• Journal of the Korean Institute of Gas
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• v.27 no.3
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• pp.35-40
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• 2023

In order to prevent an ammonia container from bursting under conditions such as overcharging and abnormal temperature rise, it is necessary to prepare accident prevention measures through analysis of the operating mechanism of the Thermally Activated Pressure Relief Devices (TPRD) attached to the container. In this study, stress analysis acting on the ammonia container under pressurized conditions, density change analysis according to temperature change, and correlation between container filling amount and temperature and pressure change were presented. In addition, the maximum filling amount of the ammonia container was calculated, and the temperature and pressure at the filling amount were calculated through the phase equilibrium diagram. Based on this, the appropriate melting point of the Thermally Activated Pressure Relief Devices was derived and verified through a melting temperature experiment. Based on the results of this study, conditions for preventing ammonia container rupture accidents were suggested.

• Journal of the Korean Data and Information Science Society
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• v.27 no.3
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• pp.749-761
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• 2016

The purpose of this study was to investigate the effects of emotional regulation between clinical practice stress and nursing professionalism in nursing students. Participants were 192 nursing students and data were collected from September to November, 2015. This study has shown that nursing professionalism is negatively associated with clinical practice stress (r=-.40, p<.001) and positively associated with emotional regulation (r=.55, p<.001). In addition, a negative correlation has been found significant between emotional regulation and clinical practice stress (r=-.20, p<.001). In a final model of hierarchial multiple regression, professor support (${\beta}=.19$, p<.01), satisfaction with nursing as a major (${\beta}=.14$, p<.05), clinical practice stress (${\beta}=-.19$, p<.01) and emotional regulation (${\beta}=.32$, p <.001) were associated with nursing professionalism. In this study, we also have shown that emotional regulation does not play a moderating role on the relationship between clinical practice stress and nursing professionalism. The results of this study suggests that, in order to improve nursing professionalism, it is important to promote support system, develop clinical-practice-stress-relief programs, and enhance emotional regulation training for nursing students.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.3
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• pp.59-65
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• 2017

The purpose of this study is to investigate the factors and effects of job stress of construction workers on construction accidents and turnover intention in order to improve the field work environment of construction industry which shows higher industrial accidents than other industries. To this end, research models and hypotheses were established based on previous research, and the questionnaire was distributed to 10 construction companies in Daejeon, Sejong, and Chungcheong provinces. The 301 data collected were performed statistical analysis such as basic statistical analysis, factor analysis, reliability analysis, correlation analysis, regression analysis, and logistic regression analysis using the statistical package (IBM SPSS 22). The results of this study are summarized as follows. First, job stress has a significant effect on accident occurrence. Among the sub-factors of job stress, there was positive (+) influence on work culture and relationship conflict between peers, and organizational system had negative influence. Job demands, compensation incompetence, and job instability were not statistically significant. Therefore, it is necessary to concentrate on the factors of work culture, organizational system, and relationship conflict in the construction site. Second, job stress has positive effect on turnover intention. Job stress, inadequacy of compensation, and work culture were positively related to turnover intention. Third, job demands have a slightly greater impact than compensatory inadequacies. The factors that make the job turnover more important are the excessive job burdens such as respect, internal motivation, responsibility rather than expectation non-conformity, time pressure, increase of work load. Therefore, in order to reduce the turnover intention of the construction worker, it is necessary to pay attention to improvement of the job requirement. Fourth, the worker's job stress could overcome by exercise and fatigue elimination, work environment management, and self-opening for others. It is necessary to establish a work environment management system for counseling and intimacy formation to open up the exercise and fatigue relief program of the workers at the construction site and to open themselves between the workers and the supervisors.

• Proceedings of the Korean Society of Crop Science Conference
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• 2023.04a
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• pp.105-105
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• 2023

Heavy metals, including lead (Pb) toxicity, are increasing in soil and are considered toxic in small amounts. Pb contamination is mainly caused by industrialization - smelting, mining. Agricultural practices - sewage sludge, pests and urban practices - lead paint. It can seriously damage and threaten crop growth. Pb can adversely affect plant growth and development by affecting the photosystem, cell membrane integrity, and excessive production of reactive oxygen species (ROS) such as hydrogen peroxide (H₂O₂)andsuperoxide(O₂.-). NO is produced via enzymatic and non-enzymatic antioxidants to scavenge ROS and lipid peroxidation substrates in terms of protecting cells from oxidative damage. Thus, NO improves ion homeostasis and confers resistance to metal stress. Our results here suggest that exogenous NO may aid in better growth under lead stress. These enhancements may be aided by NO's ability in sensing, signaling and stress tolerance in plants under heavy metal stress in combination with lead stress. Our results show that GSNO has a positive effect on soybean seedling growth in response to axillary pressure and that NO supplementation helps to reduce chlorophyll maturation and relative water content in leaves and roots following strong burst under lead stress. GSNO supplementation (200 µM and 100 µM) reduced compaction and approximated oxidative damage of MDA, proline and H₂O₂. Under plant tension, a distorted appearance was found in the relief of oxidative damage by ROS scavenging by GSNO application. In summary, modulation of these NO, PCS and prolongation of metal past reversing GSNO application confirms the detoxification of ROS induced by toxic metal rates in soybean. In summary, these NO, PCS and metal traditionally sustained rates of reverse GSNO application confirm the detoxification of ROS induced by toxic metal rates in soybean.

• Journal of Korea Water Resources Association
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• v.49 no.8
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• pp.693-705
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• 2016

In this study, the effects of sediment supply on the downstream of a large dam are investigated using a numerical model. The model simulation shows a good agreement with laboratory experiment results of sediment transport and diffusion from sediment pulses. The water surface changes from the various sediment bed elevations are also simulated using the model. The site which has a relatively stiff bed slope and meandering of a channel is selected as an appropriate location for sediment supply because of its shear stress enough to supply the sediment downstream. The model simulation shows the decrease of channel bed elevation through the simulation period with time. The well-deposition of sediment supplied from the downstream of dam is found in the location where the flow rate is relatively low. A bed relief index is increased with time and it is relatively greater in downstream compared to upstream. The channel bed variability increases as flow rate increases with a greater bed relief index. The results of this study demonstrate the importance of increasing water discharge of a large dam to increase the dynamic of channel bed and thus to enhance the efficiency of channel bed restoration by sediment supply.

• Korean Journal of Materials Research
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• v.23 no.9
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• pp.483-488
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• 2013

Over the past few decades, high-nitrogen austenitic steels have steadily received greater attention since they provide a unique combination of high strength and ductility, good corrosion resistance, and non-magnetic properties. Recently, highnitrogen 18Mn-18Cr austenitic steels with enhanced strength have been developed and widely used for generator retaining rings in order to prevent the copper wiring from being displaced by the centrifugal forces occurring during high-speed rotation. The high-nitrogen austenitic steels for generator retaining ring should be expanded at room temperature and then stress relief annealed at around $400^{\circ}C$ to achieve the required mechanical properties. In this study, four kinds of high-nitrogen 18Mn-18Cr austenitic steels with different nitrogen content were fabricated by using a pressurized vacuum induction melting furnace, and then the effects of nitrogen content, cold working, and stress relieving on tensile properties were investigated. The yield and tensile strengths increased proportionally with increasing nitrogen content and cold working, and they further increased after stress relieving treatment. Based on these results, a semi-empirical equation was proposed to predict the tensile strength of highnitrogen 18Mn-18Cr austenitic steels for generator retaining rings. It will be a useful for the effective fabrication of high-nitrogen 18Mn-18Cr austenitic steels for generator retaining rings with the required tensile properties.

• The Korean Journal of Pain
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• v.11 no.2
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• pp.235-240
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• 1998

Background: Preoperative blocking of surgical nociceptive inputs may prevent sensitization of CNS and reduce postoperative pain. The stress responses to surgical trauma consist of increase in catabolic hormones and decrease in anabolic hormones. We studied whether preoperative intravenous morphine could affect postoperative pain and change plasma cortisol and serum glucose levels. Methods: Thirty eight patients undergoing total abdominal hysterectomy were randomly assigned to one of three groups. Control group (n=11) did not received intravenous morphine, preoperative group (n=13) received intravenous morphine (0.1 mg/kg as a bolus 10 min before operation and followed by 1.5 mg/hr for 10 hours), postoperative group (n=14) received the same doses and method of intravenous morphine of preoperative group postoperatively. Postoperative pain relief was provided with i.v. fentanyl through Patient-Controlled-Analgesia Pump. Postoperative visual analogue scores (VAS), analgesic requirement (first request time, total amounts used), side effects, plasma cortisol and serum glucose levels were compared. Results: VAS were different between control group and the other two goups, but were not different between preoperative and postoperative group. Total amounts of used fentanyl were not different among groups, but first request time were significantly delayed in the preoperative group compared with the other two groups ($66.2{\pm}33.9$ vs $39.0{\pm}15.4$ and $45.0{\pm}14.9$ min respectively, p<0.05). Plasma cortisol and serum glucose levels were not different among groups. Conclusions: Above dosage of preoperative and postoperative morphine has analgesic effect, but could not block surgical stress induced plasma cortisol and serum glucose increase.

• Journal of the Korean Institute of Intelligent Systems
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• v.26 no.3
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• pp.226-232
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• 2016

The research for the improvement in math and science scores is active by the brain exercises, stress reliefs, and emotion sensitized illuminations. This principle is based on the following facts that the most effective brain turns are supported with the circumstances not only when the brain wave should keep stability and comfort in science criticism, but also when minimized stress and comfortable illumination should be adjusted in solving math problem. In this paper, in order to effectively learn mathematics and science, the most optimized simulating tests in learning conditions are conducted by using a stress relief. However, depending on the users' tastes, the effectiveness on favorite music or colors therapy have no convergency but many differentiations. Therefore, in this paper, in order to solve this problem, the proposed optimal illumination and music therapy treatment using fuzzy inference method.

• Journal of The Korean Society of Integrative Medicine
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• v.9 no.3
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• pp.19-35
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• 2021

Purpose : Recently, there has been a growing social interest in aging well. Consequently, wellness tourism has begun to attract attention. However, no studies on whether wellness tourism has any objective health benefits have been carried out yet. In this study, we assess the health benefits as well as the degree of improvement in health of a wellness tourism program. Methods : The study involved 30 adults over the age of 19 who live in the Gyeongsangnam-do region. Participants were evaluated on health indicator before and after participating in wellness tourism program. Participants took heart rate variability (HRV) test, and LFT, RFT, CBC, FBS HbA1C, and CRP test were conducted before and after the tour. Additionally, a survey was conducted before and after the program, and participant satisfaction was evaluated. Statistical differences in the tests conducted before and after the program were analyzed using a design t-test, a Wilcoxon signed-rank test, and McNemar's test. Results : The study showed that participants were very satisfied with and had significant health improvements after the wellness tourism program. The program was also found to be beneficial in improving participants' emotions as follows: BDI (p<.001), fatigue recovery (p=.006), stress relief (p=.003), improved quality of life (p<.05), and improved sleep quality (p<.001). Conclusion : Wellness tourism programs are specifically beneficial for improving participants' emotions (depression, anxiety), fatigue, stress levels, quality of life, and sleep. Therefore, they are beneficial to the overall health. Further research in the future by way of a follow-up study on the long-term effects on health after short-term interventions will provide more validation data.

• Journal of People, Plants, and Environment
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• v.21 no.6
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• pp.557-564
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• 2018

Along with the aging society, the prevalence of dementia is also increasing. Dementia causes short-term memory loss as well as difficulties of performing daily activities and gradually causes suffering of the patients and their family. In spite of various programs for prevention of dementia of older people are being implemented, there is a lack of developing natural-based program for physical and mental health promotion. Therefore, it is necessary to develop programs for the elderly living alone who are more vulnerable to dementia because of their social and economic isolation. The purpose of this study was to develop a natural-based program and investigate the effects of 10 weeks forest therapy program for dementia prevention to improve the psychological and physical health of the elderly living alone. The experimental subjects were 30 elderly (aged 65 or older) and 31 elderly participated in control group. The Stress response, depressive symptoms, weight, body mass index (BMI), fat mass and muscle mass were measured for pre and post test. The results showed that the experimental group showed subjective stress relief (t=5.249, p=.000), improvement in symptoms of depression (t=4.152, p=.000), and decreases in weight (t=2.686, p=.012), BMI (t=2.629, p=.014) and fat mass (t=2.918, p=.007) after the forest therapy program. The experimental group showed lower stress reactions(t=-7.185, p=.000) and less depressive symptoms (t=-5.303, p=.000) than control group after participating the program. These results suggest that periodic forest exposure can help having less stressful and depressive status than non-forest exposure and the forest therapy program can reduce participants' psychological and physical risk factors of dementia.