• The Korean Journal of Applied Statistics
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• v.23 no.4
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• pp.777-781
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• 2010

Yates' continuity correction of the chi-squared test for testing the homogeneity of two binomial proportions in $2{\times}2$ contingency tables is developed to lower the value of the test statistic slightly. The effect of continuity correction is expected to decrease as the sample size increases. However, in extremely unbalanced $2{\times}2$ contingency tables, we find some cases where the effect of continuity correction is eccentric and is larger than expected. In such cases, we conclude that the chi-squared test with continuity correction should not be employed as a test statistic in both asymptotic tests and exact tests.

• 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.

• Communications for Statistical Applications and Methods
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• v.13 no.2
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• pp.429-440
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• 2006

In statistical computing, it is often for researchers to need the distribution of a weighted sum of noncentral chi-square variables. In this case, it is very limited to know its exact distribution. There are many works to contribute to this topic, e.g. Imhof (1961) and Solomon-Stephens (1977). Imhof's method gives good approximation to the true distribution, but it is not easy to apply even though we consider the development of computer technology Solomon-Stephens's three moment chi-square approximation is relatively easy and accurate to apply. However, they skipped many details, and their simulation is limited to a weighed sum of central chi-square random variables. This paper gives details on Solomon-Stephens's method. We also extend their simulation to the weighted sum of non-central chi-square distribution. We evaluated approximated powers for homogeneous test and compared them with the true powers. Solomon-Stephens's method shows very good approximation for the case.

• Journal of muscle and joint health
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• v.12 no.2
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• pp.119-131
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• 2005

Purpose: The purpose of this study was to examine effect of Tai-Chi exercise program on pain, flexibility, perceived health status and instrumental activities of daily living for osteoarthritis patients. To evaluate the effects, quasi-experimental study was used for pre and post test with a nonequivalent control group. Method: Fifty-two subjects participated in the experiment(twenty-seven for experimental group and twenty-five for control group) and they were from two different senior citizen centers in J city. The experiment period was from April 2002 through August 2002. The experiment group took part in Tai-Chi exercise program for eighteen weeks(three times a week for four weeks and five times a week for fourteen week). The exercise was performed for 50 minutes at every time (15 minutes for warm-up, 30 minutes for Tai-Chi exercise, and 5 minutes for ending). In order to pursue study purpose, the SPSS/WIN 8.0 program was chosen for the statistical analysis; ANCOVA was employed in examining test hypothesis; t-test and $X^{2}-test$ were used to examine homogeneity between experimental and control group. Result: The study results were as follows: Score of pain decreased significantly after of Tai-Chi exercise program. Score of flexibility increased significantly after of Tai-Chi exercise program. Score of perceived health status increased significantly after of Tai-Chi exercise program. Score of IADL increased significantly after of Tai-Chi exercise program. Conclusion: As shown in the results, Tai-Chi exercise program can be effective nursing intervention for osteoarthritis patient to improve pain, flexibility, perceived health status and Instrumental Activities of Daily Living.

• Communications for Statistical Applications and Methods
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• v.7 no.2
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• pp.385-392
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• 2000

Many tests for multivariate normality are based on the spherical coordinates of the scaled residuals of multivariate observations. Moore and Stubblebine's (1981) Pearson chi-square test is based on the radii of the scaled residuals, or equivalently the sample Mahalanobis distances of the observations from the sample mean vector. The chi-square statistic does not have a limiting chi-square distribution since the unknown parameters are estimated from ungrouped data. We will derive a simple closed form of the Rao-Robson chi-square test statistic and provide a self-contained proof that it has a limiting chi-square distribution. We then provide an illustrative example of application to a real data with a simulation study to show the accuracy in finite sample of the limiting distribution.

• The Korean Journal of Rehabilitation Nursing
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• v.17 no.1
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• pp.38-47
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• 2014

Purpose: This study was performed to investigate the effects of Tai Chi exercise on physical fitness and quality of life (QOL) in elderly women. Methods: This study was designed as a quasi-experimental, nonequivalent control group pre-post test design. The subjects were elderly women over 60 years old who enrolled senior citizen centers and elderly welfare center. Thirty-three people were conveniently assigned to an experimental group (n=15) or a control group (n=18). The data were collected from September 2009 to May 2010. The experimental group was trained Tai Chi exercise for 8 weeks (one hour Tai Chi classes twice a week and once a week by themselves at home). Data were analyzed by Fisher's exact test, ${\chi}^2$-test and independent t-test. Results: The experimental group experienced significant improvements in flexibility. The experimental group experienced significant improvements in physical component summary (p=.017) and mental component summary (p=.027) of QOL. Conclusion: Tai Chi exercise can be used as a nursing intervention for improvement of physical fitness and QOL in elderly women.

• Journal of muscle and joint health
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• v.24 no.3
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• pp.217-226
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• 2017

Purpose: The aim of this study was to identify the effects of Tai Chi training program on physical fitness, stress response and ego-resiliency in nursing students. Methods: 28 nursing students of D metropolitan city participated in non-equivalent control group pre- and post-test group test in quasi experimental design with written consent. Fourteen participants in the control group who did usual activities and 14 experimental participants who promised to participate 24 Tai Chi training sessions for 12 weeks. Both groups completed pre- and post-test measurement for physical fitness, a questionnaire regarding their stress response and ego-resiliency. Each 60-minute Tai Chi session was consisted of 5-minute warm up, 10-minute meditation, 40-minute Tai Chi, and 5-minute finishing exercise. Results: After 12 weeks, participants in the Tai Chi group reported significantly higher score in muscle endurance (t=3.77, p=.001), leg muscular strength (t=2.14, p=.042), and balance (t=2.12, p=.044) compared to the control group. The Tai Chi group recorded significantly lower score than the control group on stress response (t=2.75, p=.011). Conclusion: The findings highlight the importance of Tai Chi for a reduction in stress response and promotion in physical fitness in nursing students. Applying Tai Chi training to nursing program will help nursing students to have better academic performance.

• Journal of Digital Convergence
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• v.16 no.10
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• pp.313-321
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• 2018

Purpose: The purpose of the study was to identify the associated factors on the metabolic syndrome among inpatients with schizophrenia. Methods: The participants were 127 inpatients with schizophrenia from G mental hospital in G city. Collected data were analized with SPSS 22.0 using descriptive statistics, ${\chi}^2$-test, t-test and logistic regression. Results: Metabolic syndrome prevalence of the participants was 46.5%. There were statistically significant differences according to physical disease (${\chi}^2=11.51$, p<.001), body mass index (${\chi}^2=13.59$, p<.001), perception of obesity (${\chi}^2=8.38$, p<.001), and taking olanzapine (${\chi}^2=6.31$, p<.05). Conclusion: Based on the study results, the nursing intervention for prevention and management of metabolic syndrome is needed to develop and provide to schizophrenia patients.

• Journal of muscle and joint health
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• v.13 no.1
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• pp.20-30
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• 2006

Purpose: To determine the effect of Tai Chi exercise program on fatigue, stress, and quality of life in middle aged women. Method: The study was designed as a nonequivalent control group pretest-posttest quasi-experimental study. Thirty subjects were assigned for experimental group and thirty four subjects were assigned for control group. The subjects in the experimental group were participated in Tai Chi exercise program for 60 minutes per session 3 times a week for 8weeks. Tai Chi exercise program consists of 10 minutes warm-up, 45 minutes main, and 5 minutes cooling down exercises. In order to evaluate the effect of Tai Chi exercise program, fatigue, stress, and qualify of life were assessed by measuring the condition of the participants in respect of fatigue, stress, and qualify of life with questionnaire. The data were analyzed by using $x^2-test$, Fisher's exact test, t-test by a SAS-pc+ 8.12 program. Result: After 8 weeks Tai Chi exercise program, there were significant improvement in fatigue, stress, and quality of life in middle aged women. Conclusion: Tai Chi exercise program can be an effective nursing intervention to improve fatigue, stress, and quality of life in middle aged women.