• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.12
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• pp.656-662
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• 2009

In this paper, the heat resistance reliability of an axial smoke exhaust fan was investigated. An axial smoke exhaust fan should be capable of operating at $250^{\circ}C$ for 2 hours. The heat resistance reliability was evaluated by the heat resistance reliability test. A B10 life with a 90% confidence level was estimated to be about 48 minute. The failure occurred in the motor due to high temperature. The main failure mechanisms of the motor were melting of bond and insulating paper and burning of insulating materials in the coil. The heat resistance reliability was improved by changing the way to unite the core and the coil and by replacing the insulating paper and the insulating materials of the coil. A B10 life with a 90% confidence level of a modified axial smoke exhaust fan was estimated to be over 120 minute.

• Journal of Korean Biological Nursing Science
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• v.24 no.4
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• pp.219-226
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• 2022

Purpose: This study aimed to investigate the status and factors associated with self-management behavior (SMB) of patients with type 2 diabetes (T2DM) in a border area of southwest China. Methods: A cross-sectional study was conducted with T2DM patients in Dali, China. The participants filled in the questionnaires including demographic and disease-related characteristics, psychosocial status, resources of DM knowledge, knowledge of DM care, competency in DM care skills, the Chinese Diabetes Management Self-Efficacy Scale (C-DMSES), and the Chinese Summary of Diabetes Self-Care Activities (C-SDSCA). All the data were analyzed with SPSS version 26. Multiple linear regression analysis examined associations between predictors and SMB. Results: A total of 470 valid questionnaires have been collected. The score for overall SMB was 50.71± 11.99; 19.6% of patients were at a good level, 48.3% were moderate, and 32.1% were poor. The significant factors that influenced SMB included self-efficacy (β= 0.37; p< .001), competency in DM care skills (β= 0.22; p< .001) and lacked in the treatment confidence (β= -0.09; p= .023). Conclusion: The level of self-management among T2DM patients in this area was medium-low state. For future studies, our findings suggest that self-efficacy, competency in DM care skills, and treatment confidence should be considered essential factors in improving the self-management behavior of T2DM patients in the border area of southwest China.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.9
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• pp.229-239
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• 2020

This paper examines the impact of gender on access to debt finance among Vietnamese enterprises. The paper investigates data and variables retrieved from the World Bank Enterprise Survey dataset using five Probit models. The regression results suggest that there exist more unfavourable debt financing conditions for women-led firms (WLF), measured as a lower probability of having loan applications fully approved. Firm's age, working sector, and perception of access to finance as a difficulty are found to have explanatory power on the discrimination. More importantly, the perception of debt finance as a difficulty or firms' level of confidence significantly explains the variance of the dependent variable of probability of loan approval, or gender effect would be more pronounced if the firm already has a low level of confidence. The paper also contributes in testing for the gender effect on Vietnamese enterprises from different sectors and scale, unlike other prior research papers focusing on specific sectors and/or small and medium enterprises only. The findings are highly useful for Vietnamese credit institutions to set out a specific business policy to attract more WLFs and help promoting gender equality in the working environment, especially in debt financing, which is often neglected in existing regulation and policy frameworks.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.18 no.1
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• pp.71-78
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• 2011

Purpose: The purpose of this study was to investigate the critical thinking disposition, problem solving ability, and clinical competence of nursing students in a 4-year baccalaureate university program. Methods: In this study, a descriptive survey design was used with convenience sample of 228 nursing students at a University in Chungbuk Province. Data were analyzed using descriptive statistics, independent t-test, ANOVA, Pearson correlation coefficient, and multiple stepwise regression. Results: The mean scores for critical thinking disposition, problem solving ability, and clinical competence were at the intermediate level. Significant positive correlations among critical thinking disposition, problem solving ability, and clinical competence were found. The regression model explained 46.8% of clinical competence. Problem solving confidence was the most significant predictor of clinical competence, other variables were intellectual fairness, intellectual eagerness/curiosity, and prudence. Conclusion: The study findings suggest that nursing students with higher levels of critical thinking disposition and problem solving ability will have a higher level of clinical competence. Furthermore, problem solving confidence might be the most important predictor in clinical competence. Therefore, it is necessary to introduce the new teaching strategies in nursing education, strategies that will improve critical thinking disposition, problem solving ability, and clinical competence.

• Journal of Integrative Natural Science
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• v.14 no.3
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• pp.123-129
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• 2021

This research examines the effect of positively skewed population distribution on the two sample t-test through simulation. For simulation work, two independent samples were selected from the same chi-square distributions with 3, 5, 10, 15, 20, 30 degrees of freedom and sample sizes 3, 5, 10, 15, 20, 30, respectively. Chi-square distribution is largely skewed to the right at small degrees of freedom and getting symmetric as the degrees of freedom increase. Simulation results show that the sampled populations are distributed positively skewed like chi-square distribution with small degrees of freedom, the F-test for the equality of variances shows poor performances even at the relatively large degrees of freedom and sample sizes like 30 for both, and so it is recommended to avoid using F-test. When two population variances are equal, the skewness of population distribution does not affect on the t-test in terms of the confidence level. However even though for the highly positively skewed distribution and small sample sizes like three or five the t-test achieved the nominal confidence level, the error limits are very large at small sample size. Therefore, if the sampled population is expected to be highly skewed to the right, it will be recommended to use relatively large sample size, at least 20.

• Journal of the Korean Institute of Telematics and Electronics
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• v.19 no.5
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• pp.43-47
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• 1982

In this paper, we derived to anlyze the correlation between the peak sidelobe of the linear isotropic random array and the design parameters, such as the element numbers, wavelength, scanning angle, confidence level and the length of aperture, with the statistical theory of random processes. The Peak sidelobe estimator was tested by the computer simulations using Honte Carlo method. Consequently, it was evident that the results of the peak lidelobe estimator were consistent with those of the computer simulations over confidence level 0.7.

• Journal of the Korean Vacuum Society
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• v.14 no.2
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• pp.59-68
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• 2005

We developed a national medium vacuum standard by static expansion method. A 133 Pa capacitance diaphragm gauge was calibrated and analysed according to the document of 'Guide to the Expression of Uncertainty in Measurement' of ISO. The results showed that the expanded uncertainty of $2.628\times10^{-3}$ Pa at $95\%$ confidence level and coverage factor of k=2.

• Corrosion Science and Technology
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• v.22 no.1
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• pp.55-63
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• 2023

The aim of this study was to propose a multiple linear regression (MLR) equation to predict ultimate tensile strength (UTS) of 316L stainless steel with unspecified pit corrosion. Tensile specimens with pit corrosion were prepared using a potentiostatic acceleration test method. Pit corrosion was characterized by measuring ten factors using a confocal laser microscope. Data were collected from 22 tensile tests. At 85% confidence level, total pit volume, maximum pit depth, mean ratio of surface area, and mean area were significant factors showing linear relationships with UTS. The MLR equation using these three significant factors at a 85% confidence level showed considerable prediction performance for UTS. Determination coefficient (R²) was 0.903 with training and test data sets. The yield strength ratio of 316L stainless steel was found to be around 0.85. All specimens with a pit corrosion presented a yield ratio of approximately 0.85 with R² of 0.998. Therefore, pit corrosion did not affect the yield ratio.

• Corrosion Science and Technology
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• v.20 no.2
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• pp.52-61
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• 2021

This study using experimental design and linear regression technique was implemented in order to predict the pitting potential of stainless steel in marine environments, with the target materials being AL-6XN and STS 316L. The various variables (inputs) which affect stainless steel's pitting potential included the pitting resistance equivalent number (PRNE), temperature, pH, Cl^- concentration, sulfate levels, and nitrate levels. Among them, significant factors affecting pitting potential were chosen through an experimental design method (screening design, full factor design, analysis of variance). The potentiodynamic polarization test was performed based on the experimental design, including significant factor levels. From these testing methods, a total 32 polarization curves were obtained, which were used as training data for the linear regression model. As a result of the model's validation, it showed an acceptable prediction performance, which was statistically significant within the 95% confidence level. The linear regression model based on the full factorial design and ANOVA also showed a high confidence level in the prediction of pitting potential. This study confirmed the possibility to predict the pitting potential of stainless steel according to various variables used with experimental linear regression design.

• Journal of East-West Nursing Research
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• v.26 no.1
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• pp.91-99
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• 2020

Purpose: The study aims to assess the inter-rater reliability of the Korean Triage and Acuity Scale between the research nurses and the triage nurses. Methods: Interrater reliability was measured on 400 adult (≧15) and 400 pediatric (<15) patients who visited the emergency medical center from January 4 to June 30, 2018. Results: The study result showed that the inter-rater reliability of the Korean Triage and Acuity Scale was substantial, with κ=.73 (95% Confidence interval= .68-.78) and 77.0 percent agreement. The inter-rater of Pediatric Korean Triage and Acuity Scale was also substantial, with κ=.76 (95% Confidence interval= .71-.82) and 83.8 percent agreement. Conclusion: Although the inter-rater reliability of the Korean Triage and Acuity Scale was acceptable, the percent agreement was lower than the desirable level (<80.0%). It was confirmed that Pediatric Korean Triage and Acuity Scale had an acceptable level of inter-rater reliability and percent agreement for clinical use. Efforts should be made to improve the reliability in the future.