• Journal of Korean society of Dental Hygiene
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• v.17 no.1
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• pp.27-37
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• 2017

Objectives: The purpose of the study is to investigate the correlation between stress and smartphone addiction in some university students. Methods: The subjects were 220 health major students in D area. The study was conducted for 2 weeks, in June, 2016. The questionnaire consisted of general characteristics of the subjects, awareness toward stress, stress-coping pattern, and smartphone addiction. Data was analyzed through SPSS 18.0 program. Results: In the analysis of stress levels according to general characteristics, female group showed higher experience compared to male group (high group 46.10, subgroup 44.38) (p<0.05). Male group and higher stress group showed higher experience in problem solving, social support, and emotional stress coping (p>0.05). Stress and stress coping (r=0.322), stress and smartphone addiction (r=0.299) showed positive correlation. The significant factors of smartphone addiction were average daily using time (${\beta}=0.477$, p<0.001), study stress (${\beta}=0.177$, p<0.05), social stress (${\beta}=0.323$, p<0.01), problem solving (${\beta}=-0.320$, p<0.001), social support (${\beta}=0.064$, p<0.05), and emotional stress coping (${\beta}=0.264$, p<0.001). These factors explained 30.8% of the variance in smartphone addiction. Conclusions: The results from this study indicated that stress had a negative impact on smartphone addictions in subjects. It is necessary to provide smartphone addiction management for stress management.

• Journal of Korean Academy of Nursing
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• v.37 no.4
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• pp.501-509
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• 2007

Purpose: The purpose of this study was to identify job stress experienced by head nurses of general hospitals. Methods: Data was collected from 10 head nurses with in-depth interviews about their actual experiences. The main questions were when, why, and from whom they get stress in the work field; how they are affected by the stressful situation; and how they cope with this stress. All the interviews were recorded and transcribed. The collected data was analyzed using a consistent comparative data analysis method. Results: Job stress of head nurse was formed by 3 axis; causes, reactions, and coping strategies in complicated situational context such as human relationship, culture of hospital, individual characteristics, social support. Conclusion: The results of this study yields very useful information for nursing mangers to identify, by stages, the demands of the head nurses in their role adaptation process. The findings of this study contributes to developing programs and supportive policies that palliates the head nurses' job stress.

• Proceedings of the Korea Concrete Institute Conference
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• 2002.05a
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• pp.221-226
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• 2002

This paper deals with the estimation of the bond stress based on experimental data that were tensed by axial force on both sides. It is certificated that the concrete stress condition clearly affects the bond-slip relationship. The proposed method utilizes the conventional bond-slip theories as well as the characteristics of deformed reinforcement and concrete cross-sectional area. An analytical equation for the estimation of the bond stress is formulated as the function of non-dimensional factors (e.g. bond stress, relative slip, etc.). The validity, accuracy and efficiency of the proposed method are established by comparing the analytical results with the experimental data of Ikki (1996, 1999) and the representative bond stress equations of Shima (1987). The analytical results presented in this paper indicate that the proposed method can be effectively estimated the bond stress-relative slip relationship.

• Journal of Ocean Engineering and Technology
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• v.17 no.6
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• pp.65-71
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• 2003

Since the preflex beam is fabricated through welding, the pre-compressive stresses that should occur over the concrete pier are diminished by the welding residual stresses. Therefore welding residual stresses must be relieved during the fabrication. Therefore, the analysis and examination of the accurate welding residual stress distribution characteristics are necessary. In this study, accurate distribution of welding residual stress of the preflex beam is analyzed by the finite element method, using 2 dimensional and 3 dimensional elements. Further, the thermo-mechanical behavior of the preflex beam is also studied. After the finite element analysis, real distribution of welding residual stress is measured using the sectioning method, and then is compared with the simulation results. The distribution of welding residual stress by finite analysis agreed well with the experimental results.

• Journal of the Korean Home Economics Association
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• v.48 no.10
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• pp.65-75
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• 2010

The main purpose of this study was to examine the relations between Children's stress, self-esteem, and subjective well-being with a sample of 320 elementary school 5th graders (of which 161 were boys and 159 were girls) living in Seoul. They completed questionnaires on Children's stress, self-esteem, and subjective well-being. The results were analyzed by means of Pearson's correlation coefficients and regressions. It was observed that children's stress of studying/mother was negatively related to subjective well-being. Children's self-esteem was positively related to subjective well-being. Children's stress of studying/mother was negatively related to self-esteem. Self-esteem tended to play a perfectly mediating role between children's stress of studying/mother and subjective well-being. These results clearly indicate that children's self-esteem plays a crucial role in improving the levels of children's subjective well-being.

• 한국기계연구소 소보
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• s.15
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• pp.91-103
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• 1985

In this paper, temperature distribution and thermal stress are investigated considering engine peak pressure and the time average temperature distribution in the piston under running conditions for the diesel engine. The induced stress are calculated by the Finite Element Method(FEM). The results obtained are summerized as follows. 1) The results calculated by the FEM present good agreement with other numerical solution in literature. 2) It is confirmed that maximum compressive stress are induced in the part of outside wall between the piston crown and the pin bush. 3) In the axial direction, the hoop stresses are changed its sigh at the portion of crown near the inner wall side 4)Large gradient of temperature is shown in the piston crown near the side wall in the axial direction, in the part between the piton crown and the pin bush in radical direction 5)in case of stress distribution of piston wall surface in the axial direction, the hoop stress is a little greater than axial stress, and the latter is greater than the radial stress

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1997.10a
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• pp.769-772
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• 1997

In this study, By employing two dimensional(2-D) Boundary Element Method(BEM) stress analysis was carried to investigate stress distributions on the brazing joint of a Hardmetal and a HSS. Two model was proposed to analyze stress singularity in brazed interface. The stress results from the BEM were considered influence of the kind of materials , thickness of filled metal and length of vertical brazing adhesive. From those obtained results , the peak point of stress was founded in the lower part of two interface was made by brazing. As the thickness and length changed, the maximum stress tended to change in the peak point.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.249-251
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• 2004

According to our fatigue tests carried out at 20 ㎐, R=0.1 on transversely butt-welded joints, fatigue strengths of as-welded specimens, that is, specimens having residual stress are higher than those of annealed specimens in short hie range, but vice verse in long life range. This behavior seems to be concerned mainly with residual stress relaxation by applied loading. After analyzing the welding process, we conducted finite element analysis to quantify the degree of residual stress relaxation. By taking into account residual stress relaxation, modified Goodman diagram, and nominal stress, we evaluated the fatigue life of the welded joint from the S-N curve for the parent material. The estimated results are in a good agreement with the experimental results.

• Journal of Advanced Marine Engineering and Technology
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• v.9 no.2
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• pp.143-152
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• 1985

In this paper, temperature distribution and thermal stress are investigated considering engine peak pressure and the time average temperature distribution in the piston under running conditions for the marine diesel engine. The induced stress are calculated by the Finite Element Method (FEM). The results obtained are summerized as follows. 1) The results calculated by the FEM present good agreement with other numerical solution in literatures. 2) It is comfirmed that the maximum compressive stresses are induced in the part of outside wall between the piston crown and the pin bush 3) In the axial direction, the hoop stresses are changed its sign at the portion of crown near the inner wall side. 4) Large gradient of temperature is shown in the piston crown near the side wall in the axial direction, in the part between the piston crown and the pin bush in radial direction. 5) In case of stress distribution of piston wall surface in the axial direction, the hoop stress is a little greater than axial stress, and the latter is greater than the radial stress.

• Journal of Korea Foundry Society
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• v.13 no.1
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• pp.81-93
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• 1993

It is well-known that the analysis of elasto-plastic thermal stress and deformation are substantially important in optimal design of metal casting mould. The unsteady state thermal stress and deformation generated during the solidification process of ingot and mould have been analyzed by two dimensional thermal elasto-plastic theories. Distributions of temperature, stress and relative displacement of the mould are calculated by the finite element method and compared with experimental results. In the elasto-plastic thermal stress analysis, compressive stress occurred at the inside wall of the mould whereas tensile stress occurred at outside wall. A coincidence between the analytical and experimental results is found to be fairly good, showing that the proposed analytical method is reliable.