carbonate. Upon being heated at 800 。C in carbon dioxide, the xerogel which had homogeneously distributed carbonaceous component in it crystallized into a single phase product of a new crystalline material, which had approximate composition of Mg8Si4Ol8C. The powder X-ray diffraction pattern of the new crystalline material did not match with any known crystalline compound registered in the powder diffraction file. Crystallization from amorphous xeroget to the new crystalline phase occurred in a very narrow range of temperature, from 750 。C to 850 。C in carbon dioxide, or in dty oxygen. Upon being heated above 850 。C, carbonaceous component was expelled from the product, accompanied by irreversible transition from the new crystalline material to forsterite.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.577-585
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• 2016

The purpose of this study is to evaluate the accuracy of beam delivery QA software using the MLC dynalog file, about the VMAT plan with AAPM TG-119 protocol. The Clinac iX with a built-in 120 MLC was used to acquire the MLC dynalog file be imported in MobiusFx(MFX). To establish VMAT plan, Oncentra RTP system was used target and organ structures were contoured in Im'RT phantom. For evaluation of dose distribution was evaluated by using gamma index, and the point dose was evaluated by using the CC13 ion chamber in Im'RT phantom. For the evaluation of point dose, the mean of relative error between measured and calculated value was $1.41{\pm}0.92%$(Target) and $0.89{\pm}0.86%$(OAR), the confidence limit were 3.21(96.79%, Target) and 2.58(97.42%, OAR). For the evaluation of dose distribution, in case of $Delta^{4PT}$, the average percentage of passing rate were $99.78{\pm}0.2%$(3%/3 mm), $96.86{\pm}1.76%$(2%/2 mm). In case of MFX, the average percentage of passing rate were $99.90{\pm}0.14%$(3%/3 mm), $97.98{\pm}1.97%$(2%/2 mm), the confidence limits(CL) were in case of $Delta^{4PT}$ 0.62(99.38%, 3%/3 mm), 6.6(93.4%, 2%/2 mm), in case of MFX, 0.38(99.62%, 3%/3 mm), 5.88(94.12%, 2%/2 mm). In this study, we performed VMAT QA method using dynamic MLC log file compare to binary diode array chamber. All analyzed results were satisfied with acceptance criteria based on TG-119 protocol.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.23 no.4
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• pp.169-176
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• 1987

The response of file Navodon modestus (GUNTHER) to attraction lamps in line and an adaptation lamp was carried out in the experimental water tank (550L$\times$58W$\times$73H cm). The rate of attraction was investigated in accordance with the intervals of time lighted on and off (1, 5, 10 minute), the intensities of adaptation lamp (1, 10, 20 W) and the two conditions of light stimulus which were the movement of lighted zone (NORMAL) and decrement of lighted zone (NEGA). The results are as follows: 1. Under Normal condition, the variation coefficients which show variation of attraction rate according to the time intervals and the intensities of adaptation lamps were 16.78% (1 min.), 9.71% (5 min.), 8.96% (10 min.), 9.71% (1 W), 15.00% (10W) and 21.08% (20 W) respectively, and attraction rates of the last section was 80.0% (1 min.), 86.0% (5 min.), 85.0% (10 mim.), 86.0% (1 W), 78.7% (10W) and 72.7% (20 W) respectively. 2. Under Nega condition, the file fish was almost distributed all in the illuminated sections, and the majority of the distribution section was adjacent to the extinguished section regardless of the time intervals and the adaptation lamps. 3. Under Nega condition, the variations of attraction rate in the last section became L type, and the attraction rates, when the rest except for the last attraction lamp was extinguished, were 96.7% (1 min.), 100% (5 min.), 96.0% (10 mim.), 100% (1 W), 100% (10W) and 88.0% (20 W) respectively.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.23 no.5
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• pp.897-907
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• 2013

Since various smart devices are being developed, a growing number of people are reading eBooks instead of paper books. However, people started making eBooks on their own by scanning paper books because there are not enough eBooks provided from market. The term "Bookscan" was made with this reason. The number of bookscan company is increasing because the equipment is too expensive. However, the commercial activity of bookscan company is against copyright law. Also bookscan files are in danger of being illegally distributed on web, because bookscan companies are not protecting copyright. Publication market follows the same procedure with sound market which was collapsed due to copyright problem. Therefore, the technical methods should be prepared for law system against bookscan. The previous ICOP(Illegal Copyrights Obstruction Program) system has been applied to sound and movie files, but not applied to publication. This paper suggests the framework for bookscan file management based on practical mechanism.