• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.274-277
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• 2004

The most important mode of subcritical crack growth is primary water stress corrosion crack, which was the reported mechanism from the root cause analysis of the crack in the bimetallic welds. Stress corrosion crack growth evaluations was carried out for several flaw shapes of both axial and circumferential flaws, using the steady-state stresses including residual stresses. This evaluation considered the possibility of additional flaws in the primary loops of nuclear power plant, even though no such flaws have been identified by Ultrasonic Test. Consequently, Results show that the predicted flaw sizes will determine acceptability for continued service and maintenance.

• 동의생리병리학회지
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• 제24권3호
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• pp.525-532
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• 2010

Dypepsia is the most common gastrointestinal disease and mainly occurs by stress or food. According to the cause of dyspepsia, the clinical characteristics and the curative process are different in patients. The purpose of this study is to compare acute dyspepsia patients depending on food factor and stress factor. For this study, we analyzed the cause, and the symptoms of 59 acute dyspepsia patients and divided them into two groups: one group is 27 acute dyspepsia patient group caused by stress factor (stress factor group). The other group is 32 acute dyspepsia patient group caused by food factor (food factor group). In addition, we carried out HRV test and compared HRV index between two groups. There was no significant difference in past illness involved in gastrointestinal tract diseases between two groups. There were big differences in the frequency of chest discomfort, thurst, lack of appetite, and exhaustion after meals between two groups. There were many changes of tongue fur in food factor group. But there were many changes of tongue body in stress factor group. The pulse pattern is mostly wiry in stress factor group. But, The pulse pattern is mostly slippery in food factor group. HF, TP were significantly lower than food factor group in stress factor group, it means autonomic nerve system was more suppressd in stress factor group than food factor group. Food factor group improved sooner than stress factor group. This study presented the clinically different characteristics (past medical history, symptoms, tongue diagnosis, pulse pattern, curative process) of acute dyspepsia depending on food factor and stress factor. Thus, it provides the necessity of oriental medical diagnosis and treatment called pattern identification for acute dyspepsia.

• 한국해양공학회지
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• 제11권1호
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• pp.113-123
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• 1997

The welding residual stresses produced by welding frequently cause a crack and promote stress corrosion etc. in heat affected zone contained with external load and weakness of material. For the purpose pof relaxation of welding residual stress, post welding heat teratment(PWHT) is widely used. In this paper, the computer program which is based on Thermal-Elasto-plastic-creep theory for plane deformation on developed by finite element method (F.E.M) and verified its propriety by experimental measurement and also by using the developed computer program. The mechanical behavior of butt welding joint is clairfied during PWHT.

• Tribology and Lubricants
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• 제12권3호
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• pp.79-84
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• 1996

One of the greatest dangers in mechanical face seals is the formation of heat checking and thermal stress cracks on the sliding surfaces. These thermal distortions due to non-uniform heating lead to increase the leakage of the sealed fluids and wear, and with balance of the seal can cause the seal faces to part. In this study heat checking and thermal stress cracks are investigated experimentally. These thermal distortions are explained using the thermal models of the conatct geometries between the seal ring and the seal seat. To overcome these thermal problems, the thermohydrodynamic seal is presented. The newly developed mechanical seal may substantially reduce the friction torque, frictional heating which causes heat checking and thermal stress cracks, and wear.

• 대한용접접합학회:학술대회논문집
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• 대한용접접합학회 2006년도 춘계 학술대회 개요집
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• pp.100-102
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• 2006

• 대한한의학방제학회지
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• 제25권4호
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• pp.483-497
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• 2017

Background : Behavioral stress has been suggested as one of the significant factors that is able to disrupt physiological systems and cause depression as well as changes in various body systems. The stressful events can alter cognition, learning, memory and emotional responses, resulting in mental disorders such as depression and anxiety. Results : We used a restraint stress model to evaluate the alteration of behavior and stress-related blood parameter. The animals were randomly divided into two groups of five animals each group. Furthermore, we assessed the change of body weight to evaluate the locomotor activity as well as status of emotional and anxiety in mice. After 7 days of restraint stress, the body weight had significantly decreased in the restraint stress group compared with the control group. We also observed stress-associated behavioral alterations, as there was a significant decrease in open field and forced swim test, whereas the immobilization time was significantly increased in the stress group compared to the control group. We observed the morphological changes of neuronal death and microglia by immunohistochemistry and western blot. In our study restraint stress did not cause change in neuronal cell density in the frontal cortex and CA1 hippocampus region, but there was a trend for an increased COX-2 and iNOS protein expression and microglia (CD11b) in brain, which is restraint stress. Conclusion : Our study, there were significant alterations observed in the behavioral studies. We found that mice undergoing restraint stress changed behavior, confirming the increased expression of inflammatory factors in the brain.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제29권2호
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• pp.108-115
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• 2003

Suppression of cellular immunity is the host responses to surgical stress. When the body is exposed to surgical stress, decreased immunocyte function is one of the surgical stress-induced biologic responses. In all patients exposed to the surgical stress, peripheral blood lymphocyte numbers and function were suppressed until at least 2 weeks postoperatively. This immunosuppression was mainly due to a decrease of helper-inducer T cells, cytotoxic T cells, natural killer cells, and an increase of suppressor T cells. The blood levels of interleukin-6(IL-6) cytokine increase in response to surgical stress and cause an increase of so-called acute phase reactants, including C-reactive protein(CRP). In the previously damaged patients group, expected to early stress expose, immunosuppression was more developed than other normal groups. Cellular immunosuppression by surgical stress was mainly due to an increase of lymphocyte subsets that depress cellular immunity coupled with a decrease of the subsets that promote it. Overproduction of CRP in response to surgical stress may play an important role in the development of immunosuppression.

• Biomolecules & Therapeutics
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• 제27권4호
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• pp.386-394
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• 2019

Trypanosoma cruzi infection results in debilitating cardiomyopathy, which is a major cause of mortality and morbidity in the endemic regions of Chagas disease (CD). The pathogenesis of Chagasic cardiomyopathy (CCM) has been intensely studied as a chronic inflammatory disease until recent observations reporting the role of cardio-metabolic dysfunctions. In particular, we demonstrated accumulation of lipid droplets and impaired cardiac lipid metabolism in the hearts of cardiomyopathic mice and patients, and their association with impaired mitochondrial functions and endoplasmic reticulum (ER) stress in CD mice. In the present study, we examined whether treating infected mice with an ER stress inhibitor can modify the pathogenesis of cardiomyopathy during chronic stages of infection. T. cruzi infected mice were treated with an ER stress inhibitor 2-Aminopurine (2AP) during the indeterminate stage and evaluated for cardiac pathophysiology during the subsequent chronic stage. Our study demonstrates that inhibition of ER stress improves cardiac pathology caused by T. cruzi infection by reducing ER stress and downstream signaling of phosphorylated eukaryotic initiation factor ($P-elF2{\alpha}$) in the hearts of chronically infected mice. Importantly, cardiac ultrasound imaging showed amelioration of ventricular enlargement, suggesting that inhibition of ER stress may be a valuable strategy to combat the progression of cardiomyopathy in Chagas patients.

• 한국조리학회지
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• 제7권2호
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• pp.195-215
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• 2001

This study is of an analysis of the kinds of influences on the subordinate variables through the adjusting variables by the independent variables which serve as the perception factor of job stress. also This study, with taking the workers for the hotel employees who are in the room, food & beverage and cook, was carried out so as to analyze deeply and throughly the stress of work they experience in doing their job and the tension incited from this stress and the strategy used for meeting this stress to grope for raising plan for the degree of satisfaction with their job of the workers for the hotel. In order for, this study ran paralled with literature study and research study, taking 615 workers who are now working in hotel. Job stress is easily negligible in hotel business not only because it is hard to identify and measure its concrete entity on account of its intangible characteristic but also because it is impossible to check physically the relationship with each direct behavior. If job stress continue, however, it can cause neglect of duty, change of occupation, deterioration of service quality and eventually aggravate the cost of a hotel business and decrease the hotel sales. Consequently, it is highly necessary to increase job satisfaction by identifying systematically and eliminating the stress factor of hotel employees in order to accomplish particularly experience unique job stress in the course of contact since they should provide the customer with their services.

• 서비스연구
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• 제11권1호
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• pp.31-44
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• 2021

국내의 의료보험 제도의 순기능은 높이 평가받지만 불완전한 보장성의 문제로 인해 국민들은 민영의료보험 가입을 통해 보장성을 확보하고자 한다. 이로 인해 최근 민영의료보험의 가입률이 높아지게 되었고, 청구율 또한 높아지게 되었다. 이처럼 민영의료보험을 찾는 사람이 늘어남에 따라 민영의료보험사의 근로자는 직무 부담이 가중되었으며, 특히 보험금 지급을 담당하는 보험심사 근무직의 경우 보험금을 고객과의 소통, 회사의 수익 상출에 기여 등 다양한 이유로 직무스트레스가 나날이 증가하고 있으며 그로 인한 부작용을 경험하고 있다. 이에 본 연구는 보험심사 근무직의 직무스트레스가 정신건강에 미치는 영향에 대해 분석하여 보험심사 근무직의 직무스트레스를 감소시키고 정신건강을 증진하고자 서술적 조사 연구를 실시하였다. 분석 결과, 보험심사 근무직의 직무스트레스는 정신건강에 유의한 정(+)의 영향을 미치는 것으로 나타났다. 세부적으로는 직무스트레스가 역할수행능력·자기신뢰도, 우울, 수면장애·불안, 일반건강·생명력의 정신건강 4가지 요인 모두에 유의한 영향을 미치는 것으로 나타났다. 본 연구를 통해 보험심사 근무직의 직무스트레스가 정신건강에 유의한 정(+)의 영향을 미친다는 사실을 알 수 있었다. 직무스트레스는 근로자로 하여금 직무수행에 대한 열의를 감소시키고 이직률, 퇴사율을 높이는 등 조직적인 측면에서의 부작용을 초래하기도 하지만 개인의 신체 건강을 악화시키고 우울, 불안 등과 같은 질환을 유발하여 정신건강을 피폐하게 만들기도 한다. 따라서 이를 예방하기 위하여 대상자의 특성에 맞는 적절한 직무스트레스 예방법과 대처법을 제공하여 직무스트레스를 감소시키고 정신건강을 증진할 수 있도록 지원하여야 할 것이다.