• Journal of Ocean Engineering and Technology
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• v.13 no.2 s.32
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• pp.58-65
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• 1999

The effect of specimen thickness on fatigue crack growth rate was studied. The objective of the present study is to investigate the effect of specimen thickness on the fatigue crack growth behavior at various stress intensity factor ranges and also the variation of material restance to fatigue crack growth. The fatigue crack growth resistance was treated as a spatial stochastic process, which varies randomly on the crack path, Compact tension specimens with a LT orientation for structural steel were used. All testing was done at a constant stress intensity level. The experimental data were analyzed for the size effect to determine the Weibull distributions of the material resistance.

• Geotechnical Engineering
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• v.10 no.3
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• pp.41-54
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• 1994

This study aims at investigating the mechanism and operation of cubical triaxial test developed by Lade in order to obtain analysis on the clayey foundation deformation. A comparison on deviator stress, pore water pressure and stress path is made between test results of clay using the cubical consolidated undrained test as well as plane strain test.

• Bulletin of the Society of Naval Architects of Korea
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• v.9 no.2
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• pp.33-42
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• 1972

This paper was studied on the behavior, crack formation and propagation of slip bands on low carbon steel which was heat-treated in three conditions in order to change metallic structure. The specimens were tested by rotating bending fatigue testing machine and also observed the variations of grains by microscope. From the test results it was clear that fatigue endurance limit and life of low carbon steel were more increased in contrast with the case that the grain size of specimen was more decreased. Slip bands developed at oil-quenched specimen and furnace-cooled specimen. Formed cracks in the first one or two grains below the surface were approximately "planar" type, there after they followed "wavy" type. It was also found that cracks at 30% higher stress than fatigue limit were usually developed inter-granular, and cracks at 12% higher stress than fatigue limit were propagated meandering path, partly trans- and partly inter-grandular.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.7
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• pp.1107-1118
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• 2001

The forming limit diagram introduced by Keeler and Goodwin has been used generally to analyze the formability of sheet metal. However, path dependent forming limit curves based on the state of strain can be explained only by a single criterion which is based on the state. In this study, experimental forming limits in strain space of some metal sheets are transformed into forming limit curves in stress space. Effects of yield criterion are investigated in transforming the forming limit curves. Some important design aspects which are based on the close prediction of movements in forming limit curves during sheet forming are concluded.

• Structural Engineering and Mechanics
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• v.7 no.6
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• pp.575-588
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• 1999

A boundary element method is applied to the analysis of crack trajectory in materials with complex microstructure, such as discontinuously reinforced composite materials, and systems subjected to complex loading, such as indentation. The path followed by the crack(s) has non-trivial geometry. A study of the stress intensity factors and fracture toughness of such systems must therefore be accompanied by an analysis of crack trajectory. The simulation is achieved using a dual boundary integral method in planar problems, and a single boundary integral method coupled with substructuring in axisymmetric problems. The direction of crack propagation is determined using the maximum mechanical energy release rate criterion. The method is demonstrated by application to (i) a composite material composed of components having the elastic properties of aluminium (matrix) and silicon carbide (reinforcement), and (ii) analysis of contact damage induced by the action of an indenter on brittle materials. The chief advantage of the method is the ease with which problems having complex geometry or loading (giving rise to complex crack trajectories) can be treated.

• Journal of Convergence for Information Technology
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• v.10 no.10
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• pp.88-99
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• 2020

This study aimed to explore the effects of perceived family stress, supportive resources, intentional rumination, and coping behaviors on posttraumatic growth of cancer survivors based on the Double ABCX Family Stress Model. Data were collected from 200 cancer survivors currently living with their spouses and analyzed by path analysis using AMOS program. The results of this study were as follows. First, perceived family stress of cancer survivors had direct effects on supportive resources, intentional rumination, and coping behaviors, and had indirect effects on posttraumatic growth mediated by supportive resources, intentional rumination, and coping behaviors. Second, supportive resources, intentional rumination, and coping behaviors had direct effects on posttraumatic growth. Third, supportive resources and intentional rumination had direct effects on coping behaviors and had an indirect effect on posttraumatic growth mediated by coping behaviors. The current study supported the applicability of the Double ABCX Family Stress Model to the posttraumatic growth process of cancer survivors.

• Journal of the Korean GEO-environmental Society
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• v.16 no.10
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• pp.5-14
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• 2015

Suction affects the unsaturated soil as the negative pore pressure, and leads to increases of the yield stress and the plastic shear stiffness of the soil skeleton due to the growth in interparticle stress. Hence, in this study, in order to account for these effects of suction under the dynamic loading condition such as the earthquake, the element simulation of the cyclic triaxial test using induced stress-strain relation based on cyclic elasto-plastic constitutive model extended for unsaturated soil considering the $1^{st}$ and the $2^{nd}$ yield functions was conducted. Through the stress path, stress-strain relation and relation between volumetric strain and axial strain, it was seen in all the cases that the simulation results demonstrated a good agreement with the experimental results. It is expected that the results of this study possibly contribute to the accuracy improvement on the prediction of unsaturated soil behavior under the dynamic loading condition.

• The Journal of the Korea Contents Association
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• v.15 no.10
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• pp.225-235
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• 2015

The purpose of this study is to investigate the relationships among young North Korean defectors' stress, self-esteem, and life satisfaction, to analyze the factors affecting their life satisfaction, and to suggest improvement plans. The study subjects were 126 young North Korean defectors. Path analysis was conducted to analyze the mediating effect of self-esteem in affects of their stress on life satisfaction. According to the analysis, stress negatively and significantly influenced self-esteem (-0.30, p<.01), and self-esteem positively and significantly affected life satisfaction (0.41, p<.001). Although stress had not a direct effect on life satisfaction, had not a indirect effect with the use of self-esteem as a mediating variable (LL 95% CI -0.093, UL 95% CI -0.002).

• Journal of the Korea Convergence Society
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• v.9 no.9
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• pp.345-352
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• 2018

This convergence study was aimed at examining the effect of university students' dietary habits on their self-esteem by the medium of health-related behaviors and stress. 390 copies of questionnaire completed by university students in Province J and Province K were used as the study data. As for the data analysis, SPSS and AMOS were used to perform correlation analysis, multiple regression analysis and path analysis. The study showed a significant correlation between dietary habits and health-related behaviors of University students, dietary habits and stress, dietary habits and self-esteem and that dietary habits exerted impact on the students' self-esteem by the medium of health-related behaviors and Stress. Therefore, in order to increase university students' self-esteem, it is necessary to provide training and programs on correct dietary habits and health-related behaviors and to prepare plans for reducing stress.

• Geotechnical Engineering
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• v.4 no.1
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• pp.17-28
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• 1988

Among several types of element tests to predict soil behalf.iota in a laboratory, the torsion shear apparatus, in which the directions of principal stresses could be rotated during shearing, wra explained. In this study, this torsion shear apparatus was improved so as to be used in tests on clay specimens . And some undrained torsion shear tests u.ere performed on remolded specimens of Ko-consolidated clay to investigate the influence of reorientation of the principal stress directions on the stress-strain behavior The soil behavior by the torsion shear apparatus without torque was compared It.ith that by the conventional triaxial compression tests . The stress path, provided by both vertical loads and torque during torsion shear tests, has much effect on the stress-strain behavior, the pore pressure and the effective principal stress ratio . The rotation angle of the principal stress and the b-value were gradually increased with increasing shear strain, but converged to the values at failure.