• 인간식물환경학회지
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• 제23권3호
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• pp.363-375
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• 2020

Background and objective: Recreation or activities in forest are regarded as therapy. Many forest therapy programs have been developed and assessed in the domestic. This study was conducted to investigate the effect of the forest therapy program on academic and job-seeking stress in college students. Methods: Thirty five subjects were selected as the experimental group and 25 as the control group, and 29 subjects in the experimental group and 11 in the control group participated in the follow-up test to verify the persistence of stress reduction effects. The forest therapy program was carried out once a week for 2 hours each from September 4 to December 4, 2018, adding up to total eight sessions. Results: The experimental group showed statistically significant reduction in both academic stress and job-seeking stress, whereas the control group did not. For the persistence of the forest therapy program, the experimental group did not show a statistically significant difference between the posttest and the follow-up test, and thus the stress reduction effect was maintained. Conclusion: This study proved the reduction of academic and job-seeking stress in forest therapy programs and the persistence of the stress reduction effect of the forest therapy program. The result is consistent with the Stress Recovery Theory (SRT) that shows the stress reduction effect of nature. In addition, it has significance in that it has verified that the program using the forest on campus can reduce stress of most college students.

• 한국산업융합학회 논문집
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• 제21권4호
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• pp.159-165
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• 2018

In electric agricultural machine a reduction gear is needed to convert the high speed rotation motion generated by DC motor to lower speed rotation motion used by the vehicle. The reduction gear consists of several spur gears. Spur gears are the most easily visualized gears that transmit motion between two parallel shafts and easy to produce. The modelling and simulation of spur gears in DC motor reduction gear is important to predict the actual motion behaviour. A pair of spur gear tooth in action is generally subjected to two types of cyclic stress: contact stress and bending stress. The stress may not attain their maximum values at the same point of contact fatigue. These types of failure can be minimized by analysis of the problem during the design stage and creating proper tooth surface profile with proper manufacturing methods. To improve its life expectation in this study modal and stress analysis of reduction gear is simulated using ANSYS workbench based on finite element method (FEM). The modal analysis was done to understand reduction gear deformation behaviour when vibration occurs. FEM static stress analysis is also simulated on reduction gear to simulate the gear teeth bending stress and contact stress behaviour.

• 동의신경정신과학회지
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• 제23권4호
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• pp.153-158
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• 2012

Objectives : The objective of the study is to examine what effects the Mindfulness-based stress reduction program can have on Hwa-byung patients. Methods : Ten Hwa-byung patients have participated in this 8-week Mindfulness-based stress reduction program for Hwa-byung. In addition, participants were interviewed regarding the experiences from the changes during meditation or everyday life. Data were collected though a consumer panel and individual interviews. Responses were coded using Consensual Qualitative Research (CQR) methodology. Results : The experiences were categorized into 7 domains and divided to 23 categories. Results showed the psychotherapeutic effects of Mindfulness-based stress reduction program, specifically, positive cognitive changes, emotional stability, and changes in attitude. Also, all participants reported improvement of anger management skill and feeling of tranquility. This means that the Mindfulness-based stress reduction program can relieve the symptoms of Hwa-byung. Conclusions : Mindfulness-based stress reduction program makes changes about emotion, physical symptoms, cognition and personal relationship. This program can be applied to psychotherapy for Hwa-byung.

• The Korean Journal of Physiology and Pharmacology
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• 제20권5호
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• pp.467-476
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• 2016

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 mg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a $G_i$ inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.

• Steel and Composite Structures
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• 제4권5호
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• pp.355-365
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• 2004

A new reduction method of residual stress in welding joint is proposed where welded metals are shaken during welding. By an experiment using a small shaker, it can be shown that tensile residual stress near the bead is significantly reduced. Since tensile residual stress on the surface degrades fatigue strength for cumulative damage, the proposed method is effective to reduction of residual stress of welded joints. The effectiveness of the proposed method is demonstrated by the response analysis using one mass model with nonlinear springs.

• 한국콘텐츠학회논문지
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• 제9권3호
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• pp.232-240
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• 2009

본 연구는 노인 스트레스 감소를 위한 명상 프로그램의 효과성을 검증하였다. 명상 프로그램은 한국형 마음챙김 명상 프로그램과 크리야 요가로 구성하였다. 프로그램은 노인집단에서 명상집단과 통제집단을 대상으로 스트레스 반응성, 우울, 불안, 삶의 질을 종속변인으로 하여 사전-사후검사를 통해 효과 검증을 하였다. 연구결과 노인 스트레스 감소를 위한 명상 프로그램이 명상집단에서 노인의 불안, 우울, 스트레스 반응성이 사전-사후검사에서 유의한 감소를 보였고, 사후검사 결과 집단비교에서도 통제 집단과 유의한 차이를 보였다. 또한 명상집단은 삶의 질의 사전-사후검사에서 유의한 증가를 보였고, 사후검사 결과 통제 집단과 유의한 차이를 보였다. 따라서 노인 스트레스 감소를 위한 명상 프로그램이 노인의 불안, 우울, 스트레스 반응성을 낮추고, 삶의 질을 개선시키는 연구 결과가 나타났다. 본 연구 결과를 추후연구를 위하여 논의하였다.

• 한국도로학회논문집
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• 제11권4호
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• pp.87-94
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• 2009

콘크리트 슬래브는 타설 후 온도와 수분 변화를 통해 체적이 변화한다. 수분증발에 의하여 발생한 건조수축은 슬래브의 자중이나 하부층과의 마찰 등에 의하여 구속되어 슬래브 내부에 응력이 유발된다. 선행 연구에 의하면 건조수축에 의하여 발생된 실제 인장응력은 이론적으로 예측된 값보다 작은 것으로 보고되었다. 이는 부분적으로 구속된 슬래브에서 발생하는 초기 재령 콘크리트의 점탄성에 기인한 응력감소 현상이다. 본 연구에서는 재령에 따른 콘크리트의 응력감소 현상을 조사하기 위하여 구속된 원주형, 구속되지 않은 자유건조 원주형, 그리고 자유건조 각주형 콘크리트 시편의 변형률을 측정하였다. 재령 1, 3, 7, 14, 28일에 콘크리트의 탄성계수를 측정하였으며 관입저항 실험을 실시하였다. 실험결과를 기존 연구자들이 제안한 이론식에 대입하여 구속된 원주형 콘크리트 시편의 응력감소를 계산할 수 있었다. 향후 본 연구의 결과를 바탕으로 구속된 콘크리트 시편의 응력감소 현상을 콘크리트 포장의 설계에 적용할 예정이다.

• 산업경영시스템학회지
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• 제43권3호
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• pp.41-52
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• 2020

This paper investigates the stress-reducing preventive maintenance model through numerical experiments. The preventive maintenance model is used to analyze the relationship between related conditions and variables to gain insight into the efficient operation of the system when performing preventive maintenance in real-world situations. Various preventive maintenance models have been developed over the past decades and their complexity has increased in recent years. Increasing complexity is essential to reflect reality, but recent models can only be interpreted through numerical experiments. The stress-reducing preventive maintenance is a newly introduced preventive maintenance concept and can only be interpreted numerically due to its complexity, and has received little attention because the concept is unfamiliar. Therefore, for information purposes, this paper investigates the characteristics of the stress-reducing preventive maintenance and the relationship between parameters and variables through numerical experiments. In particular, this paper is focusing on the economic feasibility of stress-reducing preventive maintenance by observing changes in the optimal preventive maintenance period in response to changes in environmental stress and the improvement factor. As a result, when either the environmental stress or the improve effect of stress-reducing preventive maintenance is low, it is not necessary to carry out the stress-reducing preventive maintenance at excessive cost. In addition, it was found that the age reduction model is more economical than the failure rate reduction model.

• 한국정보전자통신기술학회논문지
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• 제8권1호
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• pp.28-36
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• 2015

본 연구는 단기간 템플스테이 체험이 일상스트레스감소에 미치는 영향을 검토하였다. 그 결과 남 여 모두 템플스테이 체험 전 보다 체험 후 평균 일상 스트레스 척도 점수가 현저히 낮았다. 템플스테이 체험 전, 템플스테이 체험 1주일 후, 1개월 후, 3개월 후의 스트레스 척도 점수는 성별과 연령에 관계없이 거의 모두 템플스테이 직전이 가장 높았다. 이어 템플스테이 체험 3개월 후, 1개월 후, 1주일 후의 순서로 나타났다. 마지막으로 연령별 스트레스 척도 점수는 남성의 경우 60대에서 가장 높게 나타났으며, 여성은 30대와 40대에서 다소 높게 나타났다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2011년도 추계 학술논문 발표대회
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• pp.175-176
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• 2011

Applying previous studies performed in the moisture transportation characteristics and shrinkage of lightweight concrete application of shrinkage reduction is to discuss. Applicability of shrinkage reduction effect of lightweight concrete applies for the analysis of PSC girder bridge beam placed on the construction site. Stress of the concrete bridge deck, rebar quantity is calculated by effective elastic modulus method and crack risk is assessed by moisture transport and differential shrinkage analysis. After approximately 10 days maximum tensile stress occurs 6MPa, similar to the case of normal concrete, a maximum tensile stress occurs 3MPa in lightweight concrete and comparing to normal concrete stress was reduced to approximately 50%. Normal and lightweight concrete crack index, respectively, is reduced 1.6 to 1.2, 1.2 to 0.9 in surface and boundary region. Therefore, reduction in shrinkage of concrete were able to confirm reduction of crack risk.