• 제목/요약/키워드: $\alpha$-equivalence

검색결과 35건 처리시간 0.023초

DISCRETE PROOF OF EVEN KAKUTANI EQUIVALENCE VIA ${\alpha}$- AND ,${\beta}$-EQUIVALENCE

  • Park, Kye-Won
    • 대한수학회논문집
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    • 제13권1호
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    • pp.61-72
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    • 1998
  • It has been known that if T and S are even Kakutani equivalent, then there exists U such that T and U are $\alpha$-equivalent and S and U are $\beta$-equivalent where $\alpha$ and $\beta$ are irrationally related. In this paper we give a complete discrete proof of this theorem without using R-actions.

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REMARKS ON ISOMORPHISMS OF TRANSFORMATION SEMIGROUPS RESTRICTED BY AN EQUIVALENCE RELATION

  • Namnak, Chaiwat;Sawatraksa, Nares
    • 대한수학회논문집
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    • 제33권3호
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    • pp.705-710
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    • 2018
  • Let T(X) be the full transformation semigroup on a set X and ${\sigma}$ be an equivalence relation on X. Denote $$E(X,{\sigma})=\{{\alpha}{\in}T(X):{\forall}x,\;y{\in}X,\;(x,y){\in}{\sigma}\;\text{implies}\;x{\alpha}=y{\alpha}\}.$$. Then $E(X,{\sigma})$ is a subsemigroup of T(X). In this paper, we characterize two semigroups of type $E(X,{\sigma})$ when they are isomorphic.

Equivalence in Alpha-Level Linear Regression

  • Yoon, Jin-Hee;Jung, Hye-Young;Choi, Seung-Hoe
    • Communications for Statistical Applications and Methods
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    • 제17권4호
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    • pp.611-624
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    • 2010
  • Several methods were suggested for constructing a fuzzy relationship between fuzzy independent and dependent variables. This paper reviews the use of the method by minimizing the square of the difference between an observed and a predicted fuzzy number in an ${\alpha}$-level linear regression model. We introduce a new distance between fuzzy numbers on the basis of a mode, a core point and a radius of an ${\alpha}$-level set of a fuzzy number an construct the fuzzy regression model using the proposed fuzzy distance. We also investigate sufficient condition for an equivalence in the ${\alpha}$-level regression model.

동등성 시험을 신뢰구간을 사용하여 검정하는 경우 왜 신뢰도 90%인 신뢰구간을 사용하는가? (Why is 90% Confidence Interval Used When Confidence Interval Approach is Used for Testing Equivalence?)

  • 강승호
    • 응용통계연구
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    • 제21권5호
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    • pp.867-873
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    • 2008
  • 임상시험의 자료에 대하여 통계적 검정을 실시하는 경우 유의수준 5%를 사용하는 것이 관례이다. 하지만 동등성 시험을 신뢰구간을 사용하여 검정하는 경우, 신뢰도 90%인 신뢰구간이 사용되고 있다. 흔히 신뢰도 $1-{\alpha}$인 신뢰구간을 검정에 사용하는 경우, 그 검정법의 유의수준은 ${\alpha}$이다. 이 때문에 동등성 검정에서 신뢰도 90%인 신뢰구간을 사용하게 되면, 유의수준은 10%가 되는 것이 아닌가 하는 혼란을 일으켰다. 본 논문에서는 이와 관련된 이슈들을 관련 문헌의 검토와 시뮬레이션을 통하여 명확하게 하여, 제약회사, CRO, 대학병원 등에 종사하는 통계전문가들에게 도움을 주고자 한다.

Reliability Equivalence Factors of Non-identical Components Series System with Mixture Failure Rates

  • Mustafa, A.;El-Desouky, B.S.;El-Dawoody, M.
    • International Journal of Reliability and Applications
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    • 제10권1호
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    • pp.17-32
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    • 2009
  • The aim of this work is to generalize reliability equivalence technique to apply it to a system consists of n independent and non-identical components connected in series system, that have mixing constant failure rates. We shall improve the system by using some reliability techniques: (i) reducing some failure rates; (ii) add hot reduncy components; (iii) add cold reduncy components; (iv) add cold reduncy components with imperfect switches. We start by establishing two different types of reliability equivalence factors, the survival equivalence (SRE), and mean reliability equivalence (MRE) factors. Also, we introduced some numerical results.

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2-D LIF를 이용한 층류화염의 NO 생성특성에 관한 연구 (A Study of NO Formation Characteristics in Laminar Flames Using 2-D LIF Technique)

  • 이원남;차민석;송영훈
    • 한국연소학회지
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    • 제8권3호
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    • pp.38-48
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    • 2003
  • OH, CH and NO radical distributions have been measured and compared with the numerical analysis results in methane/air partially premixed laminar flames using 2-D LIF technique. The pick intensity of OH LIF signal is insensitive to fuel equivalence ratio: however, CH LIF intensity decreases as equivalence ratio increases and the NO concentration increases with equivalence ratio. The contribution of the prompt NO, formed near premixed reaction zone, to the total NO formation is evident from the OH, CH, and NO PLIF images in which the dilution effect of nitrogen is minimal for the highest equivalence ratio. Measured OH and NO LIF signals in counterflow flames agree with the computed concentration distributions. Both numerical and experimental results indicate that the structural change in a flame alters the NO formation characteristics of a partially premixed counterflow flame. The nitrogen dilution also changes flame structure, temperature and OH radical distributions and results in the decreased NO concentrations in a flame. The levels of decrease in NO concentrations, however, depends on the premixedness(${\alpha}$) of a flame. The larger change in the flame structure and NO concentrations have been observed in a premixed flame(${\alpha}=1.0$), which implies that the premixedness is likely to be a factor in the dilution effect on NO formation of a flame.

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ERROR ESTIMATES OF NONSTANDARD FINITE DIFFERENCE SCHEMES FOR GENERALIZED CAHN-HILLIARD AND KURAMOTO-SIVASHINSKY EQUATIONS

  • Choo, Sang-Mok;Chung, Sang-Kwon;Lee, Yoon-Ju
    • 대한수학회지
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    • 제42권6호
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    • pp.1121-1136
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    • 2005
  • Nonstandard finite difference schemes are considered for a generalization of the Cahn-Hilliard equation with Neumann boundary conditions and the Kuramoto-Sivashinsky equation with periodic boundary conditions, which are of the type $$U_t\;+\;\frac{{\partial}^2}{{\partial}x^2} g(u,\;U_x,\;U_{xx})\;=\;\frac{{\partial}^{\alpha}}{{\partial}x^{\alpha}}f(u,\;u_x),\;{\alpha}\;=\;0,\;1,\;2$$. Stability and error estimate of approximate solutions for the corresponding schemes are obtained using the extended Lax-Richtmyer equivalence theorem. Three examples are provided to apply the nonstandard finite difference schemes.

GENERALIZED VECTOR MINTY'S LEMMA

  • Lee, Byung-Soo
    • 한국수학교육학회지시리즈B:순수및응용수학
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    • 제19권3호
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    • pp.281-288
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    • 2012
  • In this paper, the author defines a new generalized ${\eta}$, ${\delta}$, ${\alpha}$)-pseudomonotone mapping and considers the equivalence of Stampacchia-type vector variational-like inequality problems and Minty-type vector variational-like inequality problems for generalized (${\eta}$, ${\delta}$, ${\alpha}$)-pseudomonotone mappings in Banach spaces, called the generalized vector Minty's lemma.

간호의 전문직업성 척도 개발을 위한 Hall의 전문직업성 척도 번역 및 동등성 비교 (Translation and Validation of Korean Version of Hall's Professionalism Inventory)

  • ;백희정
    • 간호행정학회지
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    • 제13권4호
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    • pp.509-515
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    • 2007
  • Purpose: The purpose of this study was to translate and validate the Korean version of Hall's Professional Inventory(HPI) scale to assess levels of professionalism among Korean registered nurses. Method: The 25 item HPI scale was translated and content review was done by translation panel. After the content review, a bilingual nursing scholar performed the back-translation into English. A semantic equivalence test was conducted with 5 American nursing professors. A pilot study was conducted with a sample of 164 registered nurses in Korea to test the validity and reliability of the translated HPI. Result: The content equivalence for translated version of HPI was validated by a translation panel. The finding of the semantic equivalence test of back-translated version was 72.8%. The Cronbach's alpha for the Korean version of HPI was .820. Conclusions: This study provides information about the issues of translating an instrument such as the HPI. The Korean version of the HPI is a valid and reliable instrument and can have psychometric properties equivalent to those of the original HPI. The translated version could be used for assessing levels of professionalism for other health care professionalism as well as nurses.

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교육대학원과 사범대학 예비수학교사의 교직 적성·인성 검사에 대한 측정의 동등성 분석 (An Analysis of Measurement Equivalence in a Teaching Aptitude and Personality Test for Pre-service Mathematics Teachers between a Graduate School of Education and a College of Education)

  • 김성연
    • 한국수학교육학회지시리즈A:수학교육
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    • 제57권2호
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    • pp.179-196
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    • 2018
  • The purpose of this study was to investigate the measurement equivalence and to suggest application ways in teaching aptitude and personality test results for pre-service mathematics teachers between a graduate school of education and a college of education. This study analyzed the scores of the teaching aptitude and personality test of 36 pre-service mathematics teachers enrolled in a graduate school of education and 111 pre-service mathematics teachers in a college of education by performing a multivariate generalizability analysis. The main results were as follows. First, graduate's pre-service mathematics teachers had a higher level of teaching aptitude and personality than that of college's pre-service mathematics teachers based on the total scores. In addition, graduate's pre-service mathematics teachers had higher levels of teaching aptitude and personality than those of college's pre-service mathematics teachers except for a creativity application domain based on the sub-domain scores. Second, cognitive domains were measured more precisely but affective domains were measured less precisely for graduate's pre-service mathematics teachers than for college's pre-service mathematics teachers. Third, regardless of school levels, Cronbach's ${\alpha}$ values, which might be overestimated by applying the classical test theory, were higher than dependability coefficients. Fourth, this study showed a somewhat negative result in ensuring the measurement equivalence for a problem solving exploration domain. However, regardless of school levels, this study indicated that the overall measurement was generally reliable on composite scores. Based on these results, it was confirmed that multivariate generalizability methodologies' approach can be useful for exploring the measurement equivalence issues. Finally, this study suggests how to utilize the results of the test, how to apply a multivariate generalizability analysis for detecting the measurement equivalence, and how to develop future research based on limitations.