• 제목/요약/키워드: Core Center

검색결과 2,385건 처리시간 0.03초

EVOLUTION OF NUCLEAR FUEL MANAGEMENT AND REACTOR OPERATIONAL AID TOOLS

  • TURINSKY PAUL J.;KELLER PAUL M.;ABDEL-KHALIK HANY S.
    • Nuclear Engineering and Technology
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    • 제37권1호
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    • pp.79-90
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    • 2005
  • In this paper are reviewed the current status of nuclear fuel management and reactor operational aid tools. In addition, we indicate deficiencies in current capabilities and what future research is judged warranted. For the nuclear fuel management review the focus is on light water reactors and the utilization of stochastic optimization methods applied to the lattice, fuel bundle, core loading pattern, and for BWRs the control rod pattern/core flow design decision making problems. Significant progress in addressing separately each of these design problems on a single cycle basis is noted; however, the outstanding challenge of addressing the integrated design problem over multiple cycles under conditions of uncertainty remains to be addressed. For the reactor operational aid tools review the focus is on core simulators, used to both process core instrumentation signals and as an operator aid to predict future core behaviors under various operational strategies. After briefly reviewing the current status of capabilities, a more in depth review of adaptive core simulation capabilities, where core simulator input data are adjusted within their known uncertainties to improved agreement between prediction and measurement, is presented. This is done in support of the belief that further development of adaptive core simulation capabilities is required to further significantly advance the utility of core simulators in support of reactor operational aid tools.

표면차수벽 석괴댐의 물리탐사 경향 분석 (Aanalysis of Geophysical exploration tendency of C.F.R.D)

  • 김재홍;신동훈;임은상
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2010년도 춘계 학술발표회
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    • pp.871-876
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    • 2010
  • When surface Concrete Face Rock fill Dam constructs than existent center core type rock fill dam, it is much prevalent form in domestic these day by quality control of that is profitable and weather condition etc. of coreZone. C.F.R.D is less research about seismic survey(Refractional Seismic Prospectin, Resistivity Prospecting) of levee body than fill dam. Thus as C.F.R.D seismic survey is less, safety of that consist is short most development flue is high reason. That is not checking target of minuteness safety diagnosis and so on by short operation period. Wish to analyze inquiry incidental and difference with center core type dam and acquire C.F.R.D preservation administration upper necessary inquiry condition forward hereafter.

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정밀고속 PRESS 하사점 변위량에 영향을 최소화 하는 금형 EMBO 장치에 관한 구조 연구 (A structural study on mold EMBO equipment to minimize the influence on the bottom dead center displacement of precision high-speed press)

  • 김승수
    • Design & Manufacturing
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    • 제10권3호
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    • pp.46-50
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    • 2016
  • Laminate products for motor core are developed with a structure in which the importance of quality level and clamping force is influenced by the recent performance and safety of the product. It has been confirmed that the accuracy of the mold is emphasized, and that the accuracy of the tightening force produced by the stacked product for the motor core is greatly influenced by the change in the bottom dead center displacement of the aged high speed press. The reason why setting the mold, and test the effect of bottom dead center of high speed press is to improve product pull force in embossing process at mold. We have applied the system to minimize the effect on the damping displacement under the dynamical degree of the equipment by applying the emboss complement device which can test the influence and complement in the process.

Characteristics of Ni-based Alloy Bond in Diamond Tool Using Vacuum Brazing Method

  • An, Sang-Jae;Song, Min-Seok;Jee, Won-Ho
    • 한국분말야금학회:학술대회논문집
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    • 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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    • pp.1130-1131
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    • 2006
  • We found that the """interface reaction between Ni-based alloy bond, diamond, and steel core is very critical in bond strength of diamond tool. None element from metal bond diffuses into the steel core but the Fe element of steel core was easily diffused into the bond. This diffusion depth of Fe has a great effect on the bonding strength. The Cr in steel core accelerated the Fe diffusion and improved the bond strength, on the other hand, carbon decreased the strength. Ni-based alloy bond including Cr was chemically bonded with diamond by forming Cr carbide. However, the Cr and Fe in STS304 were largely interdiffused, the strength was very low. The Cr passivity layer formed at surface of STS304 made worse strength at commissure in brazing process.

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국내 상급종합병원의 간호단위 및 임상경력별 핵심간호실무와 교육요구도 (Core nursing practice and educational requirements according to nursing unit and clinical career in tertiary hospital)

  • 김연희;정영선;최진선;이혜영;정혜련;김지수;김경희
    • 기본간호학회지
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    • 제22권1호
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    • pp.35-48
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    • 2015
  • Purpose: The purpose of this study was to provide fundamental data to develop an educational program for the development of nurses' core competences, and to improve the curriculum in nursing education institutions. Methods: This study, based on a descriptive survey, was conducted with 1,019 nurses working in a tertiary hospital in Seoul. Among 47 core nursing practice items, core nursing practices as perceived by the participants and relevant educational requirements were measured on a four-point scale. The collected data were analyzed using descriptive statistics for the mean and standard deviation, one way ANOVA, and Duncan test as post-hoc test. Results: Regarding the core nursing practice perceived as by the nurses, there were statistically significant differences in 43 out of 47 items according to nursing unit, and in 15 items according to clinical career. Regarding the educational requirements for core nursing practice, there were also statistically significant difference for the same items as perception differences according to nursing unit and clinical career. Conclusion: The results of this study suggest further study on the development of educational programs to advance the clinical expertise of nurses and for the development of curriculum reflecting the actual conditions and requirements in clinical nursing practice fields.

One-pot 공정을 이용한 InP/ZnS core/shell 나노결정 합성 및 특성 연구 (Synthesis and Properties of InP/ZnS core/shell Nanoparticles with One-pot process)

  • 주소영;홍명환;강이승;김태형;이찬기
    • 한국분말재료학회지
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    • 제24권1호
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    • pp.11-16
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    • 2017
  • In this study, simple chemical synthesis of green emitting Cd-free InP/ZnS QDs is accomplished by reacting In, P, Zn, and S precursors by one-pot process. The particle size and the optical properties were tailored, by controlling various experimental conditions, including [In]/[MA] (MA: myristic acid) mole ratio, reaction temperature and reaction time. The results of ultraviolet-visible spectroscopy (UV-vis), and of photoluminescence (PL), reveal that the exciton emission of InP was improved by surface coating, with a layer of ZnS. We report the correlation between each experimental condition and the luminescent properties of InP/ZnS core/shell QDs. Transmission electron microscopy (TEM), and X-ray powder diffraction (XRD) techniques were used to characterize the as-synthesized QDs. In contrast to core nanoparticles, InP/ZnS core/shell treated with surface coating shows a clear ultraviolet peak. Besides this work, we need to study what clearly determines the shell kinetic growth mechanism of InP/ZnS core shell QDs.

A High-efficiency Method to Suppress Transformer Core Imbalance in Digitally Controlled Phase-shifted Full-bridge Converter

  • Yu, Juzheng;Qian, Qinsong;Sun, Weifeng;Zhang, Taizhi;Lu, Shengli
    • Journal of Power Electronics
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    • 제16권3호
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    • pp.823-831
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    • 2016
  • A high-efficiency method is proposed to suppress magnetic core imbalance in phase-shifted full-bridge (PSFB) converters. Compared with conventional solutions, such as controlling peak current mode (PCM) or adding DC blocking capacitance, the proposed method has several advantages, such as lower power loss and smaller size, because the additional current sensor or blocking capacitor is removed. A time domain model of the secondary side is built to analyze the relationship between transformer core imbalance and cathode voltage of secondary side rectifiers. An approximate control algorithm is designed to achieve asymmetric phase control, which reduces the effects of imbalance. A 60 V/15 A prototype is built to verify the proposed method. Experimental results show that the numerical difference of primary side peak currents between two adjacent cycles is suppressed from 2 A to approximately 0 A. Meanwhile, compared with the PCM solution, the efficiency of the PSFB converter is slightly improved from 93% to 93.2%.

대칭 평면형 건물에서의 코어위치에 따른 구조거동 분석 (Analyses of Structural Behaviors According to Core Location in the Building with Symmetric Plan)

  • 김정래;김재요
    • 한국구조물진단유지관리공학회 논문집
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    • 제24권1호
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    • pp.116-124
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    • 2020
  • 코어 위치변화에 따른 횡력저항성능 분석을 위하여, 대칭 평면형 20층 건물을 대상으로 3차원 구조해석을 수행하였다. 중심 코어, 1축 편심 코어, 2축 편심 코어로 구분하여 4가지 해석모델을 구성하고, 고유치해석, 풍하중 해석, 지진하중 해석을 수행하였다. 중심 코어 건물에서는 비틀림이 발생하지 않았으나, 편심 코어의 배치에 따라 휨과 비틀림이 복합적으로 발생하였으며 횡력저항성능이 저하되었다. 코어의 편심 배치에 따른 풍하중 크기의 변화는 작으나, 최대 횡변위는 코어의 편심 배치에 의하여 크게 증가하는 것으로 확인되었다. 또한, 편심 코어의 경우 횡방향 강성의 저하로 인하여 중심 코어에 비해 지진하중이 다소 감소하였으나, 비틀림의 영향으로 최대 층간변위비는 크게 증가하는 것으로 확인되었다. 이러한 결과들을 바탕으로 코어의 위치에 따른 구조거동을 확인하고, 계획 및 설계 단계에서 코어 배치의 가이드라인으로 활용할 수 있다.

A Study on the Development of Core Competency Diagnostic Tools for Professors at A' University

  • Soo-Min PARK;Tae-Chang RYU
    • 융합경영연구
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    • 제11권4호
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    • pp.31-39
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    • 2023
  • Purpose: This study attempted to systematize a support system that can enhance teaching core competencies by establishing a scale for diagnosing teaching core competencies at University A. Research design, data and methodology : To this end, the first Delphi was conducted With six experts related to university core competency modeling research by extracting factors and designing structured questionnaires through a literature review process that collects and analyzes prior research related to domestic and foreign university teaching competency. The derived questions were diagnosed on 27 professors, and independent sample t-verification and ANOVA were conducted using SPSS 24.0 for analysis by key teaching competency factors. Result: What is the standard suitability of KMO. It was shown as 929 (KMO standard conformity value is close to 1), and Barlett's sphericity verification showed χ2=5773.295, df=1081, p<.It appeared as 001 and confirmed that it was suitable for conducting factor analysis. Conclusions: The core competencies of A University teachers were set based on the educational goals of A University, such as basic teaching competency, creative teaching competency, practical teaching competency, and communication teaching competency. This means that the concept and factors of the core competency of professors are likely to change, and in the end, continuous efforts to upgrade and apply research on core competency of professors are essential to quickly and organically respond to changes in competency required to increase the competitiveness of universities.