• Safety and Health at Work
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• 제6권3호
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• pp.240-248
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• 2015

Background: Recovery from fatigue is important in maintaining night workers' health. This study compared the course of self-reported recovery after 2-week 12-hour schedules consisting of either night shifts or swing shifts (i.e., 7 night shifts followed by 7 day shifts) to such schedules consisting of only day work. Methods: Sixty-one male offshore employees-20 night workers, 16 swing shift workers, and 25 day workers-rated six questions on fatigue (sleep quality, feeling rested, physical and mental fatigue, and energy levels; scale 1-11) for 14 days after an offshore tour. After the two night-work schedules, differences on the $1^{st}$ day (main effects) and differences during the follow-up (interaction effects) were compared to day work with generalized estimating equations analysis. Results: After adjustment for confounders, significant main effects were found for sleep quality for night workers (1.41, 95% confidence interval 1.05-1.89) and swing shift workers (1.42, 95% confidence interval 1.03-1.94) when compared to day workers; their interaction terms were not statistically significant. For the remaining fatigue outcomes, no statistically significant main or interaction effects were found. Conclusion: After 2-week 12-hour night and swing shifts, only the course for sleep quality differed from that of day work. Sleep quality was poorer for night and swing shift workers on the $1^{st}$ day off and remained poorer for the 14-day follow-up. This showed that while working at night had no effect on feeling rested, tiredness, and energy levels, it had a relatively long-lasting effect on sleep quality.

• 산업노동연구
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• 제17권1호
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• pp.37-70
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• 2011

통계청의 '경제활동인구조사 부가조사'(2010년 3월)와 문화체육관광부 통계청의 '국민여가활동조사'(2010년 7월)를 분석한 결과, 주40시간 근무제가 노동자들의 근로시간과 여가생활에 미치는 영향은 다음과 같다. 첫째, 주40시간 근무제는 실 근로시간을 11.3% 단축시키고, 장시간근로 확률을 1/5로 축소시킨다. 시간당 임금에 대한 근로시간 탄력성은 -0.145로, 임금이 낮을수록 실 근로시간이 길고 장시간근로 확률이 높다. 저임금과 장시간근로는 동전의 양면이다. 둘째, 주40시간 근무제는 휴일 여가시간을 매개변수로 하여 여가비용에 영향을 미친다. 휴일 여가시간이 10% 늘면 여가비용이 3% 늘어난다. 주40시간 근무제는 스포츠 등 적극적 여가활동을 늘리고, 자원봉사, 동호회 등 사회성 여가활동에 긍정적 영향을 미치고 있다. 셋째, 주40시간 근무제 이후 생활에서 나타난 가장 큰 변화로는, 10명 중 7명이 '가족과 함께 하는 여가시간 증가'(52.2%), '자기 계발을 위한 시간 증가'(15.7%) 등 긍정적 변화에 응답하고, '여가 소비지출 부담 증가'(6.3%), '수입 감소'(3.4%) 등 부정적 변화는 13.9%, '별다른 변화 없음'은 14.4% 응답했다. 긍정적 생활변화는 여가생활 만족도 증가로 이어지고 있다. 넷째, 다른 변수를 통제하더라도 주40시간 근무제는 주관적 행복수준에 직접 영향을 미칠 뿐만 아니라, 여가생활 만족도를 매개변수로 하여 간접적으로도 영향을 미치고 있다. 따라서 주40시간 근무제가 노동생활과 여가생활에 미친 영향이 긍정적이라는 사실을 분명히 인식하고, 빠른 시일 내에 모든 직장에 주40시간 근무제가 정착되도록 가능한 모든 노력을 기울여야 한다. 주40시간 근무제를 5인 미만 사업장으로 확대하고, 초중등학교에 주5일 수업제를 전면 실시하고, 적극적 여가활동 여건을 조성해야 한다. 근로감독 행정을 강화해서 주 52시간을 초과하는 탈법적인 장시간근로를 제한하고 저임금을 일소해야 한다.

• Safety and Health at Work
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• 제6권2호
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• pp.104-113
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• 2015

Background: Given the long hours on the road involving multiple and interacting work stressors (i.e., delivery pressures, irregular shifts, ergonomic hazards), commercial drivers face a plethora of health and safety risks. Researchers goal was to determine whether and to what extent long-haul trucker work schedules influence sleep duration and quality. Methods: Survey and biometric data collected from male long-haul truck drivers at a major truckstop in central North Carolina over a six month period. Results: Daily hours worked (mean = 11 hours, 55 minutes) and frequency of working over government-mandated daily HOS regulations (23.8% "frequently or always") were statistically significant predictors of sleep duration. Miles driven per week (mean = 2,812.61), irregular daily hours worked (63.8%), and frequency of working over the daily hour limit (23.8% "frequently or always") were statistically significant predictors of sleep quality. Conclusion: Implications of findings suggest a comprehensive review of the regulations and operational conditions for commercial motor vehicle drivers be undertaken.

• 생물정신의학
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• 제29권2호
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• pp.46-55
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• 2022

Objectives Many studies have reported noticeable increases in the proportion of employees working either relatively short or relatively long hours. Such trends have been accompanied by an increasing concern that how much subjective mental well-being of employees would be influenced by their hours of work. The aim of this study was to investigate the association between work hours and clinically relevant depressive symptoms with demographic variables adjusted. Methods Participants were employees of a total of 56 private companies and local government organizations in Korea, aged 19 to 65 years. A self-report questionnaire that included items on working hour, job stress, levels of depression, and socio-demographic factors was administered to 15360 Korean employees, with 14477 valid responses. Hierarchical linear regression analyses, adjusted for sociodemographic factors, job related demographic factors, job stress, were used additionally to estimate the association between working hours and depressive scores. Results We found that working more than 40 hours per week correlated positively with the level of depressive symptoms after adjusting for demographic variables and the level of job stress. Furthermore, working 40 or fewer hours per week correlated negatively with the level of depressive symptoms. Being younger (β = -0.078, β = -0.099), being a female (β = 2.770, β = 1.268), and possessing a lower level of education (β = -0.315, β = -1.125) were significantly associated with higher level of depressive symptoms in all respondents. Conclusions Both of working excessively long or short hours is significantly associated with the prevalence of depressive symptoms. Establishing proper office hours for employees is critical to improving the quality of working conditions and maintaining good mental health in the workplace.

• 태양에너지
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• 제18권4호
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• pp.101-110
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• 1998

The purpose of this research is to study the charateristics and manufacture of a composite heat pipe system with rotational and static pipe. A composite heat pipe system were tested to obtain the relationship between the expansion injector and auxiliary expansion for the motion of the working fluid by the experimental results. In addition the heat transport characteristics were found based on wall temperature of rotor, expansion injector, storage tank and vapor temperature. Water is used as working fluid of heat pipes. As the results of experiments, the composite heat pipe was operated for long times, 10 hour above with various rotational speed in performance. There were a few unexpected data by the capillary pumped loop at small working fluid, but as a whole the testing was successful.

• 벤처혁신연구
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• 제4권2호
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• pp.97-108
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• 2021

근로계약은 형식상으로는 노동력상품과 임금의 교환관계로서 나타나지만, 단순한 물물교환의 차원을 초월하는 것이기 때문에 경제학적으로 노동력상품과 화폐의 교환관계로서 '매매'로서 파악하는 것도 가능하고 '임대차'로 파악할 수도 있다. 상품교환관계를 법적인 측면에서 보면, 노동력과 임금의 교환관계를 합법적으로 지지하고 그것에 구속력을 부여하여 강제화하는 법적인 장치가 계약이다. 이러한 근로계약은 임금을 수령하고, 임금의 수령의 반대급부로 일정한 시간을 사용자의 지휘·감독하에 두는 관계를 가져오게 하였다. 근로시간은 자신의 노동력을 사용자의 처분권하에 둔 종속시간이기 때문에 장시간의 근로는 근로자의 건강과 안전을 위해할 수 있고, 더 나아가 인간으로서 누려야 할 가치를 침해하는 행위가 될 수 있음으로 그 규제가 필요하다고 할 것이다. 근로시간의 단축은 인간의 생체적 한계를 설정하고, 확대 재생산을 할 수 있도록 생산적 측면에서 근로자의 문화에 대한 향유와 인간으로서 삶의 질을 확보하는 사회적인 측면에서 단축이 필요하지만, 사용자의 기업 경영상의 노동력 확보와 생산 활동 및 자본주의 국가에서 추구하는 것과 비교하여 이 둘의 양립을 할 수 있어야 한다. 근로시간은 개인에게서의 시간과 사회전체에서의 시간으로 볼 수 있고, 개인적인 차원에서 장시간 근로는 개인에게서의 시간은 줄어들게 되어 개인적 차원에서는 바람직하지 않지만, 사회전체적인 차원에서 생산 활동에 투입시간의 증대로 인한 생산물의 증가는 사회발전에 도움이 될 수 있다. 근로시간은 이러한 개인적 차원과 사회적 차원에서의 균형을 찾아간다는 측면에서 근로시간을 고찰하는 것이 필요하다. 근로시간의 규제방법이 근로시간의 시작과 근로시간의 종료에 대한 것으로 근로시간의 총량을 규제하는 것이었다면, 근로시간의 유연화, 탄력화는 근로시간의 총량을 1주 최대 52시간의 범위 내에서 범위를 한정하면서 기업의 새로운 업무의 출현에 따라 근로시간을 탄력적으로 배분하고 편성하는 것이 가능하도록 하는 근로시간의 질적인 규제방식이다. 이에 따라 근로시간은 단축하되 기업의 상황에 따른 유연근로시간제를 확대하여 시행하는 것이 필요하다. 이를 위하여 현재 6개월로 제한되어 있는 탄력적 근로시간제의 운용의 폭의 유연화와 사용자와 근로자간의 합의에 의한 선택적 근로시간제의 실 근로시간에 대한 처리, 정보통신 기술의 발전과 4차 산업혁명에 기반한 새로운 근로형태에 출현에 따른 재량근로시간의 대상 업무를 확대하는 것이 필요하다.

• 한국산업보건학회지
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• 제29권3호
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• pp.383-393
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• 2019

Objectives: The proportion of those working beyond 53 hours a week in 2018 has reached 16.8% of the total number of workers in the Republic of Korea (Statistics Korea, 2018). Although there are many studies that have dealt with the correlation of long working hours and increasing risk of work-related health problems, studies dealing with the factors impacting work-related health problems of workers according to their working hours are few. This study aims to ascertain factors impacting work-related health problems of workers based on their working hours through thorough research on their work environment. Methods: Necessary factors for this study were extracted from 'the 4th Korean Working Conditions Survey to analyze details on normal characteristics and work environments used for the study analysis, work hours, and health problems related to work. Results: The results are as follows: First, men showed a greater probability of exposure to work-related health problems than did women, especially in the 50s age group, which showed the highest potential for health problems from work among age groups. Second, service providers and sales professionals showed a higher probability of work-related health problems. Third, for the work environment, health problems at work related to vibration, noise, chemical and poison exposure, exhaustion, pain, standing position, and repeated motion showed a higher probability if the work hours are long. Conclusions: This study suggests that the minimization of overtime labor would prevent work-related health problems and diseases, improve the well-being of workers, and decrease the negative impact on workers in the subject area.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.375-375
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• 2006

The preparation methods are to be used as "melting method" and "absorption method", respectively. The reaction mixture in the reaction container was heating up the reaction mixture to $200^{\circ}C$ for 2 hour. The mixing time of lab scale preparation should be provided quit long, instead of the short working time in a compounder vessel. And The PP-PCM mixture in the reaction container was heating up the mixture around $60-80^{\circ}C$ for 2 hour. A melting method of frozen gel with 50/50 weight ratio of polypropylene-normal octadecane was prepared by adding PP chip and normal octadecane. An absorption method of frozen gel with 70/30 weight ratio of PP 4.8-normal n-octadecane was prepared by adding PP powder and normal octadecnae.

• Journal of Chest Surgery
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• 제27권9호
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• pp.723-731
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• 1994

We have modified the isolated perfused working rabbit lung model [IPWL] by perfusing the isolated lung with a hollow fiber membrane deoxygenator.For assessment the stored lung was ventilated with FIO2 0.4 and perfused with 37$^{\circ}$C deoxygenated circulating blood at a rate 5ml/kg/min for several hours until lung failure.We chose to compare our developing solution which contained low potassium and pentastarch with the modified Euro-Collins solution .Experiments were divided into four groups[n=6] based on the type of flushing preservation solution and preservation time.The flushed lungs were then preserved into same solution at 8~10$^{\circ}$C with 100% O2 inflated condition for 1 or 20 hours.These following results were obtained.The IPWL model requires only one animal per experiment and allows for the continuous assessment of aerodynamic performance. This should therefore be used as screening test in lung preservation.One hour preservation groups, there were no significant difference in recovery rates of PaO2, PAP and Paw. Survival time in the one hour preservation groups were very significant long in the Group II[LPPS, p<0.01]. Twenty hours preservation groups, there were no significant difference in the recovery rates of PAP and Paw between Group III[m-ECS] and Group IV[NS], but PaO2 was significantly worse at onset of reperfusion in Group III when compared with Group IV [p<0.05]. And also survival time in the 20 hours preservation groups were significant long in the Group IV [p<0.05].

• 대한가정학회지
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• 제31권3호
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• pp.101-112
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• 1993

The purpose of this study is to examine the real life of married women employed in a manufacturing industry by analysis patterns of their time use. Data for 172 married working women were gathered from the use of face-to-face interview method. The results were shown as follows; 1) Married female production workers spend 8 hours 44 minutes a weekday, and 10 hours 39 minutes a Sunday on physiological activities, and on socio-cultural activities 1 hour 50 minutes(weekday), 5 hours 30 minutes (sunday). 10 hours 22 minutes, 2 hours 23 minutes were consumed for the employed time compared to 3 hours 4 minutes, 5 hours 28 minutes for household labor. 2) Married working women's employed labor time is excessively too long while for leisure and house work time is too short, which means the patterns of their time use are very unbalanced type.