• Title/Summary/Keyword: Analysis of Variance Test

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A Study of Choice for Analysis Method on Repeated Measures Clinical Data

  • Song, Jung
    • Korean Journal of Clinical Laboratory Science
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    • v.45 no.2
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    • pp.60-65
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    • 2013
  • Data from repeated measurements are accomplished through repeatedly processing the same subject under different conditions and different points of view. The power of testing enhances the choice of pertinent analysis methods that agrees with the characteristics of data concerned and the situation involved. Along with the clinical example, this paper compares the analysis of the variance on ex-post tests, gain score analysis, analysis by mixed design and analysis of covariance employable for repeating measure. Comparing the analysis of variance on ex post test, and gain score analysis on correlations, leads to the fact that the latter enhances the power of the test and diminishes the variance of error terms. The concluded probability, identified that the gain score analysis and the mixed design on interaction between "between subjects factor" and "within subjects factor", are identical. The analysis of covariance, demonstrated better power of the test and smaller error terms than the gain score analysis. Research on four analysis method found that the analysis of covariance is the most appropriate in clinical data than two repeated test with high correlation and ex ante affects ex post.

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Goodness-of-fit test for mean and variance functions

  • Jung, Sin-Ho;Lee, Kee-Won
    • Journal of the Korean Statistical Society
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    • v.26 no.2
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    • pp.199-210
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    • 1997
  • Using regression methods based on quasi-likelihood equation, one only needs to specify the conditional mean and variance functions for the response variable in the analysis. In this paper, an omnibus lack-of-fit test is proposed to test the validity of these two functions. Our test is consistent against the alternative under which either the mean or the variance is not the one specified in the null hypothesis. The large-sample null distribution of our test statistics can be approximated through simulations. Extensive numerical studies are performed to demonstrate that the new test preserves the prescribed type I error probability. Power comparisons are conducted to show the advantage of the new proposal.

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Effect of Bias on the Pearson Chi-squared Test for Two Population Homogeneity Test

  • Heo, Sunyeong
    • Journal of Integrative Natural Science
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    • v.5 no.4
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    • pp.241-245
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    • 2012
  • Categorical data collected based on complex sample design is not proper for the standard Pearson multinomial-based chi-squared test because the observations are not independent and identically distributed. This study investigates effects of bias of point estimator of population proportion and its variance estimator to the standard Pearson chi-squared test statistics when the sample is collected based on complex sampling scheme. This study examines the effect under two population homogeneity test. The standard Pearson test statistic can be partitioned into two parts; the first part is the weighted sum of ${\chi}^2_1$ with eigenvalues of design matrix as their weights, and the additional second part which is added due to the biases of the point estimator and its variance estimator. Our empirical analysis shows that even though the bias of point estimator is small, Pearson test statistic is very much inflated due to underestimate the variance of point estimator. In the connection of design-based variance estimator and its design matrix, the bigger the average of eigenvalues of design matrix is, the larger relative size of which the first component part to Pearson test statistic is taking.

Condition assessment of bridge pier using constrained minimum variance unbiased estimator

  • Tamuly, Pranjal;Chakraborty, Arunasis;Das, Sandip
    • Structural Monitoring and Maintenance
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    • v.7 no.4
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    • pp.319-344
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    • 2020
  • Inverse analysis of non-linear reinforced concrete bridge pier using recursive Gaussian filtering for in-situ condition assessment is the main theme of this work. For this purpose, minimum variance unbiased estimation using unscented sigma points is adopted here. The uniqueness of this inverse analysis lies in its approach for strain based updating of engineering demand parameters, where appropriate bound and constrained conditions are introduced to ensure numerical stability and convergence. In this analysis, seismic input is also identified, which is an added advantage for the structures having no dedicated sensors for earthquake measurement. First, the proposed strategy is tested with a simulated example whose hysteretic properties are obtained from the slow-cyclic test of a frame to investigate its efficiency and accuracy. Finally, the experimental test data of a full-scale bridge pier is used to study its in-situ condition in terms of Park & Ang damage index. Overall the study shows the ability of the augmented minimum variance unbiased estimation based recursive time-marching algorithm for non-linear system identification with the aim to estimate the engineering damage parameters that are the fundamental information necessary for any future decision making for retrofitting/rehabilitation.

Study on the Result Changes with the Size of the Variance in Taguchi Method and Factor Experimental (다구찌 기법과 요인실험의 실험 데이터의 산포 크기에 따라 결과 변화 고찰)

  • Ree, Sangbok
    • Journal of Korean Society for Quality Management
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    • v.41 no.1
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    • pp.119-134
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    • 2013
  • Purpose: The purpose of this paper is to show whether the results are changed with respect to the variance of the data, by analysis of data obtained from the Taguchi experimental techniques and general experiment. Because which cannot be prove by mathematical Formula, through experimental examples will show. Methods: Taguchi experiments were carried out with paper Helicopter experiment. Experimental Data are obtained by special designed Drop Test Equipment. While Experimental value arbitrarily changed, we looked at how Significant control Factor of Taguchi Methods and Factor experiments are changed. This process cannot be expressed as a Mathematical formula, but showed as a numerical example. Results: Saw significant changes in the factors when data is outside a certain range of the experimental data. By Test of Equivalence Variance, Experiment data is verified reliability. To find the Control Factor, Taguchi Method is better than the general experiment. Conclusion: We know that a Significant Factor is changed with the range of Variance of Experiment Data. The value of this paper is verified change process with Numerical Data obtained Experiment.

Test for reliability of MS Excel statistical analysis output and modification of macros (Focused on an Analysis of Variance menu) (MS 엑셀 프로그램의 통계분석결과 신뢰성 검증 및 매크로 보완 (분산분석 메뉴를 중심으로))

  • Kim, Sook-Young
    • Journal of the Korea Computer Industry Society
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    • v.9 no.5
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    • pp.207-216
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    • 2008
  • Statistical analysis menus of MS Excel software, with powerful spreadsheet functions has not been modified since Excel 2000 Edition and its utilization is very low. To improve utilization of Excel menu for statistical analysis, this research compared outputs of Excel statistical menus and computed test statistics, and developed high-level macros. Outputs of Excel menus, both oneway layout and twoway layout, on real data are exactly same as the computed test statistics, and therefore, Excel menus for statistical analysis are reliable. Macros to provide results for Analysis of Variance with a block and multiple comparison of means are developed using Excel functions.

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A case study of MS Excel's powerful functions for statistical data analysis. (Focused on an Analysis of Variance menu) (자료 통계 분석을 위한 MS 엑셀의 유용한 기능들에 관한 사례연구 (지하철 이용객 자료 분석))

  • Kim, Sook-Young
    • Journal of the Korea Computer Industry Society
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    • v.9 no.5
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    • pp.223-228
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    • 2008
  • A case study to show MS Excel's convenient and powerful functions was conducted to test hypotheses with subway data. Quantitative variables were described using descriptive menu, and qualitative variables were described using histogram menu of a MS Excel software. Relationships were tested using regression menu, differences were tested using t-test menu, and factors were tested using variance-layout menu of a Excel software. Data input, management, and statistical analysis were done successfully with only a MS Excel software.

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Pooling Variance Tests Using Expected Mean Square in Split-Plot Designs (분할법에서 EMS알고리즘을 이용한 풀링분산검정)

  • Choi, Sung-Woon
    • Journal of the Korea Safety Management & Science
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    • v.10 no.3
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    • pp.245-251
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    • 2008
  • The research proposes three ANOVA(Analysis of Variance) tests using expected mean square(EMS) algorithms in various split-plot designs. The variance tests consist of Never-Pool test, Sometimes-Pool test and Always-Pool test. This paper also presents two EMS algorithms such as standard method and easy method. These algorithms are useful to make a decision rule for pooling. Numerical examples are illustrated for various split-plot designs such as split-plot designs, split-split-plot designs, repetition split-plot designs, and nested designs. Pragmatically, the results are summarized and compared with popular ANOVA spreadsheets and data model equations.

The Change Point Analysis in Time Series Models

  • Lee, Sang-Yeol
    • Proceedings of the Korean Statistical Society Conference
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    • 2005.11a
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    • pp.43-48
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    • 2005
  • We consider the problem of testing for parameter changes in time series models based on a cusum test. Although the test procedure is well-established for the mean and variance in time series models, a general parameter case has not been discussed in the literature. Therefore, here we develop a cusum test for parameter change in a more general framework. As an example, we consider the change of the parameters in an RCA(1) model and that of the autocovariances of a linear process. We also consider the variance change test for unstable models with unit roots and GARCH models.

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Pridiction of chip breakability by an orthogonal array method (직교배열법에 의한 칩절단특성 예측)

  • 이영문;양승한;권오진
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.1008-1011
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    • 2001
  • The purpose of this paper is to evaluate the chip breakability during turning using the experimental equation, which is developed by an orthogonal array method. The chip breaking index(CB), non-dimensional parameter is used in the evaluation of chip breakability. The analysis of variance(ANOVA)-test has been used to check the significance of cutting parameters. And using the result of ANOVA-test, the experimental equation of chip breakability, which consists of significant cutting parameters, has been developed.

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