装备可修复备件三级库存优化配置模型研究

分析了备件库存优化研究现状,描述了可修复备件三级库存供应保障流程,以系统可用度和费用为约束,构建了备件三级库存优化配置模型,运用边际分析方法进行模型求解,得出可修复备件三级库存优化方案.以某型装备为例,对其维修备件库存方案进行优化,求得同时满足可用度和费用最优的库存方案,并分析了中继级修理时间和基层级修复概率对系统可用度的影响,可为装备维修保障工作提供决策.     

有限维修能力下作战单元装备可用度评估及备件配置优化

以作战单元长期远离保障基地执行作战任务为背景,考虑作战单元携行维修能力有限的实际情况,基于可靠性理论,提出了两级多单元保障系统下的故障件部分可修时的装备可用度评估方法。通过搭建蒙特卡洛仿真模型开展了保障过程仿真,并与所提方法做了对比验证,结果表明:该方法在处理有限维修能力下作战单元可用度评估问题时具有较高的精度。以备件购置费用为优化目标、装备可用度为约束条件,构建了有限维修能力下的备件库存优化模型,并采用边际优化方法对备件库存进行了优化配置,算例表明:根据备件优化模型和优化方法可以得到合理可靠的备件配置方案,能够为装备保障人员对作战单元备件配置方案的选取和评估提供决策支持。     

有限维修能力下多级保障系统装备时变可用度评估及保障方案优化

备件库存和站点维修能力是影响备件维修周转的重要因素,制约着装备的使用效果。针对备件需求随任务阶段动态变化时装备保障方案的评估和优化问题,考虑站点维修能力对备件维修过程的影响,结合METRIC建模方法和动态排队理论,建立了有限维修能力下多级保障系统装备时变可用度评估模型。在评估模型基础之上,以保障费用为优化目标、装备可用度为约束条件,建立任务期内多级保障系统保障方案优化模型。以任务期内的最低可用度所对应的备件短缺数为观测值,分析各项资源的边际效益值,采用边际优化算法对各项资源进行优化计算。算例分析表明,评估模型能够计算多级保障系统任务期内各阶段装备可用度;保障方案优化模型和方法能够得到各项保障资源的优化配置方案。提出的模型和优化方法能够为装备保障人员制订合理的保障方案提供决策支持。     

有限维修能力下多级保障系统装备时变可用度评估及保障方案优化

备件库存和站点维修能力是影响备件维修周转的重要因素，制约装备使用效果。针对备件需求随任务阶段动态变化的装备保障方案评估和优化问题，考虑站点维修能力对备件维修过程的影响，结合METRIC建模方法和动态排队理论，建立了有限维修能力下多级保障系统装备时变可用度评估模型。在评估模型基础之上，以保障费用为优化目标，装备可用度为约束条件，建立了任务期内多级保障系统保障方案优化模型。以任务期内的最低可用度所对应的备件短缺数为观测值，分析了各项资源的边际效益值，采用边际优化算法对各项资源进行优化计算。算例分析表明，评估模型能够计算多级保障系统任务期内各阶段装备可用度；保障方案优化模型和方法能够得到各项保障资源的优化配置方案。提出的模型和优化方法能够为装备保障人员制定合理的保障方案提供决策支持。     

装备k/N系统保障备件配置优化模型

备件是装备保障中重要的保障资源之一,是保证装备系统良好战备状态和恢复战斗力的重要因素。针对预防性维修中k/N系统备件配置模型不合理导致保障效益低下的问题,提出一种新的备件配置优化模型。模型考虑不同的故障类型对备件配置的影响,以配置备件数目最小为目标函数,以新构建的使用可用度模型和保障费用模型为约束条件,利用惯性权重递减的改进粒子群算法来提高模型求解效率。最后给出一个算例,结果表明模型能够合理的进行备件配置,给出最优备件配置方案,获取最佳的经济效益,提高装备系统保障效能。     

考虑维修因素的随舰备件配备方案研究

针对随舰备件配置问题,首先建立了考虑维修时间的随舰备件保障概率模型与使用可用度模型,研究了部件的使用可用度与备件保障概率之间的关系,并给出了部件寿命服从指数分布、维修时间为定长时的备件保障概率解析表达式;然后,以串联系统为对象,建立了基于使用可用度的系统备件配置优化模型,给出了随舰备件配置优化算法及流程;最后,定量分析了维修时间对装备使用可用度和备件保障概率的影响程度,验证了随舰备件配备方案的制定方法是合理可行的。     

基于METRIC理论的防空武器系统备件配置优化

利用C+ +Builder 6.0编程软件,编制了专门的计算备件期望短缺量的软件和查询表格,使得METRIC模型的实际运用更加方便;结合我军防空武器系统维修保障体制的现状,利用METRIC模型构建了备件配置优化模型;以备件订购费用为约束条件,装备可用度最大为目标对备件配置策略进行了优化研究;算例分析表明,结果比较合理,...     

舰船编队装备时变可用度评估模型及备件携行方案优化

针对舰船编队任务期内备件需求动态变化的现实情况,考虑已发生故障的系统修复前不产生新备件需求的实际情况,建立了需求非平稳条件下的编队装备时变可用度评估模型。以备件购置费用为优化目标,系统可用度为约束条件,提出了基于系统时变可用度的备件优化模型。以任务期内的最低可用度为观测目标,运用边际优化算法给出了模型的求解方法以及相应方案下的可用度评估曲线。算例分析表明:该模型能够为装备保障人员备件携行方案的制定提供决策支持。     

基于重要度的航材备件库存综合优化模型

航材备件的精确保障必须将装备的使用情况和备件库存控制问题结合起来,才有利于保障人员进行正确的决策。从飞机的可用度着手,根据不同的费用标准,结合飞机的可用度和边际效用分析得到相应的最优库存模型;当费用较少时,综合考虑备件的重要度和飞机的实际使用情况,用两两赋值法求出备件的重要度权系数,重新计算可用度并调整各备件的存储量,对库存进一步进行优化;最后,给出了所提方法的计算步骤。实验结果表明,所提方法在备件库存优化中既能保证重点又能兼顾一般,既能发挥装备的最大军事效益又能节约国防成本。     

基于贮存-使用可用度的舰船备件保障模型

针对舰船上露天贮存时间长、使用时间短的一类电子装备备件配置数量仅根据装备工作时间确定的不合理情况,将装备贮存时间转化为使用时间来求取装备贮存可用度的概率,并在扩展METRIC理的基础上建立了装备贮存-使用任务可用度模型。采用边际算法对装备随舰初始备件配置数量进行了优化,并对相同任务可用度下不考虑贮存时间和考虑贮存时间得到的备件方案进行了比较和评估。案例结果表明:不考虑装备贮存失效影响下优化得到的备件方案,其实际任务可用度比预期任务可用度小许多。     

On failure modeling

A promising approach to failure modeling, in particular to developing failure-time distributions, is discussed. Under this approach, system state or wear and tear is modeled by an appropriately chosen random process—for example, a diffusion process—and the occurrences of fatal shocks are modeled by a Poisson process whose rate function is state dependent. The system is said to fail when either wear and tear accumulates beyond an acceptable or safe level or a fatal shock occurs. This approach has significant merit. First, it provides revealing new insights into most of the famous and frequently used lifetime distributions in reliability theory. Moreover, it suggests intuitively appealing ways for enhancing those standard models. Indeed, this approach provides a means of representing the underlying dynamics inherent in failure processes. Reasonable postulates for the dynamics of failure should lend credence to the prediction and estimation of reliability, maintainability, and availability. In other words, accuracy of representation could lead to better, more reliable prediction of failure.     

液体火箭发动机故障诊断的最优回归方法

提出了一种基于最优回归理论的液体火箭发动机故障诊断方法，可以在测量参数较少的情况下诊断出较多的发动机故障。当发动机故障不太严重、故障因素也不多时，得到比较满意的关于故障定位和故障大小的结果；在发动机故障比较严重的情况下，仍能得到比较好的故障定位结果；当存在多个故障因素时，诊断效能有所下降。结果表明本文所提方法在比较大的范围之内具有良好的效果。     

采用SHLPN分析特种车载总线网络可靠性

针对特种车载总线网络可靠性难以评估的问题,提出采用随机高级Petri网(Stochastic High-level Petri Net,SHLPN)分析特种车载总线网络可靠性。深入分析特种车载总线网络故障模式的基础上,将其等效为冗余总线控制器模块、远程终端模块和冗余链路模块的串联,分别建立各个模块的SHLPN模型,得到了各个模块的稳态可用度计算式,进而综合得到特种车载总线网络的稳态可用度计算式。最后,实例分析验证了所提方法的有效性。     

The long term effects of an aging fleet on operational availability and cost: evidence from the U.S. coast guard

This paper empirically examines whether the aging of a fleet affects operational availability and operating cost using a unique data-set on the 117 47-foot Motor Lifeboats (MLBs) of the United States Coast Guard (USCG). Procured from 1997 to 2003, the 47-foot MLB is the standard lifeboat of the USCG and all 117 MLBs remain in service. The aging of the MLB fleet has resulted in higher annual operating costs and lower operational availability, although the nature of this relationship remains unclear. Our estimation strategy utilizes an error components estimator to examine these issues. We employ three variants of the dependent variables (i.e. the standard logarithmic transformation as is most commonly seen in the literature, inverse hyperbolic sine [IHS], and level outcomes). The point estimates from the standard logarithmic model finds operational availability for the MLBs decreases at a rate between 0.83 and 1.8% per year and cost increases at a rate between 0.33 and 7.81% per year. Similar effects are shown with the IHS and level outcome specifications. In terms of nonlinearity effects, we find the most pronounced changes in operational availability and cost occur for MLBs aged 15 years or more (in comparison to younger MLBs).     

基于镜像的高可用数据对象布局算法

镜像是提高数据可用性的流行方法。借鉴RAID的方法,在算法一级实现数据的冗余分布,提出基于镜像的高可用数据对象布局算法。在数据对象和存储节点失效时,利用冗余数据重构数据对象和存储节点,有效保证存储系统的高可用性。采用马尔可夫激励模型对存储系统进行定量的可用性分析,计算结果表明该方法是有效的。     

Investigating optimal replacement of aging air force systems

An availability‐oriented approach has been developed to decide when to replace an aging system. For an existing system, it is optimal to operate another year if and only if the incremental cost per available year is less than the lifetime average cost per available year of a new aircraft. We illustrate our approach using United States Air Force KC‐135 tanker data. In demonstrating our approach, we find it will be optimal to replace the KC‐135 by the end of the decade.     

An optimum multiechelon repair policy and stockage model

Currently, sophisticated multiechelon models compute stockage quantities for spares and repair parts that will minimize total inventory investment while achieving a target level of weapon system operational availability. The maintenance policies to be followed are input to the stockage models. The Optimum Allocation of Test Equipment/Manpower Evaluated Against Logistics (OATMEAL) model will determine optimum maintenance as well as stockage policies for a weapon system. Specifically, it will determine at which echelon each maintenance function should be performed, including an option for component or module throwaway. Test equipment requirements to handle work load at each echelon are simultaneously optimized. Mixed-integer programming (MIP) combined with a Lagrangian approach are used to do the constrained cost minimization, that is, to minimize all costs dependent on maintenance and stockage policies while achieving a target weapons system operational availability. Real-life test cases are included.     

The procurement problem: An integer programming problem well suited to a solution using duality

A procurement problem, as formulated by Murty [10], is that of determining how many pieces of equipment units of each of m types are to be purchased and how this equipment is to be distributed among n stations so as to maximize profit, subject to a budget constraint. We have considered a generalization of Murty's procurement problem and developed an approach using duality to exploit the special structure of this problem. By using our dual approach on Murty's original problem, we have been able to solve large problems (1840 integer variables) with very modest computational effort. The main feature of our approach is the idea of using the current evaluation of the dual problem to produce a good feasible solution to the primal problem. In turn, the availability of good feasible solutions to the primal makes it possible to use a very simple subgradient algorithm to solve the dual effectively.     

基于李亚普诺夫最优反馈控制的中制导

基于李亚普诺夫最优反馈控制的2种实现方法,即时间最速下降法与空间最速下降法,提出了一种混合策略。应用于导弹中制导,获得了满意的结果,可以极大地缩短中制导飞行时间并大幅度地提高中制导末端速度。仿真结果表明,该方法有一定的工程应用参考价值。     

The permutation flow shop problem with sum-of-completion times performance criterion

In this article we address the non-preemptive flow shop scheduling problem for minimization of the sum of the completion times. We present a new modeling framework and give a novel game-theoretic interpretation of the scheduling problem. A lower-bound generation scheme is developed by solving appropriately defined linear assignment problems. This scheme can also be used as a heuristic approach for the solution of the problem with satisfactory results. Its main use, however, is as a bounding scheme within a branch-and-bound procedure. Our branch-and-bound procedure improves significantly upon the best available enu-merative procedures in the current literature. Extensive computational results are used to qualify the above statements. © 1993 John Wiley & Sons, Inc.