备件储备定额研究

分析了备件储备定额研究的重要性，讨论了备件储备定额的有关问题：备件的科学分类、备件储备定额的确定方法、备件消耗量的确定及备件储备定额的管理。     

确定备件品种中的VE应用研究

本文分析了影响确定备件品种的因素, 探讨了备件的功能评价方法, 并结合实例给出了应用价值工程确定备件品种的步骤。     

基于边际分析法确定备件补给数量

建立了基于边际分析法确定备件补给数量的模型,探讨了基于有限的保障经费合理确定各类备件采购数量的问题,并通过示例分析在备件库存不为空和为空两种情况下备件补给数量的确定过程,仿真结果表明该法确定的采购方案较切合于实际情况.     

战时装备分散配置备件运行量优化研究

针对战时装备分散配置,随装备件与运行备件的使用方法不同的特点,本文对运行备件保障率进行了分析,将备件运行量优化问题理解为特殊的二级备件保障问题,建立了基于随装备件的运行备件保障率模型,给出了运行备件最优数量的通用计算公式。并给出了实例分析,验证了模型和算法,为装备分散配置的部队确定运行备件数量提供了决策依据。     

战时装备维修备件品种确定步骤与方法研究

着眼于战时特点,阐述准确确定战时装备维修备件需求的重要性,对我军在确定战时装备维修备件需求方面存在的不足进行了分析。针对现代战争“精确化”保障的特殊要求,结合我军现有的理论成果和实践经验,探讨系统科学地确定战时装备维修备件品种的程序和方法。     

基于VIKOR法的VMI备件供应商优化选择

本文基于供应链环境下,备件供应商选择的复杂性,在进行备件分类管理的基础上分析了VMI对B类备件的适用性,构建了VMI备件供应商评价指标体系,运用VIKOR算法对备件供应商进行指标体系的评价。应用熵权法确定了相应的评价指标的权重,有效地避免评价过程中对指标赋权的主观性,最后实例证明了该方法在备件供应商选择中的有效性。     

战时装备备件品种确定方法研究

着眼于新军事变革下装备备件保障的特点,首先分析了战时影响装备备件品种确定的主要因素,然后,运用模糊层次分析法与模糊综合评判理论相结合的方法,研究了备件品种确定的模型,最后,将研究结论应用于实例分析,验证了方法的可行性,为战时科学合理地确定出备件的品种提供了理论依据。     

基于综合模糊评价法的修复性维修备件确定优化研究

本文着眼提高部队备件保障水平,综合运用综合模糊评价法和层次分析法等研究方法,对部队修复性维修备件品种和数量进行优化研究,确定更加符合信息化战争时代要求的备件品种和数量,为我国新一代装备备件的确定提供科学合理的依据。     

基于模糊层次分析的备件重要性等级评价

将备件的可预测性、可得性、关键性和经济性作为评价指标;通过ABC分类确定指标权重,运用模糊层次分析法计算备件的组合权重;最终得出对备件的重要性排序。该方法可快速有效地找出重点备件,提高备件管理工作的针对性。通过算例验证,验证结果表明这种评价模型具有现实可行性。     

基于DEA的备件ABC分类模型

提出了一种基于DEA的维修备件ABC分类方法。该方法根据DEA中确定指标是输入（出）的原理，将备件的多个属性指标分成输入指标和输出指标，使得模型效率值大小能直接表示备件的重要程度，并根据相应的效率值对备件进行ABC分类。该方法不仅克服了传统ABC分类法存在的指标单一的缺陷，也解决了多指标之间数值量纲的不一致所产生的问题。该方法用于设备维修备件的分类，能科学有效地找出维修备件管理中的关键备件，提高备件分类的有效性和备件管理的针对性。     

无寿可修航材消耗定额模型

根据航材需求差均比大于、等于或小于1三种情况,提出负二项分布、泊松分布和二项分布三种需求分布。对服从泊松分布的二层级航材需求问题,采用负二项分布改进预测精确性。用满足率作为航材保障程度的衡量标准,并根据航材消耗定额的影响因素制定最低满足率。以给定的总保障经费和最低满足率为约束条件,总满足率最大为目标函数,建立航材消耗定额模型,采用边际分析法求解。算例证明本模型的预测效果良好。     

基于AHP和模糊方法的库存航材ABC分类模型

根据航材部门实际的工作需要将航材的危害度、损耗性、易得性、经济性和任务需求性作为分类准则,通过ABC分类来求解航材对分类准则的权重,然后运用层次分析法计算航材的组合权重,并使用模糊评价的方法计算航材针对各准则的优先分值,再根据组合权重对航材进行ABC分类,该方法用于航材的分类可以快速有效地找出重点航材,提高航材管理工作的针对性和有效性。     

Optimal maintenance center inventories for fault-tolerant repairable systems

In many military and commercial contexts, complex equipment which is expected to perform very reliably is often designed to be fault-tolerant, that is, able to function although some of the parts have failed. A popular fault-tolerant design is the m-out-of-n system, where there are n identical parts, at least m of which must be functional for machine operation. Complex equipment of this type often undergoes scheduled maintenance overhauls at regular intervals during which all failed components are replaced. Failure to have replacements on hand for failed parts requires emergency measures at premium cost. When repairable parts are highly reliable and expensive, both holding and shortage costs are high. A reasonable objective is to choose initial spares inventory to minimize the sum of holding costs and expected shortage costs.We first develop a model to determine the optimal repairable parts inventory for a maintenance center servicing machines containing a single m-out-of-n system. The model is then extended to handle a related problem, finding optimal maintenance center inventories for machines containing several m-out-of-n systems of different parts, minimizing total expected costs subject to a constraint on total inventory investment.We assume that there is a fleet of machines, which experience identical workloads. There is a cycle time of T days between overhauls for an individual machine. A machine arrives at the maintenance center for overhaul each day. At the overhaul, all failed parts are removed and sent to a repair shop, from which they eventually return to the maintenance center to be used again as spares. The total number of spares undergoing repair and on hand is a constant. There are no backorders; if the number on-hand spares is insufficient to meet demand at an overhaul, a shortage penalty is assessed which depends on the number and type of spares required.While computing holding costs is straightforward, computing expected shortage costs is more complex. Expected shortage costs are dependent upon several factors, including component failure rates, the values of m and n, part repair rates, and the initial number of spares on hand. We assume that the system of interest is well specified, so that the parameters of the model are known except for the number of initial spares of each type, which are the decision variables. We model the on-hand inventory of each type of part as a Markov chain with the number of spares on hand at the end of each day as the states, under the assumptions that failure rates are constant and repair times follow independent exponential distributions. We then calculate the steady-state probabilities of stockout of various numbers of spares, as a function of the initial spares inventory. The expected shortage costs for a given type of spare may then be calculated by finding the product of the penalty cost for lacking p spares and the probability of lacking p spares and summing over all possible p values.Solutions to the problem of finding optimal initial inventory level for a machine containing a single m-out-of-n system may be found easily by enumeration. Solutions to the constrained problem where the machine contains several independent m-out-of-n systems, may be found by dynamic programming. Sensitivity analysis of costs to changes in the inventory investment constraint is clear, and computational effort is reasonable. A simple example is included to illustrate the solution method for both problems.     

军用飞机备件预测仿真研究

军用飞机备件需求预测是部队目前研究的一个热点问题。为了有效地进行军用飞机备件需求预测,提出了一种用仿真进行预测的方法。通过仿真结果可以看出,该方法用于军用飞机备件需求预测是非常方便有效的。     

聚类分析在航材分类上的应用

针对航材种类繁多、规格复杂、消耗规律多样导致航材消耗研究较困难的问题,提出采用聚类分析方法根据历年航材消耗数据对大量航材进行分类,为避免量纲的影响采用马氏距离进行样本间相似性度量,为全面反映样本类间的相似性采用离差平方和进行类与类间的相似性度量。算例给出了利用聚类分析方法对一定量的样本进行分类的步骤和方法,结果表明分类效果显著。     

Improving agility and resilience of automotive spares supply chain: The additive manufacturing enabled truck model

The global supply chain disruption by the COVID-19 pandemic is difficult, if not impossible, to estimate as over 94% of the top 1000 fortune companies were badly affected. The need for building resilient supply chains to mitigate the effect of such disruptions is rising rapidly than ever before across the global business spectrum. Building resilience in the automotive spare parts (ASPs) supply chain is critically important as any disruption to automotive spares supply chain will affect the operations of the logistics sector, the backbone of global supply chains. This research work contributes to improving the resilience of the automotive spare parts supply chain by proposing a Viable Supply Chain (VSC) framework design that incorporates Additive Manufacturing (AM) enabled trucks in the automotive spares supply chain network. Based on the proposed model, conceptual case models are developed and tested with proposed AM enabled truck manufacturing closer to end customer. A heuristic approach called shortest time heuristic is also proposed to solve the routing and scheduling of an AM enabled truck to deliver customers’ orders of the spare parts through an online platform. Importantly, the study demonstrate how additive manufacturing can help the ASPs industry to switch from the existing practice of make-to-stock to a more efficient inventory management and cost saving make-to-order model while also achieving resilience and sustainability in by providing a source of spares support for discontinued models of vehicles.     

基于代理成本的企业融资决策

本文从代理成本的概念入手,分析了企业融资过程中产生的代理成本,包括股权产生的代理成本和债权产生的代理成本,论述了企业可以通过确定最优融资结构、进行包括降低企业股权代理成本和降低企业债权代理成本在内的融资决策来降低企业的代理成本、实现企业价值的最大化。     

关于市政工程不同降排水方式适用性的探讨

在市政工程施工过程中经常要进行降、排水作业,所用的降、排水方式主要有集水明排、井点降水等。集水明排参数有排水沟的坡度、集水井深度等参数;井点降水涉及管井、真空井点、喷射井点等降水方式。在实际作业过程中涉及到对于降排水方式的选择,在众多方式中我们希望找到一个符合降水要求,同时又经济、满足施工工期等要求的方式。每一种降排水有其优点也有其缺点,本文通过分析不同的降排水适用条件,以期找到符合工程工况下降排水要求的最优解。     

海洋特色流体力学系列课程群建设研究与实践

流体力学系列课程是海洋类、海洋工程类学科的重点特色基础课程。为适应多学科的专业要求,从完善系列课程群模型、充实教材内容、优化教学方式方法以及构建实践实验平台等几个方面,讨论课程群的建设问题。开展了以促进学生知识、创新能力和综合素质协调发展为目标的系列课程建设与教学创新。构建几年来通过应用实践,效果良好。     

基于审计角度的政府绩效公众满意度分析

公众满意度是对公众心理状态的测量结果,可以作为政府绩效审计的评价标准之一,这是市场经济对政府绩效审计的内在要求。政府绩效公众满意度的评价通常是通过对公众满意度的调查来进行的。调查方法主要有层次分析法和模糊综合评价法,该调查方法可以将定性指标通过模糊数学定量化。