• Journal of Korean Biological Nursing Science
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• v.21 no.3
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• pp.178-187
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• 2019

Purpose: The purpose of this study was to investigate how college students' perceived stress, cognitive stress, and somatization affect their heart rate variability (HRV). Methods: This study is a cross-sectional survey research on 191 university students, registered at the G University. The perceived stress scale (PSS) and cognitive stress response scale, were used to assess level of stress. The somatization symptom scale of the Symptom Check List 90 (SCL-90), was used to assess level of somatization caused by stress. To assess heart rate variability (HRV), we conducted a five-minute test using a pulse wave analyzer, to analyze short-term HRV. Results: The SCL-90 somatization score had relatively high positive correlation (p< .001) with cognitive stress, but low positive correlation (p< .001) with perceived stress. Cognitive stress response had low negative correlation (p< .001) with 1nSDNN and 1nRMSSD among HRV parameters. Perceived stress was not correlated with HRV. Multiple regression analysis showed that variables of perceived stress, cognitive stress, and somatization symptoms, could not explain HRV. By contrast, one of the HRV indicators, 1nSDNN, was affected by age, gender, and aggressive-hostile thought, the latter being a subscale of the cognitive stress response scale. Conclusion: This study suggests that stress evaluation for people in early adulthood will be more effective, if the evaluation examines cognitive stress and heart rate variability.

• Research in Community and Public Health Nursing
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• v.11 no.2
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• pp.321-332
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• 2000

The purpose of this study was to test the hypothetical model designed to explain nursing students' perceived stress, coping levels, and stress outcomes. This hypothetical model was based on the Kim. Jung Hee(l987)' s stress model and stress-related literature. Exogenous variables were self-efficacy. hardiness. social support. and exercise. Endogenous variables were stress perception. coping levels. and stress outcomes. Empirical data for testing the hypothetical model consisted of 205 nursing students. SAS PC Program and LISREL 8.12a program were used for descriptive statistics and linear structural relationship(LISREL) modeling. The results were as follows. 1) The overall fit of the hypothetical model to the data was good( $x^2$=78.41(p=0.010), $x^2$/ df=1.50. RMSEA=0.05, standardized RMR= 0.05, GFI=0.95, AGFI=0.91, NNFI=0.90, NFI=0.94). 2) The results of statistical testing of the hypotheses were as follows. (1) As expected. self-efficacy had a significant effect on stress perception. But. hardiness. social support, and exercise did not have a significant effect on stress perception. Self-efficacy, hardiness. social support, and exercise explained 12% of the total variance of stress perception. (2) As expected, self-efficacy, hardiness, social support, exercise, and stress perception had a significant effect on coping behavior, Self-efficacy, hardiness, social support, exercise, and stress perception explained 53% of the total variance of coping behavior. (3) As expected, stress perception and coping behavior had a significant effect on stress outcomes. Stress perception and coping behavior explained 84% of the total variance of stress outcomes. In conclusion, the hypothetical model of this study was confirmed in explaining and predicting stress perception, coping levels, and stress outcomes in nursing students. And these findings suggest the need to develop nursing intervention to enhance self-efficacy, hardiness, social support, and exercise to decrease the harmful outcomes of stress.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.5
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• pp.467-476
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• 2016

In the present study, we examined the effect of pertussis toxin (PTX) administered centrally in a variety of stress-induced blood glucose level. Mice were exposed to stress after the pretreatment of PTX (0.05 or 0.1 mg) i.c.v. or i.t. once for 6 days. Blood glucose level was measured at 0, 30, 60 and 120 min after stress stimulation. The blood glucose level was increased in all stress groups. The blood glucose level reached at maximum level after 30 min of stress stimulation and returned to a normal level after 2 h of stress stimulation in restraint stress, physical, and emotional stress groups. The blood glucose level induced by cold-water swimming stress was gradually increased up to 1 h and returned to the normal level. The intracerebroventricular (i.c.v.) or intrathecal (i.t.) pretreatment with PTX, a $G_i$ inhibitor, alone produced a hypoglycemia and almost abolished the elevation of the blood level induced by stress stimulation. The central pretreatment with PTX caused a reduction of plasma insulin level, whereas plasma corticosterone level was further up-regulated in all stress models. Our results suggest that the hyperglycemia produced by physical stress, emotional stress, restraint stress, and the cold-water swimming stress appear to be mediated by activation of centrally located PTX-sensitive G proteins. The reduction of blood glucose level by PTX appears to due to the reduction of plasma insulin level. The reduction of blood glucose level by PTX was accompanied by the reduction of plasma insulin level. Plasma corticosterone level up-regulation by PTX in stress models may be due to a blood glucose homeostatic mechanism.

• Research in Community and Public Health Nursing
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• v.10 no.1
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• pp.252-261
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• 1999

The purpose of this study was to investigate the daily stress and stress coping behavior of elementary school children. The subjects for this study were 372 children fourth, fifth and sixth graders from an elementary school in Pusan. We adopted Won - Joo Chung's research instrument (1997) for measuring stress and coping behavior in this study. Statistical techniques such as frequency, percentage, mean, standard deviation, order, and Pearson correlation were used to examine the research questions of this study. The results of this study were as follows: 1. The most common instance of stress to be experienced by all children was the stress from school life, followed by social pressures, individual pressures and family environment. 2. A positive revaluation was the most commonly used stress-coping behavior, followed by behavioral mood conversion, spiritual support, problem-facing behavior, an information search for problem-solving, physical separation for emotional relaxation, avoidance, emotional aggressiveness and emotional expression. 3. Stress-coping behavior had a positive and significant correlation with the stress score(r = .4391, p= .000). In conclusion, the stress from school life was the most common experienced by all children. While independent effort in problem-solving was unsufficient, stress coping behavior had positive results. Therefore, this study verified the necessity of minimizing the stress children experience from school life and of helping them attain desirable stress-coping behaviors.

• Journal of the Korean Society of School Health
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• v.23 no.2
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• pp.286-295
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• 2010

Purpose: This study was conducted to identify the factors affecting the job stress of school nurses and reducing their the job stress by analyzing degree of the stress according to the factors related to job stress. Methods: The participants were 136 school nurses who worked in Pusan province. The Data were collected by self-reporting questionnaires from Dec. 11th in 2006 to Feb. 9th in 2007. The data were analyzed by Frequency, Mean, t-test, ANOVA, Pearson Correlation Coefficient and Stepwise multiple regression analysis (SPSSwin 12.0s). Results: There was significant difference of the degree of job stress in age. There was significantly negative relationship between the job characteristics and job stress (r=-.473), job satisfaction and job stress (r=-.561), personal values and job stress (r=-.429), achievement motivation and job stress (r=-.215) at p<.01 level. The major factor which influence the degree of job stress was job satisfaction. Conclusion: The factors affecting the job stress of school nurses was correlated with one another and influenced to the degree of the job stress directly and indirectly. The factor that affected the degree of the job stress directly was the job satisfaction and the personal values. As shown this result, it is important that the factor of the job stress lies in the mental characteristics.

• International Journal of Reliability and Applications
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• v.15 no.2
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• pp.125-150
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• 2014

Accelerated life tests (ALTs) are extensively used to determine the reliability of a product in a short period of time. Test units are subject to elevated stresses which yield quick failures. ALT can be carried out using constant-stress, step-stress, progressive-stress, cyclic-stress or random-stress loading and their various combinations. An ALT with linearly increasing stress is ramp-stress test. Much of the previous work on planning ALTs has focused on constant-stress, step-stress, ramp-stress schemes and their various combinations where the stress is generally increased. This paper presents an optimal design of ramp soak-stress ALT model which is based on the principle of Thermal cycling. Thermal cycling involves applying high and low temperatures repeatedly over time. The optimal plan consists in finding out relevant experimental variables, namely, stress rates and stress rate change points, by minimizing variance of reliability function with pre-specified mission time under normal operating conditions. The Burr type XII life distribution and time-censored data have been used for the purpose. Burr type XII life distribution has been found appropriate for accelerated life testing experiments. The method developed has been explained using a numerical example and sensitivity analysis carried out.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.39 no.7
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• pp.612-617
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• 2011

An experimental study was carried out for the Elbrodur-NIB(copper alloy) at room temperature under stress-controlled uniaxial fatigue loading with and without mean stress. As a result, the effects of stress amplitude, mean stress and stress rate on ratcheting behavior were investigated. The ratcheting strain increased with increasing stress amplitude for a given mean stress, and with mean stress for a given stress amplitude. But, the ratcheting strain decreased as the stress rate increased. The three mean stress models were investigated and the mean stress models of Smith-Watson-Topper and Walker yielded good correlation of fatigue lives in the life range of $10^2-10^5$cycles.

• Journal of the Korean Geotechnical Society
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• v.19 no.1
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• pp.143-150
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• 2003

This study deals with the stress-strain-strain rate behaviour of overconsolidated clay. Consolidated-drained stress path tests were performed on the stress-time dependent condition. Stress history consists of rotation angle of stress path, overconsolidation ratio, and magnitude of length of recent stress path. Time history includes loading rate of recent and current stress path. Test results show that all influence factors have an increasing strain rate with time, and the strain rate varies with the change of the rotation angle of stress path. With the increase of overconsolidation ratio and loading rate of current stress path, the strain rate also increases. For the stress history, correlation between stress-strain and strain rate is indicated but the time history is not.

• The Korean Journal of Community Living Science
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• v.23 no.2
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• pp.163-175
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• 2012

The purpose of this study was to examine the effects of mother and father's parenting efficacy, parenting stress on children's daily stress. The subjects were 292 children selected from 4 elementary schools and their mothers and fathers. Data was collected using the parenting efficacy index, parenting stress index, and children's daily stress inventory, and was statistically analyzed using t-test, one way ANOVA(Scheffe test), correlation analysis and multiple regression analysis. The study showed that there were some significant differences in children's daily stress according to the children's grade and gender. Correlation analysis indicated that the mother's parenting efficacy and children's daily stress had negative correlation, and also father's parenting efficacy and children's daily stress had negative correlation. Further, mother's parenting stress had positive correlation with children's daily stress, and father's parenting stress as well. It was also found that parenting efficacy of mother's general parenting ability, parenting efficacy of father's discipline ability, father's stress of difficult child, mother's educational distress, and children's gender were all significant predictors of the children's daily stress.

• Korean Journal of Occupational Health Nursing
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• v.17 no.1
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• pp.34-44
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• 2008

Purpose: This study was conducted to find out the effects of self-efficacy on job stress symptoms and coping strategies depending on perceived job stress. Method: The subjects were 447 workers employed in a manufacturing company. Demographic characteristics, self-efficacy, job stress, job stress symptoms and coping strategies were assessed by a self-administered questionnaire. Each envelope to keep the secret sealed completed questionnaires. Result: Job stress and job stress symptoms in workers with a high level of self-efficacy were lower than those of a low level of self-efficacy. Active coping strategies in workers with a high level of self-efficacy group were higher than those of a low level of self-efficacy. In multiple regression analysis, job stress symptoms were significantly higher in increasing job stress, increasing self-efficacy, office workers, manager group and increasing age. Active coping strategies were significantly higher in increasing self-efficacy, increasing career, males and decreasing job stress. Whereas passive coping strategies were significantly higher in females, increasing job stress and increasing self-efficacy. Conclusion: This study suggests that self-efficacy is a significant factor on job stress, job stress symptoms and coping strategies. Therefore, developing a job stress management program to increase self-efficacy and verifying its effects are needed.