• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.449-458
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• 2017

This research is a descriptive correlation research for comprehending the end of life care stresses, work environment, and reduction of nurses in geriatric hospitals and analyzing the factors influencing their burnout. We recruited 195 nurses from 8 geriatric hospitals in B metropolitan city and collected data on the end of life care stress, work environment and reduction using organized questionnaires. The data were analyzed with SPSS WIN 21.0 program. The average grade of end life care stress was $3.84{\pm}0.56$, nursing work environment $3.25{\pm}0.60$, and burnout $2.93{\pm}0.52$. There was a positive correlation between the end of life care stress and reduction(r=.206, p=.004) but a negative correlation between nursing work environment and reduction(r=-.431, p<.001). The most influential factor on the reduction was nursing satisfaction(${\beta}=-.302$), followed by work environment(${\beta}=-.294$), age(${\beta}=.286$), duty style(${\beta}=-.17$), and end of life care stress(${\beta}=.164$). The overall explanatory power was 41.2%.These results suggest that in order to minimize the reduction of nurses in geriatric hospitals, the provision of a supportive work environment which enhances their pride and responsibility as a nurse and offers incentives is required with effective distribution of duties, development of the end of life nursing education and administrative tools for reducing their stress.

• Environmental Analysis Health and Toxicology
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• v.18 no.3
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• pp.165-174
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• 2003

Cr (Ⅵ) - containing compounds are well-established carcinogens, although the mechanism for chromium - induced carcinogenesis is still not well understood. The reduction of Cr (Ⅵ) to its lower oxidation states, par ticularly Cr (V) and Cr (IV), is an important step for the production of chromium-mediated reactive oxygen species (ROS). The persistent oxidative stress during the reduction process may play a key role in the mechanism of Cr (Ⅵ) -induced carcinogenesis. This paper summarizes recent studies on (1) the reduction of Cr (Ⅵ) to Cr (III) occur by a multiplicity of mechanisms depending on the nature of reducing agents including ascorbate, diol-and thiol-containing molecules, certain flavoenzymes, cell organelles, intact cells, and whole animals; (2) free-radical production with emphasis on hydroxy radical generation via Fenton or Haber-Weiss type reactions; and (3) free radical - induced cellular damage, such at DNA strand breaks, hydroxylation of 2'-deoxyguanosine, and activation of nuclear transcription factor kB.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.1-8
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• 2000

A modified low-Reynolds-number Reynolds stress model is developed for the calculation of drag-reducing turbulent flows induced by polymer injection. The results without polymer injection are compared with the results of direct numerical simulation to ensure the validity of the basic model. In case of drag reduction, profiles of mean velocity and Reynolds stress components, in two-dimensional channel flow, obtained with a proper value of viscosity ratio are presented and discussed. Computed mean velocity profile is in very good agreement with experimental data. And, the qualitative behavior of Reynolds stress components with the viscosity ratio is also reasonable.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.6
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• pp.702-707
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• 2013

Sleep is an essential biological process of which the underlying regulatory mechanisms involve numerous anatomical structures and biochemical substances that can be compromised by stress and the immune system. Gamma aminobutyric acid (GABA) is the main inhibitory neurotransmitter of the central nervous system (CNS). It is well established that activation of $GABA_A$ receptors promotes sleep. L. brevis BJ20 fermentation of sea tangle and oysters resulted in stress reduction and sleep inducing effects. This is the first study to report that GABA has the ability to induce sleep related hormones in mice; therefore, it has potential use as a natural sleep aid. These results suggested that sea tangle and oysters fermented by L. brevis BJ20 can be used as potential agents for stress reduction and sleep promotion.

• Smart Structures and Systems
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• v.17 no.5
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• pp.725-742
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• 2016

This paper is focused on stiffness ratio effect and a new method to specify the best pattern of piezoelectric patches placement around a hole in a plate under tension to reduce the stress concentration factor. To investigate the stiffness ratio effect, some different values greater and less than unity are considered. Then a python code is developed by using particle swarm optimization algorithm to specify the best locations of piezoelectric actuators around the hole for each stiffness ratio. The results show that, there is a line called "reference line" for each plate with a hole under tension, which can guide the location of actuator patches in plate to have the maximum stress concentration reduction. The reference line also specifies that actuators should be located horizontally or vertically. This reference line is located at an angle of about 65 degrees from the stress line in plate. Finally two experimental tests for two different locations of the patches with various voltages are carried out for validation of the results.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2001.04a
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• pp.639-642
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• 2001

The possibility of weight reduction of rotor part in gas-gas geater(GGH) is studied from the viewpoint of allowable stress. In this work, finite element analysis(FEA) is performed with original model and three weight-reduced models with different diaphragm thickness, respectively. Stress concentrations at rotor diaphragm happen due to the dead weight, pressure difference between treated gas and untreated gas and thermal distribution in the rotor. As the thickness of diaphragm is decreased, the stress level is increased. The direction of treated gas and untreated gas flow may affect the stress level. Fatigue life assessment is not considered because pressure difference, the only cyclic load, can be ignored. The possible weight-reduced model is presented.

• Journal of Power System Engineering
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• v.11 no.2
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• pp.32-37
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• 2007

The present study describes the effects of music and vibroacoustic stimuli to the relaxation of human body. We have carried out the experiment on 6 human subjects of which are composed 3 men and 3 women. We have investigated the electroencephalogram(EEG) of all subjects before and after the stimuli of which are made a strong noise or the meditatiom music and the acoustic vibration. The vibroacoustic device has transmitted meditation music as vibration between 20Hz and 250Hz to the body. From the experimental results, we made sure the effects that the meditation music and vibroacoustic stimuli influenced the stress reduction of human body for good as alpha wave was increased continuously during the good stimuli and after that.

• Structural Engineering and Mechanics
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• v.54 no.5
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• pp.973-986
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• 2015

Ethylene tetrafluoroethylene (ETFE) foil is a novel structural material which has being used in shell and spatial structures. This paper studies biaxial creep property of ETFE foil by creep tests and numerical simulation. Biaxial creep tests of cruciform specimens were performed using three stress ratios, 1:1, 2:1 and 1:2, which showed that creep coefficients in biaxial tension were much smaller than those in uniaxial one. Then, a reduction factor was introduced to take account of this biaxial effect, and relation between the reduction factor and stress ratio was established. Circular bubble creep test and triangle cushion creep test of ETFE foil were performed to verify the relation. Interpolation was adopted to consider creep stress and reduction factor was involved to take account of biaxial effect in numerical simulation. Simulation results of the bubble creep test embraced a good agreement with those measuring ones. In triangle cushion creep test, creep displacements from numerical simulation showed a good agreement with those from creep test at the center and lower foil measuring points.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.21 no.1
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• pp.65-69
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• 2012

According to the developments of automobile industry, a technology has been studied in a point of view of environment, which is to increase fuel consumption rate. Especially it is well known that a weight reduction is one of the main technologies to increase the fuel consumption rate and, also to decrease the cost of manufacturing. This paper presents the method for reducing weight of bracket, which connects air conditioner compressor to engine, based on dynamic stress analysis and engineer's intuition for optimal design.

• Korean Journal of Adult Nursing
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• v.14 no.1
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• pp.44-52
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• 2002

Purpose: This study is to identify the effects of muscle relaxation therapy on mood state and job stress of clinical nurses, finally to purpose the bases of nursing intervention to increased of work efficiency and job satisfaction. Method: The research design was a nonequivalent control group pretest-posttest design. The subjects were 50 clinical nurses (23 for experimental group), who were working for 1-5 years in medical and surgical ward from the 2 C-University medical center in Seoul. This study was conducted from May 12 to July 25, 2000. The muscle relaxation therapy was performed 5 weeks to experimental group. The experimental group participated in the muscle relaxation training sessions for 20minutes twice a week during five weeks. The level of job stress was measured by nurses occupational stress scale. The level of Psychological response was measured by Profile of mood state. The data was analyzed using descriptive statistics, $X^2$-test, t-test, paired t-test. Result: The results of this study were as follows: The experimental group who received the muscle relaxation therapy showed more reduction of job stress level (t=1.35, p=0.038) and profile of mood state level (t=2.27, p=0.027) after therapy than those in control group. Conclusion: This study reveals that the muscle relaxation therapy is effective in reduction of nurse's job stress and promotion of mood state. So the researcher thinks that it is useful in reduction of job stress and increased of job satisfaction in hospital.