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

• Journal of the Korea Convergence Society
• /
• v.11 no.11
• /
• pp.461-473
• /
• 2020

This study examined the effect of using web-based distance program in home health education for nursing college students in COVID-19 special disaster area. The study was carried out according a nonequivalent control group pretest-posttest design. The study subjects were 49 nursing college students from K City, Gyeongsangbuk-do. The web-based distance program was conducted for 2 weeks. The data collection period was from June 1, 2020 to June 12, 2020. Collected data were analyzed using SPSS PC+ 19.0 with the Fisher' exact test, Wilcoxon rank sum test, ANCOVA with pretest value as covariate. The experimental group had significantly different in knowledge related home health nursing, perceived motivation, and learning commitment in comparison to the control group. This suggests that the web-based distance program in the COVID-19 special disaster area can be applied as a way to increase nursing students' knowledge related home health nursing, perceived motivation, and learning commitment.

• Journal of the Korean Operations Research and Management Science Society
• /
• v.42 no.3
• /
• pp.35-49
• /
• 2017

The main objective of this paper is to empirically analyze the efficiency effects of mergers on Korean pharmaceutical firms and suggests managerial or policy implications for managers or policy makers. This study selects non-merging control firms close to the size of merging firms, as well as a set of merging firms, and measures the effects of mergers on efficiency three years before and after the merger using the non-parametric data envelopment analysis (DEA) method. To compare the differences of efficiency means among several groups, Wilcoxon rank sum test or Wilcoxon signed rank test is used. It showed that the long-term effects after the merger appeared partially. Furthermore, it was observed that there was no difference statistically in the efficiency between merging and non-merging firms. Also, there was no difference statistically in the efficiency between the pre- and post-merger periods. In conclusion, there was not any observed synergy effect through group (or affiliated) mergers between affiliates or related mergers for Korean pharmaceutical firms.

• Korea Journal of Hospital Management
• /
• v.5 no.1
• /
• pp.84-104
• /
• 2000

This paper analyzes the technical efficiency of thirty two hospitals in Korea using DEA(Data Envelopment Analysis). DEA provides an efficiency measure for each hospital compared to the most efficient one. The amount and sources of inefficiency that are identified by the DEA are useful for benchmarking to improve efficiency. The results from multiple regression analysis and Wilcoxon Rank Sum test show that bed turnover, hospital size, and average length of stay are related to hospital efficiency.

• The Korean Journal of Applied Statistics
• /
• v.21 no.6
• /
• pp.947-957
• /
• 2008

Two-arm non-inferiority trials is often applied to parametric procedure suggested by Hauschke et al. (1999). Since this design does not allow a direct comparison of a new treatment group with placebo group, parametric procedure in a three-arm non-inferiority trial with a placebo group was suggested by Pigeot et al. (2003). But, procedures in these designs are necessary for distribution assumptions. Therefore we propose, in this paper, non parametric procedures employing Wilcoxon rank sum test in a two-arm design and linear contrast test suggested by Scheirer et al. (1976) in a three-arm design. The proposed nonparametric procedures and parametric procedures are compared by Monte Carlo simulation study.

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.9
• /
• pp.4109-4114
• /
• 2015

Background: Full-field digital mammography (FFDM) with dense breasts has a high rate of missed diagnosis, and digital breast tomosynthesis (DBT) could reduce organization overlapping and provide more reliable images for BI-RADS classification. This study aims to explore application of COMBO (FFDM+DBT) for effect and significance of BI-RADS classification of breast cancer. Materials and Methods: In this study, we selected 832 patients who had been treated from May 2013 to November 2013. Classify FFDM and COMBO examination according to BI-RADS separately and compare the differences for glands in the image of the same patient in judgment, mass characteristics display and indirect signs. Employ Paired Wilcoxon rank sum test was used in 79 breast cancer patients to find differences between two examine methods. Results: The results indicated that COMBO pattern is able to observe more details in distribution of glands when estimating content. Paired Wilcoxon rank sum test showed that overall classification level of COMBO is higher significantly compared to FFDM to BI-RADS diagnosis and classification of breast (P<0.05). The area under FFDM ROC curve is 0.805, while that is 0.941 in COMBO pattern. COMBO shows relation of mass with the surrounding tissues, the calcification in the mass, and multiple foci clearly in breast cancer tissues. The optimal sensitivity of cut-off value in COMBO pattern is 82.9%, which is higher than that in FFDM (60%). They share the same specificity which is both 93.2%. Conclusions: Digital Breast Tomosynthesis (DBT) could be used for the BI-RADS classification in breast cancer in clinical.

• Journal of Korean Academy of Nursing
• /
• v.42 no.6
• /
• pp.843-852
• /
• 2012

Purpose: In this study a recreational combination gymnastics program was provided for women 75 years of age or older and the effects on physical fitness (grip strength, static balance, ability to do complex movement), depression, cognitive function and quality of life were examined. Methods: A quasi-experimental study employing a nonequivalent control group, pre-post design was conducted. Participants included 53 women elders whose cognitive function was within the normal range. The women were assigned to an experimental group (27) or a control group (26). The intervention was conducted twice a week for a period of 12 weeks. Chi-square test, t-test, paired t-test, Wilcoxon rank sum test and Wilcoxon signed rank test were used for data analysis. Results: Following completion of the program, left grip strength (t=2.17, p=.035), right grip strength (t=2.04, p=.046), static balance (t=-2.18, p=.030), depression (z=-2.88, p=.004), cognitive function (t=3.96, p<.001), and quality of life (t=-3.19, p=.002) were significantly better in the experimental group. Conclusion: Findings from this study indicate that recreational combination gymnastics programs are effective in enhancing physical fitness, cognitive function, and quality of life and in decreasing depression for female elders and could therefore be regarded as positive programs for promotion of physical and mental health for older women.

• Journal of Korean Academy of Nursing
• /
• v.40 no.5
• /
• pp.724-735
• /
• 2010

Purpose: In this study a cognitive enhancement group training program of 10 sessions was provided for communitydwelling elders and the effects on cognitive function, depression and quality of life were tested. Methods: A quasi-experimental study using a nonequivalent control group, pre-post design was used. The participants were 87 elders whose cognitive function was within the normal range. Of these elders, 45 were assigned to the experimental group and 42 to the control group. The intervention was conducted once a week for 10 weeks. Chi-square test, t-test, paired t-test, Wilcoxon rank sum test and Wilcoxon signed rank test were used to analyze the data. Results: After the program, the cognitive function (t=-2.85, p=.006), depression (z=2.82, p=.005) and quality of life (t=2.79, p=.007) of the experimental group was significantly better than those of the control group. Especially, immediate recall (z=2.45, p=.014) and concentration (z=2.58, p=.010) in the subcategory of cognitive function were significantly better than that of the control group. Conclusion: The findings indicate that the cognitive enhancement group training program was effective in enhancing the cognitive function, depression and quality of life for elders and could therefore be considered as a positive program for emotional and cognitive support for community-dwelling elders.

• Journal of Korean Academy of Nursing
• /
• v.52 no.1
• /
• pp.36-51
• /
• 2022

Purpose: The purpose of this study was to examine the effects of electroencephalogram (EEG) biofeedback training for emotion regulation and brain homeostasis on anxiety about COVID-19 infection, impulsivity, anger rumination, meta-mood, and self-regulation ability of late adolescents in the prolonged COVID-19 pandemic situation. Methods: A non-equivalent control group pretest-posttest design was used. The participants included 55 late adolescents in the experimental and control groups. The variables were evaluated using quantitative EEG at pre-post time points in the experimental group. The experimental groups received 10 sessions using the three-band protocol for five weeks. The collected data were analyzed using the Shapiro-Wilk test, Wilcoxon rank sum test, Wilcoxon signed-rank test, t-test and paired t-test using the SAS 9.3 program. The collected EEG data used a frequency series power spectrum analysis method through fast Fourier transform. Results: Significant differences in emotion regulation between the two groups were observed in the anxiety about COVID-19 infection (W = 585.50, p = .002), mood repair of meta-mood (W = 889.50, p = .024), self-regulation ability (t = - 5.02, p < .001), self-regulation mode (t = - 4.74, p < .001), and volitional inhibition mode (t = - 2.61, p = .012). Neurofeedback training for brain homeostasis was effected on enhanced sensory-motor rhythm (S = 177.00, p < .001) and inhibited theta (S = - 166.00, p < .001). Conclusion: The results demonstrate the potential of EEG biofeedback training as an independent nursing intervention that can markedly improve anxiety, mood-repair, and self-regulation ability for emotional distress during the COVID-19 pandemic.

• Korean Journal of Child Education & Care
• /
• v.19 no.3
• /
• pp.183-197
• /
• 2019

Objective: The purpose of this study was to examine the effect of a group program using theraplay on 2-year-olds' prosocial behavior. The changes of prosocial behavior in the process of program were also examined. Methods: Subjects were 12 infants who attended a child care center in W city. Subjects were attached to the experimental or control group. The experimental group participated in 11 group theraplay sessions twice a week. The adaptive social behavior inventory (Hogan et al., 1992) was used for pre and post tests. Wilcoxon rank-sum test was performed to verify the effectiveness of a group theraplay program. Every sessions was video-taped and recorded verbatim. The verbatim were analyzed using the Padgett (2001)'s qualitative data analysis method. Results: Infants who assigned to the experimental group demonstrated significant improvement in prosocial behavior. Their expressive behavior and compliant behavior gradually increased over the sessions. Conclusion/Implications: The present study showed that the use of group program utilizing theraplay was an effective strategy for improving prosocial behavior of 2-year-old infants.