Cognitive ergonomics: it's all in the mind

In this paper a distinction is made between classical ergonomics as dealing with the quality of working and cognitive ergonomics as dealing with the quality of work including the joint system products. It is argued that classical ergonomics can be seen as embracing a dualism, where the effects of work on the body are considered separately from the effects of work on the mind. This continues the mechanistic tradition of Western psychology. The aim of cognitive ergonomics is to describe (1) how work affects the mind, as well as (2) how the mind affects work. Work is all in the mind in the sense that the quality of work depends on the person's understanding of the situation (goals, means, constraints) and in the sense that the design of a worksystem depends on the designer's understanding, in particular the conceptualization of the people in the system. In cognitive ergonomics, the reliability of performance—and in particular the reliability of cognition—become central issues. The differences between classical and cognitive ergonomics are illustrated by considering two typical areas: risks at work and human-computer interaction. It is concluded that classical and cognitive ergonomics represent two complementary views of work that must be combined to meet the challenges of present day work environments.     

基于边状态枚举计算多状态网络可靠度动态界

为降低计算多状态网络可靠度的复杂性,综合考虑网络中具有多态性的边处于各中间状态的概率及从某中间状态转换到相邻状态对网络性能的影响,提出了一种基于边状态枚举计算多状态网络可靠度上下界的算法.该算法首先令网络中各边仅取完全工作和完全失效两种状态,将处于中间状态的概率分别叠加到完全工作和完全失效状态的概率上,得到可靠度上下界的初始值;而后按照对可靠度影响递减的顺序迭代枚举边的中间状态,通过集合间的比较,计算可靠度上下界的改变值,同时获得不断减小的可靠度上界和不断增加的可靠度下界,使其最终收敛于可靠度精确值.该算法不需提前求取网络d-最小割(路)集,且枚举较少的网络状态即可得到紧凑的可靠度上下界.相关引理的证明及算例分析验证了该算法的正确性和有效性.     

含缺陷压力管道可靠性研究特点及进展

从４个方面归纳总结了国外关于含缺陷压力管道可靠性的研究工作，分析了其局限性，进而提出了今后的研究方向。     

The k-out-of-n acyclic multistate-node networks reliability evaluation using the universal generating function method

In this article, a special node called the k⁻-out-of-n node, which cannot receive more than a certain amount of flows, is newly introduced. The acyclic multistate-node network (AMNN) that unsatisfied the flow conservation law is then extended to the k-out-of-n AMNN by including the k⁻-out-of-n and k⁺-out-of-n nodes. A very simple universal generating function method (UGFM) based on some intuitive properties that characterize the structure of the k-out-of-n AMNN is developed to solve the k-out-of-n AMNN reliability. The correctness of the proposed UGFM will be analyzed and proven. An example with three special cases illustrates how the k-out-of-n AMNN reliability is evaluated using the proposed UGFM. To show that the proposed UGFM can also solve the AMNN reliability, the first case of the example demonstrates that the proposed UGFM without needing to remove redundant terms and collecting like terms is more efficient and reasonable than the best-known UGFM.     

可编程控制器系统可靠性的设计

PLC广泛应用于社会生产各个行业，因此讨论其可靠性以及提出设计方案是非常必要的。文章分析了最为关注也是最为影响PLC可靠性的供电系统设计和接地设计，首先具体提出了供电系统保护措施的四种方法以及一般PLC系统供电电源设计，在I／O模板供电电源设计中则给出了24V直流和220V交流两种I／O模板的供电设计，最后分析了接地设计中应注意的问题并着重分析了接地电阻的选择。     

PLC在闭气塞自动检测装置中的应用

介绍了一种对新的火工品闭气塞自动检测装置，该技术是利用图像处理技术和PLC控制技术来实现的。从装置的原理和工作过程入手，详细讨论了PLC控制系统的设计和实现过程。实践结果表明，利用PLC实现火工品闭气塞自动检测装置的控制是一种非常有效的方法，可使整个检测过程不需人员投入自动完成，与传统检测方法相比较，显著提高了闭气塞的检测精度，并且检测效率可提高数十倍。     

机房专用空调机组设计、安装分析

本文通过分析机房专用空调机的特点,提出在机组设计、安装中需要注意的事项,并阐明了舒适型空调机及普通的恒温恒湿机是无法替代机房专用空调机组的观点,否则不仅降低了可靠性,而且造成更多的能耗.     

Hybrid Subset Simulation method for reliability estimation of dynamical systems subject to stochastic excitation

A hybrid Subset Simulation approach is proposed for reliability estimation for general dynamical systems subject to stochastic excitation. This new stochastic simulation approach combines the advantages of the two previously proposed Subset Simulation methods, Subset Simulation with Markov Chain Monte Carlo (MCMC) algorithm and Subset Simulation with splitting. The new method employs the MCMC algorithm before reaching an intermediate failure level and splitting after reaching the level to exploit the causality of dynamical systems. The statistical properties of the failure probability estimators are derived. Two examples are presented to demonstrate the effectiveness of the new approach and to compare with the previous two Subset Simulation methods. The results show that the new method is robust to the choice of proposal distribution for the MCMC algorithm and to the intermediate failure events selected for Subset Simulation.     

高可靠磁盘阵列的设计

可靠性是网络存储系统最重要的指标之一，冗余磁盘阵列(RAID)是网络存储系统的基础和关键部件，RAID一方面通过冗余数据或校验信息增强容错能力；另一方面通过硬件部件冗余来提高系统可靠性。重点研究提高RAID可靠性的关键技术。分析降低磁盘阵列可靠性的几种主要因素：系统故障、不可纠位错误和相关联的磁盘故障，研究相应的防御措施，对双重校验信息冗余技术、硬件部件冗余技术、快速故障盘重建等关键容错技术进行研究与探讨。     

并行数据包采集代理系统中的故障检测与恢复

在基于网络的IDS中，并行多采集代理技术可以有效地降低系统丢包率，但这种并行结构也造成了系统的可靠性下降。为了提高系组统可靠性．给出了并行采集代理的故障模型，针对并行采集代理中包选择算法的特点和并行采集所应用的环境，提出了基于检测代理和基于故障状态广播的两种故障检测与恢复模型，并分析了两者各自的优势和适用范围。最后定量给出了系统性能和可靠性之间的关系