攻击机靶场效能优化:概念、方法与基本问题

系统阐述了攻击机靶场攻击、靶场效能以及靶场效能优化等基本概念,在此基础上,分析了攻击机靶场效能优化的基本任务和基本问题,并给出了形式化描述。     

MEFP战斗部结构的正交优化设计

以多爆炸成型弹丸(MEFP)为计算模型,应用显式有限元程序LS-DYNA,分析了药型罩间距、锥角、壁厚、装药高度和装药直径5种因素对MEFP发散角的影响规律。结果表明:随着药型罩间距、壁厚和装药直径的增加以及药型罩锥角、装药高度的减小,MEFP的发散角在减小。在此基础上以MEFP发散角为命中和毁伤概率指标,应用正交优化方法针对5种结构因素对MEFP发散角的影响主次关系进行了分析研究。结果表明药型罩壁厚是MEFP战斗部命中和毁伤概率的主要影响因素,并得到了5种结构因素各水平的最优组合。     

常规导弹战前运输任务优化模型

制定常规导弹战前运输计划时,各车辆运输时间和运输路线的安排是一个组合优化问题.运用军事运筹学和不确定性优化理论,充分考虑节点冲突性、车辆隐蔽性、任务时间、道路容量等因素,建立了运输任务方案的优化模型.该研究为常规导弹波次作战计划的制定和优化提供模型支持,有助于提高常规导弹作战指挥自动化和部队的生存能力.     

Quantifying optimal mesh and ring design costs

During the last decade telecommunication operators have been deploying WDM (Wavelength Division Multiplexing) technology to satisfy the exponential growth in global communication. While facilitating the advanced information society of today, this has also led to a higher dependency on the networks, and furthermore the high capacity utilization of optical fibers means that a single link failure will influence many users and enterprises. For these reasons, protection of network connections has become a major competitive parameter for the operators. Currently, the most popular protection method is ring protection, due to its simplicity, requiring only basic management functionality and operating with local restoration control. While many optical rings have been deployed, little work has been published on exactly what the cost of ring networks are, compared to general mesh networks. In this article we perform a quantitative comparison between ring protection and mesh protection, using real world network data and realistic prices for network components. Extending classic LP flow models to take rings and node costs into account, and using a link‐path based mesh network LP model, we are able to perform a total cost comparison of the two architectures, and of manual ring network design. The results suggest that the price of mesh network components must be reduced significantly to be competitive with ring based networks, and also that manual network design does not necessarily lead to the most cost‐efficient designs. © 2004 Wiley Periodicals, Inc. Naval Research Logistics, 2005     

线性唯象传热规律下热机内可逆热经济学研究

对符合线性唯象传热规律(q∝Δ(T-1))的热机内可逆热经济学做了进一步研究,导出了在给定条件下Novikov热机的最优利润解析式,并得到了最优利润和相应的效率同其它参数间的关系.     

航天器交会型轨道追逃策略的滚动时域优化

针对航天器自由时域交会型轨道追逃过程中的测量误差等不确定性对交会的影响,提出了一种基于滚动时域优化的高时效策略求解方法。根据微分对策理论推导得到博弈鞍点控制策略,并对问题进行等价转换;通过预先离线求解开环鞍点策略,将问题初始状态和相应的解作为样本以进行神经网络训练,训练后的网络结构可以快速得到相应问题的近似解。为了更好地应对博弈环境中的测量噪声,基于神经网络结构设计了滚动时域求解框架,并通过周期性的滚动求解最终实现对逃逸航天器的交会。数值仿真表明,所提出的策略可以有效应对测量噪声不确定性,且相比于文献中已有的策略,计算耗时可从分钟级降至秒级。     

长向量处理器高效RNN推理方法

模型深度的不断增加和处理序列长度的不一致对循环神经网络在不同处理器上的性能优化提出巨大挑战。针对自主研制的长向量处理器FT-M7032,实现了一个高效的循环神经网络加速引擎。该引擎采用行优先矩阵向量乘算法和数据感知的多核并行方式,提高矩阵向量乘的计算效率;采用两级内核融合优化方法降低临时数据传输的开销;采用手写汇编优化多种算子,进一步挖掘长向量处理器的性能潜力。实验表明,长向量处理器循环神经网络推理引擎可获得较高性能,相较于多核ARM CPU以及Intel Golden CPU,类循环神经网络模型长短记忆网络可获得最高62.68倍和3.12倍的性能加速。     

采用可达域覆盖的多航天器协同护卫策略

针对高轨高价值目标护卫问题,提出了一种基于可达域覆盖的多航天器协同护卫策略。从相对运动视角对协同护卫任务进行了描述,并将威胁源多脉冲机动可达域问题建模为凸优化问题求解。在滚动优化框架下,根据动态更新的威胁源终端可达域,设计协同护卫平面及护卫点,以此为终端位置约束构建多航天器协同轨迹规划模型,生成相应护卫轨迹。仿真结果表明,所提出的可达域分析方法能够快速计算威胁源终端可达域,协同护卫策略在多个场景下均能有效阻止威胁源,且护卫成功率随护卫航天器机动能力增强而增大。     

VRML三维模型文件的优化技术

目前在Web3D领域,VRML是主流的开发平台。但在建模过程中,通常使用第三方三维建模软件。这样极大地减轻了制作模型的难度,节约了时间;但由于建模平台本身的原因,转换后的VRML文件的体积比较大,不利于网络传输与浏览。因此,对模型的空间位置进行调整,尽可能地优化模型的视觉效果,缩减其文件体积,是建立虚拟环境非常重要的环节。主要针对这个问题提出了一些具体的优化技术与算法以及新的数据结构。     

Adaptive random search for continuous simulation optimization

We present, analyze, and compare three random search methods for solving stochastic optimization problems with uncountable feasible regions. Our adaptive search with resampling (ASR) approach is a framework for designing provably convergent algorithms that are adaptive and may consequently involve local search. The deterministic and stochastic shrinking ball (DSB and SSB) approaches are also convergent, but they are based on pure random search with the only difference being the estimator of the optimal solution [the DSB method was originally proposed and analyzed by Baumert and Smith]. The three methods use different techniques to reduce the effects of noise in the estimated objective function values. Our ASR method achieves this goal through resampling of already sampled points, whereas the DSB and SSB approaches address it by averaging observations in balls that shrink with time. We present conditions under which the three methods are convergent, both in probability and almost surely, and provide a limited computational study aimed at comparing the methods. Although further investigation is needed, our numerical results suggest that the ASR approach is promising, especially for difficult problems where the probability of identifying good solutions using pure random search is small. © 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010