• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.3
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• pp.457-464
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• 2021

This paper investigates the achievable rate volumes for non-successive interference cancellation(SIC) non-orthogonal multiple access(NOMA) schemes, especially for 3-user correlated information sources(CIS). First, the closed-form expressions for the achievable rate volumes of non-SIC 3-user CIS NOMA are derived. Then it is numerically shown that the large correlation coefficients, as the achievable rate volumes of non-SIC 3-user CIS NOMA is larger than that of conventional SIC 3-user independent information sources(IIS) NOMA. We also demonstrate by various comparisons that the impact of the correlation coefficients of weaker channel gain users on achievable rate volume is more significant than those of stronger channel gain users.

• Journal of Digital Convergence
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• v.17 no.2
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• pp.255-264
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• 2019

This study was a cross-sectional study done to determine the relevance and impact factors of critical thinking and nursing practice environment on clinical decision making among nurses. A survey was conducted for April 2017 with self-report questionnaire. Participants were 261 registered nurses working in one tertiary hospital. Data were analyzed using descriptive statistics, independent t-test, one-way ANOVA, Pearson's correlation coefficients, and hierarchical regression analysis with SPSS/WIN(21.0). Factors affecting clinical decision making included age, educational background, position, work shift, clinical career. Clinical decision making had a positive correlation with critical thinking and nursing practice environment. And position, critical thinking and nursing practice environment accounted for 35.8% of the variance in clinical decision making. Therefore, quality management for developing nursing professionalism and administrative support for effective staffing and resource adequacy in addition improving critical thinking increase nurses'clinical decision making.

• Journal of Digital Convergence
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• v.17 no.7
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• pp.235-244
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• 2019

The purpose of the study was to investigate the effect of resilience and organizational culture on well-being in general hospital nurses. The data were collected from 188 nurses working at a general hospital from $1^{st}-30^{th}$ September 2017. The research tools were the resilience, organizational culture, and well-being. The data were analyzed by descriptive statistics, t-test, ANOVA, Pearson's correlation coefficients, and stepwise multiple regression using SPSS/WIN 21.0 program. The result showed that the difference in well-being relating to general characteristics were significant age, marital status, position, and career. It was found that resilience, organizational culture, and well-being were all significantly correlated, and that the factors affecting well-being included resilience, task-oriented cultures, relation-oriented cultures, and marital status. There is a need for a strategy to enhance nurses' resilience and aid in the development of a sound organizational culture that could help them effectively adapt to changes. This will not only improve nurses' health but also have a positive impact on patients and nursing organizations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.13 no.4
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• pp.1845-1865
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• 2019

Current Internet is designed by lots of service providers with different objects and policies which make the direct deployment of radically new architecture and protocols on Internet nearly impossible without reaching a consensus among almost all of them. Network virtualization is proposed to fend off this ossification of Internet architecture and add diversity to the future Internet. As an important part of network virtualization, virtual network embedding (VNE) problem has received more and more attention. In order to solve the problems of large embedding cost, low acceptance ratio (AR) and environmental adaptability in VNE algorithms, cognitive method is introduced to improve the adaptability to the changing environment and a cognitive virtual network embedding algorithm based on weighted relative entropy (WRE-CVNE) is proposed in this paper. At first, the weighted relative entropy (WRE) method is proposed to select the suitable substrate nodes and paths in VNE. In WRE method, the ranking indicators and their weighting coefficients are selected to calculate the node importance and path importance. It is the basic of the WRE-CVNE. In virtual node embedding stage, the WRE method and breadth first search (BFS) algorithm are both used, and the node proximity is introduced into substrate node ranking to achieve the joint topology awareness. Finally, in virtual link embedding stage, the CPU resource balance degree, bandwidth resource balance degree and path hop counts are taken into account. The path importance is calculated based on the WRE method and the suitable substrate path is selected to reduce the resource fragmentation. Simulation results show that the proposed algorithm can significantly improve AR and the long-term average revenue to cost ratio (LTAR/CR) by adjusting the weighting coefficients in VNE stage according to the network environment. We also analyze the impact of weighting coefficient on the performance of the WRE-CVNE. In addition, the adaptability of the WRE-CVNE is researched in three different scenarios and the effectiveness and efficiency of the WRE-CVNE are demonstrated.

• Atmosphere
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• v.29 no.3
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• pp.241-255
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• 2019

Bias correction (BC) and quality control (QC) are essential steps for the proper use of satellite observations in data assimilation (DA) system. BC should be calculated over quality controlled observation. And also QC should be performed for bias corrected observation. In the Korea Institute of Atmospheric Prediction Systems (KIAPS) Package for Observation Processing (KPOP), we adopted an adaptive BC method that calculates the BC coefficients with background at the analysis time rather than using static BC coefficients. In this study, we have developed an iterative QC-BC method for Advanced Microwave Sounding Unit-A (AMSU-A) to reduce the negative feedback from the interaction between BC and QC. The new iterative QC-BC is evaluated in the KIAPS 3-dimensional variational (3DVAR) DA cycle for January 2016. The iterative QC-BC method for AMSU-A shows globally significant benefits for error reduction of the temperature. The positive impacts for the temperature were predominant at latitudes of $30^{\circ}{\sim}90^{\circ}$ of both hemispheres. Moreover, the background warm bias across the troposphere is decreased. Even though AMSU-A is mainly designed for atmospheric temperature sounding, the improvement of AMSU-A pre-processing module has a positive impact on the wind component over latitudes of $30^{\circ}S$ near upper-troposphere, respectively. Consequently, the 3-day-forecast-accuracy is improved about 1% for temperature and zonal wind in the troposphere.

• Journal of Environmental Health Sciences
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• v.47 no.4
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• pp.310-319
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• 2021

Background: Humidifier disinfectant exposure is an ongoing issue, and there is still considerable related controversy. Various approaches are needed to secure scientific evidence on the extent of the victims' damages and for the determination of appropriate compensation. Objectives: The purpose of this study was to assess the association between humidifier disinfectant (HD) use and academic achievement in Korean children. Methods: This study used data from the 8th Panel Study on Korean Children in 2015. For the final study, 1,598 cases were used. T-tests and multiple linear regression analyses were conducted to determine whether the use of humidifier disinfectant is a factor that affects academic ability. Results: Children in groups using humidifier disinfectant showed statistically significantly lower scores in all areas of language, including reading, speaking and writing, and statistically lower scores in all areas of mathematics, including counting, addition and subtraction. In the multiple regression analysis results, which control for the effects of various demographic/social variables, the use of humidifier disinfectants showed statistically significant beta coefficients (β: -0.357, p<0.001), negatively affecting children's language ability. As for the 'math' variable, which was created by combining counting, addition, and subtraction scores, the use of humidifier disinfectants as independent variables also showed statistically significant beta coefficients (β: -0.200, p<0.001), negatively affecting children's math ability. Conclusions: The results of the study showed that depending on whether or not humidifier disinfectants were used, there are differences in children's language abilities, such as reading, speaking, and writing, as well as in their mathematical abilities, such as counting, adding, and subtracting numbers. These findings are thought to serve as a scientific basis for extending the perspective from health effects to more diverse areas of demographic and social impact related to humidifier disinfectant damage and compensation.

• Journal of the Korea Convergence Society
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• v.13 no.5
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• pp.435-443
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• 2022

This study was to conducted to explore predictors of emotional labor of clinical practice and resilience on professional identity in nursing students. The data were collected from September to December, 2021, for 142 nursing students in Seoul and Gyeonggi-do. Descriptive statistics, independent t-test, one-way ANOVA, Pearson correlation coefficients, and multiple regression were used to analyze the data. Satisfaction of major showed statistically significant differences in professional identity (F=19.97, p<.001). Professional identity was positively associated with resilience (r=.30, p<.001) and negatively associated with emotional labor (r=-.35, p<.001). Multiple regression analyses showed that satisfaction of major and emotional labor were statistically significant (𝛽=-.268, p<.001) in predicting professional identity with the explanatory power of 29.3%. To enhance professional identity in nursing students, it is necessary to develop strategies to improve their satisfaction of major and to provide educational programs for coping skill in managing their emotional labor in clinical practice.

• Journal of the Korean Applied Science and Technology
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• v.40 no.6
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• pp.1381-1393
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• 2023

This study was a descriptive research conducted to confirm the mediating effect of self-efficacy in the relationship between caregivers' patient safety knowledge and patient safety management activities. Subjects were 197 caregiver's and data collection was conducted from July 1 to 29, 2022. Data were analyzed using t-test, ANOVA, Scheffe's test, Pearson correlation coefficients and Hierarchical multiple regression analysis using the SPSS 28.0 program. There was a significant positive correlation between caregivers' patient safety knowledge and self-efficacy(r=.653, p<.001), and patient safety knowledge and patient safety management activities(r=.467, p<.001). In addition, the complete mediating effect of self-efficacy was confirmed in the relationship between caregivers' patient safety knowledge and patient safety management activities, and the explanatory power was 46.8%. Therefore, strengthen the patient safety management activities of caregiver's, systematic program development and educational opportunities should be provided to improve self-efficacy.

• Journal of Digital Convergence
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• v.15 no.11
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• pp.395-405
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• 2017

This study was designed to examine the degree of empathic ability, gratitude disposition, and job satisfaction, and identify that the impact on job satisfaction of psychiatric nurses. Participants were 196 psychiatric nurses from 8 psychiatric hospitals in Korea. Data were collected from October 8 to 20, 2016 and were analyzed using independent t-test, one-way ANOVA, Pearson correlation coefficients and hierarchical multiple regression with the SPSS WIN 22.0 program. The mean score of job satisfaction was $3.3{\pm}0.34$, empathic ability was $3.5{\pm}0.28$, and gratitude disposition was $4.0{\pm}0.59$. The psychiatric nurses' empathic ability and gratitude disposition affected their job satisfaction, accounting for 18.5% of the total variance. Empathic ability influenced job satisfaction significantly (B=0.52, p<.001) for 17.0% of the variance. This study suggested that the development of training programs for improving job satisfaction needs to consider their empathic ability and gratitude disposition of psychiatric nurses.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.1
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• pp.133-144
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• 2017

This study investigates firm-specific financial variables that determine investment or speculative grades from the viewpoint of firms, which are one of the major stakeholders related to the credit rating. We employ an ordered probit model for our analysis with the sample data from 1999 to 2015 for listed firms in the Korean stock markets. For investment grades, operating margin, sales, market-to-book, dividend payment, capital expenditure ratio, and tangible asset ratio have a significantly positive impact on credit ratings. In the subsample for speculative grades, the coefficients of the dividend payment, retained earnings ratio, and capital expenditure ratio are significantly positive while short-term debt ratio and R&D expenditures have a significantly negative impact on credit ratings. For the analysis before and after 2009, when the Credit Information Use and Protection Act was strengthened after the global financial crisis, the coefficients of the capital expenditure ratio, cash ratio, and tangible asset ratio are significantly positive in the subsample for investment grades before 2009, but not significant after 2010. The coefficient of the long-term debt ratio is more significantly negative than that of the short-term debt ratio before 2009, for speculative grades, but short-term debt ratio has a more negative effect on ratings than long-term debt ratio after 2010. Surprisingly, the coefficient of the R&D expenditures is significantly negative in both investment and speculative grades since 2010. Our findings are inconsistent with the conjecture that the increase in R&D expenditures enhances the possibility of creating cash-flow by raising the investment growth opportunity, and thus affects positively the credit rating.