• Journal of Preventive Medicine and Public Health
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• 제27권1호
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• pp.74-83
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• 1994

To investigate the sleeping patterns and gastrointestinal disorders of shift workers, the author studied 434 female workers who worked at textile industry ill Taejon city from September 1,1992 to September 31,1992. Shift pattern were divided into 3 categories ; 3 shift(shifts per 8 hours), 2 shift(day and night shift) and day work. The results obtained were as follows : 1 The average sleeping hours when adjusted for the education level of the total study subjects was 6.1 hours. That of 3 shift workers was 6.1 hours, 2 shift workers was 6.0 hours, but that of day workers was 6.5 hours. There were no significant difference among the shift workers. 2. For the 3 shift workers, the average physiologic adjusted duration in day shift (2.2 days) was shorter than that of night shift(2.7 days) and there were significant difference among the rotating shift works (p<0.001). The sleeping problems in day shift was less than those of night shift (p<0.001). 3. 44.9% of 3 shift workers, 39.3% of 2 shift workers and 33.1% of day workers complained gastrointestinal symptoms when adjusted for the age, education level, job tenure, work post. And the rates of gastrointestinal symptoms complained increase with job tenures (p<0.001). 4. The most frequent gastrointestinal diseases were gastitis and gastric ulcer with 14.2% , Irritable bowel syndrome with 3.1 %, duodenitis and duodenal ulcer with 2.1% and combined gastrointestinal disease with 2.1%. Age, eating habit, amount of coffee per day, job tenure, work post and shift pattern showed no significant difference with the gastrointestinal diseases when adjusted for the age. According to the above results, the author suggested that the shift pattern and job tenure can affect to the sleeping problem and gastrointestinal symptoms.

• Safety and Health at Work
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• 제10권1호
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• pp.67-74
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• 2019

Background: Few studies have examined the effects of a forward rotating shift pattern on police employee performance and well-being. This study sought to compare sleep duration, cognitive performance, and vigilance at the start and end of each shift within a three-shift, forward rotating shift pattern, common in United Kingdom police forces. Methods: Twenty-three police employee participants were recruited from North Yorkshire Police (mean age, 43 years). The participants were all working the same, 10-day, forward rotating shift pattern. No other exclusion criteria were stipulated. Sleep data were gathered using both actigraphy and self-reported methods; cognitive performance and vigilance were assessed using a customized test battery, comprising five tests: motor praxis task, visual object learning task, NBACK, digital symbol substitution task, and psychomotor vigilance test. Statistical comparisons were conducted, taking into account the shift type, shift number, and the start and end of each shift worked. Results: Sleep duration was found to be significantly reduced after night shifts. Results showed a significant main effect of shift type in the visual object learning task and NBACK task and also a significant main effect of start/end in the digital symbol substitution task, along with a number of significant interactions. Conclusion: The results of the tests indicated that learning and practice effects may have an effect on results of some of the tests. However, it is also possible that due to the fast rotating nature of the shift pattern, participants did not adjust to any particular shift; hence, their performance in the cognitive and vigilance tests did not suffer significantly as a result of this particular shift pattern.

• 한국지능시스템학회논문지
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• 제4권3호
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• pp.32-48
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• 1994

This paper proposes the compensation algorithm of conventional shift pattern using fuzzy reasoning in automatic transmission vehicles. Recently, automatic transimssion vehicles are continually increasing because of theire ease to drive. Also users require the high performance which includes the smooth shift quality and shift scheduling that matches driver;s intentions. So the shift scheduling has been inproved significantly through the application of electronic control. But, in spite of this development, vehicles using conventional shift pattern are sometimes in discord with driver's intention on roads. In this paper, the paper, the proposed compensation algorithm makes a automatic transmission vehicle be able to select an optimal gear shifting time and position using fuzzy reasoning and make a vehicle driver feel confortable even when the vehicle runs on roads which is extremely changed. Therefore, a vehicle driver can expect to reduce the nimber of unnecessary gear shifting and expect the fuel efficiency high. To show usefulness of the proposed method, some simulation are made to compared with conventional gear shifting. Paper prosposes the compensation mehtod of conventional shift pattern using fuzzy reasoning for the purpose that a vehicle can select an optimal gerar shifting time and position in automatic vehicle. Though the conventional shift pattern has no pliability, vehicle driver can feel comfortable and can reduce the number of unnecessary gear shifting using the proposed method on variable road condition. Therefore, it can be expected the fuel efficiency.

• 대한전자공학회논문지
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• 제21권4호
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• pp.17-23
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• 1984

A model analysis of pattern shift in the epitaxial growth of silicon on (111) substrates was performed. The growth rate anisotropy was considered as the most important affecting factor of pattern shift, and for the model establishment the off angle of the substrate and the process temperature were taken as the variables. We derived a theoretical equation of pattern shift by assuming the growth rate anisotropy as the trigonometric sine function of the off angle of the substrate and defining the growth rate anisotropy factor related to the process temperature. The pattern shift ratio calculated by this model had the same tendency with the experimental ones, which, however, were about twice greater than those. It was supposed that this discrepailcy was due to the second order affecting factor such as facetting and step broadening which had been exluded in model establishment.

• 대한안전경영과학회지
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• 제15권2호
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• pp.1-7
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• 2013

Based on a literature review regarding shift work, it is recognized that it has an adverse effect on workers' health. Especially, the night shift rather than the day shift imposes severe disorders on workers, which are indicated to dyssomnia, maladaptation to social life, and health problems such as gastroenteric trouble, cardiovascular diseases and depression. As the shift work can be explainable by using workers' labor ability necessarily to maintain company business consistently, it does not consider biorhythm, active mass and health condition of workers Actually duration of shit work would deprive workers of fundamental life rights by causing physical and mental effects. As a result of reviewing previous case studies related to effect of work pattern (day shift and night shift) on workers' health, an incidence of physical diseases like dyssomnia, gastroenteric trouble, cardiovascular diseases and premature delivery was higher in shift workers than normal workers. Additionally the incidence of mental disorders such as busy brain, social isolation, depression and work stress was also higher in shift workers than normal workers. These adverse physical and mental problems were intensified to night shift workers compared to day shift workers. Considering current various reports and study results, it is recommended that the shift work, especially the night work pattern, should not apply to contemporary work situation for sustaining workers' health condition constantly.

• 한국항공운항학회지
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• 제24권3호
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• pp.1-9
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• 2016

The study examined the effects of shift pattern and expertise on perceived workload and performance for aviation security screeners. 18 security screeners participated in this study, in which data were analyzed by dividing them into two groups (experts vs. less-experts). We measured their perceived workloads and performances (i.e., reading time through X-ray) as a function of shift pattern and time condition. As a result, highly experienced screeners (experts) showed high workload during the morning shift, while lowly experienced screeners (less-experts) reported high workload during the full-day and the afternoon shifts. In addition, less-experts took a longer time to inspect the baggage when they worked for the full-day and the afternoon shifts. Particularly, in the last time slot of the full-dat shift, expert screeners had a high workload, while both groups showed a high-level of workload at around 17:30 in the afternoon shift.

• Safety and Health at Work
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• 제11권3호
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• pp.367-371
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• 2020

We evaluated the eating pattern, physical activity, and daytime sleepiness level in Chilean shift workers. Fifty, middle-aged adult health workers from a public hospital in Santiago, Chile, were included: a group undergoing shift work (shift workers, including at least one "night shift" and one "long day", n = 33), and day workers under traditional schedule (from 8:00 to 17:00h, n = 17). Body composition, physical activity, and daytime sleepiness levels, and diet characteristics (diet composition, meals' timing, and diet quality) were assessed. Despite similar total energy intake, shift worker showed lower carbohydrate (% of energy) and higher protein intake (both P < 0.01), decreased diet quality, an irregular eating pattern, and delayed meal timing (all P < 0.05). Physical activity and daytime sleepiness levels did not differ between groups. Findings from this first Chilean study in healthcare shift workers support the fact that meal timing and diet quality appear as critical factors for upcoming intervention studies in this group.

• 대한한방부인과학회지
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• 제21권3호
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• pp.231-244
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• 2008

Purpose: The purpose of this study is to analyze body composition, obesity according to working pattern of working women. The subjects were workers in the automobile manufacturing industry. Methods: The subjects consisted of 514 industrial women workers who had received Korean oriental medicine health examination and submitted questionires about working pattern, during 8 months from April 2005 to November 2005. The body composition was measured by X-scan(Jawon medical, Seoul, Korea). We analyzed the relationship between body composition analysis, obesity and shift pattern with $X^2-test$ using the SPSS Ver. 12.0 Results: Regarding the realationship between body composition and working pattern, shift worker group had a significantly higher level of body weight, ratio of body fat, visceral fat and abdominal fat than normal worker. Conclusion: From this study, we can know that shift work can influence on working women's body composition and obesity.

• 한국생산제조학회지
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• 제20권5호
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• pp.639-645
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• 2011

Wheel-loader is a construction vehicle for uploading soil or sand into truck and transportation of materials, which requires large driving power and high rotational speed. To improve the working efficiency, the operator has to shift gears and control levers for bucket & boom simultaneously. Therefore, the automatic transmission has been introduced to enhance operator's convenience and enable effective operation. To develop the automatic transmission for the wheel-loader, technologies such as gears and a clutch-pack design and shift algorithm are required for improvement of shift quality. In this paper, the shift algorithm for the wheel-loader was developed and its shift pattern was analyzed. As the shift control is affected by the pressure profile for the clutch control, the shift quality depending on the pressure profile has been evaluated using experiment and simulation model analysis.

• 전자공학회논문지CI
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• 제41권6호
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• pp.55-60
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• 2004

결정된 변속선도에 의한 자동변속 패턴은 운전자에게 편리한 변속을 제공한다. 하지만, 운전자의 운전 성향이 개인마다 다양함으로 고정된 변속선도를 여러 운전자에게 동일하게 제공하는 것은 불만의 요소로 인식되고 있다. 이에, 본 논문에서는 운전자의 성향을 결정할 수 있는 입력을 이용한 학습 모듈을 설계하여 운전 성향을 판단하고자 한다. 판단된 운전 성향을 이용하여 변속선도를 조정함으로써 운전자의 의지에 부합되는 변속패턴을 제공하고자 한다. 실제 주행 시 얻은 데이터를 이용하여 제안된 모듈의 성능의 우수함을 보인다.