• Title/Summary/Keyword: chi-square test

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A Nonparametric Test for the Parallelism of Regression Lines Based on Kendall's Tau (Kendall의 Tau에 의한 회귀직선의 평행성에 관한 비모수 검정)

  • Song, Moon-Sup
    • Journal of the Korean Statistical Society
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    • v.7 no.1
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    • pp.17-26
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    • 1978
  • For testing $\beta_i=\beta, i=1,...,k$, in the regression model $Y_{ij} = \alpha_i + \beta_ix_{ij} + e_{ij}, j=1,...,n_i$, a simple and robust test based on Kendall's tau is proposed. Its asymptotic distribution is proved to be chi-square under the null hypthesis and noncentral chi-square under an appropriate sequence of alternatives. For the optimal designs, the asymptotic relative efficiency of the proposed procedure with respect to the least squares procedure is the same as that of the Wilcoxon test with respect to the t-test.

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On an Approximation to the Distribution of Product of Independent Beta Variates

  • Hea Jung Kim
    • Communications for Statistical Applications and Methods
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    • v.1 no.1
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    • pp.81-86
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    • 1994
  • A Chi-square approximation to the distribution of product of independent Beta variates denoted by U is developed. The distribution is commonly used as a test criterion for the general linear hypothesis about the multivariate linear models. The approximation is obtained by fitting a logarithmic function of U to a Chi-square variate in terms of the first three moments. It is compared with the well known approximations due to Box(1949), Rao(1948), and Mudholkar and Trivedi(1980). It is found that the Chi-square approximation compares favorably with the other three approximations.

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Clinical Analysis of Symptoms and Oriental Medical Prescriptions According to Elapsed Time of Stroke in Oriental Medical Hospital Inpatients

  • Yun, Hen-Ja;Sung, Kang-Keyng
    • Herbal Formula Science
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    • v.20 no.1
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    • pp.133-147
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    • 2012
  • Objectives : This study was intended to understand characteristics of symptoms, oriental medicine prescription and laboratory test results according to elapsed time of stroke. Methods : Through the medical records of 205 stroke inpatients in the oriental medical hospital in the year 2010, we investigated manifested symptoms, administered oriental medicine prescription and clinical pathological examination results. Collected items were classified to depend on stroke types, cerebral infarction and hemorrhage. We analyzed association between manifested symptoms, the oriental medicine prescription, and laboratory test results of stroke patients and elapsed time. Chi-square tests were performed to determine the significance level of association. Results : All symptoms, prescriptions and laboratory test results in cerebral infarction patients were associated with elapsed time. Especially, symptoms, prescriptions and pathological examination results showed very high statistical significance with elapsed time (a symptom; chi-square(df)=164.3(22), p<0.001, prescription; chi-square(df)=93.5(22), p<0.001, and pathological examination results; chi-square(df)=164.3(22), p<0.0004). But in the case of cerebral hemorrhage, there was not statistical significance. Conclusions : The elapsed time of stroke may be an essential requisite in catching symptoms and prescribing for stroke patients in oriental medical treatment.

Testing Goodness of Fit of Gravity Models (중력모형의 적합도 검증)

  • 김형진
    • Journal of Korean Society of Transportation
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    • v.14 no.1
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    • pp.43-50
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    • 1996
  • This paper is concerned with assessing goodness of fit of gravity models. The Chi-square test, or one of its asymptotic equivalents, is usually recommended for the purpose. A difficulty that frequently arises, particularly when working with urban travel data, is that the expected number of trips for most origin-destination(O-D) pairs are small. In order to test goodness of fit of gravity model, a simple approach, which depends on the number of O-D pairs and certain trip totals being large, is proposed in this paper. In addition, derivation of variance of Chi-square ratio is proposed to test the confidence interval of Chi-square ratio and application of its results with simulated data set is made to verify the usefulness of the results.

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A Note on the Chi-Square Test for Multivariate Normality Based on the Sample Mahalanobis Distances

  • Park, Cheolyong
    • Journal of the Korean Statistical Society
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    • v.28 no.4
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    • pp.479-488
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    • 1999
  • Moore and Stubblebine(1981) suggested a chi-square test for multivariate normality based on cell counts calculated from the sample Mahalanobis distances. They derived the limiting distribution of the test statistic only when equiprobable cells are employed. Using conditional limit theorems, we derive the limiting distribution of the statistic as well as the asymptotic normality of the cell counts. These distributions are valid even when equiprobable cells are not employed. We finally apply this method to a real data set.

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A Study on Personality and Ordinary Symptoms according to Soyangin's Major Constitutional Medicine (소양인(少陽人) 주요(主要) 처방(處方) 간의 성격(性格) 및 소증(素證) 차이(差異)에 관한 연구(硏究))

  • Kim, Seong-Tae;Choi, Ae-Ryun
    • Journal of Sasang Constitutional Medicine
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    • v.26 no.1
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    • pp.82-97
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    • 2014
  • Objectives The purpose of this study was to survey the Personality and Ordinary Symptoms of Soyangin and to compare the tendency of their personality and symptoms according to Soyangin's major prescription. Methods 331 Soyangin's personality and ordinary symptoms data registered to SCIB(Sasang Constitutional Information Bank) were used. All data were analyzed with Chi square test. Some data were ranked and analyzed with Kruskal-Wallis test and Mann-Whitney test(with Bonferroni correction). Chi square and Kruskal-Wallis test's significant P value was 0.05. Mann-Whitney test's significant P value was 0.005. Results & Conclusions In Chi square test, there is difference in personality and symptoms in Soyangin's major prescription as followed, the degree of masculinity and femininity, the degree of patience, the condition of stool, the degree of appetite, good or bad in digesting, amount of meal, the speed of eating, amount of drinking water, the temperature of drinking water, coldness and hotness in abdomen or not. In Kruskal-Wallis test and Mann-Whitney test, Yanggyuksanhwa-tang is more masculine than Dokhwaljihwang-tang, Hyeongbangsabaek-san, Hyeongbangjihwangtang. Dokhwaljihwang-tang is less appetite than Yanggyuksanhwa-tang and Hyeongbangsabaek-san. Yanggyuksanhwa- tang is more fast in eating than Hyeongbangjihwang-tang.

Two-sample chi-square test for randomly censored data (임의로 관측중단된 두 표본 자료에 대한 카이제곱 검정방법)

  • 김주한;김정란
    • The Korean Journal of Applied Statistics
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    • v.8 no.2
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    • pp.109-119
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    • 1995
  • A two sample chi-square test is introduced for testing the equality of the distributions of two populations when observations are subject to random censorship. The statistic is appropriate in testing problems where a two-sided alternative is of interest. Under the null hypothesis, the asymptotic distribution of the statistic is a chi-square distribution. We obtain two types of chi-square statistics ; one as a nonnegative definite quadratic form in difference of observed cell probabilities based on the product-limit estimators, the other one as a summation form. Data pertaining to a cancer chemotheray experiment are examined with these statistics.

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Analysis of the Statistical Techniques and Errors in the Field of Sasang Constitution Researches: from 2011 to 2015 (최근 5년간(2011~2015) 사상체질분야 논문의 통계기법 분석 및 오류에 관한 연구)

  • Kim, Sujung;Kim, Sanghyuk;Lee, Siwoo
    • Journal of Sasang Constitutional Medicine
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    • v.28 no.1
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    • pp.51-56
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    • 2016
  • Objectives This study was to identify the types of errors in the statistical analysis and trends of previous reported papers that used various statistical techniques.Methods We have selected 118 original articles for statistical review from the OASIS(http://oasis.kiom.re.kr) and the Pubmed(http://www.pubmed.gov) in the field of Sasang constitutional medicine. Published year was restricted from 2011 to 2015.Results 1. The ANOVA(25.72%) was the statistic of choice overall, followed by the chi-square test(21.74%), regression analysis(14.13%), t-test(11.59%), and etc. 2. By examining the errors of the statistical methods, there were 42(59.2%) thesis with errors among 71 thesis using ANOVA, 19(31.7%) thesis among 60 thesis using chi-square test, and 35(89.7%) over 39 thesis using regression analysis.Conclusions To improve the quality of Sasang Constitution, the participation of statisticians in research design will reduce the significant errors in statistical interpretation of the results.

Empirical Comparisons of Disparity Measures for Three Dimensional Log-Linear Models

  • Park, Y.S.;Hong, C.S.;Jeong, D.B.
    • Journal of the Korean Data and Information Science Society
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    • v.17 no.2
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    • pp.543-557
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    • 2006
  • This paper is concerned with the applicability of the chi-square approximation to the six disparity statistics: the Pearson chi-square, the generalized likelihood ratio, the power divergence, the blended weight chi-square, the blended weight Hellinger distance, and the negative exponential disparity statistic. Three dimensional contingency tables of small and moderate sample sizes are generated to be fitted to all possible hierarchical log-linear models: the completely independent model, the conditionally independent model, the partial association models, and the model with one variable independent of the other two. For models with direct solutions of expected cell counts, point estimates and confidence intervals of the 90 and 95 percentage points of six statistics are explored. For model without direct solutions, the empirical significant levels and the empirical powers of six statistics to test the significance of the three factor interaction are computed and compared.

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The Analysis of Association between Learning Styles and a Model of IoT-based Education : Chi-Square Test for Association

  • Sayassatov, Dulan;Cho, Namjae
    • Journal of Information Technology Applications and Management
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    • v.27 no.3
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    • pp.19-36
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    • 2020
  • The Internet of things (IoT) is a system of interrelated computed devices, digital machines and any physical objects which are provided with unique identifiers and the potential to transmit data to people or machine (M2M) without requiring human interaction. IoT devices can be used to monitor and control the electrical and electronic systems used in different fields like smart home, smart city, smart healthcare and etc. In this study we introduce four imaginary IoT devices as a learning support assistants according to students' dominant learning styles measured by Honey and Mumford Learning Styles: Activists, Reflectors, Theorists and Pragmatists. This research emphasizes the association between students' strong learning styles and a preference to appropriate IoT devices with specific characteristics. Moreover, different levels of IoT devices' architecture are clearly explained in this study where all the artificial devices are designed based on this structure. Data analysis of experiment were measured by the use of chi square test for association and research results showed the statistical significance of the estimated model and the impacts of each category over the model where we finally got accurate estimates for our research variables. This study revealed the importance of considering the students' dominant learning styles before inventing a new IoT device.