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排序方式: 共有276条查询结果,搜索用时 15 毫秒
1.
通过长期的工作实践,阐述了适当条件下的金扩散对缩短反向恢复时间,提高二极管2CK28开关速度,满足了反向恢复时间,改善了二极管的反向特性。 相似文献
2.
Persistent calls come from within the graduate medical education community and from external sources for regulating the resident duty hours in order to meet the obligations about the quality of resident education, the well-being of residents themselves, and the quality of patient care services. The report of the Accreditation Council for Graduate Medical Education (ACGME) proposes common program requirements for resident hours. In this paper, we first develop a mixed-integer programming model for scheduling residents’ duty hours considering the on-call night, day-off, rest period, and total work-hour ACGME regulations as well as the demand coverage requirements of the residency program. Subsequently, we propose a column generation model that consists of a master problem and an auxiliary problem. The master problem finds a configuration of individual schedules that minimizes the sum of deviations from the desired service levels for the day and night periods. The formulation of this problem is possible by representing the feasible schedules using column variables, whereas the auxiliary problem finds the whole set of feasible schedules using constraint programming. The proposed approach has been tested on a series of problems using real data obtained from a hospital. The results indicate that high-quality schedules can be obtained within a few seconds. 相似文献
3.
Research suggests that less than 5 h sleep in the 24 h prior to work and/or more than 16 h of wakefulness can significantly increase the likelihood of fatigue-related impairment and error at work. Studies have also shown exponential safety declines with time on shift, with roughly double the likelihood of accident or injury after 10 h relative to the first 8 h. While it is acknowledged that reduced sleep, increased wakefulness and longer work hours produce work-related fatigue, few studies have examined the impact of workload on this relationship. Studies in the rail industry have focused on drivers. This study investigated fatigue in a large sample of Australian Rail Industry Employees. Participants were from four companies (n = 90: 85m, 5f; mean age 40.2 ± 8.6 y). Data was analysed for a total of 713 shifts. Subjects wore wrist actigraphs and completed sleep and work diaries for 14-days. They also completed the Samn–Perelli Fatigue Scale at the beginning and end of shifts, and the NASA-TLX workload scale at least twice during each shift. Average (±SD) sleep length (7.2 ± 2.6 h), prior wake at shift end (12.0 ± 4.7 h), shift duration (8.0 ± 1.3) and fatigue (4.1 ± 1.3, “a little tired, less than fresh”) were within limits generally considered acceptable from a fatigue perspective. However, participants received 5 h or less sleep in the prior 24 h on 13%, were awake for at least 16 h at the end of 16% and worked at least 10 h on 7% of shifts. Subjects reported that they felt “extremely tired, very difficult to concentrate,” or “completely exhausted, unable to function effectively” on 13% of shifts. Sleep length (OR = 0.88, p < 0.01), shift duration (OR = 1.18, p < 0.05), night shift (REF = morning shift, OR = 2.12, p < 0.05) and workload ratings (OR = 1.2, p < 0.05) were significant predictors of ratings of extreme tiredness/exhaustion (yes/no). While on average, sleep loss, extended wakefulness, longer work hours and work-related fatigue do not appear problematic in this sample, there is still a notable percentage of shifts that are likely to be associated with high levels of work-related fatigue. Given the size of the Australian Rail Industry, with thousands of shifts occurring each day, this is potentially of operational concern. Further, results indicate that, in addition to sleep length, wakefulness and work hours, workload significantly influences fatigue. This has possible implications for bio-mathematical predictions of fatigue and for fatigue management more generally. 相似文献
4.
Precarious or temporary work is associated with adverse outcomes including low control over working hours, work-life conflict and stress. The rise in precarious employment is most marked in the service sector but little research has been done on its health effects in this sector. This study compares permanent and temporary workers in the hotel industry, where working hours are highly variable. Survey data from 150 workers from eight 3-Star hotels in urban and regional areas around Sydney were analyzed. Forty-five per cent were male and 52 per cent were female. Fifty four per cent were permanent full-time and 46 per cent were temporary workers. The effects of employment status on perceived job security, control over working hours, and work-life conflict are investigated using PLS-Graph 3.0. The effects of control over working hours, on work-life conflict and subsequent health outcomes are also explored. Temporary workers perceived themselves as less in control of their working hours, than permanent workers (β = .27). However, they also reported lower levels of work intensity (β = .25) and working hours (β = .38). The effects of low hours control (β = .20), work intensity (β = .29), and excessive hours (β = .39) on work-life conflict (r2 = .50), and subsequent health effects (r2 = .30), are illustrated in the final structural equation model. 相似文献
5.
客运站高峰期运输组织优化仿真 总被引:1,自引:0,他引:1
该文在对铁路客运站运输组织过程进行分析的基础上,建立了大型客运站高峰期运输组织优化的网络流模型.确定了相应的优化目标及评价方法,对客运组织方案在计算机中的表示方法进行了讨论,运用现代仿真技术,提出了大型客运站高峰期运输组织优化仿真的一般过程,对客运组织方案网络节点的类型及其表示、数据库设计及其实现等问题进行了讨论.对仿真中的关键技术提出了解决的方法。 相似文献
6.
7.
《Ergonomics》2012,55(1-3):219-225
The improvement of an irregular three-shift system with anti-clockwise rotation of workers of a disabled persons' facility covering 42 h a week was a subject for management-labour debate. Workers were complaining of physical fatigue, high prevalence of low back pain, sleep shortages associated with short inter-shift intervals, and irregular holidays. With the co-operation of trade union members, an educational and intervention programme was designed to analyse, plan, and implement improved shift rotation schemes. The programme consisted of (a) a group study on the existing system and effects on health and working life; (b) joint planning of potential schemes; (c) communication and feedback (d) testing and evaluation; and (e) agreement on an improved system. The group study was undertaken by means of time study, questionnaire and physiological methods, and the results were jointly discussed. This led to the planning of alternative shift schemes incorporating more regular, clockwise rotation. It was agreed to stage a trial period with a view to shorter working hours. This experience indicated the importance of a stepwise intervention strategy with frequent dialogues and a participatory process focusing on the broad range of working life and health issues. 相似文献
8.
Helen Clare Lingard Keith Townsend Lisa Bradley Kerry Brown 《Construction Management & Economics》2013,31(10):1101-1112
Project‐based construction workers in the Australian construction industry work long and irregular hours and experience higher levels of work‐to‐family conflict and burnout than office‐based workers, giving rise to an interest in alternative work schedules as a means of supporting work–life balance. Alternative work schedules were implemented in four case study construction projects in Australia. Interventions differed between projects, with two implementing a compressed work week, and the others introducing reduced hours schedules (one of which was optional). Data were collected from each case study project, using various combinations of focus groups, surveys, interviews and daily diary collection methods. The results were mixed. The compressed work week appears to have been favourably received where it was introduced. However, waged workers still expressed concerns about the impact on their weekly ‘take‐home’ pay. Attempts to reduce work hours by changing from a six‐ to a five‐day schedule (without extending the length of the working day between Monday and Friday) were less favourably received. Waged workers, in particular, did not favour reduced hours schedules. The results confirm the existence of two distinct labour markets operating in the Australian construction industry and markedly different responses to alternative work schedules, based upon whether workers are waged or salaried. The results clearly show that attempts to improve work–life balance must take the structural characteristics of the industry's labour markets into consideration in the design of interventions. The impact of alternative work schedules is likely to be moderated by institutional working time regimes within the construction industry. 相似文献
9.
本文结合福州市城市规划管理技术规定(暂行)以及规划局日照要求提出了如何在不同日照标准下的总平面布局及建筑户型的选择,提高了地块容积率,保证了人们享受日光的权利。 相似文献
10.
为调动学生自主学习兴趣,培养其解决工程实际问题的能力和创新能力,我们对化工原理课程(理论课、实验课和课程设计)的授课方式等进行了改进,即在教师的配备、教学内容及时间的设置上,进行了改进,并提出了改进的具体措施,取得了成效。 相似文献