• Korean Journal of Human Ecology
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• v.4 no.1
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• pp.93-107
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• 2001

The purpose of this study was examine the health and food intakes of industrial workers who worked day and night. The questionnaire asked them about their health, stress, knowledge of nutrition, food habits, food intakes and frequency. The night-time workers had a stomachache compaired with day-time workers. Male day-time workers were more prone to stress than night-time workers in the area of job. In the areas of nutritional knowledge and food habits, there were no significant differences between day-and night-time workers for both male and female. Intakes of rice, bread, noddle, meat, fish. beans, vegetables in night-time workers were less than day-time workers. Also the male night-time workers consumed more milk and carbonated drinks than the day-time workers. The night-time workers were worse than the day-time workers and the female night-time workers were the worst. Considering the above results, the night-time workers should correct their food habits and have a well-balanced diet.

• Korean Journal of Community Nutrition
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• v.7 no.5
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• pp.615-627
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• 2002

The purpose of this study was to examine the eating habits and nutrient intake of industrial workers who work day and night shifts. In the area of percentage of skipped meals, the day shift workers responded that they usually skipped breakfast and the night shift workers often skipped lunch and dinner. The day shift workers answered that they skipped meals because of lack of time. The night shift workers cited poor appetite as their main reason for skipping meals. The intake of calories, Vitamin $B_2$ and calcium of the industrial workers who worked day and night shift was lower than the Korean RDA. The intake of iron of the male night shift workers was lower than the Korean RDA The intake of calories, protein, calcium, iron, Vitamin $B_2$and niacin, vitamin C of the female night shift workers was lower than the Korean RDA. In the area of nutrient intake, the night shift workers both male and female got lower scales than the day shift workers. The nutrient intake of the female night shift workers was the worst. Because they cook for themselves and live alone, their nutrient intake and eating habits were bad. The night shift workers were worse than the day shift workers and the female night shift workers were the worst. Considering the above results, night shift workers should correct their poor eating habits, their nutrient intake and have a well-balanced diet.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.2
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• pp.344-348
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• 2004

This study regarded irregular life styles such as nigh-shifts as contrary to the norm advised in the rules of Yang-saeng to analyze the problems brought about in relation to the concept of 'Yin-deficiency syndrome'. Yin-deficiency survey was given to sales workers on a big shopping mall in Seoul to compare the measurements of daytime workers to those of nigh-shift workers. The measurement of complaining symptoms related to Yin-deficiency of daytime workers and night-shift workers were compared, In comparison of the daytime workers and the night-shift workers, night-shift workers showed higher measurements than the daytime workers in the item of irritable fever on the five Hearts, flushing of the zygomatic region in the afternoon, tidal fever, dizziness, insomnia, yellow and scanty urination, and constipation. Especially tidal fever, insomnia, and constipation showed statistically significant difference. The total of ten items consisting of Yin-deficiency-related symptoms showed statistically significant high score in night-shift workers than the daytime workers. 'Factors for deficiency-type Heat' consisting of irritable fever on the five Hearts, flushing of the zygomatic region in the afternoon, tidal fever, and dried mouth and throat showed statistically significant high score in night-shift workers than the daytime workers. 'Accompanying factors' consisting of night sweats, emaciation, dizziness, insomnia, yellowish and scanty urination, and constipation also showed statistically and significantly high score in night-shift workers than the daytime workers. From the above results that night-shift workers show high degree of Yin-deficiency than daytime workers, and those overworking irregularly also show high degree of Yin-deficiency than those who work for adequate amount of time regularly implies that sitting up at night for work and sleeping at daytime, excessive work, and irregular life styles all function as high-risk factor for Yin-deficiency.

• Journal of the Korean Dietetic Association
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• v.29 no.1
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• pp.13-30
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• 2023

This study investigates the effect of working hours on the dietary behaviors and dietary quality of male industrial workers employed in rotating shifts. The survey was conducted from February to March 2022, enrolling 209 male workers operating in rotational shifts at industries in the Chungcheongnam-do region. Eating behavior and health awareness were investigated during the morning shift, afternoon shift, and night shift for the same subjects. The shift timings were found to be associated with dietary behavior, which had an impact on the dietary quality of workers. Negative effects of shift timings on diet and health were also perceived by the shift workers. The frequency of alcohol consumption was high during the morning shift, and the frequency of night time snack intake was high during the afternoon shift. During the night shift, there was decreased vegetable intake and increased ramyeon intake. Compared to the morning shift, a significant decrease in dietary quality scores was found during the night shift. The workers recognized that rotating shift work negatively affected health, eating habits and sleep. There was a high demand for providing a variety of menus and healthy night snacks in the company cafeteria. When nutritional counseling and educational health services were provided, the willingness to participate was high. Therefore, to improve the health and dietary quality of shift workers, there is a need to provide diets suitable for the working environment and the characteristics, and to provide nutrition management services.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.188-196
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• 2005

Accident reports from 1991 to 2000 of a steel company were used to analyze which factors induce industrial accidents. The subjects were 8,311 blue-collar workers, who sustained 114 occupational injuries and work on a continuous full-day 3-team 3-shift system of backward rotation(mornings to afternoons to nights). With respect to marital status, the occupational injury rate(OIR) on the married workers was significantly higher compared to unmarried workers. With respect to no, the OIR of those in their early 20s was significantly higher when compared to other age groups. The OIR of highly educated workers showed a reduction when compared with lower educated workers. The OIR of shift workers were significantly higher compared with the daytime workers. The OIR of type of work decreased across the steel manufacturing process, rolling process, machine maintenance section forwarding products section to the field management section. With respect to the block of shift work(morning, afternoon, and night shifts) by the type of work, the OIR of the night shift was higher than those of the morning shift in the steel manufacturing process or forwarding products section. The OIR of the machine maintenance section was slightly higher in the morning shift than those of the night shift. The OIR of the time of day of the shift workers reached a peak between 09:00 and 11:00. The OIR of a slight injury to shift workers decreased across the night, afternoon, to morning shifts whereas the OIR of a serious injury tended to decrease across the night, morning, to afternoon shift. The body parts most commonly injured were the arm and the crus.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.23 no.57
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• pp.1-10
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• 2000

The purpose of this paper is to propose a method of rest to reduce work load of night shift workers for night shift work. The experiment was carried out 10minutes preparing time, 45minutes first work, 10minutes first rest, 45minutes second work, 10minutes second rest between 2 and 4 o'clock that the lowest physiological function of workers. The methods of rest set up as four patterns (1) non-action rest (2) non-action rest + listening music (3) action rest + non-action rest, (4) action rest + non-action rest + listening music. For the measurements of experiment, heart rates(R-R interval), critical flicker fusion frequency(CFF), blood pressure, oral temperature, reaction time and error rates were considered as criteria for work performance. As a result, action rest + non-action rest and action rest + non-action rest + listening music were more effective to reduce work load additional work than non-action rest and non-action rest + listening music.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.4
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• pp.426-435
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• 2016

Objectives: The major objective of this study was to analyze stress response after a change to consecutive day shifts from day and night shifts in a motor assembly factory. Methods: Using a survey conducted by a labor union, we collected data on stress response index(SRI), lifestyle factors, work-family conflict and job stress before and after a shift system change. We analyzed the transition on the SRI among 222 workers. The cut-off point for the SRI was a T-score over 60. Results: The high risk stress response group was 20.3% of the population before the shift system change. After the shift system change it decreased to 11.3%. After the shift system change, social support improved, leisure time became more sufficient, work-family conflict declined, and sleep quality in the night shift week improved. In multivariable linear regression, among workers under 40 years old sleep quality on night shift, leisure time sufficiency, social support and work-family conflict contributed to the improvement of stress response. Among workers over 40, work-family conflict contributed to the improvement of stress response. Conclusions: The change to consecutive day shifts improved stress response and mediated with improved nighttime sleep, decreased work-family conflict, increased leisure time and improved work-family conflict.

• Journal of Preventive Medicine and Public Health
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• v.37 no.2
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• pp.182-189
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• 2004

Objectives : The objective of this study is to compare the circadian patterns of heart rate variability assessed by 24-hour ambulatory electrocardiographic (ECG) recordings during day shift and night shift among the workers in the 5 days-concecutive-12-hour shift in an automobile factory in Korea. Methods : The study population consisted 300 workers, who were randomly selected among the 8700 total workers in one car factory. To analyse circadian variation, the 24-hour ECG recordings (Marquette) were measured during day shift (08:00-20:00 h) and night shift (20:00-08:00 h). Analysis was performed for all time and frequency domain measures of HRV. 233 workers completed taking 24-hour ECG recordings. Results : This study shows that the 24 hourcircadian variation mainly follows work/sleep cycle rather than day/night cycle among shift workers. This study also shows that among the night shift, the circadian variation between work and sleep cycle decreased compared to the work/sleep cycle among day shift workers. All time and frequency domain parameters (except LF/HF ratio) show significantly different between work and sleep in the day shift and night shift. Conclusion : These changes in heart rate variability circadian rhythms reflect significant reductions in cardiac parasympathetic activity with the most marked reduction in normal vagal activity among the shift workers. Especially, it suggests the circadian rhytm has blunted among the night workers. The quantification of the circadian variation in HRV can be a surrogates of workers' potential health risk, as well as suggests possible mechanisms through which the shift works compromise workers' health.

• Journal of the Ergonomics Society of Korea
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• v.22 no.3
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• pp.13-26
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• 2003

The purpose of this study is to investigate the present conditions of the night work and shift work systems in the heavy chemical industrial complexes found in Changwon, Masan, and Chinhae. Korea. We will attempt to define and classify their problems; and to discover further ways to improve their systems. Fifty production factories were carefully selected as the subjects for this study. The shift systems were classified into five categories. The consecutive night shifts were long in almost all cases with 6 days (36 factories) and 7 days (13 factories). It was found that the night work of about] 2 hours continues for a long period in the weekly rotation full-day shift systems and the night-including non-full-day shift systems, and there was no holiday during a shift cycle in the continuous full-day shift systems. The work time in most shift systems was longer than the 44-hours/week permitted by Korean law. Considering the characteristics of these various types of shift systems, the most essential thing to reduce the shift workers' work load may be to shorten their working hours and improve the schedule of shift systems. It is highly recommended as a fundamental solution. to reduce the portal-to-portal hours from 12 to 8 in the night-including non-full-day shift systems and the weekly rotation full-day shift systems, and at least to employ a 4-team 3-shift system in the continuous full-day shift systems. In addition to this, it should from now on be taken as a goal to restructure the types of shift systems by taking such measures as avoiding continuous night work if possible, providing sufficient off-duty intervals both before and after night shift, providing increased opportunities for workers to nap during night work. and increasing the number of holidays.

• Journal of the Ergonomics Society of Korea
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• v.29 no.3
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• pp.337-345
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• 2010

The purpose of this study was to investigate the effects of sleep/wake behavior for shiftwork in air traffic controllers (ATCs) using wrist actigraph for ten workers on a continuous full-day three-team three-shift system of forward rotation including on-duty and off-duty periods. The wrist actigraph data were recorded for three days (one shift cycle) for each subject. The mean activity counts during an on-duty period progressively increased from the night, the swing, to the morning shifts. The doze length during on-duty periods showed decreases in the morning and swing shifts as compared to the night shift. Total sleep time (TST) and sleep efficiency (SE) during off-duty periods increased in the morning-1 and swing-night shift compared to the morning-2 shift. Finally, I discussed the role of doze-taking during the burden on night shift ATCs.