• Journal of Digital Convergence
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• v.16 no.3
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• pp.321-331
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• 2018

The purpose of this study is to examine the effect of job stress on psychological burnout of childcare teachers and the mediating effect of self-esteem between two variables. For the study, the data collected from 520 teachers working in day-care centers in Seoul, Gyeonggi and Incheon areas were analyzed by utilizing the path analysis model. The results are as follows. First, job stress of childcare teachers had a positive effect on their psychological burnout, but it had a negative effect on their self-esteem. Second, self-esteem of childcare teachers influenced negatively their psychological burnout. Third, job stress of childcare teachers directly affected psychological burnout and its effect was indirectly mediated by their self-esteem. On the basis of the findings, the need to reduce job stress and psychological burnout and to enhance self-esteem was suggested.

• Journal of the Korean Geotechnical Society
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• v.22 no.10
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• pp.151-163
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• 2006

This paper presents the interrelationship between undrained static and cyclic shear behavior. Laboratory works were performed through the undralned static and cyclic triaxial test using Nak-Dong River sand. And static triaxial test involved the triaxial extension test for comparison with cyclic shear behavior Cyclic triaxial test was performed with a variety of combination conditions of initial static shear stress $(q_{st})$ and cyclic stress $(q_{cy})$. In this result, the stress path of cyclic shear behavior was correspondent with static shear behavior passing the critical stress ratio (CSR) line because of the development of flow deformation. After that, a failure occurred according to failure line (FL) of static shear behavior. The stress path of cyclic shear behavior showed essentially the same with static shear behavior, although it appears a little different in test method.

• Proceedings of the Korean Geotechical Society Conference
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• 1996.10a
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• pp.257-266
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• 1996

• Journal of the Korean Society of Safety
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• v.21 no.4 s.76
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• pp.19-24
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• 2006

Fatigue crack propagation tests for the brake disc cast iron were conducted for investigating fatigue crack propagation rate(da/dN), crack propagation path and fracture toughness($K_c$) of the material. The threshold stress intensity factor range, ${\Delta}K_{th}$, was found to be about $6MPa{\sqrt{m}}$ at the stress ratio of R = 0.1. Also, fracture toughness value was determined to be $24.7MPa{\sqrt{m}}$. Irregular fatigue fracture surfaces were observed, indicating that fatigue crack growth occurred at the interface between randomly scattered flak graphite and ferrite, where the interfacial strength was relatively weak.

• Korean Journal of Human Ecology
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• v.22 no.3
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• pp.405-420
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• 2013

The purpose of this study was to find pathways among factors that distinguish the mothers' intention to have a second child. As for factors affecting the childbirth intention of mothers, this study aimed to explore pathways from fathers' participation in childrearing to intention of second childbirth as mediating variables, maternal parenting stress and marital satisfaction. This study used the third wave data of the Panel Study of Korean Children (PSKC) that is a national-representative birth-cohort study. Among the 1,802 participants of the PSKC, 717 mothers who have a husband/partner and only one child have responded a decided intention of second childbirth. SPSS 19.0 and Amos 19.0 were used to implement exploratory analyses of predictors and test path models. Results showed that the hypothetical model assuming a path from paternal involvement in childrearing to mothers' intention of second childbirth, mediated by maternal parenting stress and marital satisfaction fitted the data of working mothers and non-working mothers well. The results suggest policies focusing on internal characteristics of mothers and dynamics in the family.

• Journal of the Society of Naval Architects of Korea
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• v.35 no.1
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• pp.61-71
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• 1998

This paper describes a dynamic fracture behaviors of structural elements under elastic or elasto-plastic stress waves in two dimensional space. The governing equation of this problem has the type of hyperbolic partial differential equation, which consists of the equation of motions and incremental elasto-plastic constitutive equations. To solve this problem we introduce Zwas' method which is based on the finite difference method. Additionally, in order to deal with the dynamic behavior of elasto-plastic problems, an elasto-plastic loading path in the stress space is proposed to model the plastic yield phenomenon. Based on the result of this computation, the dynamic stress intensity factor at the crack tip of an elastic material is calculated, and the time history of a plastic zone of a elasto-plastic material is to be shown.

• Advances in materials Research
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• v.6 no.3
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• pp.233-243
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• 2017

This paper describes an investigation on the effect of using three different filler metals on fatigue behavior of mechanical structures welded. The welding is carried out on the steel A510AP used for the manufacture of gas cisterns and pipes. The welding process used is manual welding with coated electrodes and automatic arc welding. Compact tension CT50 specimen has been used. The three zones of welded joint; filler metal FM, heat affected zone HAZ and base metal BM have been investigated. The results show that the crack growth rate CGR is decreasing respectively in BM, FM and HAZ; however, this variation decreases when stress intensity factor SIF increases. For low values of SIF, the CGR is inferior in the over-matched filler metal of which the value of mismatch M is near unity, but for high values of M the CGR is superior, and the effect of the over-matching on CGR becomes negative. No deviation of the crack growth path has been noticed.

• International Journal of Advanced Culture Technology
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• v.8 no.1
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• pp.98-106
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• 2020

In this paper, we show the career path of college students from the perspective of positive psychology. Specifically we conducted the study to investigate a role of grit in the relationship between college students' occupational calling and academic achievement and career stress. 151 college students participated in this study and they completed the Korean version of the Calling and Vocational Questionnaire, Grit Scale, and Career Stress Scale. To assess their academic achievement, participants agreed to obtain their GPA from online system. The results of this study showed that occupational calling had a positive correlation with academic achievement and negatively correlated with career stress. In addition, it was confirmed that grit mediated the relationship between calling and academic achievement and career stress. Based on these results, the positive effects of occupational calling of college students, implications of this study, and suggestions for future research are discussed.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.390-395
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• 2008

This study is performed to understand three dimensional characteristics of weld residual stress for the surface weld on the stainless steel plate. AISI 304 plate with one path weld on the surface was used as a test specimen. Finite element analysis was done to analyze thermal transient and residual stress due to weld. The result of finite element analysis was validated by previous paper and measurement data. Among various techniques for residual stress measurement, instrumented ball indentation method was applied. The calculated residual stresses by finite element analysis showed good agreement with the measured results.

• Journal of Korean Association for Spatial Structures
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• v.9 no.2
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• pp.45-52
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• 2009

This paper experimentally evaluates the strength characteristics of precast column-R.C. foundation anchor joint subjected to the cyclic horizontal load. The study presents differences in accurate stress transfer path and destruction mechanism between the concrete structural body applying the precast column-R.C. foundation anchor joint and the concrete structural body applying the steel joint. the result from width load experiment on reinforcing steel under the cyclic horizontal load provides the necessary minimum insertion length to construct the precast column-R.C. foundation anchor joint. This study also presents the accurate stress transfer path and destruction mechanism on the anchor joint th meet the customer's requirements, comparing stress transfer path and destruction mechanism provided by the experiment and those provided by the product manual. Eventually, this study presents all the necessary fundamental data to provide the construction design with accurate number of reinforcing steel, diameter of the steel, fixation length of the steel, etc. to build the optimum precast concrete column.