基于模糊评价的薄壁件产品可制造性复杂程度实现

传统的设计过程偏重于强调产品的功能性,不能适应现代产品的快速设计及制造的迫切需求。针对这一问题,提出了考虑产品可制造性的产品智能设计模型,并结合薄壁圆筒件的冲压成型可制造过程构建了其决策分析方法。分析讨论了平面制件的结构要素与工艺决策、规则形状拉伸件的结构要素与工艺决策,拉伸力和压边力的计算等关键问题,以此发展了基于模糊数学理论的冲压工艺决策中存在的不确定因素分析模型;并以一类薄壁冲压零部件的可制造性分析作为一个分析实例,确定了每一制造因素评判标准的因素等级,得到了其隶属度的函数关系。     

医院全面质量安全管理考核分析软件的开发与应用

医院全面质量管理考核由于业务涉及面广,参与人员多导致数据填写不规范、不完整、不清晰,数据资料查询困难、随意涂改、甚至遗失;且难于进一步对最终数据资料进行分析利用,制约医院质量安全管理考核水平的提高,成为全面质量管理有效推行的"瓶颈"。我院以《全面质量安全管理考核方法》为基础,自主研发一套"计算机医院全面质量安全管理考核与应用分析系统"。该系统简化考核过程和工作量,简便易行,规范管理流程,节约管理成本,有助于全面质量安全管理考核体系有效推广,使医院由静态管理转向动态管理、由定性管理转向定量管理、由结果管理转向过程管理、由事后管理转向事前管理,方便数据调用查询排序,提高信息利用率,全面实现医院互动动态管理。     

应用模糊方法计算构件振动可靠性

分析影响构件振动可靠性的不确定性和模糊性因素，定义构件振动模糊安全状态，构建构件振动的模糊共振失效区域及相应的隶属函数、模糊强度失效区域及相应的隶属函数，建立构件振动可靠性计算的模糊模型，并将其应用于某航空发动机压气机、涡轮叶片的振动可靠性计算。研究结果表明，应用模糊方法评估构件振动可靠性是可行的。     

对石油钻井队正职干部的考核工作初探

科学考核和评价干部,是激励干部创先争优,推进企业绩效持续提升、不断跨越的有效途径,是加强干部队伍建设的基础性工作。胜利油田渤海钻井一公司党委对井队正职的分类量化考核进行大胆探索,制定了《钻井队正职干部综合考评规定(暂行)》,建立健全了井队正职干部能上能下的岗位管理机制,形成创先争优的良好氛围,推进"人才强企"战略实现跨越式发展。     

Validation of reported events from a vertical chute marine evacuation study

Background

The use of vertical chute marine evacuation systems (MES) is now well established on board marine passenger vessels; this system has yet to be deployed in an emergency situation, however, it has been associated with a fatality and several major injuries during training. Brunel University's Ethics Committee endorsed an initial retrospective cross sectional study (Harwood and Farrow, 2008) and the present quantitative observational study. Harwood and Farrow (2008) found that the physical, physiological and psychological characteristics of potential evacuees increased the likelihood of injury and adversely affected the reliability of the system.

Purpose

The validation of factors associated with the adverse outcomes recorded by Harwood and Farrow (2008) during vertical chute MES training, and to assess the hypothesis that evacuee's clothing material will affect the efficiency of the system.

Design

Observational data in a marine training establishment providing a triangulation measurement process of evidence from the retrospective study (Harwood and Farrow, 2008). Subjects were three hundred and seventy five representative participants on training courses for evacuation from a ship into inflated life rafts. The main outcome measures were stopping during descent and exiting the chute in an undesirable position.

Results

6.1% stopped momentarily during descent; 20.3% exited the chute in an undesirable position; on entering the raft 7.7% flipped over and 9.1% had their legs tucked up under their bodies. Independent variables including evacuees' clothing material were statistically significantly associated with adverse outcomes. Participants stopping during descent had an RR of 3.03 (95% CI 1.38, 6.64) for exiting the chute in an undesirable position.

Conclusions

This quantitative observational study broadly supported the results obtained from the retrospective cross sectional study (Harwood and Farrow, 2008). Stopping during descent and evacuee clothing increased the likelihood of undesirable outcomes and impacted on the efficiency of the system.     

Activity-rest schedules in physically demanding work and the variation of responses with age

Workers in physically demanding occupations require work breaks to recover from exertion. In a laboratory setting, we investigated the impact of ergometer cycling for 7 h in two conditions with an identical total break time but with two different activity-rest schedules. We hypothesised that more frequent but shorter breaks lead to less psychophysical strain and its effects than do less frequent but longer breaks, particularly for older workers. Twenty-nine participants representing three different age groups were tested in both conditions. Heart rate, perceived exertion/tension and feelings of fatigue were assessed and used as dependent variables. Results indicate no general activity-rest differences as well as no age-related differences of break effects under the condition of subjectively equal straining load. However, heart rate was found to be lower at some measurement points in the frequent-short-break condition and perceived exertion was lower in the infrequent-long-break condition. PRACTITIONER SUMMARY: Design of activity-rest schedules in physically demanding occupations is a key issue in the prevention of strain and hence of interest to ergonomists. Our study suggests that breaks during physically demanding work have the same effect if they are frequent and short or infrequent and long, regardless of age.     

Expert systems in ergonomics: requirements and an approach

Abstract

Industry currently fails to derive maximum benefit from ergonomics. This is mainly due to an imbalance between the large amount of ergonomie knowledge available and the limited amount actually applied. The use of the methodology of expert systems in ergonomics is one possibility for reducing this imbalance. This paper presents basic requirements for the development of expert systems. The particular requirements for the application of expert systems in ergonomics are also derived. Finally, the stage of development of an expert system for assessing lifting and carrying tasks is presented, and practical examples for the application of the system are discussed.     

Characteristics of job rotation in the Midwest US manufacturing sector

Job rotation has been advocated as a suitable intervention to control work-related musculoskeletal disorders. However, little is known regarding the prevalence of job rotation, methods used to identify jobs for rotation or the benefits or limitations of job rotation. A web-based questionnaire was developed to survey job rotation practices from Midwest US manufacturing companies. Results indicated that 42.7% of the companies contacted used job rotation, where the median time for which they had used job rotation was 5 years. Job rotation was used mainly to reduce exposure to risk factors for work-related injuries and to reduce work related injuries, whereas supervisor decisions and ergonomic analyses were used to select jobs for the rotation scheme. Major limitations to successful implementation of job rotation included rotation of individuals with medical restrictions, decreased product quality and lack of jobs to rotate to. These findings suggest that further study is needed to determine if exposure to risk factors is reduced through current efforts.     

Evaluation of acoustic beacon characteristics for navigation tasks

The goal of the present study was to investigate the human factors issues related to acoustic beacons used for auditory navigation. Specific issues addressed were: (1) the effect of various beacon characteristics on human accuracy in turning toward the direction of the acoustic beacon; (2) the difference between real and virtual environments on human accuracy in turning toward the acoustic beacon; and (3) the perceived sound quality of various acoustic beacons. Three experiments were conducted in which acoustic beacons were presented in a background of 80 dBA pink noise. Results of the localization tasks revealed that (a) presentation mode (continuous versus pulsed beacon sound) did not affect the overall localization accuracy or number of front-back confusion errors; and (b) the type of acoustic beacon affected the size of localization error. Results of the sound quality assessment indicated that listeners had definite preferences regarding the type of sound being used as a beacon, with (a) non-speech beacons preferred over speech beacons, (b) a beacon repetition rate of 1.1 rps preferred over either the 0.7 or 2.5 rps rates, and (c) a continuous operation of a beacon preferred over a pulsed operation. Finally, sound quality ratings and localization errors were highly negatively correlated. This finding demonstrates the usefulness and practical values of sound quality judgements for audio display design and evaluation.     

Shoulder and neck complaints in customer relations: individual risk factors and perceived exposures at work

Perceived psychosocial and biomechanical exposures, individual factors and pain in the shoulder and neck were recorded in two groups of female service workers (healthcare and shopping centre workers). The jobs investigated were characterized by ‘much’ direct human relations, ‘little’ sitting and ‘much’ standing, and were light work by physiological or biomechanical criteria but potentially psychosocially demanding. A screening survey (n = 400 females) was the basis for the selected sample (n = 66 females), which was the object of the main investigation of this study. Reliability of the questionnaires was tested in a separate group of female healthcare workers (n = 29). Heart rate recordings through the work day estimated workload. There was a high prevalence of shoulder and neck pain (>50%) for both work groups. In the two populations it proved difficult to explain shoulder and neck pain by reported physical and psychosocial exposures or individual factors, except by the variable ‘perceived general tension’, which clearly differentiated workers with and without pain. The findings in this study indicated, first, that perceived general tension might be an independent risk factor for muscle pain and, second, that this might be related to personality factors. However, this putative relationship must be verified in a longitudinal study. As no variable describing exposures in the working environment was associated with shoulder and neck pain, the question is posed whether such complaints can be considered work-related. Alternatively, the variables used to describe mechanical and psychosocial exposures in this study may have low specificity in characterizing work-related risk factors for service workers with customer relations.