• 한국데이터정보과학회:학술대회논문집
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• 2006.04a
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• pp.203-212
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• 2006

A chi-squared test of multivariate normality is suggested which is mainly focused on detecting deviations from elliptical symmetry. This test uses Mahalanobis distances of observations to have some power for deviations from multivariate normality. We derive the limiting distribution of the test statistic by a conditional limit theorem. A simulation study is conducted to study the accuracy of the limiting distribution in finite samples. Finally, we compare the power of our method with those of other popular tests of multivariate normality under two non-normal distributions.

• The Korean Journal of Applied Statistics
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• v.17 no.1
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• pp.89-103
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• 2004

If the given information is exact, though it is the little, we had better use it than not use in analysis. In this article, the problem of independence test in a contingency table is considered when two marginal distributions of a population are given exactly. For that case, a likelihood-ratio chi-squared test statistic and its Pearsonian type chi-squared test statistic are derived. By Monte Carlo Simulations the traditional chi-square tests and the derived tests are compared. And the related some testing problems are synthetically explained on a geometrical viewpoint.

• Korean Journal of Health Education and Promotion
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• v.26 no.2
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• pp.135-148
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• 2009

Objectives: The purpose of this study is to identify the characteristics between therapy continuity group and therapy discontinuity group and to develop management program for Korean patients with hypertension and diabetes. Methods: The subject of the study were 109 therapy continuity and 66 therapy discontinuity of Korea hypertension diabetes Daegu initiative. The data collection was performed from December 5 to December 30, 2008. Analysis of data was done by using descriptive statistics, chi-square test, t-test and ANCOVA with SPSS program. Results: 1) The groups were significantly correlated with such variables systolic BP(F=4.518, p=0.035) and diastolic BP(F=17.793, p=0.000). 2) The groups with hypertensive were significantly correlated with such variables perceived susceptibility of disease($\chi^2$=25.053, p=0.000), perceived barrier of health behavior($\chi^2$=12.584, p=0.006), drinking($\chi^2$=27.545, p=0.000), diet($\chi^2$=8.645, p=0.013), regular taking medicine($\chi^2$=92.415, p=0.000) and regular measurement of BP($\chi^2$=6.045, p=0.049). 3) The groups with diabetic were significantly correlated with such variables perceived seriousness of disease($\chi^2$=6.128, p=0.047), perceived susceptibility of disease($\chi^2$=8.079, p=0.018), health knowledge and attitude(F=8.418, p=0.006), drinking($\chi^2$=6.276, p=0.043), diet($\chi^2$=7.275, p=0.026), regular taking medicine($\chi^2$=33.083, p=0.000) and regular measurement of glucose($\chi^2$=7.233, p=0.027). Conclusion: The above findings indicate that it is necessary to develop and apply special management programs according to the therapy discontinuity group.

• The KIPS Transactions:PartA
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• v.9A no.2
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• pp.267-270
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• 2002

The evaluation of the cumulative distribution function of the noncentral $\chi^2$ distribution is required in approximate determination of the power of the $\chi^2$ test. This article provides an algorithm for evaluating the noncentral $\chi^2$ distribution function in terms of a single "central" $\chi^2$ distribution function and compared various approximations.ximations.

• The Korean Journal of Rehabilitation Nursing
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• v.14 no.2
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• pp.129-135
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• 2011

Purpose: This study was done to examine the effects of Tai Chi exercise program on BMI, positive and negative psychiatric symptoms in patient with schizophrenia. Methods: The participants were patient with schizophrenia in S psychiatric hospital in D city. Twenty five patients were assigned to experimental group, and 26 patients were assigned to control group. Data were collected from May 9, to July 8, 2011. The Tai Chi exercise program was conducted with a duration of 60 minutes, 2 times a week for 8 weeks (a total 8 times). Measures were BMI, positive and negative psychiatric symptoms. Data were analyzed using descriptive statistics, chi-square test and t-test with SPSS/WIN 19.0 version. Result: The experimental group received Tai Chi exercise program had a significant changes in BMI, positive and negative psychiatric symptoms. Conclusion: The results of this study indicate that Tai Chi exercise program is an effective intervention program to improve the BMI, positive and negative psychiatric symptoms of patients with schizophrenia.

• Journal of the Korean Statistical Society
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• v.30 no.1
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• pp.63-76
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• 2001

An adaptive estimation and testing method is proposed for comparing dispersions among several ordered groups. Based upon the large sampling theory for nonparametric quartile estimators, we derive the order restricted estimators and construct a simple test statistic. This test statistic has a mixture of several chi-square distributions as its asymptotic null distribution. The proposed test is illustratively applied to survival time data for the patients with carcinoma of the oropharynx.

• 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.

• Journal of the Korean Data and Information Science Society
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• v.17 no.1
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• pp.221-231
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• 2006

A chi-squared test of multivariate normality is suggested which is oriented for detecting deviations from elliptical symmetry. We derive the limiting distribution of the test statistic via a central limit theorem on empirical processes. A simulation study is conducted to study the accuracy of the limiting distribution in finite samples. Finally, we compare the power of our method with those of other popular tests of multivariate normality under a non-normal distribution.

• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1057-1065
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• 2010

In this paper we discuss some cautionary notes in using the Pearson chi-squared test statistic for the goodness-of-fit of the ordinal response model. If a model includes continuous type explanatory variables, the resulting table from the t of a model is not a regular one in the sense that the cell boundaries are not fixed but randomly determined by some other criteria. The chi-squared statistic from this kind of table does not have a limiting chi-square distribution in general and we need to be very cautious of the use of a chi-squared type goodness-of-t test. We also study the limiting distribution of the chi-squared type statistic for testing the goodness-of-t of cumulative logit models with ordinal responses. The regularity conditions necessary to the limiting distribution will be reformulated in the framework of the cumulative logit model by modifying those of Moore and Spruill (1975). Due to the complex limiting distribution, a parametric bootstrap testing procedure is a good alternative and we explained the suggested method through a practical example of an ordinal response dataset.

• Journal of Korean Academy of Nursing
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• v.36 no.2
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• pp.278-285
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• 2006

Purpose: This study was performed to verify the effect of Tai Chi exercise on patients with rheumatoid arthritis particularly their level of pain, fatigue, sense of balance and daily lift performance(ADL). Method: It employed a non-equivalent control group pre- and post-test design. The research instruments used in this study were pain, fatigue, sense of balance and ADL. Thirty-two patients in the experimental group carried out 50 minutes of Tai Chi exercise for 12 weeks, and 29 patients in the control group did not. Before and after the experiment, both groups were tested for pain, fatigue, sense of balance and ADL. Collected data were processed using the SPSS/WIN 10.0 program analyzed by the frequency, percentage, $x^2-test$, and t-test. Results: Pain and fatigue significantly decreased in the experimental group. However the improvement in ADL of the rheumatoid arthritis patients was not statistically significant but their sense of balance was enhanced significantly. Conclusion: Tai Chi exercise is an effective nursing intervention that can be used for rheumatoid arthritis patients.