• The Korean Journal of Applied Statistics
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• v.23 no.6
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• pp.1067-1080
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• 2010

A number of methods have been developed to determine sample sizes in clinical trial, and most clinical trial organizations determine sample sizes based on the methods. In contrast, determining sufficient sample sizes needed for experiments using microarray chips is unsatisfactory and not widely in use. In this paper, our objective is to provide a guideline in determining sample sizes, utilizing reproducibility of real microarray data. In the reproducibility comparison, five methods for discovering differential expression are used: Fold change, Two-sample t-test, Wilcoxon rank-sum test, SAM, and LPE. In order to standardize gene expression values, both MAS5 and RMA methods are considered. According to the number of repetitions, the upper 20 and 100 gene accordances are also compared. In determining sample sizes, more realistic information can be added to the existing method because of our proposed approach.

• Korean Journal of Acupuncture
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• v.30 no.1
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• pp.1-8
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• 2013

Objectives : The purpose of the present study was to examine statistical methods used in articles published on the Korean Journal of Acupuncture from 2007 through 2012. Methods : Statistical methods and statistical packages used in original articles applied with descriptive statistics or inferential statistics were organized. Results : Out of a total of 195 original articles, 18 articles used descriptive statistics only and 177 articles used inferential statistics. 142 articles used 12 types of statistical packages. SPSS was used most at 97 times(63.4%). The number of descriptive statistical methods used was a total of 417 and among them 193 were presented as tables(46.3%) and 224 were presented as graphs(53.7%). The number of inferential statistics applied was a total of 256 and analysis of variance was used most at 90 times(35.2%). The number of parametric statistical methods used was a total of 170(75.6%) and that of nonparametric statistical methods used was a total of 55(24.4%). Analysis of variance and two sample t-test were most employed in both clinical and non-clinical research. The number of multiple comparison methods applied was a total of 67 and the number of Scheffe methods among them was most at 26 times(37.7%). Conclusions : In the present study, statistical methods used in the journal over the last six years were examined. The result of this study is considered to be a basic material to be referred to when evaluating the quality of the medical journal.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.20 no.4
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• pp.438-448
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• 2013

Purpose: The purpose of this study was to investigate factors influencing clinical competence in nursing students. Method: The participants were 125 nursing students and data were collected from October 8 to December 18, 2010 using questionnaires with. Collected data were analyzed using descriptive statistics, t-test, ANOVA, Pearson's correlation coefficient and stepwise multiple regression. Results: There were significant correlations for creativity, problem-solving ability, self-directed learning ability, and clinical competence. The factor influencing clinical competence the most was creativity, followed by problem-solving ability, self-directed learning ability, and grade point average score. The regression model explained 37% of variance in clinical competence. Conclusion: The results indicate that for improvement in the clinical competence of nursing students, it is necessary to develop strategies and education programs to enhance creativity, problem-solving ability, and self-directed learning ability.

• The Journal of Korean Academic Society of Nursing Education
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• v.20 no.4
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• pp.513-522
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• 2014

Purpose: This study identifies the influences of self-directed learning ability and metacognition on clinical competence in nursing students. Method: The subjects consisted of 290 second and third year nursing students. The data were analyzed using t-tests, ANOVA, Scheffe's test, Pearson's correlation coefficients and multiple linear regression via SPSS Statistics version 18.0. Results: On a scale of 1 (lowest) to 5 (highest), the mean self-directed learning ability score of the subjects was 3.19, mean metacognition score was 3.36 and mean clinical competence score was 3.29. A positive correlation was found between clinical competence with self-directed learning ability and metacognition. The strongest predictor of clinical competence was metacognition. Conclusion: To improve the clinical competence of nursing students, these findings indicate that increasing metacognition ability is required.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.3
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• pp.365-372
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• 2011

Purpose: The purpose of this study was to examine the effects of the teaching effectiveness and clinical learning environment on the clinical practice competency in nursing students. Method: Undergraduate nursing students (268) enrolled in one of 4 universities in 2 cities completed a survey questionnaire. Collected data were analyzed using descriptive statistics, Pearson's correlation coefficient and multiple regression with the SPSS/Win 11.0 program. Results: The mean score for teaching effectiveness was 3.09 (${\pm}.53$) on a 5-point scale, for clinical learning environment, 3.09 (${\pm}.50$) on a 5-point scale, and for clinical practice competency, 3.94 (${\pm}.52$) on a 6-point scale. Significant positive correlations were found between teaching effectiveness and clinical learning environment, and clinical practice competency. The regression model explained 8.8% of clinical practice competency. Teaching effectiveness and clinical learning environment were significant predictors of clinical practice competency. Conclusion: The findings of the study suggest that teaching effectiveness and clinical learning environment be considered when developing strategies to increase clinical practice competency in nursing students.

• The Korean Journal of Applied Statistics
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• v.28 no.6
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• pp.1209-1216
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• 2015

Competing-risks events are often observed in a clustered clinical study such as a multi-center clinical trial. We propose a joint modelling approach via a shared frailty term for competing risks survival data from a cluster. For the inference we use the hierarchical likelihood (or h-likelihood), which avoids an intractable integration. We derive the corresponding h-likelihood procedure. The proposed method is illustrated via the analysis of a practical data set.

• The Korean Journal of Applied Statistics
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• v.7 no.2
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• pp.35-51
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• 1994

For ethical and economic reasons, clinicla trials must be repeatedly monitored for evidence of treatment benefit or harm. Repeated testing at conventional critical values can substantially inflate the overal type I error rate. To maintain acceptable levels, group sequential procedures have been developed for clinical trials. This article gives a brief overview of the group sequential procedures.

• The Korean Journal of Applied Statistics
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• v.25 no.6
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• pp.947-958
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• 2012

When modeling event times in biomedical studies, the outcome might be incompletely observed. In this paper, we assume that the outcome is recorded as current status failure time data. Despite well-developed literature the routine practical use of many current status data modeling methods remains infrequent due to the lack of specialized statistical software, the difficulty to assess model goodness-of-fit, as well as the possible loss of information caused by covariate grouping or discretization. We propose a model based on pseudo-observations that is convenient to implement and that allows for flexibility in the choice of the outcome. Parameter estimates are obtained based on generalized estimating equations. Examples from studies in bile duct hyperplasia and breast cancer in conjunction with simulated data illustrate the practical advantages of this model.

• The Korean Journal of Health Service Management
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• v.13 no.1
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• pp.43-53
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• 2019

Objectives: This study aimed to explore and describe the factors that influence nursing professionalism in male nursing students. Methods: Participants were 172 male nursing students. Data were collected with structured questionnaires from November 1 to November 19, 2018. Data were analyzed IBM SPSS Statistics version 21 software for descriptive statistics, t-test, ANOVA, Scheffe's test, Pearson's correlation coefficient, and multiple regression. Results: Nursing professionalism in male nursing students was significantly correlated with gender stereotypes (r=-.337, p<.001) and self-leadership (r=-639, p<.001). Moreover, the significant factors of nursing professionalism in male nursing students were gender stereotypes (${\beta}=-.188$, p=.002), self-leadership (${\beta}=-.584$, p<.001), and clinical practice experience (${\beta}=-.116$, p=.046), which explained 45.3%. Conclusions: The result of this study, indicate that in order to increase nursing professionalism in male nursing students, it is necessary to develop nursing intervention programs that can improve self-leadership, reduce stereotypes, and provide positive images of clinical practice.

• The Korean Journal of Health Service Management
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• v.10 no.2
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• pp.193-204
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• 2016

Objectives : The purpose of this study was to identify the mediation effect of a positive stress coping strategy between clinical practice stress and clinical practice satisfaction in nursing students. Methods : In this study, data was collected from 248 nursing students at K University in South Korea from October of 2015 to November of 2015. The collected data was analyzed using the SPSS 22.0 Statistics Program. Results : Clinical practice stress and a positive stress coping strategy were significant predictors of clinical practice satisfaction (${\beta}$=.442, p<.001). The explanatory power of the measure of clinical practice satisfaction was increased to 29.3% (p<.001) with solely clinical practice stress, and it reached 44.2% (p<.001) when a positive stress coping strategy was reflected. The results of this study confirmed that a positive stress coping strategy has a mediation effect on clinical practice stress and clinical practice satisfaction levels. Conclusions : It is necessary to develop a program to take advantage of positive stress coping skills so that nursing college students can smoothly overcome stress during their clinical training and thus improve their clinical practice experience.