Opportunistic retooling of a flexible machine subject to failure

A set of jobs can be processed without interruption by a flexible machine only if the set of tools required by all jobs can be loaded in the tool magazine. However, in practice the total number of tools required by a job set would exceed the tool magazine capacity. In such situations, the job set has to be carefully partitioned at the start of the production run such that each partition can be processed without interruption. During the production run, if there are unscheduled machine downtimes due to machine failure, this provides an additional opportunity to optimally retool the magazine for a smaller job set consisting of just the unprocessed jobs. In this paper, we study job sequencing rules that allow us to minimize the total expected cost of machine down time due to machine failures and magazine retooling, assuming a dynamic re‐sequencing of the unprocessed jobs after each machine failure. Using these rules, we develop a branch‐and‐bound heuristic that allows us to solve problems of reasonable size. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 79–97, 2001     

Iterative coloring extension of a maximum clique

In this paper we present an improved branch and bound algorithm for the vertex coloring problem. The idea is to try to extend the coloring of a maximum clique to its adjacent vertices. If this succeeds, its successive neighbors are considered; in case of failure (i.e., in the case the initial colors are not sufficient), working on the subgraph induced by the maximum clique and its neighborhood, the lower bound is improved by seeking for an optimal coloring of this subgraph by branch and bound. The process is repeated iteratively until the whole graph is examined. The iterative scheme exploits a further lower bound obtained by integrating a simple algorithm into the maximum clique search, and a new method to compute upper bounds on subgraphs. Furthermore, a new branching rule and a method for the selection of the initial maximum clique are presented. Extensive computational results and comparisons with existing exact coloring algorithms on random graphs and benchmarks are given. © 2001 John Wiley & Sons, Inc. Naval Research Logistic 48: 518–550, 2001     

综合系统多重递阶控制设计方法研究(一)空-空航炮的机身指向火控解算方法

为了满足综合系统多重递阶控制设计方法的需求,建立了空-空航炮的机身指向火控解算方法.该方法是在期望弹丸命中目标的情况下求解机身期望指向及其变化率.在某验证机的控制增稳系统上,采用所建立的火控解算方法以及综合系统多重递阶控制设计方法,设计了综合飞行/火力控制系统.仿真结果表明,所建立的空-空航炮机身指向火控解算方法较好地满足了综合飞行/火力控制系统的设计需求,获得了良好的综合控制系统动态性能.     

某区域锅炉房节能改造措施及其效果

针对现有锅炉房供热中存在的诸如能源的大量浪费和不能充分满足热用户需求等问题,以某锅炉房节能改造为例,从区域锅炉房现有的条件下对系统实施三方面的改造:一是加装微机监控系统,二是加装锅炉分层给煤装置,三是风机的变频改造;并从技术和经济方面加以分析论证,改造方案合理,采取的措施得当,节能效果明显。     

地空导弹与弹道导弹的技术融合正在促使这两类导弹产生突破性的发展

地空导弹采用弹道导弹的抛物弹道技术 ,能够实现应用固体推进剂达到低质量远射程的目标。弹道导弹采用地空导弹末段弹道的寻的制导控制技术 ,可以达到降速、增程并实现末段有效制导控制和弹道机动的目标 ,从而大幅度提高命中精度和突防概率。地空导弹和弹道导弹之间的技术融合 ,已经开始并将很快形成这两类导弹的新一轮突破性的发展     

目标数据关联多因素分布式推理判决系统推理结构

目标数据关联多因素分布式推理判决系统 ,是一基于分布式判决分类系统理论进行目标数据关联分析的大规模推理判决系统 ,在C3I系统中有着广泛的应用前景。本文在分析推理判决系统的推理规则类型和状态类型的基础上 ,给出系统的推理结构图 ,该推理结构是正关联神经推理结构     

大型文化商贸活动的火灾危险性及消防安全措施

本文就四川泸州的一次大型文化商贸活动 ,分析了大型商贸活动的特点及火灾危险性 ,并提出相应的消防安全对策。     

基于单元体设计的装甲装备弹目交会建模方法

为了提高作战仿真效果的可信度,提出了一种基于单元体的解决思路,并通过弹头终点弹道特性、装备几何特征、弹头与目标的关系分析,建立了陆军作战仿真的弹目交会模型。试验测试结果表明:该模型能够仿真作战过程中的弹头命中点坐标,满足作战仿真系统的准确性、实时性要求。     

针对多振源密频及波动线谱主动控制的改进算法及试验

为了让船舶机械主动隔振装置在线谱频率波动和多振源密频耦合等实船复杂工况下,仍能取得良好的振动线谱主动控制效果,研究了以多通道窄带Fx-Newton算法为基础的改进算法,提出了窄带滤波相位失真的自适应补偿器,使控制算法对线谱频率波动具有高鲁棒性;研究了多参考信号Fx-Newton算法,从多振源分离提取互不相关的多参考信号,从而解决多振源密频线谱控制难题。实验结果表明,改进窄带FxNewton算法对频率波动线谱的主动控制效果良好,并且对两个激振器或两台空压机组激励出的密频波动线谱也能进行稳定、高效的主动控制。     

系统仿真技术初探

为了对系统仿真技术有一个总体认识,采用归纳和分析的方法,对系统仿真技术的体系进行了初步探讨.