• Title/Summary/Keyword: Study Stress

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A study on residual stress distribution in surface grinding (평면연삭에서의 잔류응력 분포에 관한 연구)

  • 김경년;정재천;김기선
    • Journal of the korean Society of Automotive Engineers
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    • v.13 no.6
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    • pp.109-118
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    • 1991
  • In this study, it is intended to investigate the effect of the grinding conditions such as table feed, down feed, cross feed of residual stress distribution. And this distribution is investigated upon the grinding direction and the its orthogonal direction at ground layers. The material is used carbon steel (SM20C) which usually used to motor axis. And in order to be considered as Bernoulli-Euler beam, the dimension of the specimen is appropriately designed. According as corroiding the ground surface, the residual stress layers are removed and strain which occured on account of unbalance of internal stress is detected by rosette-gate. Through A/D converter and computer, these values are saved and evaluated residual stress by stress-strain relation formula. Finally, these results are diagrammatized with Auto Cad. The results obtained are as follows. As the depth from the ground surface increases in grinding direction and its orthogonal direction, tensile residual stress exists in the surface, and subsequently it becomes compressive residual stress as it goes downward. As the table feed, the cross feed and the down feed increase, maximum residual stress is transformed form the tensile to the compressive.

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A Study on Job Stress and the Coping of ICU Nurses (중환자실 간호사의 직무 스트레스와 대처에 관한 연구)

  • Park, Hyoung-Sook;Gang, Eun-Hee
    • Journal of Korean Academy of Nursing
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    • v.37 no.5
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    • pp.810-821
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    • 2007
  • Purpose: This study investigated job stress and coping of ICU Nurses. Method: Data was accumulated from 206 ICU nurses serving at least more than one year in 500 bed order hospitals during the period of three months from June1, to August 30, 2006. Results: The average job stress was $2.96{\pm}.95$ points, which was relatively high. The average coping was $2.55{\pm}.23$ points. Conclusion: The extent of the job stress of ICU nurses was relatively high, and they received the heaviest stress from job circumstances. For the prevention of job stress, every effort is required to analyze the causes of stress caused by job circumstances and to pose an appropriate solution. Meanwhile, job stress, needs to be controlled using a solution for the central problem, and search for social support.

A Study for Mitigating Residual Stress in CRDM Penetration Nozzle Weld (제어봉구동장치 관통노즐 용접부의 잔류응력 완화를 위한 연구)

  • Lee, Seung-Gun;Kim, Jong-Sung;Jin, Tae-Eun
    • Proceedings of the KSME Conference
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    • 2004.04a
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    • pp.90-95
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    • 2004
  • In this study, we proposed new method to mitigate tensile welding residual stress for preventing PWSCC in CRDM nozzle. Residual stress analysis using finite element method is performed to confirm benefit of the new method. In case of applying existing method, tensile axial residual stress decrease by about 28% and tensile hoop residual stress decrease by about 33%. In case of applying the new method, tensile axial residual stress decrease by about 32% and tensile hoop residual stress decrease by about 43%. Therefore, we conclude the new proposed method is more effective to prevent PWSCC than existing method.

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Thermal stress analysis around a cavity on a bimetal

  • Baytak, Tugba;Bulut, Osman
    • Structural Engineering and Mechanics
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    • v.69 no.1
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    • pp.69-75
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    • 2019
  • The plates made of two materials joined to each other having the different coefficient of thermal expansions are frequently encountered in the industrial applications. The stress analysis of these members under the effect of high-temperature variation has great importance in design. In this study, the stress analysis of the experimental model developed for the problem considered here was performed by the method of photothermoelasticity. The thermal strains were formed by the mechanical way and these were fixed by the strain freezing method. For the stress measurements, the method of slicing is applied which provides three-dimensional stress analysis. The analytical solution in the literature was compared with the related stress distribution obtained from the model. Moreover, the axisymmetric finite element model developed for the problem was solved by ABAQUS and the results obtained here compared with those of the experimental model and the analytical solution. As a result of this study, this experimental method and numerical model can be used for these type of thermal stress problems which have not been comprehensively analyzed yet.

Investigation of 1D sand compression response using enhanced compressibility model

  • Chong, Song-Hun
    • Geomechanics and Engineering
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    • v.25 no.4
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    • pp.341-345
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    • 2021
  • 1D sand compression response to ko-loading experiences volume contraction from low to high effective stress regimes. Previous study suggested compressibility model with physically correct asymptotic void ratios at low and high stress levels and examined only for both remolded clays and natural clays. This study extends the validity of Enhanced Terzaghi model for different sand types complied from 1D compression data. The model involved with four parameters can adequately fit 1D sand compression data for a wide stress range. The low stress obtained from fitting parameters helps to identify the initial fabric conditions. In addition, strong correlation between compressibility and the void ratio at low stress facilitates determination of self-consistent fitting parameters. The computed tangent constrained modulus can capture monotonic stiffening effect induced by an increase in effective stress. The magnitude of tangent stiffness during large strain test should not be associated with small strain stiffness values. The use of a single continuous function to capture 1D stress-strain sand response to ko-loading can improve numerical efficiency and systematically quantify the yield stress instead of ad hoc methods.

Stress Experience of Nursing Students to Clinical Practice : Q-methodological Approach (간호학생의 임상실습 스트레스 경험유형 : Q방법론적 접근)

  • Jang Hye Sook;Kim Soon Ae;Kim Hung Kyu
    • Child Health Nursing Research
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    • v.5 no.1
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    • pp.5-17
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    • 1999
  • This study was designed to determine the schemata and their characteristics of stress experience the subjectivity of stress experience(structure of subjectivity) would be a basic step for the effective clinical education through the stress management for characteristics of these types. Q-methodological method was used for that purpose. The research method statements were collected prior to the study through indepth interviews. For the study, 31 Q-statements were selected. There were 34 nursing students as subjects for the research. The 34 nursing students sorted the 31 statements using the principal of forced normal distribution. The principle of forced normal distribution, which has 9 scales to measure the individual opinions, was called. Q-factor analysis by using PC QUANL program supply the material. According to the outcomes of this study, there were 3 types of special opinion about the stress experience of clinical practice. The first type is called 'Influence of practical atmosphere type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The second type is called 'conflict of nursing role type'. Members of this type experienced stress by an inadequate orientation and undesirable role model of nursing. The third type is called 'Lack of confidence type'. Members of this type experienced stress because of a lack of confidence for their own nursing knowledge and skill. As a result, we now need further study to identify individual psychological aspects of stress for clinical practice. The findings will guide the development in effective approaches for clinical education. Finally, the result of the study will provide us the need for developing systematic and integrated practice education program for students and active involvement of clinical instructor.

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A Study on the Mediation Effects of Depression and Self-efficacy on College Students' Stress and Subjective Happiness (대학생의 스트레스가 주관적 행복에 미치는 영향 -우울과 자기효능감의 매개효과를 중심으로-)

  • Ahn, Seong-Ah;Sim, Mi-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.7021-7033
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    • 2015
  • This study aims to verify the structured relationship between college students' stress and their stress in the meditating depression and self-efficacy. Findings of the research are summarized as follows. The study looked into how stress would directly affect depression and self-efficacy. It was found that the stress would have immediate effects on depression and self-efficacy. In addition, it was noticed that stress indirectly influences college students' subjective happiness in meditating factors of depression and self-efficacy. After the investigation on the immediate effects of depression in relation to the self-efficacy, results of the study indicated that depression has an immediate negative influence on the self-efficacy. Self-efficacy appeared to affect subjective happiness positively and directly. However, its indirect effects on the subjective happiness was confirmed. Although the study failed to find any direct influence of the stress on subjective happiness, it was learned that stress causes an indirect effect through the meditating factors of depression and self-efficacy. In conclusion, the study suggests that subjective happiness can be improved by stress and depression relaxation, and improvement of self-efficacy.

An Analysis of Work Stress of Physical Therapist and Reaction (물리치료사의 업무 스트레스 현황과 대응수준 -부산지역을 중심으로-)

  • Dong, Jong Ick;Ryu, Hwang Gun;Bae, Sung-Kwon
    • The Korean Journal of Health Service Management
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    • v.2 no.1
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    • pp.37-55
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    • 2008
  • This study aims to enhance work efficiency and satisfaction by offering data that make a physical therapist cope with stress coming from the job efficiently by identifying and analyzing the job satisfaction and work stress perceived by a physical therapist, and the level of reaction of a physical therapist. The study distributed survey questionnaires to 300 physical therapists working in medical institutions in Busan via mail and by visit from March 3, 2007 by selecting them simply and randomly from the physical therapist list, and collected the questionnaires by March 20, 2007, 103 respondents were working at 17 general hospitals including a university hospital, 65 respondents at 12 medical centers, and 79 respondents at 39 doctor's offices. The study collected 251 copies, which showed the collection rate of 83.7%, and analyzed 247 copies (82.3%) excluding 4 copies of insincere answers. As a research tool for measuring job satisfaction the study used a tool employed for research into the job satisfaction of physical therapists who work at medical institutions in Gwangju, Jeonnam, and Jeonbuk by Kim Hee-Gwon(1992) and research regarding job satisfaction by Jeong Jeong-Hee(2004) as well as research regarding the factors of job satisfaction by Flippo(1980) & Seberhagen(1970) after adjusting the research tools to the purpose of the study. Also for questions about work stress, the study employed nurses' job stress measurement tool developed by Kim Mae-Ja and em Mi-Ok(1984) by modifying the tool to the purpose of the study, and for a measurement tool for reaction to stress, the study used a tool employed for research into reaction to stress of nurses at general hospitals by Choi Eun-Deok(2005) without modification. For data analysis, the study used the SPSS12.0 as a statistical method, and then used t-test or ANOVA for verifying actual numbers, percentile, average :score, standard deviation, rank, and difference. Also, the study conducted which is a post-test method for variables that show a significant difference at the level of p<.05 level after the analysis. The findings include the following. 1) The respondents' job satisfaction score was 3.21 points on the average (out of 5 full points). The peer relationship ranked the highest, posting 4.02 points on the average, and the job satisfaction with rewards was proven the lowest, posting 2.51 points. For the job satisfaction level by characteristics, there were significant differences (p<.05) in gender, hospital type, weekly working hours, monthly working days, number of patients per day, department in charge of therapy, and number of peers, and there was no significant difference in characteristics other than that. 2) The respondents' work stress score was 2.72 points (out of 5 full points) on the average. The respondents were shown to be under the highest stress when they suffered from excessive workload, posting 3.49 points on the average, and they were shown to be under the least stress when they had a conflict with peers at another department, recording 1.90 points on the average. for the job stress level by the characteristics of job, there was a significant difference in the reflection of job assessment(p<.05). 3) 1n respondents' reaction to stress, most of them were shown to make efforts in coping with stress, posting 2.80 points (out of 5 full points). For their experience of being wider stress, they answered that 'they felt depressed (2.85 points)" for their experience of coping with stress, they answered that 'they were indifferent to it or thought about something else' (2.62 points). Also, for their efforts in coping with stress, they answered that 'they were motivated to remove their strain by taking leave, playing, or using their preferences' (3.52 points), which ranked higher. For the level of reaction to stress by characteristics, there were significant differences by age, gender, marital status, total service years as a physical therapist, monthly working days, and department in charge of therapy(p<.05). It is necessary to offer correct information by conducting an in-depth analysis of the stressful situations of physical therapists who exert efforts in rehabilitating patients at hospitals by factor, and seeking management plans based on the research results. Also, it is necessary to develop a program for coping with stress efficiently for removing stress and to conduct research into the understanding and cooperation of administrators and persons in charge of physical therapists for reducing physical therapists' stress at hospitals.

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A Study on Job Stress and Work Ability of Technical Workers and Simple Labor Workers in Apartment Construction (아파트공사 기능직 종사자와 단순노무 근로자의 직무스트레스와 작업능력에 관한 연구)

  • Lee, Jong-Bin;Chang, Seong Rok
    • Journal of the Korean Society of Safety
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    • v.29 no.5
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    • pp.129-135
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    • 2014
  • In recent studies, construction industry workers with higher job stress and lower work ability were more likely to experience accidents at their workplace. Likewise, fatal accidents rate was higher among simple labor workers compared to technical workers. Therefore the evaluation of a worker's job stress and work ability seems to be important in preventing the occurrence of fatal accidents. To search for ways to reduce job stress and to improve work ability, the current study conducted a job stress analysis based on age, years of service, skill level, hobbies, sleep patterns, and monthly income. For this, the Korean occupational stress questionnaire short form and the Work Ability Index (WAI) developed by the Finnish Institute of Occupational Health (FIOH) were used. In this study, SPSS 12.0K statistics program was used for statistical analysis and significance was verified by the Kruskal-Wallis test and non-parametric tests. The results of this study can be summarized as follows : (1) Simple labor workers had higher job stress and less work ability than technical workers. (2) The more experienced workers had lower job stress and higher work ability. (3) In the case of workers who slept a lot, work ability was higher and job stress was less. (4) Monthly income influenced on the job stress and work ability. (5) Job stress and work ability in accordance with the age difference was not significant.

The Work Stress and Coping Type of Nurses in Hospital (병원 간호사의 직무스트레스와 대처유형)

  • Lee, Young-Mee
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.17 no.11
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    • pp.230-235
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    • 2016
  • The purpose of this study was to investigate the stress from work and stress coping methods of hospital nurses. The study design was a descriptive survey research. There were a total of 168 hospital nurses included in this study. Data were analyzed by t test, ANOVA (Sheffe's test), and Pearson's correlation coefficient using SPSS/WIN17.0. The stress level from work was 4.27 and stress coping methods was 2.67. Marital status was positively correlated with education level, current department, career duration, and current position. The education level was positively correlated with career period and current position. Current position was positively correlated with stress coping methods. A further follow-up study on nurses in hospital is necessary to relieve stress from work and to increase better stress coping methods. Moreover, to decrease the stress from work of nurses, it is necessary to develop a program that helps them to cope with stress. In addition, these findings contribute to the development of such program.