• Journal of Engineering Education Research
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• v.16 no.4
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• pp.15-20
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• 2013

The result of the English test for freshmen showed wide difference in the ability of students, which means the graded class is strongly required. This paper describes the case study about the graded English class that was carried out for the freshman. Every freshman must take an English placement test from problems bank and were classified according to the result of the test. In order to resolve the dissatisfaction of the high level students, the statutes of my university for credit were modified. In order to analyze the effect of the graded class, evaluation test using similar problems was carried out at the end of the semester. The effect of the graded class was analyzed by using the paired samples t-test method and there was a meaningful performance improvement at the average score. Additional improvements in the method of classification and credit granted were made by analyzing the results of the evaluation test and survey.

• Proceedings of the Korean Statistical Society Conference
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• 2003.10a
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• pp.173-177
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• 2003

When we have both a paired data set and two independent data sets, neither a paired t-test nor a two-sample t-test can be used to detect differences between two samples. In order to identify differentially expressed genes in a mixed data set, a new test statistic is proposed.

• Journal of Veterinary Clinics
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• v.26 no.5
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• pp.401-407
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• 2009

In the previous article in this series we introduced the basic concepts for statistical analysis. The present review introduces hypothesis testing for continuous and categorical data for readers of the veterinary science literature. For the analysis of continuous data, we explained t-test to compare a single mean with a hypothesized value and the difference between two means from two independent samples or between two means arising from paired samples. When the data are categorical variables, the $x^2$ test for association and homogeneity, Fisher's exact test and Yates' continuity correction for small samples, and test for trend, in which at least one of the variables is ordinal is described, together with the worked examples. McNemar test for correlated proportions is also discussed. The topics covered may provide a basic understanding of different approaches for analyzing clinical data.

• Science of Emotion and Sensibility
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• v.13 no.3
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• pp.501-510
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• 2010

The knowledge base on emotional information is one of the key elements in the implementation of emotion retrieval systems for contents design of Mobile devices. This study proposed a new approach to the knowledge base implementation by automatically extracting color components from full-color images. In this study, the validity of the proposed method was empirically tested. Database was developed using 100 interior images as visual stimuli and a total of 48 subjects participated in the experiment. In order to test the reliability of the proposed 'emotional information knowledge base', firstly 'recall ratio' that refers to frequencies of correct images from the retrieved images was derived. Secondly, correlation Analysis was performed to compare the ratings by the subjects to what the system calculated. Finally, the rating comparison was used to run a paired-sample t-test. The analysis demonstrated satisfactory recall ration of 62.1%. Also, a significant positive correlation (p<.01) was observed from all the emotion keywords. The paired Sample t-test found that all the emotion keywords except "casual" retrieved the images in the order from more relevant to less relevant images and the difference was statistically significant (t(9)=5.528, p<.05). Findings of this study support that the proposed 'emotional information knowledge base' established only with color information automatically extracted from images can be effectively used for such visual stimuli search tasks as commercial interior images.

• Korean Journal of Clinical Laboratory Science
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• v.56 no.1
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• pp.32-42
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• 2024

This study compared the results of hemolyzed samples and re-collected samples to investigate a hemolysis influence and an acceptable hemolysis index (HI). Before and after hemolysis, alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase (Amy), direct bilirubin (D-bil), total bilirubin (T-bil), creatine phosphokinase (CK), gamma glutamyl transferase (GGT), iron, potassium (K), lactate dehydrogenase (LDH), magnesium (Mg), phosphorus (Phos), total protein (TP), and uric acid (UA) showed significant results in the paired t-test. LDH, K, iron, AST, CK, GGT, TP, Amy and Phos had a high correlation between the degree of hemolysis and the results of samples. When comparing Roche's cut-off HI with HI^QChigh obtained using quality control (QC) high standard deviation (SD), AST, D-bil, CK, and LDH were similar, but Amy, GGT, K, iron, Phos, and TP were lower than the cut-off HI of Roche, while ALP and ALT were higher. Some analytes which showed no significant results in the paired t-test, were found to have significant results in HI>200. Hence, it is suggested that the hemolyzed sample should be rejected if HI>200. Based on this study that some analytes were affected when HI<100, we recommend to set the standard of hemolysis starting from HI>50.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.47 no.2
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• pp.84-92
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• 2024

The purpose of this study is to analyze effect of Army Risk Assessment System(ARAS) which is used to prevent safety accident in ROK army. Based on prior research, we select 4 indicators which are related to accident prevention effect and analyze the differences before and after ARAS operation for each indicators by using Paired-Samples T-Test. Also, we analyze the correlation between degree of ARAS operation and status of safety accidents of 112 ROK Army units. We conduct an evaluation of each function within the system using IPA method. The results of this study are as follows; All 4 indicators are improved compared to before ARAS operation, and the differences are statistically significant. Also, there is negative correlation between the degree of ARAS operation and the occurrence of safety accidents. So, the operation of ARAS has a positive effect on preventing safety accidents. Finally among the 15 functions of ARAS, 4 functions require improvement. The findings of this study have implications for proposing necessity of computerized system in enforcing Risk Assessment. Also, whether or not operating ARAS is important, but it is also important to operate it well. Lastly, We propose improvement plans for each function to operate it well.

• The Korean Journal of Nuclear Medicine Technology
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• v.18 no.1
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• pp.153-157
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• 2014

Purpose: SLE (systemic lupus erythematosus) is an inflammatory autoimmune disease, characterized by various autoantibody. The detection of Anti double-stranded DNA (Anti-ds DNA) is important in the diagnostics of SLE, and include the American College of Rheumatology (ACR) diagnostic criteria for SLE. Also SLE disease activity and correlativity with the level Anti-ds DNA antibody have been reported and Anti-ds DNA antibody quantitative test is very useful for tracing before and after SLE treatment. When These Anti-ds DNA antibody test (Farr assay: $^{125}I$ labeled ds-DNA and bound Anti-ds DNA antibodies complex in serum is precipitated by ammonium sulfate and used to centrifugation, measured it) inhaled supernatant after centrifugation, a lipemic specimen does not facilitate the formation of precipitate and also occurs situation was inhaled with precipitate. To solve these problems, The Influence of the degree of lipemic specimen was evaluated. Materials and Methods: September 2012 to February 2013, We selected lipemic samples (n=81) of specimen commissioned by Anti-ds DNA antibody test. Lipemic samples were done pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) used a micro-centrifuge (Eppendorf Model 5415D). At the same time lipemic specimen and pre-treatment samples were performed Anti-ds DNA antibody test (Anti-ds DNA kit, Trinity Biotech, Ireland). Statistical analysis were analyzed Pearson's correlation coefficients and regression and paired t-test, and Difference (%). Results: Experimental group 1 (Lipemic Specimen Anti-ds DNA Ab concentration ${\leq}7IU/mL$) at y=0.368X+4.732, $R^2=0.023$, Pearson's correlation coefficient was 0.154, paired t-test (P=0.003), Difference (%) mean 65.7 and showed a statistically significant difference. Experimental group 2 (Lipemic Specimen Anti-ds DNA Ab concentration ${\geq}8IU/mL$) at y=0.983X+0.298, $R^2=0.994$, Pearson's correlation coefficient showed 0.997, paired t-test (P=0.181), Difference (%) mean -5.53 made no statistically significant difference. Conclusion: Lipemic sample of low Anti-ds DNA Ab concentration (2.5-7 IU/mL) and the result is obtained pre-treatment (high-speed centrifugation: 14,000 rpm 5 mins) were made a significant difference statistically. Anti-ds DNA is one of the primary auto-antibodies present in patients with SLE, and remain an important diagnostic test for SLE. Therefore, we recommend preprocessing (high-speed centrifugation: 14,000 rpm 5 mins) in order to exclude the influence of lipemic specimen.

• The Journal of Korean Academic Society of Nursing Education
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• v.21 no.1
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• pp.28-35
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• 2015

Purpose: The purpose of this study was to examine the effects of prior information about ICU environment on the anxiety and environmental stress of cardiac surgery ICU patients. Methods: A non-equivalent control group non-synchronized quasi-experimental research design was used. Participants were 60 (control 30, experimental 30) patients who had been admitted to ICU. Prior information about the ICU environment was provided to the experimental group. The anxiety level of subjects was measured by State-Trait Anxiety Inventory (STAI) and the stress level of subjects was measured by the Intensive Care Unit Environmental Stressor Scale (ICUESS). Data were analyzed using a Chi-square test or a Fisher's exact test, independent samples t-test, and paired samples t-test. Results: There was no difference in Anxiety (t=-0.58, p=.563), but there was a significant difference in environmental stress (t=10.46, p<.001). Conclusion: Providing prior information would be an effective nursing intervention to reduce environmental stress.

• Journal of Acupuncture Research
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• v.21 no.1
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• pp.176-188
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• 2004

This study was carried out to investigate statistical validity of medical articles that used various statistical techniques such as t-test, analysis of variance, correlation analysis, regression analysis and chi-square test. For study 429 original articles using those statistical methods were selected from Journal of Korean Acupuncture & Moxibusition Society published from 1984 to 2002. 429 original articles were reviewed to analyzed the statistical procedures. Results are summarized as follows : 1. In this study 93 articles(21.68%) of 429 ones didn't report statement of statistical method in detail. 2. 53 articles(12.53%) didn't report p-value in correctly, and 245 articles(57.11 %) used mean${\pm}$standard error (Mean${\pm}$SEM.) and 109 articles used mean${\pm}$standard deviation(Mean${\pm}$SD.). All of 23 articles using nonparametric statistical techniques made an error to central tendency or dispersion. 3. 175 articles(59.93%) and 14 articles(4.79%) of 292 ones made an error to description of equal variances and normal distribution. 4. 99 articles(50%) of 185 ones misused t-test and 4 articles of 5 ones misused chi-square test. 5. 28 articles(73.68%) of 38 ones using discrete variable misused parametric technique such as t-test or ANOVA. 2 articles and 1 article of 125 ones choosing paired samples misused independent t-test and Mann-Whitney U test. 6. 20 articles using analysis of variance didn't use multiple comparison.

• Journal of Korean Academy of Nursing
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• v.34 no.3
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• pp.421-429
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• 2004

Purpose: This study is to evaluate the effects of drug abuse prevention program for elementary school students. Method: The design of this study is nonequivalent control group pretest-posttest design. The subjects of experimental group were 27 students and the subjects of control group were 25 students in fifth grade of elementary school in C City, Gyeongsangbuk-do. The experimental group had Drug Abuse Prevention Program, which was two days per week program, for 5 weeks. And post-test was carried out in the same way as the pre-test. Data analysis was done using frequency, percentage, mean, standard deviation, Chi-square test, t-test, Paired Samples t-test using with SPSS WIN 11.0. Result: the experimental group, to which drug abuse prevention program was given, was improved in knowledge of drug and unacceptable attitude of drug compared to the control group, but there were no significant differences of self-esteem and assertiveness between two groups. Conclusion: The drug abuse prevention program was effective to increase knowledge and attitude of drug in elementary school students.