• YAKHAK HOEJI
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• v.53 no.5
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• pp.241-249
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• 2009

Various neurotransmitters are involved in regulating stress systems. In this study, we investigated the combination relieving effect of green tea extract(GTE) and L-theanine on the stress induced by electric foot shock. Four week oral administration of GTE (24 mg/kg), L-theanine (4 mg/kg) or their combination reduced the levels of dopamine, noradrenaline and corticosterone in blood, brain cortex, hippocampus, and striatum, wherease increased serotonin level. The combination of GTE and L-theanine showed much greater effects than single treatment of each component, and the effects are comparable to diazepam (2 mg/kg). Therefore, this study suggests that the combination of GTE and L-theanine may act effective and be useful for stress relieving treatment.

• Proceedings of the KWS Conference
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• 2007.11a
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• pp.260-262
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• 2007

In nuclear power plants, residual stress of dissimilar metal weld propagates cracks in the weld metal which is susceptible to stress corrosion cracking. Overlay welding is a process widely used to mitigate residual stress replacing inside tensile stress by compressing stress. The purpose of this paper is to predict the effect of weld overlay by finite element analysis.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.9
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• pp.100-106
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• 2020

This study analyzes the residual stress of AISI 1536V for an engine shaft of the shipbuilding industry and AISI A387 for a reactor shell of the chemical refining industry by the hole drilling method with a strain gauge rosette, which transforms fine mechanical changes into electrical signals. Tensile residual stress is generated in the forging and heat treatment process because specimens are affected by thermal stress and metal transformation stress. In the heat treatment process, the residual stress of AISI A387 is almost 170% the yield strength at 402 MPa. Since during the machining process, variable physical loads are applied to the material, compressive residual stress is generated. Under the same condition, the mechanical properties greatly affect the residual stress during the machining process. After the stress-relieving heat treatment process, the residual stress of AISI A387 is reduced below the yield strength at 182 MPa. Therefore, it is necessary to control the temperature, avoid rapid heat change, and select machining conditions depending on the mechanical properties of materials during manufacturing processes. In addition, to sufficiently reduce the residual stress, it is necessary to study the optimum condition of the stress-relieving heat treatment process for each material.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2001.10a
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• pp.102-105
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• 2001

The spring back taking place after the coiling process of steam generator tube leads to the dimensional inaccuracy. In order to reduce the spring back, tension force was applied to the one end of the tube during forming. In this work, parametric study using FEM was performed to find the appropriate magnitude of tension force. The force that induces minimum suing back was found by simultaneously taking account of suing back amount, cross-sectional ovality, and thickness of the tube wall after deformation. In addition, stress relieving by heat treatment was also simulated as an alternative to the former method. The latter was found to be more effective under the given constraints.

• Transactions of Materials Processing
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• v.11 no.3
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• pp.238-245
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• 2002

The spring back taking place after the coiling process of steam generator tube leads to the dimensional inaccuracy. In order to reduce the spring back, tension force was applied to the one end of the tube during forming. In this work, parametric study using FEM was performed to find the appropriate magnitude of tension force. The force that induces minimum spring back was found by simultaneously taking account if spring back amount, cross-sectional ovality, and thickness of the tube wall after deformation. In addition, stress relieving by heat treatment was also simulated as an alternative to the former method. The latter was found to be more effective under the given constraints.

• Transactions of the Korean Society of Automotive Engineers
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• v.4 no.1
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• pp.55-62
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• 1996

The dynamic photoelastic technique has been utilized to investigate the possibility of relieving the large local singular stresses which are induce in the corner of a right angled indenter. The indenter compresses a semi-infinite body dynamically with an impact load applied on the top of the indenter. The effect of geometric changes to the indenter in terms of the diameter (d) and the location (ℓ) of the notch on the relieving of the dynamic contact stresses are investigated. A multi-spark-high speed camera with twelve sparks was used to take dynamic photographs. The contact singular stresses were found to be released by introducing the relief notch along the indenter. The optimal location and geometry of the relief notch need further experimental investigation.

• Journal of the Korea Safety Management & Science
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• v.22 no.2
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• pp.57-71
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• 2020

The purpose of this study is to explore the effects of fire officers' experience of traumatic events and subsequent forest healing on their occupational burnout. The results are as follows: First, the experience of traumatic events, social and psychological healing, and relieving stress by strolling had a significant effect on burnout. The more fire officers are exposed to traumatic events, the more they lose self-control in social and psychological aspects, and the lower the level of stress relieved through strolling, the higher the level of burnout. Thi sresult suggests that the more fire office rsare called out for fire fighting, the more they see their colleagues with severein juries, and the higher the level of mental and physical an xiety, the more they areex hausted. Moreover, for es thealing help store duce the irmental and physi calfatig uecaused by traumatic events, thu spreven ting them from suffering from burn out. Second, the experience of traumatic events, social and psychological healing, and relieving stress by strolling had a significant impact on occupational stress. The more fire officers are exposed to traumatic events, the more they lose self-control in social and psychological aspects, and the lower the level of stress relieved through strolling, the higher the level of occupational stress. This result indicates that to relieve job stress caused by fire fighting, increased forest healing activities, including various programs such as psychotherapy, developing interpersonal relationships and self-control, and creating a positive mind-set, can reducejobstress and help fire officers recover from it. Lastly, job stress had a mediation effect on the effects of the experience of traumatic events and forest healing on burnout. This implies that burnout can be prevented when fire officers gain high emotional stability through social and psychological healing and stress-relief strolling over a traumatic experience, and stronger support from the organization and family can keep them from being emotionally drained, thus contributing to the prevention of burnout.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.177-185
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• 2017

In this study, we evaluated the efficacy of a commercial vaccine stress-relieving agent (Anti VS-2 injection) to reduce the adverse effects of foot-and-mouth disease (FMD) vaccination site in 120 pigs on two tested pig farms. The results showed that incidence of pig with abnormal meat, size of abnormal meat and weight of discarded abnormal meat are significantly decreased in Anti VS-2 injection-supplemented FMD vaccinated pig groups (n=60) compared to the non-supplemented FMD vaccinated pig groups (n=60) (P<0.05). And the average economic loss by discard of abnormal meat were estimated 99,382 won or 21,514 won in the non-supplemented FMD vaccinated groups or in the Anti VS-2 injection-supplemented FMD vaccinated groups, respectively, showing that the cost saving effect was 78% (77,869 won). In conclusion, it is expected to reduce the incidence and severity of abnormal meat in the FMD vaccinated pigs and to contribute not only to the reduced economic loss of pig farmers but also to the promotion of food hygiene when the Anti VS-2 injection is mixed with FMD vaccine.

• Journal of Digital Convergence
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• v.18 no.4
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• pp.469-478
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• 2020

The purpose of this study was to investigate the effects of meditation therapy on stress relief and quality of life. The experimental group included 85 Sojucheon meditation members in Gwangju and Jeonnam, and the control group was a survey of 48 members including general office workers and beauty school students. One-way ANOVA was performed for the statistics of differences in study variables between the two groups. The results of the analysis showed a significant difference in stress, and the F test also showed a significant difference in quality of life. Therefore, most of the meditation practitioners have been found that meditation therapy has a positive effect on stress relief and quality of life. These results suggest that Sojucheon meditation therapy is effective in relieving stress and quality of life, and it can be said that it is sufficient to provide a reference of meditation therapy for psychological stability.

• Journal of Korea Entertainment Industry Association
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• v.15 no.8
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• pp.443-456
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• 2021

This study was conducted to determine the extent to which music and art education had an effect on relieving depression and stress caused by COVID-19 and social distancing for teenagers in Seoul. To this end, with the cooperation of the Seoul Metropolitan Office of Education, an official document was issued to elementary, middle, and high schools in Seoul, and a study on the current status of about 1,745 students was conducted. Therefore, this study intends to prove through this study that music activity can significantly contribute to relieving depression and stress in adolescents on the basis that COVID-19 has a significant effect on the induction of depression and stress in adolescents. To this end, based on previous research, while examining the changes in the psychological state of Koreans due to COVID-19, we would like to analyze the depression and stress of adolescents intensively. And by experiencing music activities, it will be confirmed that depression and stress caused by COVID-19 can be relieved to a large extent through physiological and emotional changes. Furthermore, based on the survey, we intend to suggest that music activities will help adolescents to improve their emotional stability, cultural sensitivity, and self-esteem, and ultimately develop into healthy cultural people in terms of education.