• Title/Summary/Keyword: consistency tests

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Consistency of a Modified W Test for Exponentiality

  • Kim, Namhyun
    • Communications for Statistical Applications and Methods
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    • 제9권3호
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    • pp.629-637
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    • 2002
  • Shapiro and Wilk(1972) developed a test for exponentiality with origin and scale unknown. The procedure consists of comparing the generalized least squares estimate of scale with the estimate of scale given by the sample variance. However the test based on the statistic is inconsistent Kim(2001a) proposed a modified Shapiro-Wilk's test statistic using the ratio of two asymptotically efficient estimators of scale. In this paper, we study the consistency of the proposed test.

초등학생용 공간 시각화 검사지 개발 및 표준화 (Development and Validation of Spatial Visualization Tests for Elementary School Children)

  • 박성선
    • 한국수학교육학회지시리즈C:초등수학교육
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    • 제17권2호
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    • pp.159-171
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    • 2014
  • 본 연구는 초등학생용 공간시각화 검사지를 개발하고 표준화하는데 목적이 있다. 이를 위하여 총 24문항으로 구성된 초등학생용 공간시각화 검사지를 개발하였으며, 초등학생 1482명을 대상으로 검사를 실시하여 신뢰도와 타당도를 분석하였다. 분석결과는 다음과 같다. 첫째, 초등학생용 공간시각화 검사지의 문항내적일관성 신뢰도는 Cronbach's ${\alpha}$=.794로 양호한 것으로 나타났다. 둘째, 검사지의 24문항에 대한 타당도를 검증하기 위하여 확인적 요인분석을 한 결과, 검사지의 타당도가 양호한 것으로 판단되었다. 셋째, 검사지 24문항에 대한 문항난이도는 .200에서부터 .886으로 나타났으며, 평균 문항난이도는 .544인 것으로 나타났다. 이상의 연구 결과로 볼 때, 본 연구에서 개발한 초등학생용 공간시각화 검사지는 신뢰도와 타당도를 확보한 것으로 보이므로, 초등학생들의 공간시각화 능력을 측정하는데 활용할 수 있을 것이다.

Influence of Grease Consistency on the Wear of Gear Surfaces

  • Li, Chen-Xiao;Park, Haneum;Lee, Chul-Hee
    • Tribology and Lubricants
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    • 제38권3호
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    • pp.115-119
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    • 2022
  • This paper selected three kinds of grease with the same type but different consistency for the experiment. The purpose of the experiment is tested the effect of different consistency of grease on the wear of the gear surface. Different torque test groups were selected in the test, and the lubrication effect of different greases was tested in the test groups with the same torque. After each set of tests, the wear of the gear surfaces was observed and recorded. The data recorded in the experiment included the area of the wear area on the gear surface, the type of wear and the volume of wear. After the test, the gear surface roughness was measured. By calculating the wear volume, the effects of different concentrations of grease on the gear surface wear were compared. The experimental results show that under different stress conditions, the consistency of the grease has a great influence on the lubricating effect of the gear surface and the gear wear. Under the condition with low speed and high torque, different grease consistency affect the gear surface wear, the high consistency grease can reduce the wear of the gear surface, so that the gear can get better lubrication effect during the work.

미시적 교수설계이론에 의한 현행 과학교수의 일관성 분석 - 과학 I (하) 'V.l.태양계' 단원을 중심으로 - (An Analysis of Current Science Instruction Consistency by Micro Instructional Design Theory)

  • 백성혜;김승화;홍성일;양일호;이재천
    • 한국과학교육학회지
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    • 제13권3호
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    • pp.366-376
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    • 1993
  • In this study, a part of high school science instructional materials is evaluated by Instructional Quality Profile(IQP) based on the Merrill's Component Display Theory(CDT). The CDT is based on the Gagne's assumption of different conditions of learning for different outcomes. The IQP enables the user to check both the consistency and adequacy of existing cognitive instruction. The IQP can be used to predict student performance, and also to design and develop new instructional materials. The instructional components are classified according to 5 task levels; An Use-Generalities on Newly Encountered Examples(UGeg), A Remember-Paraphrased-Generalities(RpG), A Remember-Verbatim-Generalities(RvG), A Remember-Paraphrased-Examples (Rpeg). A Remember-Verbatim-Examples (Rveg). The analyses are composed of 3 parts; Justifying the task level of objectives, Objective-test consistency, and Test-presentation consistency. The objectives, the presentations and the tests given in a teacher's guide and a textbook are analyzed. The results show that the task levels and the content levels of the objectives are not consistent with those of the tests. And the indices of the test-presentation consistency indicate the presentation problems of the instructional materials.

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복셀 칼라링 성능 향상을 위한 개선된 칼라 일치성 기법 (Advanced Color Consistency Method for Improving Voxel Coloring Performance)

  • 천영주;정승도;최병욱
    • 한국콘텐츠학회:학술대회논문집
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    • 한국콘텐츠학회 2005년도 추계 종합학술대회 논문집
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    • pp.622-626
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    • 2005
  • 복셀 칼라링은 보정된 여러 장의 2차원 영상에서 3차원 형상을 복원하기 위한 널리 알려진 방법들 중 하나이다. 본 논문에서는 기존 복셀 칼라링 기법에서의 칼라 일치성 테스트의 문제점을 해결하기 위해 개선된 복셀 칼라링 기법을 제안한다. 제안하는 기법에서는 칼라 일치성 테스트에서 이중 문턱치와 가중치 요소를 이용하여 적응적인 문턱치를 주므로 향상된 복원 성능을 얻을 수 있게 하였다. 실제 영상을 이용한 복원 실험을 통해 제안하는 방법의 성능을 검증한다.

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Some Distribution Free Tests for Exponential Distributions

  • Jeon, Jong Woo;Han, Suk Ki;Nam, Eun Woo
    • 품질경영학회지
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    • 제14권1호
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    • pp.39-46
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    • 1986
  • This paper considers two sided tests for exponential null distribution against NBUE or NWUE alternative in life testing. The main results concern the strong consistency of two proposed statistics, one being similar to Kolmogorov - Smirnov statistic, the other similar to Cramer-Von Mises statistic. Also obtained are the asymtotic null distribution and the exact Bahadur slope of the statistic similar to Kolmogorov-Smirnov.

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자동차 환경을 고려한 커넥터의 가속시험에 관한 연구 (Highly Accelerated Life Tests for Auto-Connector in Use-Environment)

  • 김종걸;김진환
    • 대한안전경영과학회:학술대회논문집
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    • 대한안전경영과학회 2004년도 추계학술대회
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    • pp.229-235
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    • 2004
  • This paper treats accelerated life tests for automotive connector. The contact resistance of connector is explained by some factors; the use time(calender time, real cycle), stresses and loads adapted in auto test. The relationships between contact resistance and some factors are compared and analyzed by regression models in various test conditions; field use-environment, manufacturer's test environment, and accelerated test condition. The consistency between of manufacturer's test and field test is examined. Finally, the future study on accelerated test for automotive connector is presented.

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APPLYING FUZZY MATHEMATICS TO QUANTIFYING HUMAN RESPONSES

  • R.C.Steinlage;T.E.Gantner;Lim, P.Y.W.
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.1362-1365
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    • 1993
  • Fuzzy mathematics is used to elicit and evaluate human psychophysical responses in panel tests. The fundamental instrument used is a bar graph whose data is then converted to a paired comparison matrix. Form this matrix we use the theory of Perron and Froebenius to obtain an eigenvalue and eigenvector which indicates not only the panelist's comparitive responses but also the consistency of the responses from that panelist. Tests were done to evaluate the procedure.

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A Comparison of Size and Power of Tests of Hypotheses on Parameters Based on Two Generalized Lindley Distributions

  • Okwuokenye, Macaulay;Peace, Karl E.
    • Communications for Statistical Applications and Methods
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    • 제22권3호
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    • pp.233-239
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    • 2015
  • This study compares two generalized Lindley distributions and assesses consistency between theoretical and analytical results. Data (complete and censored) assumed to follow the Lindley distribution are generated and analyzed using two generalized Lindley distributions, and maximum likelihood estimates of parameters from the generalized distributions are obtained. Size and power of tests of hypotheses on the parameters are assessed drawing on asymptotic properties of the maximum likelihood estimates. Results suggest that whereas size of some of the tests of hypotheses based on the considered generalized distributions are essentially ${\alpha}$-level, some are possibly not; power of tests of hypotheses on the Lindley distribution parameter from the two distributions differs.

간극수의 pH가 점성토의 강도와 압밀특성에 미치는 영향 (The Characteristics of Strength and Consolidation of Clayey Soil Dependent on pH of Soil Pore Water)

  • 이호진;김병일;박상규;김수삼
    • 한국지반공학회:학술대회논문집
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    • 한국지반공학회 2005년도 춘계 학술발표회 논문집
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    • pp.1047-1054
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    • 2005
  • The purpose of this study is the understanding to changes in the characteristic of soil structure and classification, atterberg limits, undrained shear strength and consolidation of clayey soil dependent on pH of soil pore water. A series of tests including consistency tests, uniaxial compressive tests, vane tests and oedometer tests are performed on. The test results indicated that pH changes in the soil pH resulted in changes in the soil structure and classification, stress-strain behavior. Specially, when pH is conditioned to 7, liquid limit, undrained shear strength and preconsolidation pressure are the largest.

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