不常用备件基于AHP的ABC分类模型

分析了传统ABC分类法在不常用备件库存分类中的应用,针对传统ABC分类法的缺陷.文章应用基于AHP的ABC分类方法,将备件单价、采购提前期、年采购费用、年使用次数、备件类型、重要性等级作为分类准则,对每一备件相对准则层进行ABC分类,然后结合准则层对目标层的权重计算备件组合权重并再次进行ABC分类,建立了不常用备件基于...     

成组更换策略下的备件库存决策仿真研究

针对成组更换策略下备件需求的特点,建立了无限使用期的成组更换策略与备件库存控制联合优化仿真模型。该模型通过模拟系统在预防维修间隔期T内的维修活动,得到1个预防维修间隔期内的总费用,然后在系统运行M(M足够大)个周期下,以期望单位时间总费用最小为目标,优化预防维修间隔期T和最大库存水平S。最后,基于案例,运用MATLAB对模型进行仿真优化计算,并分析了相关参数对模型优化结果的影响。     

面向协同产品商务的零件信息表达与共享

根据协同产品商务中各方对零件信息统一表达和共享的需要,提出一种面向协同产品商务的零件信息表达与共享方法。该方法分析零件信息特征构成及特征间关系,并基于特征建模技术建立面向协同产品商务的零件信息特征模型,将零件信息特征模型转化为统一的XML Schema信息模式,阐述转化的基本规则,构建面向协同产品商务的零件信息共享与交换平台,该平台以XML Schema信息模式进行检验,零件信息由XML描述并通过各种XSL样式表映射,满足不同用户的显示需要,实现零件信息的共享与交换。应用实例证明了该方法的有效性和可行性。     

Making use of prognostics health management information for aerospace spare components logistics network optimisation

Although research has evolved significantly over the last decade, there are still a large number of Grand Challenges confronting modelling, model deployment, and model-based decision making of large-scale complex Discrete Event Logistics Systems (DELS) to be tackled, as identified and reviewed during a Dagstuhl workshop in March 2010. This paper illustrates how several of these challenges are already being addressed, based on a series of case studies from the Aerospace Spare Components Logistics domain, where consolidated operational Prognostics and Health Management (PHM) information can be used for tactical planning and optimisation of spare components logistics networks. In this setting, the growing potential of PHM technology to facilitate the maintenance and support of commercial and military aircraft emphasises the need for tools to determine the impacts and benefits of a PHM system. To achieve this, the prognostics parameters and related logistics policies were identified, modelled, and subsequently incorporated into a simulation-based decision support framework.     

确定简单多边形旋转时碰撞部位的扫描算法

给定平面内任意两个互不相交的简单多边形Ｐ是Ｑ。若Ｐ在平面内绕０点旋转时与ＡＱ碰撞,讨论其碰撞部位的判定问题,通过分析多边形关于０点的单调边,在平面扫描算法的榧耻提出了曲线扫描法,给这一总理２的Ｏ（（ｍ＋ｎ）ｌｏｇ（ｍ＋ｎ））算法,与现有的算法相比,降低了时间复杂性,这一方法在计算几何和计算机图形学等领域具有一定的理论和实吓价值。     

IP/MPLS over WDM网络生存性的研究

该文首先分析了IP/MPLS over WDM网络单层生存性和多层联合生存性,并就生存性策略的性能进行对比,然后对多层空闲资源分配进行了研究。     

On spam detection based on cognitive pattern recognition

A method of spam detection, based on cognitive pattern recognition, had been proposed. The connection between Email category and cognition of Email user interest within life and work, had been analyzed. Under the guidance of cognitive pattern recognition theory, the mechanism of spam detection, based on intelligent cognition of Email user interest within life and work, had been discussed. Then the spam detection algorithm and its concrete implementation was given. Experimental results demonstrate that the spare detection algorithm has a good learning ability, scalability, and a good ability to achieve high recognition accuracyn     

零件几何参数的计算机测量系统

介绍了一种利用视频测量、计算机图像处理技术实现的零件几何参数测量系统。该系统具有较高的测量效率 ,能够达到较高的测量精度。阐述了系统组成原理、图像处理算法以及影响系统测量精度的主要原因     

轴承腔两相流动流型特征参数及鲁棒性分析

航空发动机轴承腔的润滑设计和换热分析依赖于对轴承腔中润滑介质两相流动特性的理解,依据流型进行轴承腔油气两相介质流动研究是获取流动特性的有效途径。针对通过试验判断油气两相介质流动形式的需要,结合数值分析和试验数据,在辨识能力和试验获取等方面的考虑前提下,提出了辨识航空发动机轴承腔中均相流动与含油滴气/液分层流动两种主要油气两相流型的特征参数——体积含油率和无量纲速度,探讨了两个特征参数在较宽工况范围内保持流型辨识能力的鲁棒性。研究工作对于借助于试验判断油气两相流型,从而可以在严谨理论指导下基于流型进行航空发动机轴承腔润滑介质两相流动特性分析,实现准确高效的润滑设计和换热分析的设计路线实施是很有意义的工作。     

DOP与CPE的含量对BaSO4填充聚氯乙烯基隔音复合材料性能的影响

将邻苯二甲酸二辛酯(DOP)与氯化聚乙烯(CPE)按照不同的质量份数加入到BaSO4填充聚氯乙烯基(PVC)隔音复合材料中,探讨DOP与CPE的含量对BaSO4填充聚氯乙烯基隔音复合材料隔声性能的影响,利用BSWA VS302USB双通道声学分析仪,万能材料试验机,动态热机械分析仪测试了材料的隔声性能,力学性能,阻尼性能。结果显示:当PVC相对质量为100份,DOP为50份,CPE为20份时对低频具有较好的隔声性能,当DOP相对质量为80份,CPE为20份时对中频具有较好的隔声性能,对高频影响较小。