• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.27 no.5
• /
• pp.750-757
• /
• 2003

In order to determine creep stress intensity limit of high-temperature components, the usefulness of the creep work and time equation, defined as W$\_$c/t$\^$p/ = B(where W$\_$c/ = $\sigma$$\varepsilon$ is the total creep work done during creep, and p and B are constants), was investigated using the experimental data. For this Purpose, the creep tests for generating 1.0% strain for commercial type i16 stainless steel were conducted with different stresses; 160 MPa, 150 MPa, 145 MPa, 140 MPa and 135 MPa at 593$^{\circ}C$. The plots of log W$\_$c/ - log t showed a good linear relation up to 10$\^$5/ hr, and the results of the creep work-time relation for p, B and stress intensity values showed good agreement to those of isochronous stress-strain curves (ISSC) presented in ASME BPV NH. The relation can be simply obtained with only several short-term 1% strain data without ISSC which can be obtained by long-term creep data. Particularly, this relation is useful in estimating stress intensity limit for new and emerging class of high-temperature creeping materials.

• Safety and Health at Work
• /
• v.7 no.3
• /
• pp.175-184
• /
• 2016

Stress at work and in the family is a very common issue in our society that generates many health-related problems. During recent years, numerous studies have sought to define the term stress, raising many contradictions that various authors have studied. Other authors have attempted to establish some criteria, in subjective and not very quantitative ways, in an attempt to reduce and even to eliminate stressors and their effects at work and in the family context. The purpose of this study was to quantify so-called cushioning variables, such as control, social support, home/work life conciliation, and even sports and leisure activities, with the purpose of, as much as possible, reducing the negative effects of stress, which seriously affects the health of workers. The study employs data from the Fifth European Working Conditions Survey, in which nearly 44,000 interviewees from 34 countries in the European Union participated. We constructed a probabilistic model based on a Bayesian network, using variables from both the workplace and the family, the aforementioned cushioning variables, as well as the variable stress. If action is taken on the above variables, then the probabilities of suffering high levels of stress may be reduced. Such action may improve the quality of life of people at work and in the family.

• Journal of the Korean Society of Safety
• /
• v.32 no.4
• /
• pp.73-78
• /
• 2017

In this study, the risk level of architectural works was calculated by applying work period and number of input workers based on accidents records from 2012 to 2014 and the architectural works were divided into four groups(High-High, High-Low, Low-High, Low-Low) according to risk levels of fatal accidents and loss time accidents. And then questionnaire on the job stress level of workers was performed for 670 workers working in the architectural work using Korean Occupational Stress Questionnaire Form developed by KOSHA. And then the relationship between the risk level and job stress level of four groups was analyzed. Results showed that 1) risk levels of fatal and loss time accidents applied by work period and input workers were analyzed to be different with those of previous research based on the number of fatal and loss time accidents; 2) job stress level of workers has been analyzed to have a significant relationship with the risk level of fatal and loss time accident; 3) specially, the average of job stress level of 'HH(High-High)' group was higher than those of other groups; 4) among the subfactors of job stress, interpersonal conflict, job insecurity, organizational system and lack of reward were analyzed to be key factors to affect the risk level.

• The Journal of the Korea Contents Association
• /
• v.13 no.11
• /
• pp.740-753
• /
• 2013

The purpose of this study was to examine present condition of social work field education, students' stress/stress coping strategies in their field practicum, and to find out the difference according to the factors related field education. This study carried out a survey targeting 202 students who finished their social work field practicum and took their course work in 2012, from 4 different universities in the northern Gyeonggi province & Seoul. As the result, in the area of stress, the highest rank was the lack of professional knowledge/skills, the second was the environment of field practicum, and the third was the burden of tasks that they had to perform. About the coping strategies, it was found that students utilized 'problem-solving focused' the most, pursuing 'social support' as the second, and 'avoidance' strategies as the least. Factors influencing on differences of stress level depending on field work experiences were whether they had previous field experience, how much time they participated in previous volunteer activities, whether they attended orientation for their field practicum, regularity/frequency of supervision, the satisfaction on their social work/welfare major, and the satisfaction on their field practicum or supervision. Based on the results, suggestions for development in field education system were presented.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.7 no.2
• /
• pp.161-167
• /
• 1983

In this study the phenomenon of cutting stress which arises on cutting tools and work pieces in cutting process is investigated by rake angle of cutting tools and feed for this measurement, P$_{s}$-1 (high modulus, photolastic Inc.) was used as a cutting tool, P$_{s}$-3 (medium modulus, photolastic Inc.) was used as work piece and reduction apparatus was attached to the head stock, and orthogonal cutting was adapted as a cutting method and transparent glass was used to block the strain in the orientation of thickness. The followings are the results of this study. (1) Photoelastic experimental equipments have made it possible to make dynamic measurement and analyze stress distribution in cutting tool and work piece surface which has hitherto been conducted only in static measurement and analyzing method. (2) The maximum stress arising at tools and work pieces in cutting process is on the tool edge tip, and the maximum stress arising on the tip of cutting tools is equal to that on the contacting area of work pieces in values. (3) The distributions of maximum shear stress on certain parts of the cutting tools and work pieces are as follows; for cutting tools, .alpha.=12.deg., .alpha.=0.deg., .alpha.=-12.deg. in order, and for work pieces, .alpha.=-12.deg., .alpha.=0.deg., .alpha.=12.deg. in opposite order.der.

• Journal of the Korean Society of Safety
• /
• v.24 no.6
• /
• pp.132-135
• /
• 2009

The population over 65 years of age in Korea will be 10.3% of the entire population in 2008 indicating that Korea is already in an aging society. In addition, it is expected that Korea will be in an aged society in 2018 (population over 65 years of age : 14.3%) and that it will be in a post-aged society in 2026 (20.8%). Consequently, aged workers may also increase. It is well-known that the possibility to work longer and to live better is highly related to the work ability of individual. The objective of this study was to evaluate the work ability of each age group using the Work Ability Index(WAI) in the shipbuilding industry, and to assess the effects of social psychological stress, drinking characteristics, smoking characteristics, etc. on the WAI score. The results showed no significant difference on the effects of aging, drinking, and smoking characteristics. Interestingly, a statistical analysis on the effects of social psychological stress revealed a significant difference by stress levels. The difference of the average WAI score between the healthy group and the high risk group was about 10 points. Based on this result, it can be concluded that the stress level is an influential factor on WAI.

• Korean Journal of Occupational Health Nursing
• /
• v.20 no.1
• /
• pp.74-82
• /
• 2011

Purpose: This study investigated how shift work nurses' fatigue influences job stress and turnover intention, and how job stress mediates the relationship between fatigue and turnover intention. Methods: As a descriptive research design, the data were collected from 203 shift work nurses in a city. It was analyzed using the SPSS/WIN 14.0 and AMOS 5.0. Results: fatigue and job stress in shift work nurses influenced turnover intention. Job stress worked as a partial mediation between fatigue and turnover intention. Conclusion: It is necessary to reduce fatigue and job stress for reducing turnover intention in strategies of hospital manpower.

• Journal of the Korean Society of Safety
• /
• v.21 no.4 s.76
• /
• pp.108-113
• /
• 2006

The Work-Related Musculoskeletal Disorders(WMSDs) have been an rising issue since the 1970s. So many manufacturing companies have been tried to improve the work environments for the control and the prevention of the WMSDs. Specific risk factors associated with WMSDs include repetitive motion, heavy lifting, forceful exertion, contact stress, vibration, awkward posture and rapid hand and wrist movement. But recently it has reported that besides working conditions, job stress is the important hazard causes which lead to WMSDs. This study investigates the relation between WMSDs and Job stress from 1426 workers in Heavy Industry. Job stress was evaluated by Karasek's model. Job stress was associated with job satisfaction. Job demand was associated with the WMSDs, but job control was not associated with the WMSDs. The results can be used to design the management program for the WMSDs and the job stress.

• Korea-Australia Rheology Journal
• /
• v.13 no.3
• /
• pp.109-123
• /
• 2001

A stress jump, defined as the instantaneous gain or loss of stress on startup or cessation of a deformation, has been predicted by various models and has relatively recently been experimentally observed. In 1993, Liang and Mackay measured shear stress jump data of xanthan gum solutions, and in 1996, Orr and Sridhar reported extensional stress jump data of Boger fluids. Shear stress jumps of suspensions and liquid crystal polymers have also been observed. In this contribution, experimental work as well as a variety of theoretical models, which are able to predict a stress jump, are reviewed.

• Journal of the Korea Safety Management & Science
• /
• v.11 no.4
• /
• pp.57-67
• /
• 2009

The psychosocial stress and musculoskeletal disorders(MSDs) have been one of major health problems for hospital workers. This study tried to understand the relationship between symptoms associated with MSDs and risk factors such as working posture, job stress, psychosocial stress and fatigue. A total number of 655 hospital workers participated in this study. Specifically, REBA was applied for evaluating working posture and a checklist prepared by KOSHA(Korean Occupational Safety and Health Agency) was used for symptom survey. A questionnaire from KOSHA was also used for collecting data associated with job stress, psychosocial stress and fatigue. All these data were formulated and modeled by path analysis which was one of major statistical tools in this study. Specifically, path analysis for the data we collected came up with several major findings. As a result, as for body part(neck), (waist) and (arms) the degree of risk of work posture measured with the use of job stress(KOSS), psycho-social stress(PWI-SF) and REBA is significantly more affected by fatigue than muscular skeletal disease related consciousness symptom. However, regarding bod(wrist), the degree of risk of work posture measured with the use of job stress(KOSS) and REBA is directly affected by muscular skeletal disease related consciousness symptom. This study is meaningful in that the study clarified the causal relations of the degree of risk of work posture, degree of fatigue, and muscular skeletal disease related consciousness symptoms by each body part measured with the use of work stress(KOSS), psycho-social stress(PWI-SF) and REBA.