• Journal of Korean Academy of Nursing
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• v.21 no.2
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• pp.129-149
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• 1991

Circadian rhythm is entrained in the 24-hour time interval by periodic factors in the environment, known as zeitgeber. But most rotating work schedules are outside the range of the entrainment of the pacemaker timing the human circadian sleep - wake cycle. It has been postulated that physiological and emotional disturbances occur in most human functions when the circadian rhythm is disturbed. So application of circadian principles to the design of shift schedules can aid in maintaining the temporal integrity of the circadian system and thereby minimize for the shift worker any detrimental consequences of circadian disruption. This study was a quasi-experimental study to test the effect of shift intervals for the clinical nurse on the circadian rhythm. Twenty nurses newly employed in general units of two hospitals were selected as an experimental group and twelve college nursing students as a control group. Both groups were selected according to an established criteria using a purposive sampling technique. Ten subjects were assigned to a weekly shift group and another ten to a biweekly shift group engaged in a semi -continuous shift schedule(sunday off) with a backward direction, that is, morning -evening - night shift. The control group worked a morning shift for 42 days. Oral temperature rhythm, waking tim, sleep - wake cycle, fatigue, and mental performance were measured during the experimental period. The data collection period was from April 30, 1990 to June 10, 1990. MANOVA, paired t-test, ANOVA, and Student Newman Keuls method were used for statistical analysis. The results are summarized as follows. 1. Phase delay in the acrophase of temperature rhythm was shown according to the backward rotating shift. A complete adaptation to work on the night shift was achieved between the sixth and ninth day of the night shift. 2. There was no difference in either waking time or sleep- wake cycle according to the duration of the working day for every shift group. Significant difference was found in the waking time and the sleep -wake cycle for subjects on the morning, evening, and night shift in both of the shift groups(weekly shift group : λ＝0.121, p＜0.01, λ＝0.112, p＜0.01, biweekly shift group : λ＝0.116, p＜0.01, λ＝0.084, p＜0.01). 3. There was no difference in fatigue between the first working day and the last working day for the control group and for the biweekly shift group. In the weekly shift group, physical fatigue was significantly different for the first day and the sixth day of the night shift(t＝-2.28, p＜0.05). Physical fatigue and total fatigue on the first day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝5.79, p＜0.01, F＝4.56, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05), Physical fatigue, neurosensory fatigue and total fatigue on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝12.65, p＜0.01, F＝7.77, p＜0.01, F＝9.68, p＜0.01). There was a significant difference between the shift groups and the control group(p＜0.05). 4. No difference in mental performance was seen between the first day and the last day of work in each case. An arithmatic test on the first day of the night shift revealed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.79, p＜0.05). There was a significant difference between the shift groups and the control group(p＜0.05) . The digital symbol substitution test and the arithmetic test on the last day of the night shift showed a significant difference among the control group, the weekly shift group, and the biweekly shift group(F＝3.68, p＜0.05, F＝5.55, p＜0.01), and both showed a significant difference between the shift groups and the control group(p＜0.05). Accordingly, this study showed that during night duty, the waking time, sleep- wake cycle, and fatigue increased and mental performance decreased compared with morning and evening duty. It was also found that the weekly shift group had a higher fatigue score on the sixth day of night duty as compared to the -first day, but the waking time, sleep- wake cycle, and mental performance revealed no difference for the duration of the night duty or between shift groups, and complete adaptation of temperature rhythm was achieved between the sixth and ninth day of night duty. It is possible to conclude from these results that for intermediate circadian type in a healthy young woman, a biweekly shift system is more compatible with the circadian timing system than weekly shift system.

• Women's Health Nursing
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• v.24 no.3
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• pp.252-264
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• 2018

Purpose: To understand the essentials of rearing conflict experience by three shift nurses in advanced general hospitals. Methods: The design was a qualitative research of phenomenology. Participants were 7 shift nurses working in advanced general hospitals who were rearing young children. Data were collected individually through in-depth interview on their life experiences. Data were analyzed by Colaizzi's phenomenological methodology. Results: Eighteen themes were drawn from 256 meaningful experiences and these themes were integrated to six theme clusters. The most influencing themes were 'Regret that I cannot satisfy even the slightest wish', 'Fail to care for kids', and 'Mutual feeling to care giver between appreciation and inconvenience'. Other themes were as follows: 'Body and mind are broken', 'The need for a three-shift system to support nurses who are rearing children', 'Doing my best for work and child rearing'. Conclusion: The nature of three-shift nurses working in advanced hospital and caring kids is explained as 'lives with conflict' between work and home. This study suggests it is necessary to establish a 24-hour care center for 3-shift nurses to keep working while rearing their children.

• Women's Health Nursing
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• v.27 no.2
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• pp.113-127
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• 2021

Purpose: This study examined health behaviors, use of health services, and depression among women who perform daytime and shift work in Korea, as well as factors related to depression. Methods: We conducted a secondary analysis using data from the 2018 data of the 7th Korea National Health and Nutrition Examination Survey. Data on women, 1,493 regular daytime workers and 322 shift workers, were analyzed. Results: Women shift workers (χ²=43.97, p<.001), had a lower education level (χ²=45.56, p<.001), and lower personal income (χ²=16.85, p=.030) than their daytime counterparts. A higher proportion of shift workers were unmarried (χ²=37.47, p<.001) and they typically worked fewer than 40 hours per week (χ²=69.94, p<.001). The depression score of shift workers was higher than that of daytime workers (t=2.85, p=.005). A higher proportion of shift workers also drank alcohol (χ²=6.49, p=.032) and smoked (χ²=30.79, p<.001). Over 8% of shift workers typically slept fewer than 5 hours per night (χ²=14.17, p=.024). It was confirmed that depression in women shift workers was affected by age, personal income, marital status, health status, and smoking status, in addition to cancer screening participation, unmet medical care needs, and unmet dental care needs. Conclusion: More attention should be given to the health needs of women working shifts. Health promotion programs specific for women shift workers are needed to improve their physical and mental health, encourage use of medical care services, and improve public health policies and systems.

• Journal of Preventive Medicine and Public Health
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• v.25 no.4 s.40
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• pp.374-385
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• 1992

Some circadian rhythms can become disorgnized due to rotating shift work. This lack of organization, termed desynchronization, can produce a group of symptoms such as insomnia, GI disturbance and fatigue among many rotating shift workers. The magnitude of these symptoms are influenced by personal and environmental factors and the patterns of shift work. This study was carried out to investigate the subjective symptoms related to rotational schedules of shift work after personal and environmental factors adjusted. 182 male workers in rapidly rotating shift system and 86 male workers in weekly rotating shift system were conducted the questionnaire on personal factors and subjective sleep, GI and fatigue symptoms. Major findings obtained from this study are as follows: 1. The symptoms of 'feeling tired at work' and 'being irritable' were more frequent in weekly rotating shift workers (P<0.05), and the mean of symptom score was significantly higher in weekly rotating shift workers(P<0.01). 2. According to 6 hours of sleeping which is a definite elevation point of fatigue, there was not a significant difference between two groups in sleeping hours. Among workers in rapidly rotating shift system, the mean of symptom score was significatly higher in workers of less than 6 hours of sleeping(P<0.05), but it was not different among weekly rotating shift workers. 3. The symptoms of GI disturbance were more frequent in weekly rotating shift workers but statistically not significant. 4. The positive rate of mental and physical fatigue symptoms were significantly higher in weekly rotating shift workers(P<0.01) and mental and physical fatigue symptoms were more frequent in them (P<0.01). 5. After the effect of the factors that were significantly different between two groups by $X^2-test$ were controlled, the mean score of sleep disturbance was significantly higher in weekly rotating shift workers (P<0.01) and mental physical fatigue symptoms were more frequent in them (P<0.01). Based on these study results, subjective symptoms were more common in the weekly rotating shift workers. In future, medical examination and laboratory test will be also administered to evaluate a more accurate health outcomes and the review of current shift schedules will be required.

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

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 1998.03a
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• pp.148-153
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• 1998

In order to control thermal deformation of machine origin of machine tools due to internal and external heat sources, the real-time compensation system has been developed. First, GMDH models were constructed to estimate thermal deformation of machine origin for a vertical machining center through the measurement of deformation data and temperature data of specific points on the machine tool. Thermocouples and gap sensors are used respectively for measurement. These models are nonlinear equations with high-order polynomials and implemented in a multilayered perceptron type network structure. Secondly, work origin shift method were developed by implementing digital I/O interface board between CNC controller and IBM-PC. The work origin shift method is to shift the work origin by the compensation amounts which is calculated by pre-established GMDH model. From the experimental result, thermal deformation of machine origin was reduced to below $\pm$5${\mu}{\textrm}{m}$.

• Journal of Korean Public Health Nursing
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• v.18 no.1
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• pp.103-118
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• 2004

The purpose of this study was to understand the process and investigate basic theory of fatigue experience of shift work nurses. The present study adopted grounded theory methodology on fatigue of shift work nurses. The participants for this study were 15 shift work nurses who were in the age of 25 to 35, the clinical experience of 2 to 14 years and the work department of ICU. ER. ward and delivery room. The data were collected from 2000 to 2003 by using interviews and observations. The contents of the interviews were tape-recorded and were drawn through repeated method. And then were analyzed into the concept, subcategories, and categories with the open coding process and axial coding was done to identify the relationships of the concepts and categories according to the paradigm models. The core category generated, which was a central phenomena of the exhaustion process. The causal condition is change events. The central condition of exhaustion were sorted as physical discomfort, decreasing vigor, psychological instability, feeling of sleeping desire, changing face impression and being heavy body. The intervening condition were discovered as social$\cdot$ psychology$\cdot$physical resist and positive$\cdot$negative interaction strategies. The consequences of the fatigue process is the short term exhaustion relief and long term residual exhaustion. The fatigue process of this study was 'break through exhaustion' of change event-exhaustion-resist-resolve intervention-adaptation. This study offers better understanding on fatigue process of shift work nurses and may facilitate more appropriate interventive strategies to support, information and knowledges according to fatigue process.

• Journal of Convergence for Information Technology
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• v.7 no.6
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• pp.35-43
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• 2017

The purpose of this study was to analyze the converged influencing factors on the stages of exercise behavior changes in shift work nurses. The subjects were 120 shift work nurses working in hospitals who understood the purpose of the study and agreed to participate in the study. Data were analyzed using frequency, percentage, mean, standard deviation, t-test, $X^2$ test, and multiple logistic regression analysis. The exercise motivation factors of shift work nurses had a significant effect on stages of exercise behavior change (${\beta}=2.480$, p=.022), health status perceptions(${\beta}=1.151$, p=.013). Social support factors (${\beta}=1.819$, p=.002) and marital status (${\beta}=-1.820$, p=.004) also had significant effects on the stages of exercise behavior change of shift work nurses. In other words, subjects with change in exercise behavior had 11.9 times higher motivation and 3.1 times higher health status perception than those without change in exercise behavior, social support was 6.1 times higher, and unmarried subjects showed 16 times showed higher than that of married subjects. Therefore, it is important to develop a strategy to practice continuous and regular exercise in consideration of the exercise motivation, social support, and health status perception of the nurses in shift work.

• Journal of East-West Nursing Research
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• v.17 no.2
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• pp.81-86
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• 2011

Purpose: The purpose of this study was to examine job involvement according to working pattern and daytime sleepiness in hospital nurses. Methods: At 2 hospitals in affiliation of university, after obtaining participant's consent form, data were collected from October to November, 2007. Twohundred fifty nurses participated in the study. Questionnaire consisted of Epworth Sleepiness Scale (ESS), Job Involvement. Collected data was analyzed with SPSS 14.0 program, which was used for frequency, percentage, mean, standard deviation, t-test and Pearson correlation coefficients. Results: Major findings of this study were as follows 1) The nurses for 3 shift work was 172 (68.8%), the nurses for 2 shift work was 3 (1.2%) and the nurses for day fixation was 75 (30.0%). 2) Mean of ESS was 5.94 (3.28), daytime sleepiness was 13.2% and Job involvement had a mean of $21.27.{\pm}4.61.3$) There were significant differences between shift work and day fixed work on ESS (t=4.33, p<.001), job involvement (t=6.54, p<.001). Higher ESS were significantly related to lower job involvement (r=-.185, p=.003). Conclusion: The finding of this study gives useful informations about sleep and work involvement of hospital nurses. It is need to develop systemic management for shift work nurses by hospital, nurse organization, and government.

• Convergence Security Journal
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• v.19 no.4
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• pp.143-150
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• 2019

Recently, As ICT technology develops, cyber attacks are becoming more intelligent and advanced. In order to cope with such cyber attacks, the security control system must be maintained 24 hours a day, 365 days a year. Security personnel should be able to respond in real time to cyber attacks through shift work for 24 hours, but the workforce law was revised in 2018 to affect manpower and security control work systems. Therefore, in this paper, we propose an effective security control work system by reducing 52 working hours per week.