• Journal of Preventive Medicine and Public Health
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• v.52 no.5
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• pp.299-307
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• 2019

Objectives: While occupational stress has long been a central focus of psychological research, few studies have investigated how immigrant microbusiness owners (MBOs) respond to their unusually demanding occupation, or how their unresolved occupational stress manifests in psychological distress. Based on the job demands-resources model, this study compared MBOs to employees with regard to the relationships among emotional demands, job resources, and depressive symptoms. Methods: Data were derived from a cross-sectional survey of 1288 Korean immigrant workers (MBOs, professionals, office workers, and manual workers) aged 30 to 70, living in Toronto and surrounding areas. Face-to-face interviews were conducted between March 2013 and November 2013. Results: Among the four occupational groups, MBOs appeared to endure the greatest level of emotional demands, while reporting relatively lower levels of job satisfaction and job security; but MBOs reported the greatest job autonomy. The effect of emotional demands on depressive symptoms was greater for MBOs than for professionals. However, an inspection of stress-resource interactions indicated that though MBOs enjoyed the greatest autonomy, the protective effects of job satisfaction and security on the psychological risk of emotional demands appeared to be more pronounced for MBOs than for any of the employee groups. Conclusions: One in two Korean immigrants choose self-employment, most typically in family-owned microbusinesses that involve emotionally taxing dealings with clients and suppliers. However, the benefits of job satisfaction and security may protect MBOs from the adverse mental health effects of job stress.

• International journal of advanced smart convergence
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• v.8 no.3
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• pp.151-160
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• 2019

Korea has the highest suicide rate among the OECD countries, and the suicide rate is highest among young adults in their 20s, most of whom are university students. Therefore, suicide among Korean university students is a public health issue that is of interest to us. The purpose of this study is to investigate the factors affecting the suicidal ideation of university students in Korea, and to use them as a basis to establish effective intervention for university suicide prevention through it. This was a cross-sectional descriptive study using convenience sampling method. The participants were 344 university students at universities in S and G cities. Data were collected with a structured questionnaire and analyzed using descriptive analysis, t-test, ANOVA, Pearson correlation coefficients, and hierarchical regression analysis using with the SPSS/Win 23.0 program. There was a significant correlation between depression (r=.45, p<.001), drinking alcohol (r=.14, p=.008), social support (r=-.26, p<.001), quality of life (r=-.46, p<.001), and suicidal ideation. In the first step of hierarchical regression analysis, satisfaction of school life (${\beta}=.198$, p<.001) was the significant factor influencing the suicidal ideation. Explanatory power was 25.2%. In the second step of the hierarchical regression analysis, absence of parents (${\beta}=-.095$, p=.044), depression (${\beta}=.247$, p<.001), quality of life (${\beta}=-.280$, p<.001), and explanatory power were increased to 42.0%. The results of the study indicate the need to actively identify the group of university students in their 20s with high risk of suicide through continuous evaluation of depression, and to improve the quality of life as a method of preventing suicide. In addition, the effect of absence of parents on the suicidal ideation among Korean university students suggests that parental support may play an important role in suicide prevention.

• Journal of Korean Academy of Nursing
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• v.49 no.4
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• pp.411-422
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• 2019

Purpose: The purpose of this study was to adapt, modify, and validate the Nursing Anxiety and Self-Confidence with Clinical Decision-Making Scale ($NASC-CDM^{(c)}$) for Korean nursing students. Methods: Participants were 183 nursing students with clinical practice experience in two nursing colleges. The construct validity and reliability of the final Korean version of the $NASC-CDM^{(c)}$ were examined using exploratory and confirmatory factor analyses and testing of internal consistency reliability. For adaptation and modification, the instrument was translated from English to Korean. Expert review and a cross-sectional survey were used to test the instrument's validity. Results: The Korean version of the $NASC-CDM^{(c)}$ (KNASC-CDM) was composed of 23 items divided into four dimensions: (i) Listening fully and using resources to gather information; (ii) Using information to see the big picture; (iii) Knowing and acting; and (iv) Seeking information from clinical instructors. The instrument explained 60.1% of the total variance for self-confidence and 63.1% of the variance for anxiety; Cronbach's ${\alpha}$ was .93 for self-confidence and .95 for anxiety. Conclusion: The KNASC-CDM can be used to identify anxiety and self-confidence in nursing students' clinical decision-making in Korea. However, further research should be done to test this instrument, as it is classified differently from the original $NASC-CDM^{(c)}$ version.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.47 no.9
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• pp.642-648
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• 2019

In this study, Image-based computational analysis using the developed models was performed to predict the degradation of effective properties by ablation. The ablation tests of carbon/phenolic composites were performed using a 0.4 MW arc-heated wind tunnel. The carbon/phenolic composite samples were scanned using the micro-computed tomography (Micro-CT) to analyze the ablation characteristics according to a duration time of the ablation test. By calibrating the scanned images, computational models were developed that reflect the actual microstructure of the ablation composites. Also, nine computational models that reflect the actual pore shape were developed using the created cross-sectional images. Image-based computational analysis using the developed models was performed to predict the degradation of effective properties by ablation and the decrease of effective properties was confirmed with increase of porosity.

• Composites Research
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• v.32 no.4
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• pp.191-198
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• 2019

The basic mechanical properties of helicopter rotor blade are important parameters for the analysis of helicopter performance. However, it is difficult to estimate these properties because the most of rotor blades consist of various materials such as composite materials and metals, etc. In this paper, the bending/torsional stiffness for composite rotor blade of unmanned helicopter were evaluated through experimental and analytical studies. In finite element analysis, the bending/torsional stiffness were evaluated through the relationship of load-displacement and element stiffness matrix. The evaluated stiffness from the measured strains and displacements in bending and torsional test agreed well with the derived results of FEA.

• The Journal of Korean Society for School & Community Health Education
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• v.20 no.2
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• pp.37-51
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• 2019

Purpose: This study aims to substantiate a correlation between the period of living alone in a shabby one-room and a depression experience. Methods: We conducted a cross-sectional study using data from the Korea Homeless Survey carried out by the Korea Institute for Health and Social Affairs in 2016. In the study, the data included 485 survey participants who resided in a single room. The period of single-room occupancy being divided into three groups: less than 1 year, 1 to 4 years, and more than 5 years was considered a primary independent variable. The outcome variable which represented a depression experience was measured by CESD-11(The Center for Epidemiological Studies-Depression Scale). We carried out a Chi-square test and multiple logistic regression to evaluate the association. Results: The rate of depression experienced in this population was 77.5%. Almost 83.9% of the participants were reported as being unable to receive the mental health counselling in the last 12 months. After controlling for covariates, subjects who were living in a single room occupancy for 1-5 years(OR=3.89; 95% CI=1.43-10.56) and more than 5 years(OR=2.71; 95% CI= 1.05-6.95) were found to be more likely to experience depression. Conclusions: The results showed that living alone in a shabby one-room had a high correlation with experiencing depression. We proposed that there is a need to develop a new strategy for mental health promotion program for the poor, vulnerable and deprived population.

• Journal of Oral Medicine and Pain
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• v.44 no.3
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• pp.92-102
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• 2019

Purpose: To investigate the masticatory function of patients with different temporomandibular disorders (TMD) phenotypes, and to explore the risk factors for the masticatory function of TMD patients among multiple biopsychosocial variables using patient-reported outcomes (PROs). Methods: Clinical features and TMD diagnoses of 250 cases were investigated by reviewing medical records. Psychosocial factors were evaluated using four questionnaires representing pain severity and pain interference (Brief Pain Inventory), pain catastrophizing (Pain Catastrophizing Scale, PCS), psychological distress (Symptom Check List-90-Revised, SCL-90R) and kinesiophobia (Tampa Scale for Kinesiophobia for Temporomandibular Disorders, TSK-TMD). Masticatory function, as a dependent variable, was determined using the Jaw Functional Limitation Scale (JFLS). Kruskal-Wallis test and Spearman's rank correlation were used for analyses. Results: A total of 145 cases were included and classified into four subgroups including group 1: TMD with internal derangement without pain (n=14), group 2: TMD with muscle pain (n=32), group 3: TMD with joint pain (n=60) and group 4: TMD with muscle-joint combined pain (n=39). Pain severity (p=0.001) and interference (p=0.022) were the highest in group 2, but the mean global score of JFLS was the highest in group 3, followed by group 4, group 2, and group 1 (p=0.013). Pain severity, pain interference, the mean global score of PCS and the mean global score of TSK-TMD showed significant and moderate correlation with the mean global score of JFLS. All subdimensions and the global severity index of SCL-90R had significant, but weak correlations with all scores of JFLS. Conclusions: The results suggest that masticatory functional limitation depends on the TMD phenotypes. Among the various PROs, pain perception, pain catastrophizing and kinesiophobia seem to be more influential risk factors on jaw function than psychological distress, such as depression and anxiety.

• Clinical and Experimental Pediatrics
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• v.62 no.6
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• pp.240-243
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• 2019

Purpose: Coronary arterial lesion assessment in children can be difficult, depending on the coronary dominance pattern. Although it is easier to determine coronary dominance with echocardiography in children than in adults, it is still difficult. This study aimed to examine the coronary dominance pattern according to the objective coronary artery (CA) indices. Methods: The CA diameter, aortic valve annulus, and abdominal aorta of 69 children without any cardiovascular disease were measured with cross-sectional echocardiography at Chungnam National University Hospital. To evaluate the coronary dominance pattern, echocardiography was primarily used; additionally, coronary computed tomographic angiography or coronary angiography (CAG). Coronary dominance was determined according to the status of the CA that gives rise to the posterior descending artery. Results: The mean age was $4.02{\pm}2.78years$, and the mean body surface area (BSA) was $0.70{\pm}0.22m^2$. Right dominance was present in 78% and left in 22% of the subjects. In those with left dominance, the CA to aortic valve annulus diameter ratio was $0.125{\pm}0.021$ in the right coronary artery (RCA) and $0.255{\pm}0.032$ in the left coronary artery (LCA). In those with right dominance, the corresponding ratio was $0.168{\pm}0.028$ in the RCA and $0.216{\pm}0.030$ in the LCA (P<0.05). Significant differences were also found in the diametric ratios of the CA to BSA and abdominal aorta (P<0.05). Conclusion: The CA indices showed significant difference according to the coronary dominance pattern in early childhood. It is possible to indirectly determine the coronary dominance pattern with the CA indices in children using echocardiography. The accuracy of coronary artery lesion diagnosis can be improved by taking coronary dominance into account.

• Clinical and Experimental Pediatrics
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• v.62 no.8
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• pp.317-323
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• 2019

Purpose: Investigating the prevalence of hyperuricemia and its association with metabolic syndrome (MetS) and cardiometabolic risk factors (CMRFs) in Korean children and adolescents. Methods: This cross-sectional survey used data from the 7th Korea National Health and Nutrition Examination Survey (2016-2017); 1,256 males and females aged 10-18 years were included. Hyperuricemia was defined as serum uric acid levels were >6.6 mg/dL at 10-11 years of age (both sexes), >7.7 mg/dL for males at 12-18 years of age and >5.7 mg/dL for females at 12-18 years of age. MetS was defined by the International Diabetes Federation criteria. Logistic regression analysis was used to analyze hyperuricemia-associated risk factors. Results: The prevalence of hyperuricemia was 9.4% (male, 8.4%; female, 10.5%) (P<0.281). After adjusting for sociodemographic factors and health behaviors in multivariate analysis (model 1), the odds ratio (OR) for hyperuricemia of MetS was 3.05 (95% confidence interval [CI], 1.17-7.92; P=0.022). After adjusting for the same variables in model 1 plus obesity and all MetS components (model 2), only abdominal obesity was significant, and the OR for hyperuricemia was 3.38 (95% CI, 1.72-6.63; P<0.001) After adjusting for the same variables in model 1 plus body mass index (BMI) z scores and all MetS components except abdominal obesity (model 3), only BMI z scores was significant, and the OR for hyperuricemia was 1.59 (95% CI, 1.34-1.89; P<0.001). Conclusion: MetS, abdominal obesity, and BMI z scores were CMRFs significantly associated with hyperuricemia in Korean children and adolescents. Therefore, attention should be paid to hyperuricemia in patients with obesity or MetS.

• Clinical and Experimental Pediatrics
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• v.62 no.7
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• pp.261-268
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• 2019

Purpose: This study aimed to evaluate the time trends of waist circumference (WC) and waist-height ratio (WHR), and to present WC and WHR distributions with optimal WHR cutoff for abdominal obesity in Korean children and adolescents. Methods: We performed a retrospective cross-sectional analysis of data from 13,257 children and adolescents (6,987 boys and 6,270 girls) aged 6-18 years who were included in the third to sixth Korea National Health and Nutrition Examination Survey (KNHANES, 2005-2015). Linear regression analyses were used to identify secular changes in WC and WHR by age, sex, and KNHANES waves. A receiver operating characteristic curve analysis was used to determine the optimal WHR cutoff values for abdominal obesity and cardiometabolic risk factors. Results: The mean WC and WHR distributions from 2005 to 2015 showed no significant secular changes between the KNHANES 4 waves (P for trend ${\geq}0.05$ in all ages and both sexes). The mean WCs in the present study were lower than those in the 2007 Korean National Growth Charts. The mean WHR at ages <13 years was statistically higher in the boys than in the girls, but did not significantly differ between the sexes among those aged 13 to 18 years. The optimal WHR cutoff for abdominal obesity was 0.48 (area under the curve, 0.985; 95% confidence interval, 0.985-0.985) in the 13- to 18-year-old adolescents. Conclusion: WC and WHR showed no secular changes over 10 years. The optimal WHR cutoff for abdominal obesity of 0.48 is useful for diagnosing and managing obesity and thus preventing obesity-related cardiometabolic complications in 13- to 18-year-old Korean adolescents.