• Journal of Korean Academy of Fundamentals of Nursing
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• v.3 no.2
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• pp.183-199
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• 1996

The Purpose of this study is to develop and test a nursing model which can be applied to prediction of the quality of life for the patient receiving hemodialysis. A hypothetical model was constructed on Johns & Meleis's empowerment model framework which has 3 contsructs(stress, resource, empowerment). 6 Factors(perceived stress, self-esteem as personal resource, perceived social support as social resource, perceived fertigue, perceived health status & self efficacy as empowerment) were selected to pre dict the quality of life of receiving hemodialysis patients. 4 Factors(self-esteem, perceived social support, perceived health status & self efficacy) had direct effects on the quality of life significantly. Self-esteem had indirect effect on the quality of life via perceived heath status significantly. Perceived social support had indirect effect on the quality of life via self-effcacy significantly. Perceived stress had no direct and indirect effect on the quality of life significantly. Revised model from hypothetical model showed better fit to the data by eliminating unsignificant path. From results of this study we suggest that to improve quality of life of hemodialysis patient nurses provide nursing interventions which improve self-esteem, perceived social support, self-efficacy & perceived health status.

• Journal of Welding and Joining
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• v.21 no.6
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• pp.77-83
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• 2003

The finite element analysis was performed for the cracks existing in residual stress fields in order to investigate the effects of configuration of residual stress distribution to the fatigue crack opening behaviour. And the variation of stress distributions adjacent to the crack caused by uploading was examined. The finite element model with contact elements for the crack plane and plane stress elements for the base material and the analytical method based on the superposition principle to estimate crack opening behaviour and the stress distribution adjacent to the crack subjected to uploading were used. The results of the analysis showed that crack opening behaviors and variations of stress distribution caused by uploading were changed depending on the configuration of residual stress distribution. When the crack existed in the region of compressive residual stress and the configuration of compressive residual stress distribution were inclined, a partial crack opening just behind of a crack tip occurred during uploading. Based on the above results, it was clarified that the crack opening behaviour in the residual stress field could be predicted accurately by the finite element analysis using these analytical method and model.

• Journal of Welding and Joining
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• v.21 no.6
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• pp.71-76
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• 2003

For the purpose of clarifying the influence of welding residual stress to the fatigue crack propagations behaviour, an analytical investigation based on finite element method is performed to examine the opening behaviour of tip-closed crack in the compressive residual stress. A finite element model comprised of contact elements for the crack plane and plane stress elements for the base material is used to evaluate crack opening stress of the crack existing in the residual stress field. Also an analytical method based on the superposition principle to estimate the length of opened part of tip closed crack and the stress distribution adjacent to the crack during uploading is applied to the finite element model. The software for the analysis is ABAQUS, which is a general purpose finite element package. The results show that stresses distributed on the crack surfaces are reduced and approached to zero as the applied stresses are increased up to crack tip opening stress and no mechanical discontinuity is found at the boundary of contact elements and plane stress elements. It is verified that the opening behavior of the fatigue crack in the residual stress can be predicted by finite element method with the proposed analytical method.

• Nuclear Engineering and Technology
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• v.51 no.4
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• pp.1060-1068
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• 2019

This work aims to establish a model of a primary water stress corrosion crack growth rate of Alloy 690 material for the head penetration nozzles of Korean pressurized water reactors. The test material had an inhomogeneous microstructure with bands of fine-grains and intragranular carbides in the matrix of coarse-grains, which was similar to the archive materials of the head penetration nozzles. The crack growth rate was measured from the strain-hardened materials as a function of the stress intensity factor in simulated primary water at various temperatures and dissolved hydrogen contents. The effects of strain-hardening, temperature, and dissolved hydrogen on the crack growth rate were analyzed independently, and were then introduced as normalizing factors in the crack growth rate model. The crack growth rate model proposed in this work provides a key element of the tools needed to assess the progress of a stress corrosion crack when detected in thick-wall Alloy 690 components in Korean reactors.

• 한국전산유체공학회:학술대회논문집
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• 1999.05a
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• pp.192-198
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• 1999

The present study proposes modified temperature-dependent non-Newtonian viscosity model and investigates flow characters and heat transfer enhancement of the viscoelastic non-Newtonian fluid in a 2:1 rectangular duct. The proposed modified temperature dependent viscosity model has non-zero value near the high temperature and high shear rate region while on the existing viscosity models have zero value. Two versions of thermal boundary conditions involving difference combination of heated walls and adiabatic walls are analyzed in this study. The combined effect of temperature dependent viscosity, buoyancy, and secondary flow caused by second normal stress difference are ail considered. The Reiner-Rivlin model is adopted as a viscoelastic fluid model to simulate the secondary flow caused by second normal stress difference. Calculated Nusselt numbers by the modified temperature-dependent viscosity model gives under prediction than the existing temperature-dependent viscosity model in the regions of thermally developed with same secondary normal stress difference coefficients with experimental results in the regions of thermally developed. The heat transfer enhancement of the viscoelastic fluid in a 2:1 rectangular duct is highly dependent on the secondary flow caused by the magnitude of second normal stress difference.

• Journal of Korean Academy of Nursing
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• v.24 no.4
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• pp.666-677
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• 1994

In comparison with the long and continuous his-tory of research in the general area of stress and coping, theoretical and clinical interest in family stress and adaptation is a recent phenomenon. To understand the phenomena of family behavior, a comprehensive theoretical framework is needed to us provide an adequate background to for research. This study was designed to develop and test a hypothetical model for family stress and adaptation in families with handicapped children. A hypothetical model was constructed on the basis of the family stress theory developed by McCubbin etc. The model included six paths. For the purpose of model testing, empirical data was collected from May to August, 1992. The subjects of the study were 190 parents of chidren in five special schools and one private institute in Seoul and Choong Nam. An SPSS P $C^{+}$ and PC-LISREL 7.13 computer programs were used for descriptive and covariance structure analysis. The results of the study are as follows. (1) Family Stress(${\gamma}$$_{3l}$=-.288, T=-4.942) had a direct effect on Family Adaptation. (2) Family Functioning ($\beta$$_{21}$=-.373, T=5.595) had a direct effect on Situational Definition. (3) Family Functioning ($\beta$$_{31}$ =.334, T=5.375) had a direct effect on Family Adaptation. (4) Situational Definition( a2=.270, T=4.285) had a direct effect on Family Adaptation The model was supported by the empirical data. Thus it is suggested that the model could be adequately applied to family nursing care of families with a mentally handicapped child. In particular, the nursing interventions that enhance family functioning and the situational definition would improve family adaptation in families with mentally handicapped children.n.n.

• Journal of Korean Tunnelling and Underground Space Association
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• v.9 no.2
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• pp.143-155
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• 2007

The earth pressure acting on a circular shaft wall is smaller than that acting on the wall in plane strain condition due to the three dimensional axi-symmetric arching effect. Accurate estimation of the earth pressure is required for the design of the shaft wall. In this study, the stress model considering the decrease of earth pressure due to the horizontal and vertical arching effect and the influence of shape ratio (shaft height/radius) is proposed. In addition, model test on the sandy soil is conducted and a comparison is made between the stress model and the test results. The comparison shows that the proposed stress model is in agreement with test results; decrease of shape ratio (increase of radius) leads to stress state equal to the plane strain condition and approximate stress distribution is found between stress model and model test results.

• Journal of the Korean Society of School Health
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• v.34 no.2
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• pp.115-122
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• 2021

Purpose: The purpose of this descriptive research is to identify how stress from Covid-19, health beliefs, and social support of college students affect health prevention. Methods: The subjects of the study were 128 university students, excluding health major students, at one university in D City. The survey was conducted from August 1 to 31, 2020. The survey questionnaire consists of 8 items on stress from COVID-19, 12 items adapted from a health belief measurement tool, 12 items from a social support measurement tool, and 11 items adapted from a tool that measures health preventive behaviors. The collected data were analyzed using the hierarchical multiple regression analysis method with SPSS 26.0. Results: In model 1, stress from COVID-19 was statistically significant (β=-.403, p=.003). Model 2 added four health belief factors into Model 1. Stress (β=-.419, p<.001), perceived severity (β=-.193, p=.030), and perceived barriers (β=-.182, p=.009) were statistically significant. In model 3, stress (β=-.413, p<.001), perceived barriers (β=-.147, p=.034), and social support (β=.194, p=.011) were statistically significant. The regression equation was significant (F=15.395, p=<.001) and the model's explanatory power was 53.1%. Conclusion: The results show that when college students had a high degree of health beliefs about COVID-19, the degree of health preventive behaviors was proportionally high. To make them practice preventive health behaviors, it is necessary to develop infection control education programs to improve health beliefs.

• Journal of the Korean Geotechnical Society
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• v.24 no.4
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• pp.37-46
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• 2008

Application of resilient modulus, representing mechanical behavior of pavement materials, has become general concept for pavement design, analysis and maintenance after '86 AASHTO selected it as a basic input property of subgrade. It is known that resilient modulus of domestic subgrade soil is affected greatly by material factors, such as water content and dry weight unit, and stress components, such as deviatoric stress and confining stress, while effects of loading frequency and loading repeat were regarded negligible. If design based on resilient modulus is to be successfully implemented, design input variables of relevant models should be able to reflect local conditions. In this study, generalized mechanical model for subgrade is proposed. Model parameters are estimated from test results. Verification of the model was performed through finite element analysis using the proposed model, which showed good agreement with measured results of pavement deflections.

• Transactions of the Korean Society of Automotive Engineers
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• v.24 no.5
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• pp.504-511
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• 2016

This study investigates the durability of strut bar at car through structural and fatigue analyses. In this study, there are model 1 and model 2 as the analysis subjects. Model 1 is the existed one and model 2 is the improved one added with the reinforced part. Model 1 has the maximum equivalent stress of 165.11 MPa shown intensively at the welding part between the bracket and the bar. This stress is distributed over at the part of model 2 reinforced with this part. In case of fatigue analysis, there are three kinds of fatigue load as SAE bracket history, SAE transmission and sample history. The maximum fatigue life at SAE bracket history among three kinds of fatigue loads has the least value of $3.3693{\times}10^5$ cycles. The maximum fatigue life of model 2 becomes longer than that of model 1. As model 2 has the fatigue damage less than model 1, model 2 has the safety than model 1. As the fatigue durability about the configuration of strut bar is analyzed, it is thought to apply this study result into the real part effectively.