• Journal of Forest and Environmental Science
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• v.36 no.4
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• pp.318-325
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• 2020

This study was carried out to find the effects of aromatherapy using natural fragrance on reducing stress and improving job satisfaction of transportation workers in the taxi industry. A total of 120 workers were divided into the experimental group and the control group according to the inhalation of the fragrance and tested for 2 weeks. After 2 weeks, the difference of emotional change, stress analysis, and evaluation of job satisfaction according to aromatherapy were compared between the two groups. The result showed that the experimental group had a higher interest in scent products than the control group and that they wanted to encounter a lot of real scents, indicating that aromatherapy caused positive interest in general scent likability. In addition, the experimental group said that the inhalation of fragrance would refresh the feeling of the passengers in the vehicle and smoothly communicate with the passengers. Especially, it showed a significant difference between the two groups in terms of tension relief, pleasure and good mood by inhalation of fragrance, indicating the positive effect on job satisfaction.

• Transactions of the Korean Society of Mechanical Engineers
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• v.9 no.1
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• pp.40-46
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• 1985

Some problems such as toughness decrement and stess relief cracking (SRC), many occur when post weld heat treatment (PWHT) is applied to remove residual stress adn hydrogen. In this paper PWHT was carried out under the stress of 0, 98, 196 and 294 MPa (0, 10, 20 and 30kgf/mm$^{2}$ each) to simulate residual stress in HAZ of Cr-Mo steel. The effect of applied stress during PWHT on fracture toughness was evaluated by COD fracture toughness test, micro-hardnes test and observation of SEM. The experimental results are as follows; (1) Fracture toughness of weld HAZ was improved by PWHT, but it decreased as heat treated under the stress. (2)Hardness ratio under the stress of 294MPa (30kg/mm$^{2}$) was lower and fracture toughness was decreased than that of the no stress. (3) Applied stress in weld HAZ during PWHT assisted precipitation of over saturated alloying elements in the structure, so fracture surface at the stress of 294MPa (30kg/mm$_{2}$) appeared the grain boundary failure possibly one of the reasons for PWHT embrittlenment.

• Korean Journal of Materials Research
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• v.23 no.1
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• pp.18-23
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• 2013

In this study, the effects of cryogenic treatment cycles on the residual stress and mechanical properties of 7075 aluminum alloy (Al7075) samples, in the form of a tube-shaped product with a diameter of 500 nm, were investigated. Samples were first subjected to solution treatment at $470^{\circ}C$, followed by cryogenic treatment and aging treatment. The residual stress and mechanical properties of the samples were systematically characterized. Residual stress was measured with a cutting method using strain gauges attached on the surface of the samples; in addition, tensile strength and Vickers hardness tests were performed. The detailed microstructure of the samples was investigated by transmission electron microscopy. Results showed that samples with 85 % relief in residual stress and 8% increase in tensile strength were achieved after undergoing three cycles of cryogenic treatments; this is in contrast to the samples processed by conventional solution treatment and natural aging (T4). The major reasons for the smaller residual stress and relatively high tensile strength for the samples fabricated by cryogenic treatment are the formation of very small-sized precipitates and the relaxation of residual stress during the low temperature process in uphill quenching. In addition, samples subjected to three cycles of cryogenic treatment demonstrated much lower residual stress than, and similar tensile strength compared to, those samples subjected to one cycle of cryogenic treatment or artificial aging treatment.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.33 no.4
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• pp.44-54
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• 2020

Objectives : In the present study, we investigated whether or not an herb mixture including Lycii fructus(HML) has attenuation effects on light stress in rats. Methods : Light stress was induced by exposure to 300 lx of constant lifht for 24 h and 1mg/kg of caffeine was injected into the rat. Rats were orally treated with distilled water of HML for 21 days at 100mg/kg/d. The changes of mortality rate, clinical signs, body, blood chemistry, melatonin and IL-2 expression were analyzed after experiment. Results : Normal weight changes were observed in all treatment groups. In addition, no changes were observed in dead animals and general symptoms. At the time of autopsy, the appearance of all groups and gross examination of major organs were observed, and no gross findings were observed. Blood biochemical tests showed that total cholesterol and HDL cholesterol levels were statistically significantly decreased in the group treated with HML compared to the stress-induced group. Melatonin was measured in the blood, but there was no significant difference in the group treated with HML compared to the group with stress-induced group, but it tended to increase. IL-2 was measured in the blood, no significant change was observed in the group treated with HML compared to the stress-induced group. Conclusions : According to the above results, HML maybe help with hematological changes expressed by caffeine and light-induced stress.

• The Journal of the Korea Contents Association
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• v.18 no.12
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• pp.185-196
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• 2018

Current study was conducted to examine the mediating effect of maladaptive cognitive emotion regulation strategies and negative affect on the relationship between perceived stress and smartphone addiction of adults and to explore suggestions for counseling adults with smartphone addiction symptoms. Three hundred adults(146 males, 154 females) were administered perceived stress scale, maladaptive cognitive emotion regulation strategy scale, negative affect scale, and smartphone addiction scale. The main results are summarized as follows: First, perceived stress had positive influence on smartphone addiction. Second, negative affect showed mediating effect on the relationship between perceived stress and smartphone addiction. Third, maladaptive cognitive emotion regulation strategies did not show mediating effect on the relationship between perceived stress and smartphone addiction. Forth, maladaptive cognitive emotion regulation strategies and negative affect showed double mediating effect on the relationship between perceived stress and smartphone addiction. Based on the above results, it was suggested to include stress management and relief of negative affect through modification of maladaptive cognitive emotion regulation strategies in the treatment program for adults at high risk of smartphone addiction.

• Stress
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• v.25 no.4
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• pp.239-245
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• 2017

Background: A quasi-experimental study with non-equivalent control groups was performed to determine an effect of aromatherapy foot bath on stress and autonomic nervous activity. Methods: To confirm the effect of aromatherapy foot bath, aromatherapy foot bath group was asked to have a bathing by dropping 0.5 cc in 18 L water after blending with a ratio of 6:3:1 with essential oil lavender, lemon, and tea tree and a foot bath group was asked for bathing only by water. Results: Aromatherapy foot bath group showed significant decrease in subjective stress score (t=3.465, p=0.001) and stress index (t=3.021, p=0.004) in addition to simultaneous increase in sympathetic nervous activity (t=-2.913, p=0.005). However, no significant stimulation of parasympathetic nervous system was observed (t=-1.831, p=0.072). Conclusions: As aromatherapy foot bath is a possible effective intervention for stress relief, it can be applied as an effective method to relieve the stress for healthy adults and patients.

• The Korean Journal of Health Service Management
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• v.13 no.3
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• pp.149-162
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• 2019

Objectives: The purpose of this study was to identify differences in characteristics of the people who frequently drink alone between those in old-city regions and those in other regions in Busan, focusing on socio-demographic factors and the level of drinking according to the types of stress. Methods: The analysis confirmed the differences based on Busan Social Statistics Data in 2012, 2014, and 2016. Frequencies by each variable were presented, and ${\chi}^2$ and logistic regression analysis were also used in the analysis. Results: The residents of Busan showed higher odds ratios of "frequent drinking alone" when they felt considerably higher-than-normal levels of stress. In addition, in the residents of old-city regions, the odds ratios of those who frequently drank alone were not different between people who could easily relieve stress, who experienced economic stress, or who had relationship stress and people who did not. However, higher odds ratios of frequently drinking alone were reported when such participants felt some stress related to work, family, relationships, and so on. Conclusions: Interventions for the appropriate relief of stress caused by different reasons, as well as other stress-relieving methods, should be implemented for the people's benefits.

• Journal of the Korea Convergence Society
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• v.11 no.12
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• pp.301-307
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• 2020

This study aimed to determine the association between stress recognition and oral symptom experiences among adolescents. We analyzed it, based on the 14th Korea Youth Risk Behavior Web-based Survey (2018), using the chi-square test and logistic regression. The distribution rate of stress recognition and oral symptom experience within one year were 81.7% and 48.9%, respectively. The group with stress recognition had a higher rate (52.2%) of oral symptom experience than the group that did not recognize stress (p<0.001). In the stress recognition group, the odds ratio for oral symptom experience was 1.86 (95% CI: 1.78-1.95). We suggest that stress is associated with oral health in adolescents. In the future, it will be necessary to study stress relief and oral health education in adolescents.

• Journal of The Korea Institute of Healthcare Architecture
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• v.18 no.1
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• pp.45-52
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• 2012

This study aims to examine the outdoor environment of a geriatric hospital and explore its stress-relief impact upon those who utilize it. Post Occupancy Evaluation is employed to assess the effectiveness of a healthcare setting. This study is based on survey questionnaire including the users' perception of outdoor environment, their perceived restorativeness, and quality of life. A total of one hundred and sixty individuals including patients, families and visitors, and healthcare staffs. As a result, it turns out that the therapeutic outdoor environment and its users' health outcomes, such as reststroativeness and quality of life are significantly correlated. In conclusion, the finding of this research seems to demonstrate the potential that the therapeutic outdoor environment has for the improvement of its users' health by enhancing.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.10
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• pp.1752-1758
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• 2008

This paper deals with the reduction of friction torque in permanent magnet motors by using the heat treatment of stator core. The stator core is made of electrical steel sheared by the punching die. From the punching process, large mechanical stress acting on the edge of stator tooth induces significant plastic and elastic deformation and then cause the change of magnetization properties. Then, the mechanical and magnetic unbalance in the sheared region of stator tooth produced by material cutting has influence on the friction torque. This paper investigated the effect of the punching process on the magnetization process and the mechanical deformation, and then proposed the stress relief annealing method for the reduction of friction torque among one of motor characteristics.