• Computers and Concrete
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• v.31 no.1
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• pp.9-21
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• 2023

The published studies usually used analytical method, numerical methods or experimental method to determine the stress-strain state and displacement of the single-layer or multi-layer curved shell types, but with a small scale model. However, a full scale multi-layer doubly curved concrete shell roof model should be researched. This paper presents the results of the experiment and simulation analysis involving stress-strain state, sliding between layers, the formation and development of the full scale double-layer doubly curved concrete shell roof when this shell begins to crack. The results of the this study have constructed the load-sliding strain relationship; strain diagram; stress diagram in the shell layers; the N_x, N_y membrane force diagram and deflection of shell. Thisresults by experimental method on a full scale model of concrete have clarified the working of multi-layer doubly curved concrete shell roof. The experimental and simulation results are compared with each other and compared with the Sap2000 software.

• Corrosion Science and Technology
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• v.3 no.3
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• pp.87-97
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• 2004

This paper presents a new approach with meso scale structure models to express mechanical property, such as stress - strain relationships, of concrete. This approach is successful to represent both uniaxial tension and uniaxial compression stress - strain relationship, which is in macro scale. The meso scale approach is also applied to predict degraded mechanical properties of frost-damaged concrete. The degradation of mechanical properties with frost-damaged concrete was carefully observed. Strength and stiffness in both tension and compression decrease with freezing and thawing cycles (FTC), while stress-free crack opening in tension softening increases. First attempt shows that the numerical simulation can express the experimentally observed degradation by introducing changes in the meso scale structure in concrete, which are assumed based on observed damages in the concrete subjected to FTC. At the end applicability of the meso scale approach to prediction of the degradation by combined effects of salt attack and FTC is discussed. It is shown that clarification of effects of frost damage in concrete on corrosion progress and on crack development in the damaged cover concrete due to corrosion is one of the issues for which the meso scale approach is useful.

• Journal of the Korean Society of Safety
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• v.30 no.1
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• pp.72-78
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• 2015

According to the report of the WHO, workers have been exposed to much job strain such as job load, responsibility, role, interpersonal conflict etc. In Korea, studies on job strain started to become active from 1990s and now hundreds of studies are actively under going or publishing so that the studies are contributing to development and improvement of job strain. Representative measurement models of job strain are Job Strain Model of Karasek, Job Stress Model of NOISH, Korea Occupational Stress Scale, JSQ(Job Stress Questionnaire), K-OSI(Korea Version of Occupational Stress Inventory) etc. (Lee Kwan-Suk, 2012 ; KOSHA, 2003). Among them, Job Strain Model of Karasek had been loved by many researchers of job strain before Korea Occupational Stress Scale was developed. Job Strain Model of Karasek had been fitted to Korean style and then, used to analyze job strain of Korean people so that this Scale highly contributed to seeking relationship with cardiovascular disease, musculoskeletal disease caused by job, smoking, drug, alcohol poisoning, and pulse(Lee Kwan-Suk, 2012). But as this Model was studied and developed based on foreign culture and life pattern, a model fit to Korea was developed to measure job strain for Korean people, which is Korea Occupational Stress Scale now most frequently used in measuring job strain. Accordingly, after this study made questionnaire survey about same population using the two methods used most frequently in measuring job strain, the study investigated what features appeared, what correlations appear between two models, and comparatively analyzed characteristics each independent and dependent variable. Based on this, the study aimed to exactly express job strain of Korean people. The subjects of the study were a population of 233, and Karasek's Questionnaire and KOSS's Questionnaire were surveyed at the same time. The results were analyzed by statistical program to obtain significant difference between two models. Four particular groups were divided with Job Strain Model of Karasek and the four particular groups were measured with Korea Occupational Stress Scale. And job strain come from combination of two models was measured, with which new comparative analysis method was suggested.

• Korean Journal of Human Ecology
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• v.16 no.5
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• pp.933-944
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• 2007

The relationships of parenting beliefs, parental satisfaction, and child rearing stress were examined in a sample 400 parents who have 3-7 aged children. Parents completed three kinds of questionnaires such as parenting beliefs scale, parental satisfaction scale, and child rearing stress scale. Data analysis was by mean, percentile, t-test, oneway-ANOVA, pearson correlation, and multiple regression. The major findings of this study were as follow; First there was a significant difference between parenting beliefs and child rearing stress. Second, there was a significant difference between parental satisfaction and child rearing stress. Third, conflict of parental role in parental satisfaction and problem solving in parent beliefs was the most predicting variables in child rearing stress.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.2
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• pp.259-266
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• 2010

Purpose: The purpose of this study was to investigate self-esteem, family function, and social support which might influence stress in college students. Method: Data were collected from October 15 to December 20, 2007 when 411 students completed a questionnaire which included Self-esteem scale, Family APGAR questionnaire, Multidimensional Scale of Perceived Social Support and Global Assessment of Recent Stress scale. The collected data was analyzed with the SPSS Win 14.0 statistics program. Results: The scores for stress showed significantly negative correlations with the scores for self-esteem (r= -.394, p<.001), family function (r= -.215, p<.001), and social support (r= -.249, p<.001). Self-esteem, family function and social support by friends were significant predictors and accounted for 18.5% of the variance in stress in undergraduate students. Conclusion: Future stress management programs for undergraduate students should be developed to reinforce self-esteem, family function and social support by friends.

• Research in Community and Public Health Nursing
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• v.18 no.3
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• pp.452-459
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• 2007

Purpose: The purpose of this study was to examine stress and social support according to Internet addiction in juveniles. Method: Subjects were middle and high school students in Daegu (N=492). Data were collected using a self-rating questionnaire including demographic data, which was the Korean versions of an Internet addiction scale, a stress scale and a social support scale. Results: Stress and social support were significantly different according to Internet addition. Significant correlations were observed between Internet addiction and stress and between Internet addiction and social support. Conclusion: These results indicate that the more addictive to the Internet a student is, the more stress and the less social support he/she has. Therefore, further studies are needed to generalize these results and examine widely the effects of Internet addiction.

• Journal of Korean Public Health Nursing
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• v.24 no.2
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• pp.197-210
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• 2010

Purpose: The study investigated the relationships among perceived stress, mental health, and social support in community residents. Method: A self-reporting questionnaire was completed by 302 community residents aged 19-64-years-of-age from October 7 to November 30, 2008. Assessment tools were an The established perceived stress scale, standardized mental health scale, and established social support scale. The data was analyzed by descriptive statistics, t-test, one-way ANOVA, Scheffe's test, and Pearson's correlation coefficient using the SPSS WIN 12.0 program. Result: Significantly negative correlations were evident between perceived stress and social support, and between social support and mental health. But, there was a significantly positive correlation between perceived stress and mental health. Conclusion: It is necessary to develop a strategy to decrease perceived stress, improve mental health, and increase social support for community residents.

• Korean Journal of Social Welfare
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• v.63 no.2
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• pp.319-336
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• 2011

There is recent recognition that the approach toward family members is crucial for understanding problems in multi-cultural families by emerging from typical approach focused on migrant women. While researches have reported serious conflicts and adaptation problems from cultural difference between parent-in-law and foreign daughter-in-law, cultural stress of parent-in-law has not been systematically examined. The purpose of this study was to develop and validate a scale to measure acculturation stress of parent-in-law who have a foreign daughter-in-law. The sample consisted of 266 parents-in-law from three provinces of South Korea. Initially, 16 items were generated based on the existing scale of acculturation stress and they are tested by item-analysis through the descriptive and correlational analysis. An exploratory factor analysis was conducted to investigate the factor structure of the scale and a confirmatory factor analysis was used to validate the scale. By item-analysis, five items were deleted from initial scale items because of redundancy. Findings from an exploratory factor analysis provided the evidence that the scale consists of three factors which are the perception of prejudice and discrimination, conflicts from different cultural value, and daily discomfort. Cronbach's ${\alpha}$ for the scale is 0.86. Multiple fit indices from confirmatory factor analysis indicated that the hypothesized three-factor model for acculturation stress achieved a good fit with the data. Results showed the evidence for the reliability and validity of the scale for acculturation stress of the parent-in-law who have foreign daughter-in-law. The scale would have potential effects for assessing psychological stress for parent-in-law in research and clinical practice. Further implications and limitation of the study and suggestions for future studies were discussed.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.1
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• pp.41-48
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• 2024

Purpose : This study aims to understand the effects of job-seeking stress on depression and self-esteem in college students majoring in health science. Methods : In this study, in order to measure college students' employment stress, depression, self-esteem, and social support, a measurement tool was used by modifying and supplementing the questionnaire to suit the purpose and method of this study. The subjects, 210 students (46 men and 164 women) enrolled in colleges located in Busan, had their scores on the Beck depression inventory (BDI), job-seeking stress scale, and self-esteem scale measured. Results : There was a positive correlation between all sub-variables of employment stress, and a negative correlation between employment stress and self-esteem. Additionally, a positive correlation was found between employment stress and depression, and a negative correlation was found between self-esteem and depression. The result taken from the job-stress scale showed that women experienced an overall higher level of stress than men while seeking jobs. Furthermore, in terms of the BDI, men exhibited a higher level of depression than women when subjected to job-seeking stress. Finally, the results from the self-esteem scale reveal that men exhibited less self-esteem than women. Conclusion : A comprehensive review of the study's findings suggested that women had greater job-seeking stress than men. Additionally, it found that, for men, job-seeking stress had a greater impact on depression levels and self-esteem. These results suggest that a higher level of job-seeking stress may lead to higher levels of depression and lower levels of self-esteem. It will be useful to conduct follow-up research by operating self-esteem and depression programs.

• Transactions of Materials Processing
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• v.33 no.3
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• pp.200-207
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• 2024

In this study, we developed a semi-analytical approach for the numerical analysis of residual stress in oxide scales formed on hot-rolled steels. The oxide scale, formed during the hot rolling process, experiences complex interactions due to thermal and mechanical influences, significantly affecting the material's integrity and performance. Our research focuses on integrating various stress components such as thermal stress, growth stress, and creep behavior to predict the residual stress within the oxide layer. The semi-analytical method combines analytical expressions for each stress component with numerical integration to account for their cumulative effects. Validation through instrumented indentation tests confirms the reliability of our model, which considers thermal expansion coefficient (CTE) differences, scale growth, and creep-induced stress relaxation. Our findings indicate that thermal stress resulting from CTE differences significantly impacts the overall residual stress, with growth stress contributing a compressive component during cooling, and creep behavior playing a minor role in stress relaxation. This comprehensive approach enhances the accuracy of residual stress prediction, facilitating the optimization of material design and processing conditions for hot-rolled steel products.