• Clean Technology
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• v.24 no.4
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• pp.332-338
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• 2018

Currently graphite is used as an anode active material for lithium ion battery. However, since the maximum theoretical capacity of graphite is limited to $372mA\;h\;g^{-1}$, a new anode active material is required for the development of next generation high capacity and high energy density lithium ion battery. The maximum theoretical capacity of Si is $4200mA\;h\;g^{-1}$, which is about 10 times higher than the maximum theoretical capacity of graphite. However, since the volume expansion rate is almost 400%, the irreversible capacity increases as the cycle progresses and the discharge capacity relative to the charge is remarkably reduced. In order to solve these problems, it is possible to control the particle size of the Si anode active material to reduce the mechanical stress and the volume change of the reaction phase, thereby improving the cycle characteristics. Therefore, in order to minimize the decrease of the charge / discharge capacity according to the volume expansion rate of the Si particles, the improvement of the cycle characteristics was carried out by pulverizing Si by a dry method with excellent processing time and cost. In this paper, Si is controlled to nano size using vibrating mill and the physicochemical and electrochemical characteristics of the material are measured according to experimental variables.

• Journal of Convergence for Information Technology
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• v.9 no.7
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• pp.85-93
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• 2019

The purpose of this study is to identify the influence of demographic characteristics such as inappropriate lifestyle, stress, and health status among health risk factors of early adolescents according to gender. There is a gender difference in the perception of mental and physical health of early adolescents, and the result can be different in behavior patterns between men and women. This study was conducted to identify the health risk factors as independent variables for early adolescents in Daegu and Gyeongbuk area, and to analyze the determinants of gender (male, female) differences by parents, family environment, friends, academic background, appearance, grade, location, school grades, family situation, and health status as demographic factors. And, the Odds Ratio of the early adolescents was analyzed through logit analysis and the differences according to the influence relationship of each of them were examined. As a result of the analysis, the more the sleep and physical activity, parents, home environment, friends, academic background, and appearance are increased, the more the influence is likely to become on the male students. On the contrary, the rest of the health risk factors can increase, and the threat to the health risk factors is likely to become severe to the female students.Among them, it is necessary to develop a pre-preventive program for early adolescents' health risk factors, provide basic data for practical application in the field, and seek a detailed program according to the gender of early adolescents.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.448-457
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• 2019

This descriptive study was conducted to identify the factors affecting the psychological well-being of nursing students. A questionnaire survey was conducted on 298 nursing college students attending two universities in G city from April 10 to May 9, 2018. The research tools were used 27 items of Professor Trust Scale, 25 items of emotional regulation, 25 items of Connor-Davison Resilience Scale, and 18 items of psychological well-being scale. psychological well-being was significant different according to gender(p=.019), grade(p=.011), motivation of choosing a nursing(p=.003), major satisfaction(p<.001), stress of clinical practice(p=.002), and current health status(p<.001). There were significant positive correlations between psychological well-being and professor trust, active emotion regulation, support-seeking emotion regulation, and ego-resilience and negative correlation between psychological well-being and avoidant-distractive emotion regulation. The results of multiple regression analysis are as follows. Factors influencing the psychological well-being of nursing students were ego-resilience, support-seeking emotion regulation, avoidant-distractive emotion regulation, major satisfaction and these variables explained the psychological well-being by 55.0%(F=30.92, p<.001). It is necessary to develop a curriculum/comparative programs and student coaching plans for improving ego-resilience which is the most influential variable. Also internal or environmental and social support should be strengthened so that negative emotions caused by various causes can be efficiently managed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.12
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• pp.614-626
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• 2018

This study was conducted to review the literature and examine the factors related to problem behaviors among students of multicultural families in Korea. A systematic review of the literature was conducted using domestic documents retrieved through July 4, 2018 based on online searches of domestic databases (the Research Information Sharing Service, Korean Studies Information Service System and the National Diet Library). A total of 2,084 studies were searched, and 21 studies were used for analysis. The factors related to problem behaviors were related to individual factors (gender, school record, self-esteem, etc.), family factors (family type, parent support, mothers' enculturation stress, etc.) and environmental factors (friend support, teacher support, social support). The variables measured the problem behaviors among students of multicultural families were school life adjustment (10), psychological, social adjustment or maladjustment (4), and emotional problem behavior (3). Overall, the results indicate that social and policy efforts are needed to improve individual, family, and environmental factors based on more specific and consistent theoretical definitions related to problem behaviors among students of multicultural families in Korea.

• Journal of agricultural medicine and community health
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• v.45 no.4
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• pp.183-193
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• 2020

Objectives: As an ecological study, this study was performed to identify the community-level variation of health related quality-of-life (HRQOL), and to explore the factors that explain the variation, using 2017 Korean Community Health Survey (KCHS) data. Methods: Community health indicators of KCHS, which are correlated with the EQ-5D index of Si-gun-gu districts, were selected as independent variables. Multiple linear regression model was used to derive factors that explain regional variations in the EQ-5D index. Results: The EQ-5D index variation in 229 districts nationwide was 1.1 times for extremal quotient (EQ) and 1.0 for coefficient of variance (CV). The Si-gun-gu districts with the EQ-5D index in the lower 25% were more distributed in the province (27.7%) than in the metropolitan area (20.3%). As a result of multiple linear regression analysis, the depressed mood experience rate, perceived stress rate, suicide ideation rate, and physician diagnosed arthritis rate were derived as major factors of the variation. Conclusions: In order to reduce the gap in HRQOL between the districts, the priority of local health policies should be placed on the above factors including psychosocial factors.

• Journal of the Korea institute for structural maintenance and inspection
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• v.25 no.3
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• pp.77-84
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• 2021

In this study, flexural tests of prestressed high strength spun concrete (PHC) piles reinforced with infilled concrete and longitudinal rebars were conducted, where the longitudinal rebar ratio and the presence of sludge formed on the inner surface of PHC pile were set as key test variables. A total of six PHC pile specimens were manufactured, and their flexural behaviors including failure mode, crack pattern, longitudinal strain distribution in a section and end slip between external PHC pile and infilled concrete were measured and discussed in detail. The test results revealed that the flexural stiffness and strength increased as the longitudinal rebar ratio became larger, and that the sludge formed on the inner surface of PHC pile did not show any detrimental effect on the flexural performance. In addition to the experimental approach, this study presents a nonlinear flexural analysis model considering compatibility conditions and strain and stress distributions of the PHC piles and infilled concrete. The rationality of the nonlinear flexural analysis model was verified by comparing it with test results, and it appeared that the proposed model well evaluated the flexural behavior of PHC piles reinforced with infilled concrete and longitudinal rebars with a good accuracy.

• The Journal of the Korea Contents Association
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• v.21 no.3
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• pp.301-313
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• 2021

This study was conducted on 253 artists for a month from April 19, 2020 to study the influence and countermeasures of COVID-19. The analysis results are as follows. First, as a result of frequency analysis, the timing of the occurrence of COVID-19 and the period of the decrease in artist's artistic activities were consistent, and the subjective socioeconomic level perceived by the artist was degraded from COVID-19. Second, as a result of the multivariate variance analysis, the income level and employment environment of artists affected the variables associated with COVID-19. Third, as a result of the hierarchical analysis analysis, the income level and the socioeconomic level changes due to COVID-19, and concerns about COVID-19 infections, have been shown to have had a significant impact on the level of stress felt by artists. Fourth, as a result of qualitative research, the artist reported that he was experiencing economic and psychological difficulties due to the influence of COVID-19, and emphasized the need for policy support as a way to cope with them. We hope that the results of this study will be used as empirical data in the process of developing support systems and programs for artists experiencing economic constraints and social alienation due to COVID-19.

• Health Policy and Management
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• v.31 no.1
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• pp.74-90
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• 2021

Background: It is getting important to improve the oral health status of the elderly because oral health status may affect their health status of the whole body. In this respect, we aimed to explore the association of oral health status and behavior factors with self-rated health status by sex. Methods: Using the data from the 7th Korea National Health and Nutrition Examination Survey for health surveys and oral examinations (2016-2018), we analyzed a total of 3,070 people aged 65 or older (men: 1,329; women: 1,741). Our dependent variable, self-rated health status, was divided into two groups: not good (bad and very bad) and good (very good, good, and fair), whereas our independent variables of interest were oral health status and behavior factors. In addition to descriptive analysis and the Rao-Scott chi-square test, reflecting survey characteristics, we conducted hierarchical multivariable logistic regression analyses adjusted for socio-demographics and health status and behavior factors. All analyses were stratified by sex. Results: The proportion of people having 'not good' self-rated health was 36.5% in women but 24.5% in men. In a model adjusted for all covariates, the self-rated health status showed significant association with the self-rated oral health status. For example, in men, the risk of having 'not good' self-rated health was high in people having 'poor' (odds ratio [OR], 5.31; 95% confidence interval [CI], 2.34-12.03) self-rated oral health status and in those having 'fair' (OR, 4.03; 95% CI, 1.68-9.70) in comparison with those having 'good' self-rated oral health status. Dental status regarding speaking difficulty seemed to be very important in influencing self-rated health status. For instance, in women, compared to people having 'no discomfort' speaking difficulty, the risk of having 'not good' self-rated health was high in people having 'not bad' (OR, 1.60; 95% CI, 1.14-2.24) and 'discomfort' (OR, 1.79; 95% CI, 1.30-2.47) speaking difficulty. The covariates significantly associated with the risk of having 'not good' self-rated health were: physical activity, chronic disease, stress, and body mass index in both sexes; health insurance type and drinking only in men; and economic activity only in women. Conclusion: Oral health status and behavioral factors were associated with self-rated health status among the elderly, differently by sex. This suggests that public health policies toward better health in the elderly should take their oral health status and oral health behaviors into account in a sex-specific way.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.234-242
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• 2021

The purpose of this study was to examine the effectiveness of drama therapy in Korea by using method of meta-analysis. For the purpose of this study, master's theses, doctoral dissertations, and journal articles published in Korea up to June, 2021 were systematically reviewed. As a result, a total of 18 studies were eligible for the inclusion criteria. The mean effect sizes and test for homogeneity of effect size(Q-statistic) were analyzed by using Comprehensive Meta-Analysis Software 2.0. The main findings of the study were as follows. First, the average effect sizes for drama therapy were ES=1.325 of self-esteem, ES= -1.230 of depression and anxiety, ES= 1.025 of stress, ES=1.018 of sociability, Es=0.907 of emotional intelligence, ES= 0.897 of psychological wellbeing. Second, by analysing the moderate variables of the effect size for drama therapy, 'adult', 'the number of session' 'performance based drama therapy' of self esteem were statistically significant. Based on this study results, the drama therapy research and practice implications in Korea were discussed.

• The Journal of the Korea Contents Association
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• v.21 no.11
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• pp.609-625
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• 2021

It has now been more than a year since the start of the COVID-19 pandemic in Korea, which has claimed thousands of lives and changed every aspect of life. The corona pandemic not only caused physical damages but also psychological one which is a collective social stress phenomenon often termed as 'corona blue'. The purpose of this study is to examine how empathy affects anxiety and depression through risk perception and indirect trauma, which are psychological variables related to the corona pandemic as a disaster. The survey data from 214 people were analyzed with a structural equation modelling. The results shows that 53.3 % of the participants experienced anxiety and 35.7% suffered from depression, which were about 6 times higher than ones from the 2019 government data. Affective empathy had a significant effect on risk perception, and cognitive empathy had a significant effect on indirect trauma. Risk perception and indirect trauma both had a significant effect on anxiety, and anxiety had a significant impact on depression. Only cognitive empathy had a significant indirect effect on anxiety and depression. This study provides an important insight into understanding a social phenomenon of 'corona blue' from a empathic perspective.