• 한국컴퓨터정보학회논문지
• /
• 제14권7호
• /
• pp.113-121
• /
• 2009

DRM이 최근에 많은 사이트에서 제거되어짐에 따라 비디오 서버 상에서 콘텐츠 보호는 중요해졌다. 그러나 기존에 존재하는 보호 방법들은 한계 들을 가지거나 스트리밍 성능을 저하시키므로 사용되어지지 않는다. 본 논문은 eCryptFS와 SELinux를 사용하는 콘텐츠 보호 방법을 제안하고 다양한 벤치마크들을 사용하여 제안한 방법의 성능을 측정한다. 그런 후 본 논문은 제안한 방버이 다른 성능 들은 저하시키지만 스트리밍 성능은 저하시키지 않아서 콘텐츠 보호를 위하여 사용할 수 있다는 것을 증명한다.

• 한국음향학회지
• /
• 제22권7호
• /
• pp.545-553
• /
• 2003

압전 변환기를 사용하는 초음파유량계에서 고온의 유체로부터 압전 변환기를 보호하기 위하여 도파관을 사용하면서 종진동 초음파 전파성능을 향상시키기 위한 연구를 하였다. 도파관을 따라 전달되는 열을 효율적으로 차단하는 도파관 재질을 선정하였고, 압전 변환기를 보호할 수 있는 도파관의 최소 길이를 파악하였다. 균일한 원형 봉의 종진동 가진 응답을 구하여 진폭을 최대로 하는 도파관 길이를 선정하였다. 원추형 테이퍼 봉의 가진 응답을 구하여 도파관의 단면 크기가 길이방향으로 작은 쪽에서 파동이 증폭됨을 확인하였다. 균일한 도파관에서 단면 반지름이 작을수록 펄스 파 분산이 줄어듬을 파악하고, 단일 봉 도파관을 사용한 실험으로 이를 입증하였다. 실용적 도파관으로서 철심 조합형 도파관을 제시하고 제작과 평가를 통하여 파동 전파의 우수성을 확인하였다.

• 반도체디스플레이기술학회지
• /
• 제15권3호
• /
• pp.35-39
• /
• 2016

Extreme Ultraviolet Lithography (EUVL) is the most promising technique in the field of Next Generation Lithography (NGL) expected to be used in the 1x-nm node for High Volume Manufacturing (HVM). But there exits remaining challenges for proper defect control of EUV mask. It was considered development of EUV pellicle for protecting the EUV mask has many obstacles due to high extinction coefficient of EUV wavelength. Recently researchers in the industry of semiconductor argue about the necessity of EUV pellicle and make effort to achieve it. In this paper, we investigated that the relationship between imaging performance and transmittance of EUV pellicle quantitatively. We made in-house EUV pellicle and analyzed its imaging performance of the dependence of pellicle transmittance using Coherent Scattering Microscopy(CSM). The imaging performance of EUV mask with pellicle is affected by its transmittance and we found that the performance of EUV mask improved with higher transmittance pellicle.

• 산경연구논집
• /
• 제13권8호
• /
• pp.19-27
• /
• 2022

Purpose: CEOs develop policies through their effective decision-making while employees implement the policies so that a business realizes the expected returns. This research focuses on the importance of the CEO's sustainable leadership to distribute environmental education culture to improve employees' environmental performance. Research design, data and methodology: The PRISMA that is selected by the present research is an evidence-based minimum group of entities for reporting in systematic reviews and meta-analyses. The core focus of the concept is to note studies that evaluate the impacts of intervention and can also be utilized as a basis for writing systematic reviews rather than intervention evaluations. Results: The current investigation indicates that there are four kinds of suggestions (a. Increased organizational learning, b. Open communication, c. Participative decision making, d. Psychological empowerment) how the management should develop sustainable leadership for distributing green culture and improving employee green performance. Conclusions: Based on four solutions, the present research concludes that sustainable leadership for CEOs is not only of advantage in terms of protecting the environment and the people, but it fosters increased organizational learning. Increased organizational learning leads to better employee sustainable performance, which includes financial performance and the social and environmental initiatives the organization implements.

• Computers and Concrete
• /
• 제30권6호
• /
• pp.409-419
• /
• 2022

The purpose of this study is to examine the effectiveness of biological repairing mortars on restoring the structural performance of a sewage culvert deteriorated by sulfate attack. The biological mortars were developed for protecting concrete structures exposed to sulfate attack based on the block membrane action of the bacterial glycocalyx. The diffusion coefficient of sulfate ions in the biological mortars was determined from the natural diffusion cell tests. The effect of sulfate-attack-induced concrete deterioration on the structural performance of culverts was examined by using the moment-curvature relationship predicted based on the nonlinear section lamina approach considering the sulfuric-acid-induced degradation of the structure. Typical analytical assessments showed that biological mortars were quite effective in increasing the sulfate-resistant service life of sewage culverts.

• Journal of Ship and Ocean Technology
• /
• 제8권1호
• /
• pp.31-41
• /
• 2004

A ducted marine propulsor has been widely used for the thruster of underwater vehicles for protecting collision damage, increasing propulsive efficiency, and reducing cavitation. Since a single-stage ducted propulsor contains a set of rotor and stator inside an annular duct, the numerical analysis becomes extremely complex and computationally expensive. However, the accurate prediction of viscous flow past a ducted marine propulsor is essential for determining hydrodynamic forces and the propulsive performances. To analyze a ducted propulsor having rotor-stator Interaction, the present work has solved 3D incompressible RANS equations on the sliding multiblocked grid. The flow of a single stage turbine flow was simulated for code validation and time averaged pressure coefficients were compared with experiments. Good agreement was obtained. The hydrodynamic performance coefficients were also computed.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2018년도 춘계 학술논문 발표대회
• /
• pp.10-11
• /
• 2018

In the building, the opening penetrates the wall and serves as a spreading channel for smoke and flame in case of fire. In Korea, more than 1,500 fire plume are generated annually, and the number has increased by about 30% over the past five years. Therefore, in the case of windows protecting the opening, fire protection performance is important to prevent the spread of fire. However, in Korea, the standard for window is not clear. In this study, fire tests (EN 13823) for windows were conducted in Korea, and then fire protection performance of windows was compared. As a result of the experiment, PVC windows showed a phenomenon that they could not withstand the temperature during the fire experiment, and AL windows showed a difference in the degree of cracking of the glass.

• Tribology and Lubricants
• /
• 제21권6호
• /
• pp.263-267
• /
• 2005

The tribological performance of multi-walled carbon nanotubes (MWNT) in mineral oils is investigated at ambient temperature. The frictional forces, wear amounts and cycles to scuffing of the oils with nanotubes and without those were measured using the ball-on-disk tester. It was found that there were little differences in the frictional forces and wear amounts of two oils. However, the scuffing times of oils with nanotubes were much longer than those of oils without nanotubes in sliding tests. The nanotubes were very effective on maintaining the oil gap and protecting the surfaces in boundary lubricated sliding.

• 대한건축학회논문집:구조계
• /
• 제34권1호
• /
• pp.69-78
• /
• 2018

The purpose of this study is propose eco-friendly remodeling while protecting the living environment of existing residents and preserving the living in pleasant by considering the characteristic of high density sloped residential area. And then, the optimum insulation condition is analyzed based on the energy efficiency, economic analysis and environmental effect. It will be possible as the basic information for remodeling of each housing in sloped area. The energy demanding, cost and the carbon emission reduction is analyzed with the residential area in Seo-gu, Busan by eco-remodelling.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
• /
• pp.318-320
• /
• 2006

A control valve with deadband characteristics influences on the control dynamics. A control loop with deadband component shows cyclic control results and causes the wears of mechanical parts. A valve on the important process that require nonstop operation cannot be improved during operation. In case of control loops with deadband dynamics, the optimal control parameters based on the performance only are not sure of the good operation in point of protecting the control component. To improve the control performance and control oscillation, the control parameters should be changed to meet both control qualify and protection of control components.