• Nuclear Engineering and Technology
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• 제45권3호
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• pp.323-334
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• 2013

During a hypothetical core-disruptive accident (CDA) in a sodium-cooled fast reactor (SFR), degraded core materials can form roughly conically-shaped debris beds over the core-support structure and/or in the lower inlet plenum of the reactor vessel from rapid quenching and fragmentation of the core material pool. However, coolant boiling may ultimately lead to leveling of the debris bed, which is crucial to the relocation of the molten core and heat-removal capability of the debris bed. To clarify the mechanisms underlying this self-leveling behavior, a large number of experiments were performed within a variety of conditions in recent years, under the constructive collaboration between the Japan Atomic Energy Agency (JAEA) and Kyushu University (Japan). The present contribution synthesizes and gives detailed comparative analyses of those experiments. Effects of various experimental parameters that may have potential influence on the leveling process, such as boiling mode, particle size, particle density, particle shape, bubbling rate, water depth and column geometry, were investigated, thus giving a large palette of favorable data for the better understanding of CDAs, and improved verifications of computer models developed in advanced fast reactor safety analysis codes.

• 대한전자공학회논문지SP
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• 제46권3호
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• pp.119-124
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• 2009

본 논문에서는 AMR Core(R)를 이용해서 AMR-WB+ 오디오 부호화기를 실시간 구현하였다. 구현 시 사용된 최적화 방법은 어셈블리어 단계에서 수행되었고, latency를 제거하고 32비트 레지스터를 사용하였다. 구현된 음성 부호화기는 평균 복잡도가 ARM9E 버전에서 인코더 160.76MHz, 디코더 33.05MHz으로 총 193.81MHz로 측정되었다. 사용된 ROM의 크기는 인코더 65.21Kbyte, 디코더 32.01Kbyte, 공통소스 279.81Kbyte이다. 구현된 AMR-WB+ 소스 코드는 3GPP에서 제공하는 테스트 벡터들을 CodeWarrior와 목표 PDA 상에서 모두 bit-exact하게 통과함을 보임으로써 검증되었다.

• 멤브레인
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• 제20권3호
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• pp.185-196
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• 2010

현재 우리나라가 세계최고 수준을 보유한 해수담수화기술과 해외 플랜트 수주확대를 위한 정부정책의 필요성에 따라 지속적인 해수담수화 시장 선점을 위한 새로운 핵심기술개발이 중요해지는 시점이다. 본 연구에서는 그 중요성이 부각되고 있는 물산업의 동향, 해수담수화기술의 개요 및 시장현황을 고찰하고, 국가 R&D지원 정책방향 및 기술개발지원현황 자료를 분석하였다. 그 결과 다음과 같은 시사점을 얻을 수 있었다. 기업의 담수플랜트 운전경험 축적을 바탕으로 신뢰성을 확보할 수 있도록 제도적 장치가 필요하며, 원천기술확보를 위한 전략적 R&D지원이 이루어져야 한다. 또한, 담수화 플랜트에 소요되는 핵심기자재에 대한 국산화가 선행되어야 할 것이다.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.393-394
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• 2004

To get rid of cell assembly margin and have more process room of upper substrate, we developed truly COT (Color Filter On TFF Array) LCDs in that B/M (Black Matrix) as well as C/F (Color Filter) layer is located on TFT substrate. Novel B/M material is also developed for this COT structure. Difficulty in making contact hole through C/F layer was solved by making each C/F pattern isolated from others. We think this configuration will be core technology for prominent COT LCDs.

• 대한치과보철학회지
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• 제42권3호
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• pp.280-293
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• 2004

Statement of problem. Glass fiber post is one of recent developments to accommodate esthetic restoration for endodontically treated teeth. This has many advantages over conventional post system in physical properties, esthetic factor, risk of root and restoration fracture, adhesion to core, radiopacity, removal and retrievabilty, biocompatibility and chemical stability. Purpose. This in vitro study was to evaluate the most suitable type of resin core for the glass fiber post through surveying the fracture modes and the maximum load that fractures the tooth. Material and methods. 50 sound maxillary premolars restored with glass fiber posts($ParaPost^{(R)}$ Fiber White) and different types of resin cores(ParaCore, $Z100^{TM}$, $Rebilda^{(R)}$ and $Admira^{(R)}$) were prepared and loaded to faiure in a universal test machine. The maximum fracture load and fracture mode were investigated in the specimens that were restored with resin and those of metal cast and core. With the data, Wilcoxon rank sum test was used to validate the significance between the test groups, and Tukey' s studentized range test was used to check if there is any significant statistical difference between each test group. Every analysis was approved with 95% reliance. Results. On measuring the maximum fracture load of teeth specimens, there was a significant difference between the maximum fracture loads of the tooth specimens. ParaCore showed the highest mean maximum fracture load followed by $Z100^{TM}$. And, the distribution of fracture mode of tooth specimens showed generally Type D, the three parted fracture of the core around the post was mostly seen(62.5%), and specifically, ParaCore showed 90% and $Z100^{TM}$ showed 100% Type D fracture. Conclusion. Referring to the values of maximum fracture load and mean compressive fracture load, ParaCore and $Z100^{TM}$ had high values and are recommended as tooth colored resin core material for glass fiber post. CLINICAL IMPLICATIONS. This study was carried out intending to be of aid in selecting the appropriate resin core for the glass fiber post. The dual cure type composite resin ParaCore and light cure type composite resin $Z100^{TM}$ have good properties and are recommended as tooth colored resin core material for glass fiber post.

• Steel and Composite Structures
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• 제24권2호
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• pp.151-176
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• 2017

This paper deals with general equations of motion for free vibration analysis response of thick three-layer doubly curved sandwich panels (DCSP) under simply supported boundary conditions (BCs) using higher order shear deformation theory. In this model, the face sheets are orthotropic laminated composite that follow the first order shear deformation theory (FSDT) based on Rissners-Mindlin (RM) kinematics field. The core is made of orthotropic material and its in-plane transverse displacements are modeled using the third order of the Taylor's series extension. It provides the potentiality for considering both compressible and incompressible cores. To find these equations and boundary conditions, Hamilton's principle is used. Also, the effect of trapezoidal shape factor for cross-section of curved panel element ($1{\pm}z/R$) is considered. The natural frequency parameters of DCSP are obtained using Galerkin Method. Convergence studies are performed with the appropriate formulas in general form for three-layer sandwich plate, cylindrical and spherical shells (both deep and shallow). The influences of core stiffness, ratio of core to face sheets thickness and radii of curvatures are investigated. Finally, for the first time, an optimum range for the core to face sheet stiffness ratio by considering the existence of in-plane stress which significantly affects the natural frequencies of DCSP are presented.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.134-136
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• 2003

This paper proposes moving mechanism theory & magnetic core analysis regarding mini magnetic contactor and differential mechanism & bimetal analysis regarding mini thermal overload relay. In shortage of technique, we have experienced many difficulties in magnetic switch development. By this research, we developed core parts about mini magnetic switch and applied the results to optimum mini magnetic switch development

• 기술혁신연구
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• 제15권1호
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• pp.87-113
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• 2007

For the realization of the national self-defense, the trend of the defense R&D projects becomes global and diverse with the increase of their budget. Thus, for the effective execution of the budget and the successful performance of the projects, the importance of selection, management and evaluation of the R&D projects is emphasized. This study suggests the applicability of a meta-evaluation model for the realization of the successful defense R&D project evaluation system. This study focused on the development of the meta-evaluation model design which can be applicable to the national defense R&D projects. Using the proposed meta-evaluation model, we propose a technique to enhance the fairness and the reliability of the national defense R&D projects evaluation system.

• 기술혁신학회지
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• 제6권3호
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• pp.373-390
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• 2003

With limited resources, proper allocation of the national R&D budget is very crucial matter for reinforcing the national competence, and the importance of selecting strategic R&D fields have been increasingly emphasized by technology policy-makers and CTOs. This paper deals with technology relevance/cluster analysis, which measures technological dependency and relevancy among technologies, and how it can be used for selecting the strategic R&D fields especially satisfying SMEs(small and medium enterprises)' specific needs. As a result of this study, technology-product tree composed of 7 major technology fields, 22 clusters, 41 groups, 335 core-need technologies and hundreds of related business items are produced that can be used for designing SMEs' R&D/business portfolio as well as R&D investment decision-making of the Ministry of Small and Medium Business Administration.

• 임상간호연구
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• 제21권1호
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• pp.67-79
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• 2015

Purpose: The study was aimed to describe the relationships between ego-resilience, disaster experience, and core competencies among emergency room (ER) nurses. Methods: Data were collected from ER nurses in Incheon and Kyunggi province from May to June 2014. Data were analyzed with descriptive study, t-test, ANOVA, and Pearson's correlation coefficient using SPSS/WIN 18.0 version. Results: Male respondents showed significantly higher ego-resilience than female respondents (t=-2.04, p=.043), and education (F=4.96, p=.002) and position (F=7.70, p=.001) were statistically significant. The differences in disaster experience was found in gender (t=-2.29, p=.023), age (F=4.25, p=.006), marital status (t=-2.02, p=.045), education (F=6.34, p<.001), religion (F=3.69, p=.015), and position (F=3.55, p=.031). Regarding core competencies for disaster nursing, age (F=7.80, p<.001), marital status (t=-3.00, p=.001), education (F=16.53, p<.001), career (F=5.40, p<.001), position (F=12.52, p<.001) were significantly different. Positive associations were found between core competencies for disaster nursing and ego-resilience (r=.66, p<.001), disaster experience and core competencies for disaster nursing (r=.52, p<.001), and disaster experience and ego-resilience (r=.33, p<.001). Conclusion: Core competencies were higher among ER nurses when they have higher ego-resilience, and more disaster experience. This finding suggests the need for improving ego-resilience among ER nurses. In addition, disaster education needs to be considered as a part of core nursing curriculum in college and clinical settings.