• 정보보호학회논문지
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• 제20권1호
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• pp.129-134
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• 2010

본 논문에서는 홈 네트워크 내 차별적인 성능을 가지는 장치들이 장치 성능에 적응적으로 콘텐츠를 재분배하는 메커니즘을 제안한다. 제안 시스템은 최근에 표준화 된 H.264/SVC 스케일러블 코딩 기법에 의해 압축 암호화된 콘텐츠를 각 장치 성능에 적합한 수준(level)으로 제공하는 DRM 시스템의 콘텐츠 재분배 메커니즘이다. 본 논문은 SVC 콘텐츠를 효율적으로 재분배하기 위해 제시된 3가지 요구사항을 티켓을 사용하여 해결하고, 도메인 키를 사용하여 도메인 내의 장치들이 콘텐츠를 효율적으로 사용할 수 있도록 한다.

• 한국멀티미디어학회논문지
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• 제12권7호
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• pp.979-988
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• 2009

디지털 콘텐츠의 불법 복제와 저작권 침해는 디지털 콘텐츠의 산업의 발전을 저해하고 있다. 이러한 문제로 인해 다양한 DRM(Digital Rights Management) 시스템이 개발되고 있다. 그러나 초기 DRM 시스템은 콘텐츠의 사용 권리가 있는 사용자만이 해당 콘텐츠를 접근할 수 있기 때문에 사용자가 다른 사용자에게 콘텐츠를 재배포하는 것은 쉽지 않았다. 이러한 문제를 해결하기 위해 다운로드 큰텐츠에 국한되어 재배포를 위한 초유통 서비스 구조가 출현하였다. 하지만 스트리밍 콘텐츠는 사용자가 직접 스트리밍 서버에 접속하여 콘텐츠를 접근하기 때문에 초유통이 제한되었다. 본 논문에서는 스트리밍 콘텐츠의 초유통을 위한 스트리밍 서버와 사용자를 연결할 수 있는 중계파일을 제안하였다.

• Steel and Composite Structures
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• 제49권5호
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• pp.571-585
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• 2023

The application of relatively low volumes of fibres in normal strength concrete has been shown to be of significant benefit when applied to composite slabs with profiled sheet decking. This paper reports on an experimental study aimed at quantifying further potential benefits that may arise from applying ultra-high performance fibre reinforced concrete. To assess performance six simply supported beams were tested under hogging and sagging loading configurations along with three two span continuous beams. Fibre contents are varied from 0% to 2% and changes in strength, deformation, crack width and moment redistribution are measured. At the serviceability limit state, it is shown that the addition of high fibre volumes can significantly enhance member stiffness and reduce crack widths in all beams. At the ultimate limit state it is observed that a transition from 0% to 1% fibres significantly increases strength but that there is a maximum fibre volume beyond which no further increases in strength are possible. Conversely, member ductility and moment redistribution are shown to be strongly proportional to fibre volume.

• 한국산림과학회지
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• 제112권4호
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• pp.490-501
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• 2023

본 연구에서는 강우의 침투과정 및 수분 재분포 현상을 분석하기 위하여 실내 컬럼실험을 수행하였으며, 토층 내 함수비를 효율적으로 측정하기 위하여 딥러닝 기법 중 하나인 합성곱신경망(Convolutional Neural Network, CNN)을 사용하여 함수비 예측 모델을 구축하였다. 컬럼실험으로부터 획득된 디지털 이미지를 구축된 CNN 모델에 적용한 결과 시간에 따른 토층별 함수비를 효과적으로 측정할 수 있었으며, 토층별로 설치된 함수비 센서에 따른 함수비와도 비교적 잘 일치하는 것으로 나타났다. 결과적으로 CNN을 활용하여 토층 내 연속적인 함수비 분포를 파악하는 것이 가능하였으며, 토성 및 지반 함수비 조건에 따른 침투 과정을 효과적으로 분석할 수 있었다.

• Corrosion Science and Technology
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• 제8권2호
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• pp.81-88
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• 2009

Chloride induced corrosion of steel reinforcement inside concrete is a major concern for concrete structures exposed to a marine environment. It is well known that transport of chloride ions in concrete occurs mainly through ionic/molecular diffusion, as a gradient of chloride concentration in the concrete pore solution is set. In the process of chloride transport, a portion of chlorides are bound in cement matrix then to be removed in the pore solution, and thus only the rest of chlorides which are not bound (i.e. free chlorides) leads the ingress of chlorides. However, since the measurement of free/bound chloride content is much susceptible to environmental conditions, chloride profiles expressed in total chlorides are evaluated to use in many studies In this study, the capacity of chloride binding in cement matrix was monitored for 150 days and then quantified using the Langmuir isotherm to determine the portions of free chlorides and bound chlorides at given total chlorides and the redistribution of free chlorides. Then, the diffusion of chloride ion in concrete was modeled by considering the binding capacity for the prediction of chloride profiles with the redistribution. The predicted chloride profiles were compared to those obtained from conventional model. It was found that the prediction of chloride profiles obtained by the model has shown slower diffusion than those by the conventional ones. This reflects that the prediction by total chloride may overestimate the ingress of chlorides by neglecting the redistribution of free chlorides caused by the binding capacity of cement matrix. From the evaluation, it is also shown that the service life prediction using the free chloride redistribution model needs different expression for the chloride threshold level which is expressed by the total chlorides in the conventional diffusion model.

• Journal of Information Processing Systems
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• 제6권2호
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• pp.253-260
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• 2010

Communication devices aim to provide a multimedia service without spatial or temporal limitations in an IP-based environment. However, it is incapable of allowing for fair use by consumers who legally buy content, and damages provider contents through the indiscriminate distribution and use of illegal contents. The DRM system that emerged to solve this problem cannot protect licenses stored on communication devices, and manage licenses by redistribution. This paper proposes a license audit model, which checks for illegal access, modification and redistribution, and reports alert logs to the server.

• 한국재료학회지
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• 제13권7호
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• pp.473-477
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• 2003

The hydrogen redistribution induced by thermotransport at temperatures likely to be encountered in nuclear power reactors (300-$340^{\circ}C$) was investigated in modified Zircaloy-4 alloys. Modified Zircaloy-4 alloys were prepared by altering the chemical composition of Zircaloy-4; the oxygen content of Zircaloy-4 (0.1 wt%) was increased to 0.2, 0.5 and 1.0 wt%. The heat of transport ($Q^{*}$ ) for hydrogen was measured by changing the initial hydrogen and oxygen concentrations. It was found that the heat of transport was not affected by increases in the initial hydrogen concentration from 63.3 to 91.7 ppm. However, the value of $Q^{Q}$ decreased from 6.8 to 4.5 ㎉/mol as the initial oxygen concentration was increased from 0.2 to 1.0 wt%.

• 한국표면공학회지
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• 제27권5호
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• pp.273-284
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• 1994

Thermal behavior of Cu-Cr thin alloy films has been investigated by SEM, AES, and TEM. Cu-Cr alloy films containing 3wt% Cr, 8wt% Cr have been sputter-deposited onto polyimide substrates and heat treated at $400^{\circ}C$ for 2hrs in the various atmosphere. Before heat treatment, Cu and Cr content in the film are uniform through the thickness and oxygen content in the film is negligible. Redistribution of Cr, Cu, and O in the film due to heat treatment depends on the Cr content and heat treatment atmoshpere. There kinds of thermal behavior are ascribed to the formation of surface and interface oxides as well as internal oxidation. Hillocks are observed on the surface of Cu-Cr alloy films which have been heat treated in N2. The hillocks are composed of large grainss of Cu.

• 한국정보통신설비학회:학술대회논문집
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• 한국정보통신설비학회 2006년도 하계학술대회
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• pp.99-102
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• 2006

This paper describes a article how to protect from illegal indiscriminate copy of digital broadcasting content using DRM and CCI. With the start of terrestrial / satellite digital broadcast and the preparation of Digital Cable broadcast, we can view HD digital contents through the various channel. Also we can record, play, redistribute digital contents in PVR. The protection of Digital Contents Right became of the important issue to protect CopyRight. In this paper, we implement a manager that prevents indiscriminate digital contents redistribution of the digital broadcast contents. For protection of Digital contents Right, we use BF(Broadcast Flag) and CCI (Copy Control Information) which we can control viewing or copy digital contents with.

• 한국방송∙미디어공학회:학술대회논문집
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• 한국방송공학회 2004년도 정기총회 및 학술대회
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• pp.285-288
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• 2004

High-quality digital broadcasting contents are susceptible to illegal copy and unauthorized redistribution, which makes broadcasters difficult to protect valuable media assets. So, broadcasters and content providers need the technology for copyright protection of professional digital content. Digital watermarking technology is one of the most actively developed solutions for the copyright protection. This paper suggests the requirements of watermarking technology in DTV(Digital TV) environment for copyright protection and shows the developed real-time watermark embedding/detecting system for HD(High Definition)/SD(Standard Definition) video and experimental results of the system against watermark attack tests. Our watermarking system meets the watermarking requirements of invisibility, robustness and security of DTV environment.