• 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.

• Journal of the Korean Data and Information Science Society
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• v.11 no.1
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• pp.83-90
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• 2000

The chi-squared test statistic is usually employed for testing independence of two categorical variables in a two-way contingency table. It is well known that, under independence, the test statistic has an asymptotic chi-squared distribution under multinomial or product-multinomial models. For the case where both margins fixed, the sampling model of the contingency table is a multiple hypergeometric distribution and the chi-squared test statistic follows the same limiting distribution. In this paper, we study the difference between the small sample and large sample distributions of the chi-squared test statistic for the case with fixed margins. For a few small sample cases, the exact small sample distribution of the test statistic is directly computed. For a few large sample sizes, the small sample distribution of the statistic is generated via a Monte Carlo algorithm, and then is compared with the large sample distribution via chi-squared probability plots and Kolmogorov-Smirnov tests.

• The Korean Journal of Rehabilitation Nursing
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• v.9 no.1
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• pp.42-48
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• 2006

Purpose: The purpose of this study was to explore the effect of Tai Chi exercise on pain, balance, gait and physical function of patients with low back pain. Method: This study was designed one group pretest-posttest design. Tai Chi exercise was conducted by researcher and carried out for sixty minutes per one time and two times a week for six weeks. The subjects of this study consisted of 23 low back patients. Using the SPSS win 10.0 program was used for data analysis, which included frequency, percentage and paired t-test. Result: Tai Chi exercise decreased pain, improved balance and gait, increased physical function(back muscle strength, leg muscle strength and flexibility). Conclusion: The results suggested Tai Chi exercise can be effective nursing intervention to improve pain, balance, gait and physical function of patients with low back pain.

• 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.

• Communications for Statistical Applications and Methods
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• v.23 no.5
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• pp.433-444
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• 2016

When we observe binary responses in a cluster (such as rat lab-subjects), they are usually correlated to each other. In clustered binomial counts, the independence assumption is violated and we encounter an extra-variation. In the presence of extra-variation, the ordinary statistical analyses of binomial data are inappropriate to apply. In testing the homogeneity of proportions between several treatment groups, the classical Pearson chi-squared test has a severe flaw in the control of Type I error rates. We focus on modifying the chi-squared statistic by incorporating variance inflation factors. We suggest a method to adjust data in terms of dispersion estimate based on a quasi-likelihood model. We explain the testing procedure via an illustrative example as well as compare the performance of a modified chi-squared test with competitive statistics through a Monte Carlo study.

• Communications for Statistical Applications and Methods
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• v.16 no.4
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• pp.697-705
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• 2009

The Pearson chi-squared statistic or the deviance statistic is widely used in assessing the goodness-of-fit of the generalized linear models. But these statistics are not proper in the situation of continuous explanatory variables which results in the sparseness of cell frequencies. We propose a goodness-of-fit test statistic for the cumulative logit models with ordinal responses. We consider the grouping of a dataset based on the ordinal scores obtained by fitting the assumed model. We propose the Pearson chi-squared type test statistic, which is obtained from the cross-classified table formed by the subgroups of ordinal scores and the response categories. Because the limiting distribution of the chi-squared type statistic is intractable we suggest the parametric bootstrap testing procedure to approximate the distribution of the proposed test statistic.

• The Journal of the Korea Contents Association
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• v.18 no.2
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• pp.240-247
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• 2018

The purpose of this study was to identify the completion and related factors on Advance Directives (AD) in olde adults. A cross-sectional descriptive study design was used. Participants were 196 old adults, 65 and over aged in D metropolitan city. Collected data were analyzed using descriptive statistics, ${\chi}^2-test$, t-test, and logistic regression with SPSS 22.0 program. The rate of completion intention toward AD was 58.2% in the participants. There were different age, Living alone, subjective health status, awareness toward AD, and negative attitude toward death by completion intention toward AD. In the regression analysis results, the predictors of completion intention toward AD was awareness toward AD in old adults. The findings of the study reveal that positive awareness toward AD can predict completion of AD of healthy old adults in community.

• 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.

• The Transactions of the Korea Information Processing Society
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• v.3 no.2
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• pp.225-230
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• 1996

We propose a statistical test for the nonlinear combiner logics which are usually combined with two maximal Linear Feedback Shift Registers and generate pseudorandom bit sequences. This test uses the mutual information between the output and set of inputs which will be a random variable and its distribution is obeyed to an approximate $\{chi}^2$ -distribution. We adopt this statistic to a $\{chi}^2$ -test of independence by using contingency table. We also apply a proposed test to some non-linear crptosystems and show that this useful to evaluate the strength of the cryptosystems.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.12
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• pp.254-263
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• 2017

This study was conducted to identify the relationship between negative emotion and obesity and provide adequate information to enable effective nursing intervention in elderly. Participants were 216 elderly who had been attending two geriatric welfare facilities in Chungbuk. The data were collected between 14 and 30 August, 2017 with a structured questionnaire and body measurement. The questionnaires were CES-D, RULS, BPS and collected data were analyzed using descriptive statistics, t-tests, ${\chi}^2-test$, Fisher' exact tests, Pearson's correlation, and logistic regression with SPSS/WIN 22.0. The mean BMI of participants was $23.59{\pm}3.48$ and the prevalence of obesity was 31.9%. Significant differences were observed in age (${\chi}^2=8.16$, p=.003), gender (${\chi}^2=9.27$, p=.002), smoking (${\chi}^2=7.78$, p=.004), depression (t=2.54, p=.012) and social isolation (t=2.98, p=.003) between the normal and obesity groups. Depression (OR,1.04; 95% CI, 1.00-1.09) and social isolation (OR, 1.06; 95% CI, 1.02-1.11) was associated with an increased risk obesity. Therefore, it was necessary to measure and quantify the depression and social isolation for weight management among the elderly. Moreover, it is necessary to develop health promotion programs and nursing intervention, including the need for physical, mental, and social relationships.