• Title/Summary/Keyword: ANOVA statistic

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Power Comparison in a Balanced Factorial Design with a Nested Factor

  • Choi, Young-Hun
    • Journal of the Korean Data and Information Science Society
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    • v.19 no.4
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    • pp.1059-1071
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    • 2008
  • In a balanced factorial design with a nested factor where crossed factors as well as a nested factor exist simultaneously, powers of the rank transformed FR statistic for testing the main, nested and interaction effects are superior to those of the parametric F statistic. In heavy tailed distributions such as exponential and double exponential distributions, powers of the FR statistic show much higher level than those of the F statistic. Further powers of the F and FR statistic for testing the main effect show the highest level in an absolute size as compared with powers of the F and FR statistic for testing the nested and interaction effects. However powers of the FR statistic for testing the nested and interaction effects rather than the main effect are greater in a relative size than powers of F statistic for the all population distributions.

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Rank Transformation Technique in a Two-stage Two-level Balanced Nested Design (이단계 이수준 균형지분모형의 순위변환 기법연구)

  • Choi Young-Hun
    • The Korean Journal of Applied Statistics
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    • v.19 no.1
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    • pp.111-120
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    • 2006
  • In a two-stage two-level balanced nested design, type I error rates for the parametric tests and the rank transformed tests for the main effects and the nested effects are in overall similar to each other. Furthermore, powers for the rank transformed statistic for the main effects and the nested effects in a two-stage two-level balanced nested design are generally superior to powers for the parametric statistic When the effect size and the sample size are increased, we can find that powers increase for the parametric statistic and the rank transformed statistic are dramatically improved. Especially for the case of the fixed effects in the asymmetric distributions such as an exponential distribution, powers for the rank transformed tests are quite high rather than powers for the parametric tests.

Analysis of Agricultural Characters to Establish the Evaluating Protocol and Standard Assessment for Genetically Modified Peppers (GM 고추의 환경위해성 평가 프로토콜 작성을 위한 농업적 형질 분석)

  • Cho, Dong-Wook;Chung, Kyu-Hwan
    • Journal of Environmental Science International
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    • v.20 no.9
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    • pp.1183-1190
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    • 2011
  • This study was aimed to establish the evaluating protocol and standard assessment for genetically modified (GM) hot pepper and to find out a proper statistic method to analyze for equality of agricultural characters between GM and non-GM pepper lines. GM and non-GM hot pepper lines were cultivated in two GMO fields in the middle region of Korea and total of 52 agricultural characters were collected during the plant growing season for 4 years, 2007 to 2010. Levene's test was conducted to confirm the homogeneity of raw data before statistic analysis. Two-way ANOVA in the multivariate tests and t-test were conducted to analyze 52 agricultural characters in order to find out the equality between H15 and P2377. From the statistical analysis through two-way ANOVA, 16 out of 16 plant growth traits, 9 out of 18 green fruit traits and 7 out of 18 red fruit traits among 4 years and 9 out of 16 plant growth traits, 4 out of 18 green fruit traits and 3 out of 18 red fruit traits between H15 and P2377 have shown the statistic differences. With the same raw data of 52 agricultural characters, t-test was also conducted. Based on the result from t-test, only 1 out of 16 plant growth traits, 2 out of 18 green fruit traits and 1 out of 18 red fruit traits have shown the differences between H15 and P2377, so that it was concluded that there is no statistic difference between H15 and P2377 in terms of agricultural characters. Also, the t-test is a proper statistic method to analyze each trait between GM and its control lines in order to evaluate agricultural characters.

The Nonparametric Test for Detecting Main Effects for Three-Way ANOVA Models

  • Park, Young-Hun
    • Journal of the Korean Statistical Society
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    • v.25 no.3
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    • pp.419-432
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    • 1996
  • When interactions are not present in a three-way layout, the lim-iting null distribution of the F statistic for testing main effects when applied to the rank-score transformed data is the same as the limiting null distribution of the usual F statistic when applied to the normal data. The simulation results exhibit that the rank transform test is robust with respect to significance level and powerful for testing main effects in a three-way factorial experiment.

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Unbalanced ANOVA for Testing Shape Variability in Statistical Shape Analysis

  • Kim, Jong-Geon;Choi, Yong-Seok;Lee, Nae-Young
    • The Korean Journal of Applied Statistics
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    • v.23 no.2
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    • pp.317-323
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    • 2010
  • Measures are very useful tools for comparing the shape variability in statistical shape analysis. For examples, the Procrustes statistic(PS) is isolated measure, and the mean Procrustes statistic(MPS) and the root mean square measure(RMS) are overall measures. But these measures are very subjective, complicated and moreover these measures are not statistical for comparing the shape variability. Therefore we need to study some tests. It is well known that the Hotelling's $T^2$ test is used for testing shape variability of two independent samples. And for testing shape variabilities of several independent samples, instead of the Hotelling's $T^2$ test, one way analysis of variance(ANOVA) can be applied. In fact, this one way ANOVA is based on the balanced samples of equal size which is called as BANOVA. However, If we have unbalanced samples with unequal size, we can not use BANOVA. Therefore we propose the unbalanced analysis of variance(UNBANOVA) for testing shape variabilities of several independent samples of unequal size.

Power analysis for 3 ${\times}$ 3 Latin square design (3 ${\times}$ 3 라틴방격모형의 검정력 분석)

  • Choi, Young-Hun
    • Journal of the Korean Data and Information Science Society
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    • v.20 no.2
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    • pp.401-410
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    • 2009
  • Due to the characteristics of 3 ${\times}$ 3 Latin square design which is composed of two block effects and one main effect, powers of rank transformed statistic for testing the main effect are very superior to powers of parametric statistic without regard to the type of population distributions. By order of when all three effects are fixed, when on one block effect is random, when two block effects are random, the rank transform statistic for testing the main effect shows relatively high powers as compared with the parametric statistic. Further when the size of main effect is big with one equivalent size of block effect and the other small size of block effect, powers of rank transformed statistic for testing the main effect demonstrate excellent advantage to powers of parametric statistic.

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Power study for 4 × 4 graeco-latin square design (4 × 4 그레코라틴방격모형의 검정력 연구)

  • Choi, Young-Hun
    • Journal of the Korean Data and Information Science Society
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    • v.23 no.4
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    • pp.683-691
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    • 2012
  • In $4{\times}4$ graeco-latin square design, powers of rank transformed statistic for testing the main effect are superior to powers of parametric statistic without regard to the effect structure with equally or unequally spaced effect levels as well as the type of population distributions such as exponential, double exponential, normal and uniform distribution. As numbers of block effect or effect sizes are decreased, powers of rank transformed statistic are much higher than powers of parametric statistic. In case that block effects are smaller than a main effect or one block effect is higher than other block effects, powers of rank transformed statistic are much higher than powers of parametric statistic in $4{\times}4$ graeco-latin square design with three block effects and one main effect.

A Survey of Patient Satisfaction with Physical Therapy Servics and Physical Therapist According to General Characteristics and Medical Institution - Focused on Gimcheon City - (환자의 일반적 특성과 의료기관에 따른 물리치료 서비스 및 물리치료사에 대한 만족도 조사 - 김천지역 중심으로 -)

  • Park, Hung-Ki;Jung, Byeong-Ok;Kim, Geun-Jo;Ahn, Byung-Heon
    • Journal of Korean Physical Therapy Science
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    • v.15 no.4
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    • pp.51-60
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    • 2008
  • Background: The purpose of this study show the degree of physical therapy service and physical therapist according to medical institution by measuring and determining the factor affecting patient satisfaction in the Gimcheon city. Methods: For this study 100 questionnaires were distributed to medical institution, Gimcheon city from Jul 20 to Aug 5, 2008. The consisted of total 28 items. The contents item divided the general characteristics into nine heads, the satisfaction of physical therapy service into nine heads, and the physical therapy into ten heads. Survey data were collected by a written questionnaire. The collected date were analyzed by t-test, ANOVA. Results: There was difference with statistic value in physical therapy according to medical security and handicapped or non-handicapped(p<.05). There was difference with statistic value in physical therapy service and physical therapist according to medical institution. The score of patient satisfaction at welfare facilities was significantly lesser than other medical institution(p<.05). Conclusion: There was difference with statistic value in physical therapy service and physical therapist according to a number of patients of physical therapy a day.

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An Evaluation of the Statistical Techniques Used in Papers of the Journal of Sasang Constitutional Medicine (2000-2009) (최근 10년간(2000-2009) 사상체질의학회지 게재논문의 통계분석방법에 대한 연구)

  • Park, Ki-Hyun;Kim, Sang-Hyuk;Kim, Hong-Gie;Lee, Si-Woo
    • Journal of Sasang Constitutional Medicine
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    • v.22 no.4
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    • pp.49-55
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    • 2010
  • 1. Objectives The purpose of this study is to assess the statistical methods used in the Journal of Sasang Constitutional Medicine and to identify the types of errors in the statistical analysis. 2. Methods We have reviewed quantitative articles published in the Journal of Sasang Constitutional Medicine from 2000 to 2009. Except for the case report, a total of 505 articles was reviewed by year. We focused on the methods of statistics in these articles. We have analysed the number of thesis used the statistical methods, the number of the statistical methods, the types of the statistical methods, and the errors of the statistical methods with the object of 202 thesis used the statistical method. 3. Results 1. Of the 370 articles, 202 used inferential statistics. 2. The most dominant was the thesis with one type of the statistical method forming 61.9% (125 thesis) of the total. 3. The ANOVA was the statistic of choice overall (40.1%), followed by the t-test (35.6%). 4. By examining the errors of the statistical methods, there were 49 thesis with errors among 81 thesis using ANOVA, 25 thesis among 72 thesis using t-test, and 18 over 62 thesis using chi-squared test. 4. Conclusions We have found various mistakes or misuses in the applications of statistical methodologies in the articles published in the Journal of Sasang Constitutional Medicine. It is necessary to present the cases of inappropriate statistical methods in order to improve the quality of academic researches. So long as Sasang constitutional medicine uses the statistical methods, researchers should fully examine and be aware of the statistical methods which they wish to use through other research articles, and statistic publications.

Robust inference with order constraint in microarray study

  • Kang, Joonsung
    • Communications for Statistical Applications and Methods
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    • v.25 no.5
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    • pp.559-568
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    • 2018
  • Gene classification can involve complex order-restricted inference. Examining gene expression pattern across groups with order-restriction makes standard statistical inference ineffective and thus, requires different methods. For this problem, Roy's union-intersection principle has some merit. The M-estimator adjusting for outlier arrays in a microarray study produces a robust test statistic with distribution-insensitive clustering of genes. The M-estimator in conjunction with a union-intersection principle provides a nonstandard robust procedure. By exact permutation distribution theory, a conditionally distribution-free test based on the proposed test statistic generates corresponding p-values in a small sample size setup. We apply a false discovery rate (FDR) as a multiple testing procedure to p-values in simulated data and real microarray data. FDR procedure for proposed test statistics controls the FDR at all levels of ${\alpha}$ and ${\pi}_0$ (the proportion of true null); however, the FDR procedure for test statistics based upon normal theory (ANOVA) fails to control FDR.