• Journal of the Korean Society for Precision Engineering
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• 제24권5호
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• pp.44-55
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• 2007

The method for fatigue life prediction of ball bearing is proposed applying the algorithm of contact fatigue prediction based on stress analysis. In order to do this, a series of simulation such as initial surface stress analysis, EHL analysis, subsurface stress analysis and fatigue analysis are conducted from the loading at each ball location calculated for a bearing subjected to external bearing load and contact shape function. And uniaxial fatigue tests are performed to obtain fatigue parameter of AISI 52100 steel. It was found that since stress is usually higher at the inner raceway contact than at the outer raceway contact, fatigue failure occurs on the inner raceway first. When the fatigue life calculated in the stress-based method are compared with L50 life of L-P model, Crossland criterion for the radial load increment is similar to L50 life and Dang Van criterion for the axial load increment is similar. In the case of EHL contact, there is no difference of fatigue life between dry contact and EHL contact, when maximum Hertz pressure exceeds 2.5GPa.

• Asian-Australasian Journal of Animal Sciences
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• 제32권8호
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• pp.1095-1103
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• 2019

Objective: Among stress responses, the unfolded protein response (UPR) is a well-known mechanism related to endoplasmic reticulum (ER) stress. ER stress is induced by a variety of external and environmental factors such as starvation, ischemia, hypoxia, oxidative stress, and heat stress. Inositol requiring enzyme $1{\alpha}$ ($IRE1{\alpha}$)-X-box protein 1 (XBP1) is the most conserved pathway involved in the UPR and is the main component that mediates $IRE1{\alpha}$ signalling to downstream ER-associated degradation (ERAD)- or UPR-related genes. XBP1 is a transcription factor synthesised via a novel mechanism called 'frame switch splicing', and this process has not yet been studied in the horse XBP1 gene. Therefore, the aim of this study was to confirm the frame switch splicing of horse XBP1 and characterise its dynamics using Thoroughbred muscle cells exposed to heat stress. Methods: Primary horse muscle cells were used to investigate heat stress-induced frame switch splicing of horse XBP1. Frame switch splicing was confirmed by sequencing analysis. XBP1 amino acid sequences and promoter sequences of various species were aligned to confirm the sequence homology and to find conserved cis-acting elements, respectively. The expression of the potential XBP1 downstream genes were analysed by quantitative real-time polymerase chain reaction. Results: We confirmed that splicing of horse XBP1 mRNA was affected by the duration of thermal stress. Twenty-six nucleotides in the mRNA of XBP1 were deleted after heat stress. The protein sequence and the cis-regulatory elements on the promoter of horse XBP1 are highly conserved among the mammals. Induction of putative downstream genes of horse XBP1 was dependent on the duration of heat stress. We confirmed that both the mechanisms of XBP1 frame switch splicing and various binding elements found in downstream gene promoters are highly evolutionarily conserved. Conclusion: The frame switch splicing of horse XBP1 and its dynamics were highly conserved among species. These results facilitate studies of ER-stress in horse.

• Journal of the Korean Home Economics Association
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• 제33권5호
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• pp.89.2-98
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• 1995

This study examined whether specific coping strategies for the university entrance examination stress are related to high school seniors' depression and whether these strategies moderate the relationship between additional life event stress and depression. A sample of 358 high school seniors reported their level of additional life event stress, coping strategies they were using to handle examination stress, and their levels of depression. Problem-focused coping strategies and affective-regulation coping strategies were found to be related to reduction in depression. And, coping with examination stress was found to be related to depression independent of the level of additional life event stress.

• Journal of Oriental Neuropsychiatry
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• 제11권1호
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• pp.47-57
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• 2000

This study was designed and performed to identify the effects of oriental medical therapy on hwabyung patients by investigating the life events as the cause of Hwabyung, recent stress perception which influences the clinical appearances and change of symptoms by means of objective scales. 1. Through life events rating scale, life events are reported as follows, in the order of majority. Health, discord within family, martial life, friendship and interest, religion etc. Hwabyung patients experienced negative stress much more than positive stress. 2. Through the GARS (Global Assessment of Recent Stress), there were some significant decreases of stress perception in stress4(stress of sickness or injury), stress7(stress of change or no change in routine) and stress8(overall global stress)(p<0.05, respectively), but there were no significant decreases in five items out of eight items. 3. There were significant decreases of all rated symptoms(feeling of chest oppressed, stuffy in the chest or epigastric mass, feeling of something pushing-up, flushing of body or face, abrupt impulsion of anger, resentment), which were checked weekly for 4 times (p<0.05, respectively). In this study the symptoms of hwabyung were improved regardless of stress perception. It means that hwabyung can be improved significantly with oriental medical therapy.

• The Journal of Korean Society for School & Community Health Education
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• 제12권2호
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• pp.43-67
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• 2011

Objectives: The purpose of this study was to analyze factors affecting school life adjustment of athletes in middle and high school. Methods: The data in this study came from the survey which conducted to 500 students of physical education high school athletes and elite athletes in general school from the beginning of December 2009 to the end of January 2010 in Seoul and Kyunggi. Finally 436 cases was used. The dependant variable in this study was school life adjustment. And the independent variables were socio-demographic factors, stress and depression factors, social support factors. The analysis methods were T-test, ANOVA, correlation analysis, stepwise multiple regression analysis by using SPSS Ver. 12.0. Results: First, there was a statistically significant result between school life adaptation and sex, family circumstances, life satisfaction variables Second, there was a negative correlation between social support and stress, depression. Third, there was a negative correlation between school life adjustment and some stress factors, all depression factors. Also relationship between school life adjustment and social support showed a positive correlation. Fourth, Taking a look at the impact on school life adjustment, family factors and practical environmental factors in the stress factors and the feeling of worthlessness in the depression factors appeared to influence negatively. Also teachers' support in the social support factors showed positive effects. Explanatory power of the final regression model was 25.6%. Conclusions: The first step in order to improve the school life adjustment of athletes in middle and high school is the teachers' support. Athletes in middle and high school can have capability, responsibility, initiatives through teachers' attention and affection. The effective prevention education and health education programs on stress and depression should be introduced and carried out in the health education programs actively for student athletes to be free from stress, depression.

• Journal of Korean Academy of Nursing
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• 제52권3호
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• pp.324-340
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• 2022

Purpose: This study determined acculturative stress' effect on the life satisfaction of multicultural adolescents based on Roy's Adaptation Model and some earlier studies. Further, it examined the sequential multiple mediating effects of bicultural acceptance attitude, self-esteem, and social withdrawal on life satisfaction. Methods: Participants included 1,163 multicultural adolescents who participated in the sixth Multicultural Adolescents Panel Study. A hypothesis test was conducted using Hayes' Process Macro Model 81. Results: Life satisfaction increased with a decline in acculturative stress. Each of bicultural acceptance attitude, self-esteem, and social withdrawal had a single mediating effect on the relationship between acculturative stress and life satisfaction in multicultural adolescents. The sequential multiple mediating effects of bicultural acceptance attitude and self-esteem were confirmed significant after their impact on the relationship between acculturative stress and life satisfaction was analyzed. Bicultural acceptance attitude and social withdrawal were found to have a significant sequential multiple mediating effect on the relationship, as well. Conclusion: This study's results demonstrate that acculturative stress reduction is critical to improving multicultural adolescents' life satisfaction. Bicultural acceptance attitude, self-esteem, and social withdrawal have a single mediating or sequential multiple mediating effect on the relationship between multicultural adolescents' acculturative stress and life satisfaction. The findings, which highlight mediating effects, indicate that by increasing bicultural acceptance attitude and self-esteem, and reducing social withdrawal, multicultural adolescents' life satisfaction can be improved.

• Journal of Applied Reliability
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• 제17권2호
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• pp.112-121
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• 2017

Purpose: The most previous works on designing accelerated life tests (ALTs) are focused on the application of a single stress. Because of the difficulty to obtain the sufficient information in a reasonable duration using single stress only, there is needed in practice to use multiple-stress ALTs frequently. This paper presents new practical plans with two stresses for Weibull distribution. Methods: The four-level practical plans based on rectangle test region are proposed and compared with the corresponding three-level statistically optimal plans. Sensitivity analyses for assumed design parameters and life-stress relationship are conducted. Results: A procedure to choose practical ALT plans is illustrated with a numerical example and guidelines for planning two-stress ALTs are provided. Conclusion: The proposed two-stress ALT plans on practical constraints to assess a quantile of Weibull lifetime distribution at the use condition are efficient and robust.

• Journal of Technologic Dentistry
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• 제35권4호
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• pp.405-414
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• 2013

Purpose: The purpose of this study was to examine the relationship of the general characteristics of health-related majors to their life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, somatic symptom scale and college life stress scale. And it's also meant to analyze influential factors for their stress about college life. Methods: The subjects in this study were the students who were in the department of dental laboratory technology and the department of dental hygiene at a college located in the region of Iksan, North Jeolla Province. Data were gathered in November and December, 2012. The life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, physical symptom scale, somatic symptom scale and college life stress scale of the general characteristics were analyzed by t-test and one way analyses of variance (ANOVA) and the Duncan's multiple range test at the 95% confidence level to assess the statistical significance. And stepwise multiple regression analysis was conducted to determine what factors would affect the stress of the students about college life. The data were analyzed with the windows ver. 12.0(SPSS GmbH, Germany) statistical software program. Results: Among the general characteristics, there were significant differences according to gender and age in all the variables that were life expectancy scale, depression scale, health perception scale, subjective wellbeing scale, physical symptom scale and college life stress scale. 61.3% of the students responded they slept for six hours or less, and the respondents who slept for six hours or less scored significantly statistically lower in health perception scale, subjective wellbeing scale and physical symptom scale. As for college life stress, the respondents who got depressed more often, whose subjective peace or happiness was lower, whose life expectancy was lower, who had worse physical symptoms, whose living standard was lower and whose academic year was lower were under heavier stress about their college lives. Conclusion: As the worse physical health and worse mental health(life expectancy, depression, health perception, subjective wellbeing and physical symptoms, etc.) of the college students led to heavier stress about college life, how to promote their physical health and mental health should discreetly be considered, and every necessary measure should be taken to improve their physical and mental health.

• Korean journal of food and cookery science
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• 제22권6호통권96호
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• pp.783-791
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• 2006

The consciousness and eating habits of the housekeeper directly influence the stress level and health quality of the household occupants. In Korea, most housewives are in charge of dietary life. Accordingly, their attitudinal clusters toward dietary (eating) life were researched in relation to their stress and health. The research results showed that irregular eating habits cause stress. Therefore, it is necessary for housewives to have a regular eating habit. The results were as follows. The house wives' attitudes toward dietary life were categorized into 5 clusters: regular and speedy overeating, regular and frequent eating, regular and light eating, irregular and light eating, irregular and speedy overeating. The cluster of regular and frequent snacks was 24.3%. The cluster of irregular and speedy overeating caused the most stress. Especially the house wives' group belonging to the cluster of irregular and speedy overeating were under social and emotional stress, while the cluster of regular and light eating and the cluster of irregular and light eating were under concentration stress. The cluster of regular and frequent snacks and the cluster of irregular and light eating had negative effect on their health, while the cluster of regular and speedy overeating had negative effect on their family's health by their social stress.

• Journal of Korean Academy of Nursing
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• 제46권4호
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• pp.583-597
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• 2016

Purpose: The study was done to evaluate the effects a Stress Management Program (SMP) on stress, problem solving skills, and quality of life for hospitalized patients with Schizophrenia. Methods: A mixed method design was used: a combination of a repeated-measure design with a non-equivalent control group and qualitative data collection. The participants were 40 patients with schizophrenia admitted in three psychiatric hospitals. The experimental group (n=20) received the SMP twice a week for a total of 8 weeks. Results: Study results revealed that the SMP was effective for stress (F=321.02, p<.001), problem solving ability (F=246.28, p<.001), and quality of life (F=63.35, p<.001) for hospitalized persons with schizophrenia. Conclusion: The results suggest that a SMP can be an effective strategy to reduce patients' hospitalization stress, and improve problem solving skills and quality of life. Therefore, it is recommended that mental health nurses use this stress management program in clinical practice to assist adaptation to hospitalization for persons with schizophrenia.