• Journal of Power System Engineering
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• v.14 no.1
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• pp.47-52
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• 2010

In this study, Finite Element Analysis have been adopted to analyze reducing stress effect and used to induce the sensitivity of design parameter on various techniques which was used for reducing stress. And so it can be utilized as a data to design on similar model. The effect of reducing stress with respect to change of relief groove radius can be increased by 27.3~18.2 % more than radius of fillet. And if a shoulder fillet radius is larger, additional reducing stress by relief groove radius is not obtained. And there was only little effect on reducing stress by changing the center point of groove radius along horizontal direction. In the case that undercut radius is 1.5mm, Max. Equivalent stress is reduced by 5.71% under bending force and 11.11% under torsion. The best effect of reducing stress at undercut model was yielded when the undercut radius is a forth of difference of stepped shaft radius.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.3
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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.

• Journal of Korean Academy of Nursing
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• v.34 no.2
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• pp.213-224
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• 2004

Purpose: This study was aimed to evaluate the effect of progressive muscle relaxation training using biofeedback on perceived stress, stress response, immune response and climacteric symptoms, Method: This was a crossover, pre-post test design, The study subjects are 36 middle-aged women who were selected at 2 public health centers, The independent variable was Biofeedback training for 4 weeks, twice a week and home training for 4 weeks, Dependent variables were perceived stress, stress response, immune response, and climacteric symptoms measured with Hildtch's scale (1996), Result: Progressive muscle relaxation training using biofeedback was not effective in reducing perceived stress, but it was shown to be effective in reducing physiological stress responses such as pulse rate and EMG, Though blood pressure and skin conductance were repeatedly down, and skin temperature slowly increased, there were no statistically significant differences. Progressive muscle relaxation training using biofeedback was not effective in reducing serum cortisol, enhancing immune responses, or decreasing climacteric symptoms. Conclusion: The findings point to a pressing need for further, well-controlled and designed research with consideration in selection of subjects and instruments, frequency of measurements, the sampling method, and intervention modalities.

• Journal of the Korean Society for Aviation and Aeronautics
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• v.26 no.3
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• pp.77-86
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• 2018

Stress is the main source of a human error or can potentially contribute to it. Recently, the rate of accidents which is associated with human factors among the total aircraft accidents is showing a tendency of gradual increase. In order to prevent the accidents related to human factors, stress mitigation of the mission personnel is highly required. In this study, a 'stress cognitive alteration' technique, which is one of the stress relief methods, is applied to the Air Force pilots to verify if the technique is effective in reducing stress. The 'stress cognitive alteration' technique is comprised of two parts: a positive function of stress and a process to positively alter the physical, psychological response to stress. As a result of the application, it is found that this technique has an effect of reducing stress of the pilots under a relatively high level of stress.

• Proceedings of the Korean Institute of Landscape Architecture Conference
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• 2007.10b
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• pp.84-88
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• 2007

When people recognize a landscape, they first need to see it for a definite period time. This study clarified the way green space in a landscape is recognized using eye movement analysis, and evaluated the Pffi9bility for quantifying stress-reducing effects of seeing a landscape. The results of the experiments on eye movement analysis suggest that the way of recognizing green space in a landscape may depend on a ratio of the amount of scenic greenery in a landscape, color and greenery layout. Especially, this study also suggests that the possibility of the greenery layout guiding eye movement could be verified by conducting a study on planting patterns. In addition, the results of the experiments for quantifying stress-reducing substances found that it is likely that a green space in an urban area has stress-reducing effects.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.06a
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• pp.797-798
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• 2008

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.73-77
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• 2006

This paper shows a study of the efficiency of expansive additive and shrinkage reducing admixture in controlling restrained shrinkage cracking of high performance concrete at early age. Free autogenous shrinkage test of $100{\times}100{\times}400mm$ concrete specimens and simulated completely-restrained test with VRTM(variable restraint testing machine) were performed. Creep and autogenous shrinkage of high-performance concrete with and without expansive additive and shrinkage reducing admixture were investigated by experiments that provided data on free autogenous shrinkage and restrained shrinkage. The results showed that the addition of expansive additive and shrinkage reducing admixture effectively reduced autogenous shrinkage and tensile stress in the restrained conditions. Also, it was found that the shrinkage stress was relaxed by 90% in high-performance concrete with and without expansive additive and shrinkage reducing admixtures at early age.

• Journal of Korean Academy of Nursing
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• v.29 no.4
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• pp.855-869
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• 1999

The purpose of this study was to test the effectiveness of self-management relaxation training through biofeedback and progressive muscle relaxation methods. The effectiveness of the experimental methods was tested by measuring the degree of symptoms of stress (SOS), the McNair's profile of Mood States (POMS), the levels of ephinephrine, norepinephrine, pulse rate, blood pressure and natural killer cells. The subjects of this study were sixty six nursing students divided into four groups : two groups were the biofeedback and progressive muscle relaxation groups, the other two groups served as control groups. One was a group of sophomores with no experience at all, the other a junior group without self -management or relaxation training. This study was conducted for eight weeks of clinical practice from April, 26th 1998 to June, 20th 1998. Biofeedback training was done with software developed by J&J company (1-410 form for abdominal respiration training). Progressive muscle relaxation training was done with u audiotape recorded according to Jacobson's Theory. The data were analyzed with frequencies, means, and analysis of covariance using the SPSS program and the significance level of statistics was 5%. The results of the study are : 1) The importance of clinical practice stress reduction is shown in that the level of symptoms of stress in the experimental groups in clinical practice was higher than in the group receiving only a lecture. 2) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in reducing the symptoms of stress under the clinical practice stress conditions. 3) The effectiveness of the biofeedback training relaxation method to reduce symptoms of stress was higher than that of progressive muscle relaxation. 4) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in reducing stressful mood states. 5) The relaxation training methods of biofeedback and progressive muscle relaxation were not effective in reducing epinephrine and norepinephrine levels. 6) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in increaing the number of natural killer cells. 7) The relaxation training methods of biofeedback and progressive muscle relaxation were effective in decreasing high systolic and diastolic values of blood pressure and high pulse rates. In summary, the relaxation methods of biofeedback and progressive muscle relaxation in reducing clinical practice stress were effective in lowering the level of symptoms of stress and the profile of stressful mood states. They were also effective in lowering high blood pressure and pulse rates. The relaxation methods were effective in increasing the number of natural killer cells as part of the immune function. However, relaxation methods were not effective in reducing the catecholamine level. The biofeedback training method for reduction of symptoms of stress was more effective than the progressive muscle relaxation method.

• Journal of The Korea Institute of Healthcare Architecture
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• v.8 no.1
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• pp.61-67
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• 2002

It is the well-documented fact that most patients experience considerable stress in hospital. Stress is also a problem for families of patients, visitors and for hospital staffs. To promote wellness. It is fundamentally important that hospital be designed to foster copying with stress. By Literature review, this study presents stressors of patients, families, hospital staffs and various healing design elements. And then, it cross-checks the relations between stress-reducing conditions and healing design elements. Finally, this presents the healing design conditions for each stress-reducing conditions of patients, families and staffs.

• Journal of Mechanical Science and Technology
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• v.18 no.4
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• pp.606-621
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• 2004

A dynamic analysis using a hybrid finite element method was performed to characterize the effects of a number of manufacturing errors on bearing forces and critical tooth stress in the elements of a planetary gear system. Some tolerance control guidelines for managing bearing forces and critical stress are deduced from the results. The carrier indexing error for the planet assembly and planet runout error are the most critical factors in reducing the planet bearing force and maximizing load sharing, as well as in reducing the critical stress.