• Safety and Health at Work
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• v.12 no.3
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• pp.351-358
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• 2021

Backgrounds: Irregular and unpredictable work schedules have become more common in most societies. The purpose of this study was to investigate the association between unpredictable work schedules and depressive symptoms in Korea. Methods: Data from 34,486 workers who participated in the Korean Working Condition Survey in 2017 were used. Unpredictable work schedules were measured by questions about the frequency of changes in work schedule and limited advanced notice. Depressive symptoms were assessed by a single item asking if the participants had depressive symptoms over the last 12 months. Multivariable-adjusted logistic regression analysis was used to calculate odds ratios (ORs) for high depressive symptoms. Results: The OR for depressive symptoms was significantly higher in the workers with unpredictable work schedules compared to those with predictable work schedules after controlling for age, sex, education, salary, marital status, occupation, contract period, full-time versus part-time, shift work, weekly working hours, and having a child under the age of 18 years (OR = 2.43, 95% confidence interval 1.93-3.07). Conclusion: Unpredictable work schedules were associated with depressive symptoms controlling for the other dimensions of precarious employment in a representative working population in Korea.

• Journal of Korean Institute of Industrial Engineers
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• v.19 no.4
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• pp.87-96
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• 1993

Spectrum analysis of surface electromyogram (FMG) signals is an effective approach to the study of localized muscular fatigue during isometric contraction. Many investigators have con firmed the frequency of the EMG signals being lowered during sustained contaction. In this study, the cyclic loading tasks were performed, and a comparison was made for the median power frequency shift pattern of the EMG signals with the sustained contraction of the same load. The median power frequency shift of the EMG signals for the cyclic loading task was found to be a part of that for the sustained contraction. Based on this result, a new muscle fatigue index was computed by normalizing the duration of the sustained contraction. A fatigue index was obtained as a function of exertion level and the work/rest schedule. With the proposed fatigue index, it is possible to evaluate or predict the degree of muscular fatigue for a physically demanding task.

• Research in Community and Public Health Nursing
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• v.30 no.3
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• pp.368-376
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• 2019

Purpose: In Korea, the prevalence of dementia patients has increased, which makes the care burden of nurses important. The purpose of this study is to identify factors affecting the care burden of nurses caring elderly patients with dementia. Methods: A cross-sectional design was conducted using a convenience sample of 127 nurses from two hospitals and a nursing home in Korea. Participants completed questionnaires on knowledge of and attitudes toward dementia, social support, self-esteem, dementia problematic behavior (DPB), and professional caregiver burden index. The data were analyzed by using the t-test, ANOVA, Pearson correlation, and multiple regression with the SPSS/windows version 21.0 program. Results: The influencing factors for nurse burden include day shift, DPB, self-esteem, social support, which explain 28.0% of care burden of nurses. Conclusion: To reduce the burden of the nurses, there needs to be an administrative system that focuses on enhancing their self-esteem and social support. Active institutional support may be necessary for the nurses taking care of elderly patients with dementia.

• Safety and Health at Work
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• v.12 no.3
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• pp.359-364
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• 2021

Aim: We aimed to examine the cross-sectional and longitudinal associations between sleep and work-related impaired cognitive and emotional functioning in police employees. Methods: This study included 410 participants (52% men) employed in a police district in Norway at baseline, of which 50% also participated in the study at 6 months later follow-up. The questionnaires included items measuring work schedule, sleep length, insomnia, as well as impaired cognitive and emotional functioning at work. Results: The results showed that insomnia was related to impaired work-related emotional functioning measured at baseline, and to impaired cognitive functioning measured at both baseline and follow-up. Sleep length and rotating shift work were not associated with future decline in cognitive or emotional functioning. Conclusion: Our study indicates that the relationship between insomnia and emotional functioning at work may be transient, whereas insomnia can be related to both immediate and future impaired cognitive functioning. Replication of the findings in larger samples is advised. The findings call for an emphasis on the prevention and treatment of sleep problems among police employees as a mean of maintaining and improving cognitive and emotional functioning at work, and thereby reducing the risk for impaired performance and negative health and safety outcomes.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.23 no.1
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• pp.21-31
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• 2016

Purpose: This study is a qualitative research to identify new nurses' adaptation experience to sleep changes. Method: Grounded theory methodology was utilized. Participants were 10 new nurses from one university hospital. The information was collected and analyzed using the grounded theory of Corbin and Strauss'(2008). Results: Through constant comparative analysis, central phenomenon was identified as 'Shaky daily life due to the sleep change'. A core category emerged as 'In the shaky daily life, go grab my position', Causal conditions were 'Heaviness in shift work', 'Not released after getting off work', and 'Body and mind are exhausted'. Context were 'An environment that does not tolerate mistakes' and 'Clogged breathing due to worries'. Intervening factors were 'Support of colleagues', 'Recovery volition in restoration of altered relationships due to sleep'. Action/Interaction Strategies were 'To strive for a good sleep', 'Require a reasonable duty schedule' and 'Find a breakthrough'. Consequences were 'Become the master of shaky daily life' and 'Accepting the life of a nurse'. Conclusion: New nurses experience sleep patterns changes from the hospital shift system. but throughout the process of adaptation, came to accept sleep disorder as part of the life of a nurse.

• Journal of the Korea Society of Computer and Information
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• v.25 no.3
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• pp.57-64
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• 2020

Today, with the development of information technology, hospitals are actively researching hospital information systems that are not limited by time and space to integrate mobile computing technology into the medical field to manage the bulk data of medical information. Nevertheless, most hospitals still spend a lot of time and effort creating manual schedules. In this paper, we studied an optimization model for organizing nurses' shift work and constructed an automated nurse-type job organization system. For nurses working in S hospital, information data, requirements and constraints of nurses were constructed. By applying this, we proposed an optimized scheduling method and built a web-based platform used by head nurses and a mobile app platform used by general nurses to enable real-time interchange and sharing around web servers. Therefore, through the developed nurse needs type automated system, the head nurses will increase the convenience of the nurses to organize the work every month, and general nurses will help them to work more accurately through personal schedule management. It is also expected to increase work efficiency by sharing work schedules among nurses.

• Journal of Korean Academy of Nursing
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• v.50 no.5
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• pp.646-657
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• 2020

Purpose: The purpose of this study was to identify the quality of sleep in novice and experienced shift work nurses and compare the factors associated with their quality of sleep. Methods: We analyzed the data of 192 and 256 novice and experienced nurses, respectively. The quality of sleep, sleep hygiene, job stress, and fatigue were measured using Insomnia Severity Index, Sleep Hygiene Practice Scale, the Korean Occupational Stress Scale, and Fatigue Severity Scale. Data were analyzed using SPSS 25.0 to calculate descriptive statistics and logistic regression. Results: Sleep quality was lower in experienced nurses (12.55 ± 5.71) than in novice nurses (11.18 ± 5.78). Fatigue was more severe in experienced nurses (4.47 ± 1.13) than in novice nurses (4.23 ± 1.12). In the logistic regression, factors related to sleep quality in novice nurses were sleep hygiene (odds ratio; OR = 1.06, p < .001) and fatigue (OR = 2.49, p < .001). Factors related to sleep quality in the experienced nurses were also sleep hygiene (OR = 1.04, p = .001) and fatigue (OR = 1.53, p = .012). Conclusion: Sleep quality of experienced nurses is lower than those of novice nurses. Factors associated with sleep quality in novice and experienced nurses are equally identified as sleep hygiene and fatigue. Therefore, personal efforts to improve sleep hygiene, such as providing comfortable sleep environment, are needed. Furthermore, organized efforts to decrease fatigue, such as constructing a working environment with a bright light at night and providing a fatigue-decreasing program that includes meditation, are required.

• 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.

• Proceedings of the ESK Conference
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• 1997.04a
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• pp.90-94
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• 1997

Many workers like welders are working in squat sitting postures with te object on the ground for an entire work shift. It is suspected that such prolonged squat sitting without any supporting stool would gradually cause musculoskeletal injuries to workers. This study is to quantitatively evaluate the physical stress caused by the prolonged squat sitting and to recommend a safe work/rest schedule for the task with squat sitting posture based on the lab experiment. In this study, 8 healthy student subjects participated in the experiment. They maintained a squat sitting posture for 16 minutes with 4 different stool height conditions: no stool, 10cm hight, 15cm height, 20cm height. Every 2 minutes, the discomfort was subjectively assessed using the magnitude estimation method for the whole body, lower back, upper leg and lower leg. Based on discomfort rating, we found that 10cm height stool relieved the workload most. Discomfort rating results also indicated that 20cm height stool showed the heghest workload, and that there was no difference in workload between 15cm height and no stool. We recommend to provide the workers with 10cm height stool for prolonged squat sitting tasks.

• Sleep Medicine and Psychophysiology
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• v.21 no.2
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• pp.74-79
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• 2014

Objectives: Shift work is a stressful situation. It is important to know the factors associated with the ability to adapt to a shift work schedule. The aim of the present study was to investigate the association between sleep, as well as personality variables, and the resilience of shift work nurses. Method: Self-report questionnaires were administered to 95 nurses who worked in one national university hospital. Connor-Davidson resilience scale, hospital anxiety and depression scale, morningness-eveningness scale, Pittsburgh sleep quality index, other sleep-related questionnaires, and Korean defense style questionnaires were used. Results: Age, shift work duration, off-day oversleep, depression, anxiety, adaptive defense style, and self-suppressive defense style were significantly associated with resilience (p < 0.05). Multiple regression analysis showed that age (${\beta}=0.34$, p < 0.05), depression (${\beta}=-0.25$, p < 0.05), adaptive defense style (${\beta}=0.45$, p < 0.001), and self-suppressive defense style (${\beta}=-0.19$, p < 0.05) significantly predicted the resilience of shift work nurses. Concerning individual defense mechanisms, resignation (${\beta}=-0.20$, p < 0.05), sublimation (${\beta}=0.19$, p < 0.05), omnipotence (${\beta}=0.19$, p < 0.05), and humor (${\beta}=0.20$, p < 0.05) significantly predicted the resiliency. Conclusion: The findings indicate that a specific defense style and other mechanisms were associated with the resilience of shift work nurses. A future prospective study with more participants could further clarify the relationship between sleep-related variables, as well as personality factors, and resilience of shift work nurses.