计算机通信网总可靠度的割集状态提取法

本文提出了一个简单而快速的计算网络总可靠度的新算法——割集状态提取法。其特点是对图每进行一次割集状态提取的变换,图的边和顶点数就明显减少,一般图只要经过数次变换就成了平凡图,于是产生了图的不交生成树集,也就很容易得出网络总可靠度的表达式。对于顶点少而边多的图更能显示出本算法快速精确的特点。

面向系统总质量可靠度的建筑分包商选择模型

为规避工程项目分包时项目质量不合格、工期延迟和管理成本增加等风险,建立了以系统总质量可靠度最大为目标的分包商选择模型。为进一步约束分包项目之间工期、成本和质量等因素的相互影响,模型引入惩罚函数,以此对超出约束的值加以惩罚。针对该模型,利用粒子群算法的原理,设计了用于模型求解的MATLAB程序,实现了建筑分包商的优化选择。最后,将提出的模型和算法应用在建筑项目的分包商选择活动中,验证了所提方案的正确性和可行性。

煤矿仪器本质安全栅的可靠性研究

煤矿仪器本质安全栅的可靠性研究［印度］Ｋ库马尔，Ｄ钱德拉等在煤矿仪器中，本质安全栅一直被人们谨慎使用。随着生产过程的机械化程度增大，生产过程的监视和控制仪器中必须应从电气和电子线路。但是，由于开关操作时，产生的潜在火花具有点燃瓦斯（甲烷和空气的混合可...

The Effects of Stochastic Characteristics of Materials on the Reliability of a Composite Ship Hull

The effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials under longitudinal moment were extensively studied using reliability and sensitivity calculations of a composite ship hull which was sagging.The reliability indices and failure probabilities of the ship in three kinds of failure modes (buckling,material failure,and ultimate collapse) were calculated by the surface response method and JC method.The importance factors of random variables in stochastic models,such as the model errors in predicting the ultimate longitudinal strength of ship and the longitudinal bending moment that the ship withstands,as well as the stochastic characteristics of materials in the models used,were calculated.Then,the effects of these random variables,including the stochastic characteristics of materials on the reliability index and the failure probability of ships which were sagging,were discussed with their importance factors.The results show that the effects of stochastic characteristics of materials on the reliability of ship hulls made of composite materials should be considered during the reliability assessment of composite ships.Finally,some conclusions and recommendations were given for high-speed ship design and safety assessment.