某型号燃气发生器故障的仿真再现

为对某次失败的火箭发射过程进行故障分析,本文对可能的故障情况进行了数值仿真研究.根据飞行过程的故障现象及箭载测量数据分析了可能的故障原因,并根据燃气发生器的特点对该燃烧室内雾化、燃烧过程进行了数学建模和数值仿真.根据可能的故障情况进行了逐一的数值仿真和结果分析,并与有限的箭载数据进行了对比.结果表明:采用该数学模型能够很好地对火箭发射过程中的故障进行再现;该型号的燃气发生器存在一定的设计缺陷,需要进行设计优化;扰流环倾斜是此次飞行最有可能的故障情况.     

竞争失效产品恒应力加速寿命试验优化新方法

对加速寿命试验设计优化的相关知识进行研究分析,确定以竞争失效产品恒应力加速寿命试验为应用背景。在对加速寿命试验统计分析深入研究的基础上,通过分析方案要素、约束条件等建立优化目标函数,提出基于模拟退火算法的优化方法和具体实现思路。最后通过实例验证方法的可行性和实用性。     

高可靠性软件的极值统计分析

提出了极值统计分析的方法.对于失效数据极值分布函数的拟合检验,采用了相关系数法;对于母体分布的参数估计,则分别采用了最小二乘估计(LSE)和极大似然估计(MLE);最后通过一个实例说明了统计过程,并用模拟的方法证明了最小二乘估计较好.     

Production‐inventory systems with imperfect advance demand information and updating

We consider a supplier with finite production capacity and stochastic production times. Customers provide advance demand information (ADI) to the supplier by announcing orders ahead of their due dates. However, this information is not perfect, and customers may request an order be fulfilled prior to or later than the expected due date. Customers update the status of their orders, but the time between consecutive updates is random. We formulate the production‐control problem as a continuous‐time Markov decision process and prove there is an optimal state‐dependent base‐stock policy, where the base‐stock levels depend upon the numbers of orders at various stages of update. In addition, we derive results on the sensitivity of the state‐dependent base‐stock levels to the number of orders in each stage of update. In a numerical study, we examine the benefit of ADI, and find that it is most valuable to the supplier when the time between updates is moderate. We also consider the impact of holding and backorder costs, numbers of updates, and the fraction of customers that provide ADI. In addition, we find that while ADI is always beneficial to the supplier, this may not be the case for the customers who provide the ADI. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Optimal control of a capacitated inventory system with multiple demand classes

This article studies the optimal control of a periodic‐review make‐to‐stock system with limited production capacity and multiple demand classes. In this system, a single product is produced to fulfill several classes of demands. The manager has to make the production and inventory allocation decisions. His objective is to minimize the expected total discounted cost. The production decision is made at the beginning of each period and determines the amount of products to be produced. The inventory allocation decision is made after receiving the random demands and determines the amount of demands to be satisfied. A modified base stock policy is shown to be optimal for production, and a multi‐level rationing policy is shown to be optimal for inventory allocation. Then a heuristic algorithm is proposed to approximate the optimal policy. The numerical studies show that the heuristic algorithm is very effective. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 43–58, 2011     

从《孙子兵法》管理思想看密切官兵关系的重要性

《孙子兵法》作为兵学圣典,对当前部队的日常管理具有重要的指导作用。从《孙子兵法》对自古以来官兵紧张关系的具体描述,剖析当前官兵关系紧张的成因,探讨科学解决官兵紧张关系的方法。     

舰艇编队网络化反导作战系统研究

首先,按照网络中心战的概念,研究舰艇编队网络化反导作战系统的体系结构,以传统作战单元的功能系统为基本单元(作战节点),建立了传感器网、指控网和武器网三层逻辑网结构,定义各层的基本组成和主要功能,并在认真分析传统指挥体制和指挥方式不足的基础上,提出了“动态网络型”指挥结构和“动态分权式”指挥方式;然后,深入分析了舰艇编队网络化反导作战过程,定义了舰艇编队网络化作战模式下4种新的作战方式;最后,指出了系统实现的关键技术,阐明了各关键技术下一步的研究方向及重点.     

海上对空弹目偏差精度试验的设计分析与应用

对空射击的弹目偏差测量需求十分迫切,利用空间声传感器阵测量弹目偏差向量,提取所需N波的时间宽度和各N波出现的时间,计算处理得到炮手坐标系的弹目偏差。由于采用测偏结果,使得系统射击时直接命中目标。具有测偏校射功能的新型观测设备,对舰炮武器系统和跟踪雷达、光电跟踪仪定型试验是必不可少的测量设备。脱靶向量是定量分析计算舰炮武器系统最重要的性能——射击效力,即命中概率和毁伤概率的依据。虽多次试验结果很好,但仍需要大量试验数据信息进一步验证完善。     

业主延期条件下FIDIC施工合同条件调价公式研究

调价公式作为FIDIC合同中最重要的风险分配方式之一,通过对可调价要素价格指数或价格的调整,把合同中的隐性风险在业主和承包商之间的分配比例作了明确规定.从承包商的角度,并基于业主的原因造成工期延长的条件下,对调价公式中各个组成因子及其权重对调价结果的影响进行了研究,探索把调价公式同成本管理有机结合起来,以期达到降低成本...     

地空导弹兵混编群作战仿真研究

应用离散事件动态系统仿真的基本理论,建立了地空导弹兵混编群作战过程仿真模型,并用Arena仿真平台实现了仿真。通过仿真实例,分析了不同空袭目标流密度和空袭目标采取低空突防时对目标突防概率的影响。仿真结果表明,在该实例中,增大空袭目标流密度对目标突防概率没有显著的影响,而采取低空突防对目标突防概率影响显著。最后,对仿真结果进行了分析,证明了仿真模型的有效性。