• 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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    • v.9 no.3
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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.

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

  • Park, Sungsun
    • Education of Primary School Mathematics
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    • v.17 no.2
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    • pp.159-171
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    • 2014
  • Spatial ability has been valued as one component of intelligence and as an talented domain. And it is associated with the achievements in science, technology, engineering, and mathematics (STEM) disciplines. So, the instrument for measuring spatial ability is very important. The purpose of this study is to develop Spatial Visualization Tests for Elementary School Children and examine internal consistency reliability evidence and construct validity evidence on confirmatory factor analysis of that instrument. For this purpose, 'The Spatial Visualization Tests for Elementary School Children was administered to 1482 Korean elementary school students. As a result, this study show that internal consistency reliability evidence using Cronbach' alpha showed item consistency and construct validity evidence from confirmatory factor analysis in the Spatial Visualization Tests for Elementary School Children. And also, this study show ed that item difficulty and item discrimination of the Spatial Visualization Tests for Elementary School Children were within an acceptable range.

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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    • v.38 no.3
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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.

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

  • Paik, Seoung-Hey;Kim, Seung-Hwa;Hong, Sung-Il;Yang, II-Ho;Lee, Jae-Cheon
    • Journal of The Korean Association For Science Education
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    • v.13 no.3
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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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Advanced Color Consistency Method for Improving Voxel Coloring Performance (복셀 칼라링 성능 향상을 위한 개선된 칼라 일치성 기법)

  • Chun Young-Ju;Jeong Seung-Do;Choi Byung-Uk
    • Proceedings of the Korea Contents Association Conference
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    • 2005.11a
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    • pp.622-626
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    • 2005
  • Voxel Coloring is one of the well known methods to reconstruct three dimensional shape from calibrated two dimensional multiple-view images. This paper proposes an advanced Voxel Coloring to complement drawbacks of previous color consistency tests. We propose an adaptive threshold using double threshold and an weight component to test color consistency. From the reconstruction experiment, we have verified that our proposed method outperforms the previous one.

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Some Distribution Free Tests for Exponential Distributions

  • Jeon, Jong Woo;Han, Suk Ki;Nam, Eun Woo
    • Journal of Korean Society for Quality Management
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    • v.14 no.1
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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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Highly Accelerated Life Tests for Auto-Connector in Use-Environment (자동차 환경을 고려한 커넥터의 가속시험에 관한 연구)

  • Kim Jong-Gurl;Kim Jin-Hawn
    • Proceedings of the Safety Management and Science Conference
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    • 2004.11a
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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.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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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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    • v.22 no.3
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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.

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

  • Lee, Ho-Jin;Kim, Byung-Il;Park, Sang-Kyu;Kim, Soo-Sam
    • Proceedings of the Korean Geotechical Society Conference
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    • 2005.03a
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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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