• 성인간호학회지
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• 제14권1호
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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.

• 한국정밀공학회지
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• 제23권5호
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• pp.162-169
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• 2006

Steel cord which is used as reinforcement in car tires is produced by wet-drawing process. Recently the quality improvement of the steel cord product is demanded by the tire market. After cold drawing process, produced residual stresses have a harmful effect on the durability of the wire and become the cause which decreases the quality of the product. Therefore, to improve the quality of the steel cord product, the research regarding the method of residual stress relaxation is necessary. To evaluate the quality of the cold drawn wire, it is very important to measure the residual stress, because the residual stress decides a variety of the quality level which is demanded in the cold drawn wire. The aim of this study is to propose residual stress relaxation method in the drawn wire using FE-analysis. The validity of the analysis results was verified by Nano indentation test.

• Journal of Biosystems Engineering
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• 제16권1호
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• pp.37-48
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• 1991

Rice plants are subjected to various forces such as natural force of wind and mechanical force of cultivating machines. Rheological behavior of the rice stem can be expressed in terms of three variables : stress, relaxation and time. The objectives of this study are to examine stress relaxation, creep and recovery characteristics on the rice stem in case of axial and radial loading. Stress relaxation with time was studied on three levels of loading rate and on four levels of applied stress. The results were summarized as follows : 1. The hysterisis losses of the rice stem distinctly observed at the radial compression in comparison with axial compression. The hysterisis loss implied that the stem to absorbed energy without being deformed beyond the yield point. 2. Ageneralized Maxwell model consisting of three elements gave a good description of the relaxation behavior of the rice stem. Rate of loading was more significant on the observed relaxation behavior within the short relaxation time, but there were little influences of rate of loading on the relaxation time. 3. The stress relaxation intensity and the residual stress increased in magnitude as the applied stress increased, but the relaxation time was little affected by the applied stress. 4. The coefficients of the stress relaxation model showed much differences in the radial compression and the axial compression, especially the higher relaxation stress of the third element was observed in the radial compression. 5. The behaviors of rice stem in creep and recovery test also might be represented by a four element Burger's model. But the coefficients of the creep model were different from those of the recovery model. 6. The steady-state phenomena of creep appeared at the stress larger than 20 MPa in Samkang and 1.8 MPa in Whajin. 7. The elastic modulus of the stem showed the range from 40 to 60 MPa. It could be considered, as a result, the rice stems had viscoelastic properties.

• 한국농공학회지
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• 제30권3호
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• pp.38-50
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• 1988

carried out to present a rheology model which is able to treat time-dependent properties of clay. The results were summarized as follow ; 1. The slope (a(e1)) of deviator stress in strain rate test was independent on axial strain, and pore water pressure was decreased with increment of strain rate. 2. The pore water pressure in a stress relaxation condition was not changed when the strain rate before stress relaxation was 0.05%/min., but it was increased with increment of time when the strain rate before stress relaxation was 0.2%/min 3. The greater the stress condition (q/qmax) and the strain rate before creep test became, the greater the increment rate of axial strain in creep test became. 4. SEKIGUCHI's constitutive equation was slightly overpredicted while empirical equation proposed in the study was well coincided with measured values. 5. The constitutive equation induced by a strain function could be dealed with a behavior of the pore water pressure increased with increment of elapsed time after primary consolidation.

• Structural Engineering and Mechanics
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• 제22권5호
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• pp.563-574
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• 2006

This paper studies mechanical behavior of the superelastic shape memory alloy (SMA) rods in terms of local deformations and time via tensile loading-unloading cycles for both ends fixed end constraints. Besides the unique stress induced martensitic transformation (SIMT), SMA's time dependent behavior when it is in mixed-phase condition upon loading and unloading, also need careful attention with a view of investigating the local deformation of the structural elements made of the same material. With this perspective, the so-called stress-relaxation tests have been performed to demonstrate and investigate the local strains-total strains relationships with time, particularly, during the forward SIMT. Some remarkable phenomena have been observed pertaining to SIMT, which are absent in traditional materials and those unique phenomena have been explained qualitatively. For example, at the stopped loading conditions the two ends (fixed end and moving end of the tensile testing machine) were in fixed positions. So that there was no axial overall deformation of the specimen but some notable increase in the axial local deformation was shown by the extensometer placed at the middle of the SMA specimen. It should be noted that this peculiar behavior termed as 'inertia driven SIMT' occurs only when the loading was stopped at mixed phase condition. Besides this relaxation test for the SMA specimens, the same is performed for the mild steel (MS) specimens under similar test conditions. The MS specimens, however, show no unusual increase of local strains during the stress relaxation tests.

• 대한간호학회지
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• 제29권4호
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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.

• 대한물리치료과학회지
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• 제22권2호
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• pp.37-42
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• 2015

Background : The purpose of this study is to identify how the relaxation music listening during exercise influences body flexibility and stress. Methods : Twenty healthy adults 20s and 30s who lack of body flexibility were recruited and each subjects performed exercise during the relaxation music listening or no listening. Bach, aria of linear G was used as the relaxation music. The experiment was conducted for 4 weeks. In this study, PASW ver 18.0 was utilized to perform non-parametric tests for comparisons. Result : The result with respect to the dependent variables are as follows: When non-parametric tests were conducted to compare body flexibility at the test of the right ear touch behind head by left hand and the stretching hands test between the two groups after exercise, they showed significant differences in statistical terms (p<.05). Conclusion : From the above results of the study it was found that the application of the relaxation music during the exercise is effective, it improved the body flexibility of the right ear touch behind head by left hand and the stretching hands more than the exercise without the relaxation music did. The outcome of the experiment may provide basic data for developing an effective way to increase body flexibility.

• 한국식품조리과학회지
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• 제5권1호
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• pp.49-52
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• 1989

도토리 조전분겔과 정제전분겔에 대하여, 변형의 정도를 달리한 응력완화시험을 실시하였다. 그 결과 초기응력($\sigma$$_{o}$ )은 변형정도에 무관하게 항상 정제전분겔이 큰값을 나타내었고, 평형응력($\sigma$$_{e}$)은 조전분겔이 더 큰 값을 보여주었다. 그러나 초기응력에 대한 평형응력의 비($\sigma$$_{e}$/$\sigma$$_{o}$ )는 60%변형의 경우에 최소값을 나타내었다. 응력완화곡선의 물성론적 모형 분석은 축차잔차법을 사용하였다. 60%변형의 경우, 조전분겔은 7-element 정제전분겔 은 5-element generalized Maxwell model로 분석되었고, 45%변형의 경우에는 조전분겔은 5-element, 정제전분겔은 3-element model로 표현할 수 있었다. 즉 조전분겔에 비해 타 성분들이 좀 더 제거된 정제전분겔이 보다 더 단순한 모형으로 분석되었다.

• 기본간호학회지
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• 제6권2호
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• pp.240-254
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• 1999

The purpose of this study was to investigate the effect of exercise therapy and relaxation therapy on catecholamine and heart rate in people in white color jobs and to determine this information the effectiveness of applied exercise therapy and relaxation therapy as a nursing intervention method for stress patients. The subjects were divided into an exercise therapy group, a relaxation therapy group, and control group and the research design was a nonequivalent control group pretest-post test design(exercise therapy : n= 12, relaxation therapy : n=12, control group, the group without any treatment in exercise on relaxation therapy : n=12), The subjects in the exercise therapy group were given a particular intensity for each kp during 30min, bicycle ergometer which is using an LX PE training system before & after 4weeks of training. The exercise therapy that was used was Astrard load method which tested absolute exercise load of heart rate before & after four weeks, and resting heart rate was tested for exercise and relaxation therapy before, after four weeks, and at eight weeks. The results of each kp & absolute exercise load were calculated with the target rate formula(maximal heart rate-rest heart rate) x exercise intensity(%) + rest heart rate so the subjects could continue 60-70% exercise intensity for exercise therapy over eight weeks. The relaxation therapy subjects were trained using a modified Jacobson's relaxation technique for eight weeks. The exercise and relaxation therapy were trained at the following intensity for eight weeks(3times/week, 30min/day) to see changes in catecholamine & heart rates. After eight weeks, statistical analysis of exercise & relaxation therapy were carried out Two-way ANOVA and multiple range test(SNK : Student Newman Keul) were used. The results are as follows : 1. The change of epinephrine & norepinephrine in the exercise therapy, relaxation therapy, and control group was statistically significant at the .05 level after four weeks & eight weeks. Also, exercise therapy was statistically significant at .05 level over that of the control group after 4weeks. 2. The change of heart rate in relaxation therapy was statistically significant at the .05 level, and was statistically significant at the .05 level over that of the exercise therapy and control group. In conclusion, it is obvious that exercise therapy and relaxation therapy should be one of the most effective stress treatment and desirable nursing interventions methods for job stress in people in white color jobs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제16권12호
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• pp.3943-3959
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• 2022

People are constantly exposed to stress and anxiety environment, which could contribute to a variety of psychological and physical health problems. Therefore, it is particularly important to identify psychological stress in time and to find a feasible and universal method of stress reduction. This research investigated the influence of different music, such as relaxation music and natural rhythm music, on stress relief based on Electroencephalogram signals. Mental arithmetic test was implemented to create a stressful environment. 23 participants performed the mental arithmetic test with and without music respectively, while their Electroencephalogram signal was recorded. The effect of music on stress relief was verified through stress test questionnaires, including Trait Anxiety Inventory (STAI-6) and Self-Stress Assessment. There was a significant change in the stress test questionnaire values with and without music according to paired t-test (p<0.01). Furthermore, a model based on Transformer for stress level classification from Electroencephalogram signal was proposed. Experimental results showed that the method of listening to relaxation music and natural rhythm music achieved the effect of reducing psychological stress and the proposed model yielded a promising accuracy in classifying the Electroencephalogram signal of mental stress.