集成神经网络的飞机作战效能评估

根据飞机作战效能的指标体系和集成神经网络的原理,提出了一种基于集成神经网络的飞机作战效能评估模型.模型由空对空作战效能评估神经网络、空对地作战效能评估神经网络和决策融合神经网络组成,当训练结束后,输入飞机的能力参数可得到飞机的单项和综合作战效能.最后用米格-29、F-15E和Su-20等三个机型作为评估的对象,结果表明该模型能有效减少评估中的人为因素及克服单神经网络结构的不足,使评估结果更为客观可信.     

Optimal and asymptotically optimal policies for assemble‐to‐order n‐ and W‐systems

We consider two specially structured assemble‐to‐order (ATO) systems—the N‐ and W‐systems—under continuous review, stochastic demand, and nonidentical component replenishment leadtimes. Using a hybrid approach that combines sample‐path analysis, linear programming, and the tower property of conditional expectation, we characterize the optimal component replenishment policy and common‐component allocation rule, present comparative statics of the optimal policy parameters, and show that some commonly used heuristic policies can lead to significant optimality loss. The optimality results require certain symmetry in the cost parameters. In the absence of this symmetry, we show that, for systems with high demand volume, the asymptotically optimal policy has essentially the same structure; otherwise, the optimal policies have no clear structure. For these latter systems, we develop heuristic policies and show their effectiveness. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 62: 617–645, 2015     

导弹预警卫星对助推段导弹的探测能力建模

导弹预警卫星在导弹防御体系中处在最前沿,在导弹的早期预警中起着其他装备无法替代的作用。分析了导弹预警卫星的工作原理与作战流程,从覆盖范围、最大探测距离以及检测概率3个方面对导弹预警卫星的探测能力进行了数学建模,并利用所建模型分析了美国导弹预警卫星的探测能力,为导弹预警卫星的探测能力评估奠定了理论基础。     

全CFRP筋混凝土柱低周反复荷载试验研究

考虑轴压比、剪跨比和配箍形式的影响,对6根全CFRP筋混凝土柱进行低周反复荷载试验,通过分析滞回曲线、骨架曲线、位移延性系数和耗能能力等特征,研究CFRP筋混凝土柱的抗震性能。试验结果表明:CFRP筋混凝土柱具有较强承载能力和变形能力;轴压比和剪跨比是影响试件抗震性能的主要因素,轴压比越小,试件的变形和耗能能力越强,刚度退化越平缓,剪跨比越大,试件的变形能力越强;通用屈服弯矩法计算得到的延性系数能够较好反映CFRP筋混凝土柱的延性,轴压比越小、剪跨比越大,试件的延性越好;新型螺旋式矩形箍筋在试件延性及耗能方面表现良好,可以应用于工程实际。     

基于改进截断正态概率密度模型的防发散多尺度卡尔曼滤波

借鉴对机动频率建模的思想,对机动目标的截断正态概率密度模型进行改进,提出了一种改进的截断正态概率密度模型(ICN模型),并将防发散算法与多尺度估计理论结合,用克服滤波器发散的S(k)算法对基本的多尺度估计进行机动检测和相应改进,得到单模型单传感器系统的防发散多尺度估计算法,旨在减小噪声影响,减小机动目标模型不准确带来的跟踪误差,改善跟踪效果。     

Information disclosure with endogenous channel structure

This article investigates the firms' optimal quality information disclosure strategies in a supply chain, wherein the supplier may encroach into the retail channel to sell products directly to end consumers. We consider two disclosure formats, namely, retailer disclosure (R-C) and supplier disclosure (S-C), and examine the optimal disclosure format from each firm's perspective. We show that either firm prefers to delegate the disclosure option to its partner when the supplier cannot encroach. However, the threat of supplier encroachment dramatically alters the firm's preference of disclosure. The supplier may prefer the S-C format to the R-C format when the entry cost is low and the disclosure cost is high to achieve a higher quality information transparency. Meanwhile, the retailer may prefer the R-C format to the S-C format when the entry cost is intermediate to deter the possible encroachment of the supplier. In this sense, the firms' preferences of disclosure format can be aligned due to the threat of supplier encroachment. The consumer surplus is always higher under the S-C format while either disclosure format can lead to a higher social welfare. We also consider an alternative scenario under which the supplier encroaches after the product quality information is disclosed. An interesting observation appears that the supplier may encroach when the product quality is low but foregoes encroachment when the product quality gets higher.     

Coping with shortages caused by disruptive events in automobile supply chains

Unpredictable disruptive events significantly increase the difficulty of the management of automobile supply chains. In this paper, we propose an automobile production planning problem with component chips substitution in a finite planning horizon. The shortage of one chip can be compensated by another chip of the same type with a higher-end feature at an additional cost. Therefore, the automobile manufacturer can divert the on-hand inventory of chips to product lines that are more profitable in the event of shortages caused by supply chain disruptions. To cope with this, we propose a max-min robust optimization model that captures the uncertain supplies of chips. We show that the robust model has a mixed-integer programming equivalence that can be solved by a commercial IP solver directly. We compare the max-min robust model with the corresponding deterministic and two-stage stochastic models for the same problem through extensive numerical experiments. The computational results show that the max-min robust model outperforms the other two models in terms of the average and worst-case profits.     

弹道导弹微动模型及微多普勒特征研究

通过微多普勒可以提取弹道导弹目标的微动特征,利用弹头和诱饵微动特征的差异可识别出真弹头.运用角动量守恒定理分析了弹道导弹目标在各阶段的微动形式,运用叉乘矩阵、泰勒级数等原理,推导出了弹道导弹目标的微动模型,给出了弹道导弹目标的微多普勒计算公式,从理论上分析了其微多普勒特征.利用时频分析方法从回波信号中提取了弹道导弹目标的微多普勒,从回波信号中提取的微多普勒与理论上计算的微多普勒一致,表明分析方法有效,结论正确.     

基于层次聚类法的化工装置火灾爆炸灾害事故模式分析

化工装置灾害事故模式的研究,有益于从源头上做好灾害事故的预防工作。在介绍传统事故模式分析方法的基础上,提出了基于层次聚类法的化工装置火灾爆炸灾害事故模式分析方法,并对近20年100起相关灾害事故案例进行了模式分析研究。