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31.
Bentley T 《Applied ergonomics》2009,40(2):175-180
The vast majority of the published workplace slips, trips and falls (STF) literature is exceedingly narrow in its focus and often ignores wider systems issues in workplace STF aetiology. There is little recognition within the published literature of the importance of latent failures or the upstream organisational and cultural contexts within which workplace STF occur. This is unfortunate, as a systems approach to workplace STF analysis, that is inclusive of latent design and work organisation factors that often shape worker behaviour patterns related to STF risk (e.g. rushing, risk taking), is fundamental to the development of effective prevention measures. The aims of this paper are to provide an understanding of workplace STF causation that is cognisant of the potential role of both active and latent failures in STF causation. The paper presents an ergonomics model for workplace STF analysis that highlights information processing in STF aetiology, the STF incident process and the interaction between latent and active failures in STF causation. The paper draws upon ergonomics research conducted in a range of occupational contexts to illustrate the key features of the model as it applies to workplace STF. Implications of the model for analysis and prevention of STF are discussed. 相似文献
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The protection design is a key issue in survivable wavelength division multiplexing (WDM) optical networks. Most researches focused on protecting unicast traffic against the failure of a single network component such as a link or a node. In this paper, we investigate the protection scheme for multicast traffic in meshed WDM optical networks under dual-link failure consideration, and propose a novel protection algorithm called shared segment protection with reprovisioning (SSPR). Through dynamically adjusting link-cost according to the current network state, SSPR establishes a primary light-tree and corresponding link-disjoint backup segments for each multicast connection request. A backup segment can efficiently share wavelength capacity of its working tree or the common resource of other backup segments. Capacity reprovisioning establishes new segments for the vulnerable connections after a link failure and tolerates following link failures. The simulation results show that SSPR not only can make good use of wavelength resources and protect multicast sessions against any single-link failure, but also can greatly improve the traffic restorability in the event of dual-link breakdown. 相似文献
34.
为了明晰英语学习和教学的基本侧重点,采用语料库研究方法,以自建小型英语笔语语料库为基础,以其中出现的语言失误现象为研究对象,归纳出学习者在英语笔语输出时的主要问题。在此基础上,通过对比英汉语言的文字及句式特点,指出英语语言知识的欠缺,以及母语负迁移的影响是导致其用语失误的深层根源,进而建议英语教学与英语学习应首先以英汉语言的基本区别为重,达到事半功倍的效果。 相似文献
35.
The leak detection is of great importance in the reliable operation and management of a pipeline system. Recently,attention is shifted to the use of the time domain or frequency domain methods based on the transient analysis. These methodssometimes require accurate pressure signals obtained during the transient period or by creating ideal conditions in testing. This paperproposes a method that does not require transient simulations over the whole or an extended period of time, but uses the first transientpressure oscillation to detect leaks. The method considers the propagation of the pressure oscillation wave created from a fast valveclosure and the reflected damp wave from the leak. A leak in the pipe gives rise to reflected waves which in turn creatediscontinuities in the observed signal at the measurement section. The timing of the reflected damp wave and the magnituderepresent the location and the size of the leak, respectively. An analytical expression is derived based on the Method OfCharacteristic (MOC) for the relationship between the leakage and the reflected magnitude. The leak detection procedure based onthe method is also given. Then the reliability of the method is tested on numerically simulated pressure signals and experimentalpressure signals with calibrated leak parameters, and the results indicate a successful application and the promising features of themethod. 相似文献
36.
氢系统对于发电机的安全运行起到了关键的作用.介绍了庄河发电公司QFSN-600—2YHG型汽轮发电机组,在运行中发现严重漏氢现象,叙述了对氢系统进行全面检查的过程,及漏点的处理工艺和原因分析.实践表明:采用标准的工艺流程对机组漏氢进行检修,可得到满意的效果. 相似文献
37.
闫茹 《陕西科技大学学报》2013,(2):127-131
针对现有的传统浸水试漏机二维设计方法的不足,利用Solidworks软件,介绍了缸盖浸水试漏机的总体结构,详细阐述了试漏机的浸水机构、封堵夹具等关键零部件的三维设计,并实现了整机的虚拟装配,为产品的系列化奠定了基础. 相似文献
38.
A k-out-of-n system with independent exponential components is investigated. It is assumed that some working components are suspended as soon as the system is down, repair starts immediately when a component fails and repair times are independent and exponentially distributed. Formulas for various reliability indices of the system including mean time between failures, mean working time in a failure–repair cycle, and mean down time in a failure–repair cycle are derived. 相似文献
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对HL环流器系列装置,开发了蒽-丙酮荧光液渗透检漏用于真空内衬的零部件检漏,灵敏度可以达到10-9Pa.m 3.s-1,示漏位置分辨小于0.5mm;对大容器真空检漏,采用四极质谱计和氦质谱检漏仪相配合的检漏法;对压力容器检漏,开发了真空罩吸枪-氦质谱检漏系统,还研制了适于抽除大量水汽的检漏真空机组。对氘氚放电的JET,使用普通的氦质谱检漏仪(扇形磁体型)受到真空室壁释放所吸留的氢同位素的、尤其是氘的严重干扰,因为示漏气体氦(4H e,4.0026u)与氘(D2,4.0282u)的质量数十分相近。在氦质谱检漏仪入口处串接选择性抽气泵——用液氮冷阱来抽除可凝气体、用分子筛泵或10K低温泵来抑制氢同位素本底,并前置一个涡轮分子泵来压缩加强采样气流等。这种加强组合能使原先的氦质谱检漏系统灵敏度提高3个量级以上。 相似文献