• Journal of Korean Institute of Industrial Engineers
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• v.18 no.1
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• pp.47-62
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• 1992

This paper describes a procedure for optimizing the route selection and production conditions in alternate process plans under a cellular manufacturing environment. The type of production is mainly production-to-order which deals with unexpected products as the changes factor. The flexible cellular manufacturing can be viewed as a complete unification of both flexible manufacturing process and flexible production management. The integrated problem for designing flexible cellular manufacturing associated with determining the optimal values of the machining speeds, overtime, and intercell flow is formulated as Nonlinear Mixed Integer Programming(NMIP) in order to minimize total production change cost. This is achieved by introducing the marginal cost analysis into the NMIP, which will compute the optimal machining speed, overtime, intercell flow, and routing. The application of this procedure offers greater flexibility to take advantage of the cellular manufacturing due to the optimum use of resources. A solution procedure for this problem was developed and a numerical example is included.

• Annals of Occupational and Environmental Medicine
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• v.35
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• pp.20.1-20.7
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• 2023

The policy proposal by the current Korean government that proposes flexible overtime rules is causing social controversy. This study has explored the 612 experts' opinions on the occupational safety and health impacts of the policy using an online self-report survey. They expected short-term overwork (87.25%), overwork inequality (86.44%), irregular working hours (84.31%), chronic overwork (84.15%), long working hours (83.66%), and unpredictability of working hours (81.86%) as a result of the policy change. They also responded that the policy change would increase industrial accident deaths (87.25%), mental illnesses (87.09%), deaths due to overwork or cardiovascular diseases (83.84%), and accidents (83.33%). They disagreed that the government's flexibilization policy, while agreeing that the necessity of policies on regulating night work (94.77%), guaranteeing wages to eliminate overtime (90.36%), establishing working time regulations for the bogus self-employed (82.84%), and applying the 52-hour workweek system to all workplaces (76.47%). These expert opinions are consistent with previous research on the health effects of working hours.

• The Journal of Pediatrics of Korean Medicine
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• v.22 no.2
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• pp.171-186
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• 2008

Objectives : The purpose of this study is to investigate necessity of overtime hospital business hours and patient's visiting time preferences. Methods : The study was composed of 117 children's protectors who visited the pediatrics department in Kyunghee university oriental medicine hospital between on April 14th and on July 4th in 2008. Results and Conclusions : 1. Question for asking the preference of weekdays regular consultation hours 27% of preschool children preferred time around 11 am to 12 pm, each 32% of school aged children preferred time around 3:30 to 4:30 pm, 4:30 to 5:30 pm. 2. Question for 'Have you ever experienced inconvenience for regular consultation hours' 41% of them said 'Yes', and 59% said 'No'. 3. School aged children more experienced inconvenience for regular consultation hours than preschool children, and more likely to come at overtime hospital business hours. 4. Question for 'If the hospital extends the business hours for holidays and weekdays and Saturdays, would you prefer to come at that time?' 88% of them answered 'Yes'. 5. Question for asking the preference time on weekdays, 35% of them preferred 6:30 to 7:00 p.m. 6. Question for asking the preference time on Saturdays, 44% of them preferred 1:30 to 2:30 p.m. 7. Question for 'Do you willing to pay extra charges if you visit in non office hours?' 66% were willing to pay, 24% of them said "no", 'the other opinion' is 10%.

• Journal of Korean Clinical Nursing Research
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• v.27 no.2
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• pp.165-178
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• 2021

Purpose: To analyze nurses' shift work according to the government guidelines for night work and their perceptions of their work schedules. Methods: The study sample included 487 nurses who provided information on their schedules, including the normal working hours of each shift, and overtime per shift during September 2020. Nurses' perceptions were measured in terms of satisfaction, appropriateness for work-life balance, and fairness to their work schedule. Results: One-third of the respondents worked more than 40 hours per week. The average overtime hour was 1.14 hours per shift. Unsocial hours (8 pm to 6 am on weekdays, midnight to midnight on weekends and public holidays) accounted for 56.4% of all working hours. During their last night shift, on average, nurses worked 9.62 hours and had a break of 39 minutes, although 20.5% reported no break. Sixty-eight percent of nurses had at least one between-shift break shorter than 48 hours after a consecutive night shifts. Fifty-seven percent were satisfied with their schedule. One-third perceived their schedule as appropriate for work-life balance, and two-thirds perceived that days off on weekends and nights were fairly distributed within the unit. Working and overtime hours had an inverse relationship with all three aspects of nurses' perceptions. A higher proportion of unsocial hours and having no breaks during the night shift were associated with lower perceptions of fairness. Conclusion: Reducing working hours, ensuring breaks during night shifts, and increasing rewards for unsocial hours are required to improve nurses' perceptions and reduce turnover due to shift work.

• Korean Journal of Clinical Laboratory Science
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• v.46 no.1
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• pp.31-37
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• 2014

Metabolic syndrome such as, hypertension, diabetes, obesity, dyslipidemia etc are well known lifestyle diseases which threaten a health state. The purpose of this study is to evaluate antioxidant status and reactive oxygen species (ROS) in various stressful conditions. A group of persons (n=28) were enrolled in this study and stress status was evaluated using questionnaire of psychological well-being index (PWI-SF) and hematologic analysis of free oxygen radical defense (FORD), free oxygen radical test (FORT), lipid profiles and serum cortisol level. Analysis was done according to stress index, BMI status and overtime working. Blood samples from diabetics were used for control. Results are as in followings: Higher PWI-SF group showed higher FORT. Obese persons with BMI > $25kg/m^2$ showed statistically lower FORD (p<0.05) and higher FORT level (p<0.01). When compare with diabetics, an overweight group had similar levels in FORD and FORT while a normal body weight group showed quite different with diabetics in FORD (p<0.001). Higher ROS group has higher triglyceride, CRP and insulin levels but lower in FORD and HDL-cholesterol levels. Overtime working at night showed no meaningful result against our expectations. These results suggested that obesity showed most unfavorable correlations in an antioxidant status in various situations.

• Journal of the Korean Society of Safety
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• v.21 no.5 s.77
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• pp.84-91
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• 2006

The purpose of this study was to find out morbidity rate and pattern of occupational disease and affect of variables related disease of Fishing sailors'. The subjects this study were 624 fisheries sailors' who took a safety education course in Korea Institute of Maritime and Fisheries Technology. This questionnaire was focused on finding the basic data for prevention of occupational disease and promotion health on the fishing sailors'. The collected data were analyzed by using descriptive statistics, Chi-square, cross tab by SPSS package. The result of this study are as follow. 1) The morbidity rate within recent 12 months was 70.2%. There were significant differences of occurred disease in age, rank, perceived health status, fatigue symptoms, rest time, workload, overtime duration 2) The more aging(p<0.01), perceived fatigue(p<0.01), workload(p<0.01), overtime(p<0.05) and the less perceived health status(p<0.01), rest time(p<0.01), the higher morbidity rate. 3) Considering disease unable to work more than 4 hour, the number of those who had musculoskeletal disease were 20.9%, which revealed the highest rate, digestive disease 14.3%, traumatic disease 13.5%.

• The Korean Journal of Health Service Management
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• v.12 no.1
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• pp.123-135
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• 2018

Objectives : The purpose of this study was to analyze the effects of welfare workers who are economically active as wage earners after undergoing industrial accidents on their turnover intention in terms of demographic, working environment, and health characteristics. Methods : The data were analyzed in this study with the chi-square test and logistic regression using SPSS ver. 22.0 to analyze the factors influencing the turnover intention of industrial workers(PSWCI, 2016, N=1,083). Results : Model 1 included age, education, average wage, and union, Model 2 includer the number of workers in the workplace, average number of working days, overtime, and employment status were statistically significant. Model 3 included characteristics of health, Model 4 includer education, average wage, union, average number of working days, overtime, employment status were statistically significant. Conclusions : It is necessary to develop tools, indicators, and systematic and step-by-step programs to evaluate the stable work environment in the workplace, as well as to improve workers' return to work.

• Korean Journal of Child Studies
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• v.20 no.3
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• pp.339-349
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• 1999

Multiple regression and stepwise logistic regression was conducted to examine the relationships of work conditions, individual characteristics, and burnout (emotional exhaustion, depersonalization, personal fulfillment). Subjects were 144 early childhood educators. Teachers most likely to leave the profession were more educated, has less teaching experience and reported higher levels of burnout (i.e. high emotional exhaustion and lower personal fulfillment). Turnover was also predicted by high depersonalization, lower personal fulfillment, working overtime, and perceived choice of other jobs. Implications of these results for early childhood programs were discussed.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.6 no.8
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• pp.41-48
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• 1983

On the studies of the occurrence & countermeasures of industrial fatigue, the authors obtained the following results in the prevention & recovery of the industrial fatigue. Do not overtime work. To remove the unnecessary behaviors movement. To decide the standard amounts of work. Take a rest property in the procedures of work. Adjust & Arrange the work environments. Take a sufficient mutvition calories. Have plenty in reserve worktime. Set up modernizing machinery. To pay living wages.

• Journal of dental hygiene science
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• v.18 no.5
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• pp.271-279
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• 2018

This study aims to contribute to managing the human resource of dental hygienists and qualitatively enhancing dental medical services by examining factors that affect their turnover intention. Therefore, it attempted to examine their degrees of emotional labor, job satisfaction, and social support and the effects of each variable on turnover intention. This study administered self-reporting questionnaires to dental hygienists working in dental hospitals, dental clinics, and general or university hospitals in Seoul Metropolis and Gyeonggi-do by conducting convenience sampling, from May 18, 2017 to August 4, 2017. Among a total of 224 copies that were distributed, a total of 223 copies, excluding 1 copy with poor responses, were used in the data analysis. The research tools comprised 12 questions on general characteristics, 24 questions on emotional labor (4-point Likert scale), 16 questions on job satisfaction (5-point Likert scale), 8 questions on social support (4-point Likert scale), and 4 questions on turnover (5-point Likert scale). The scores of dental hygienists were as follows: emotional labor, 2.49 out of 4; job satisfaction, 3.14 out of 5; social support, 3.04 out of 4; and turnover intention, 3.07 out of 5. Their turnover intention has a positive correlation with emotional labor, but a negative correlation with job satisfaction and social support. It was found that some factors that significantly influence turnover intention included the amount of overtime work and job satisfaction. Thus, dental medical institutes should search for measures, including improvement of the working environment, to reduce the amount of overtime work and enhance job satisfaction.