• 제목/요약/키워드: critical property

검색결과 558건 처리시간 0.027초

중성자 조사를 위한 초전도 선재의 기초 물성 (Properties of Superconducting wires for Neutron Irradiation)

  • 이상헌;최용
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2007년도 추계학술대회 논문집
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    • pp.243-244
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    • 2007
  • The improvement of critical current property as well as the mechanical property is important for the application. The improvement of the critical current can be achieved by forming the nano size defect working as a flux pining center inside the superconductor. The nano size defect can be effectively formed by using neutron iradiation. All properties of most of materials after irradition become bad On the contrary, the critical current property of the superconductor is largely improved after irradiation.

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Design of flux pinning property in REBCO coated conductors with artificial pinning centers

  • Matsushita, Teruo;Kiuchi, Masaru
    • 한국초전도ㆍ저온공학회논문지
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    • 제20권1호
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    • pp.1-10
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    • 2018
  • The improvement of critical current properties of $REBa_2Cu_3O_{7-x}$ (REBCO) coated conductors by introducing artificial pinning centers (APCs) is examined with respect to the field-angle anisotropy, high-field performance and relaxation property with time. Nano-rods along the c-axis introduced by PLD method and isotropic nano-particles introduced by TFA-MOD method are treated. The theoretical analysis is also shown to understand the effect of APCs quantitatively. The effects of superconducting layer thickness that influences the high-field performance and relaxation property are also discussed. It is shown that the upper critical field, which is another important factor to determine the high-field property, can be improved by introduction of APCs through electron scattering at interfaces with the superconducting matrix. The optimum critical current property can be obtained by properly designing the morphology and number density of APCs and the superconducting layer thickness.

지식재산의 관리 측면에서 본 연구성과 지향형 연구개발을 위한 제언 (Suggestions for Outcome-Oriented R&D Activity in Terms of Intellectual Property Management)

  • 김승군;고명숙
    • Toxicological Research
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    • 제23권2호
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    • pp.115-121
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    • 2007
  • Biotechnology is often described as the 'exploitation of biological processes for industrial purposes'. The last twenty years have seen phenomenal growth in this industry. The 21 century promises to see further advances in the field. However, since the cost of research is high, and the potential returns are linked to exclusivity, intellectual property protection is critical to this burgeoning industry. Without protection such investments in R&D would not be made and, the benefit that BT-related development are expected to bring, would not occur. BT industry are eager for high technology, and the technology must be transferred to a corporation from a research organization. In order to be successful, it is important that scientist must be directed toward R&D outcome beyond performance assessment. The process to gain a outcome involves multiple steps to turn the idea into the profit, and intellectual property issues are considered into the critical factors to affect the quality of R&D. The management of Intellectual property is very important in R&D. However, According to the survey conducted by KIIP (Korea Institute of Intellectual Property) and KOSEF (Korea Science and Engineering Foundation) in 2006, it is estimated the ability to treat Intellectual property is not sufficient because 82.5% of the respondents have not received an education. Governmental Support is needed to prompt systematically the ability of intellectual property management through education and consulting.

Fourier 변환을 이용한 ZnCdSe 전이점 연구 (Study on critical point of ZnCdSe by using Fourier analysis)

  • 윤재진;공태호;김영동
    • 한국진공학회지
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    • 제16권6호
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    • pp.458-462
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    • 2007
  • 타원편광분석법은 반도체 물질의 광 특성과 전이점 연구에 유용하게 쓰이는 기술이다. 측정된 유전율 함수로부터 전이점을 구하기 위해서 전통적으로 이차 미분스펙트럼을 이용하여 분석하는데, 이 방법은 high frequency 의 잡음을 크게 증폭시키는 단점이 있다. 본 연구에서는 역 공간 푸리에 변환 (Fourier transform)을 이용하여 low-, medium-, high-index 의 푸리에 계수로부터 baseline, 정보, high frequency 잡음을 분리하는 방법을 소개하고자 한다. 이 방법을 이용하여 광전자소자에 폭넓게 사용되는 ZnCdSe 화합물 반도체의 $E_1,\;E_1+{\Delta}_1$ 전이점에 대한 연구를 하여 전통적인 이차 미분법과 비교해 보았다.

Development of an Intellectual Property Core for Floating Point Calculation for Safety Critical MMIS

  • Mwilongo, Nelson Josephat;Jung, Jae Cheon
    • 시스템엔지니어링학술지
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    • 제17권2호
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    • pp.37-48
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    • 2021
  • Improving the plant protection system against unforeseen changes/transients during operation is essential to maintain plant safety. Under this condition, it requires rapid and accurate signal processing. The use of an Intellectual Property (IP) core for floating point calculations for Safety Critical MMIS can make numerical computations easier and more precise, improving system accuracy. It can represent and manipulate rational numbers as well as a much broader range of values with dynamic range in nuclear power plant. Systems engineering approach (SE) is used through the development process, it helps to reduce complexity and avoid omissions and invalid assumptions as delivers a better understanding of the stakeholders needs. For the implementation on the FPGA target board, the 32-bit floating-point arithmetic with IEEE-754 standards has designed using Simulink model in Matlab for all operations of addition, subtraction, multiplication and division and VHDL code generated.

초등학생의 성격특성과 과학적 태도 분석과 이들의 상관관계 연구 (An Analysis of Elementary School Students과 Personality, Scientific Attitude and Correlation Analysis of between Them)

  • 배진호;김언경;김재영
    • 한국초등과학교육학회지:초등과학교육
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    • 제23권1호
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    • pp.1-7
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    • 2004
  • The purpose of this study is to analyze elementary school students' personality, scientific attitude and to find the correlation between elementary school students' personality and scientific attitude. To determine this, the distribution of sixth graders' personality and scientific attitude was examined and correlation between the lower categories of each one was analyzed. The test tools and the subject were decided through the two preliminary examination, personality test and scientific attitude test were investigated appling to a total of 354 sixth-grade students at eight elementary schools in this study. The test results were analyzed with averages, standard deviations, correlations, ANOVA using SPSS/PC/sup +/. The major results of analysis are as follows. First, the distribution of scientific attitude proved that the average of boys' curiosity was higher than that of girls' curiosity, but girls' average was higher than boys' average in criticalness property, cooperation property, preparation property, continuation property and patience property. The distribution of upper group and lower group in personality properties revealed that the ratio of upper group was higher than that of lower group in activity property, social property, but the ratio of lower group was higher than that of upper group in responsibility and reflective property. Second, the socio-populational variables affecting 6th graders' personality' and science attitude were a sex, a sibling order. The cognition variables affecting 6th graders' personality and science attitude were preference, extent of usability to practical life and interest of science. Third, analyzing the correlation between lower categories of personality and lower categories of science attitude revealed that activity property of personality rather highly correlated to willingness property, critical property at .399(p<.01), .351(p<.01) respectively. and that consideration property of personality highly correlated to curiosity, critical property at .451 (p<.01), .415(p<.01) respectively.

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단순지지 변단면 압축재의 임계하중 (Elastic Critical Laod of Tapered Columns)

  • 홍종국;김순철;이수곤
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1999년도 봄 학술발표회 논문집
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    • pp.252-259
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    • 1999
  • One of the most important factors for a proper design of a slender compression member may be the exact determination of the elastic critical load of that member. In the cases of non-prismatic compression member, however, there are times when the exact critical load becomes impossible to determinate if one relies on the neutral equilibrium method or energy principle. Here in this paper, the approximate critical loads of symmetrically or non-symmetrically tapered members are computed by finite element method. The two parameters considered in this numerical analysis are the taper parameter, $\alpha$ and the sectional property parameters, m. The computed results for each sectional property parameter, m are presented in an algebraic equation which agrees with those by F.E.M The algebraic equation can be easily used by structural engineers, who are engaged in structural analysis and design of non-prismatic compression member.

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단순지지 변단면 압축재의 임계하중 (Elastic Critical Loads of Tapered Compression Members with Simply Supported Ends)

  • 송창영
    • 한국공간구조학회논문집
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    • 제7권5호
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    • pp.83-87
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    • 2007
  • 비대칭 및 대칭 변단면 압축재( = m)의 임계하중을 수치 해석법의 하나인 유한 요소법으로 결정하였다. 해석에서 고려한 변수는 taper parameter(=a) 와 단면 성능 변수 m이다. 구조설계 및 구조의 안전 검토에 임하는 구조 기술자들의 편의를 위하여 유한요소법으로 결정한 임계하중의 계수 변화는 하나의 대수식으로 표시하였다. 대수식에 나타나는 계수들은 회귀분석법으로 결정하였다.

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Bending Strain Effect on the Critical Current of Jointed BSCCO Tapes

  • Shin, Hyung-Seop;Dedicatoria, Marlon
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2009년도 추계학술대회 논문집
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    • pp.217-217
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    • 2009
  • In this study, the effect of bending strain on the transport property and critical current of lap and butt-jointed BSCCO tapes have been investigated. The samples were joined using a mechanically controlled jointing procedure. In order to ensure a uniform pressure application at the joint part, a single point contact has been devised and also to achieve a uniform thickness at the joint interface.

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Relationship Between Properties Degradation and Critical Aging Time of Super Austenitic and Duplex Stainless Steels

  • S. H. Choi;Y. R. Yoo;S. Y. Won;G. B. Kim;Y. S. Kim
    • Corrosion Science and Technology
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    • 제22권5호
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    • pp.330-340
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    • 2023
  • The objective of this study was to analyze effects of aging time on property degradation of super austenitic stainless steel of PRE 52.8 and super duplex stainless steel of PRE 48.7. To analyze corrosion properties based on aging time, a critical pitting temperature test was performed in a solution of 6% FeCl3 + 1% HCl and an anodic polarization test was performed in deaerated 0.5N HCl + 1N NaCl solution at a temperature of 50 ℃. Surface hardness was measured to analyze mechanical properties. It was found that corrosion properties and mechanical properties deteriorated rapidly as aging time increased. Critical pitting temperature had the most effect on critical aging time at which property changes occurred rapidly, followed by pitting potential and hardness. This trend was found to be closely related to the fraction of sigma phase. Rate of sigma phase formation was found to be significantly faster in duplex stainless steel than in austenitic stainless steel.