A bidirectional heuristic for maximizing the net present value of large‐scale projects subject to limited resources

We consider the scheduling of large‐scale projects to maximize the project net present value given temporal and resource constraints. The net present value objective emphasizes the financial aspects of project management. Temporal constraints between the start times of activities make it possible to handle practical problem assumptions. Scarce resources are an expression of rising cost. Since optimization techniques are not expedient to solve such problems and most heuristic methods known from literature cannot deal with general temporal constraints, we propose a new bidirectional priority‐rule based method. Scheduling activities with positive cash flows as early and activities with negative cash flows as late as possible results in a method which is completed by unscheduling techniques to cope with scarce resources. In a computational experiment, we compare the well‐known serial generation scheme where all activities are scheduled as early as possible with the proposed bidirectional approach. On the basis of a comprehensive data set known from literature containing instances with up to 1002 activities, the efficiency of the new approach is demonstrated. © 2003 Wiley Periodicals, Inc. Naval Research Logistics, 2003     

一种多约束条件下高超声速导弹对地攻击的三维最优变结构制导律

针对高超声速空地导弹多约束高精度末制导的基本需求,在三维解耦的俯仰平面和转弯平面上分别设计制导律。在综合考虑脱靶量、落角、入射角等多种约束条件后,运用最优控制构造的最优制导律设计了一种三维最优变结构制导律,接着利用梯度自适应下降法和T-S模型改进了速度约束控制。最后通过典型弹道的结果显示该制导律能够满足多约束高精度制导的需要,具有良好的弹道性能。     

Fully sequential procedures for comparing constrained systems via simulation

We consider the problem of finding the system with the best primary performance measure among a finite number of simulated systems in the presence of a stochastic constraint on a single real‐valued secondary performance measure. Solving this problem requires the identification and removal from consideration of infeasible systems (Phase I) and of systems whose primary performance measure is dominated by that of other feasible systems (Phase II). We use indifference zones in both phases and consider two approaches, namely, carrying out Phases I and II sequentially and carrying out Phases I and II simultaneously, and we provide specific example procedures of each type. We present theoretical results guaranteeing that our approaches (general and specific, sequential and simultaneous) yield the best system with at least a prespecified probability, and we provide a portion of an extensive numerical study aimed at evaluating and comparing the performance of our approaches. The experimental results show that both new procedures are useful for constrained ranking and selection, with neither procedure showing uniform superiority over the other.© 2010 Wiley Periodicals, Inc. Naval Research Logistics, 2010     

复杂系统的MTTR建模研究

现代武器系统的结构越来越复杂,在进行系统修复前,系统往往发生多个故障的情况,致使原来的维修性模型不能完全地反映系统的维修性水平。针对多重故障的维修,推导出一种能反映这种情况下的维修性预计的平均修复时间(MTTR)数学模型。模型中的一次维修事件由原来的只进行单一故障维修扩展到可以对多个不同故障进行维修的情况,更好地反映了复杂系统的实际维修情况。通过实例验证了该模型能实际地反映出复杂系统的维修性情况,从而更加准确地预计出系统的维修性水平。     

具有吞吐量和时延约束的软件无线电波形部署决策算法

针对当前具有吞吐量和时延约束的软件无线电波形部署决策算法在内存开销方面考虑的不足,提出一个更为通用的波形部署决策系统模型,将波形的处理开销、内存开销和通信带宽开销都纳入到波形部署决策过程中,并设计了一种基于动态规划的波形部署决策算法以最小化波形对平台各种计算资源的占用总和。仿真结果表明,内存对波形部署决策具有重要影响,与未考虑内存开销的解决方案相比,平台支持的平均最大波形数目和平均处理资源利用率均下降40%左右。     

A decomposition heuristic for the twin robots scheduling problem

This article provides an efficient heuristic based on decomposition for the twin robots scheduling problem (TRSP). TRSP concerns two moving robots executing storage and retrieval requests in parallel along a shared pathway. The depots are located at both ends of the line and a dedicated robot is assigned to each of them. While moving goods between their respective depots and some storage locations on the line, noncrossing constraints among robots need to be considered. Our heuristic uses a dynamic programming framework to determine the schedule of one robot while keeping the other one's fixed. It finds near‐optimal solutions even for large problem instances with hundreds of jobs in a short time span. © 2014 Wiley Periodicals, Inc. 62:16–22, 2015     

战场要素的认知处理

针对多弹编队飞行时如何判断当前复杂战场环境下的战场态势问题,采用层次分析法、属性识别理论方法和数据融合的方法,研究了实时认知处理战场要素模型问题。首先,对复杂战场要素进行分析,对这些战场要素进行分类;对不同的战场要素分别建立数学模型;然后,采用层次分析法和属性识别理论方法对导弹认知的数据进行评估,得到数据的精度评估等级后,采用数据融合方法对数据进行融合,得到融合后数据,以此对导弹中的数据进行实时更新。最后,将所建立的战场要素模型进行实例化仿真,仿真结果表明该方法的有效性。     

中继卫星调度问题的CSP模型

中继卫星在地球同步静止轨道上运行,既能直视中、低轨道用户航天器,又能直视地面站,是沟通用户航天器与地面站的桥梁。中继卫星调度问题是一类非常重要的调度问题。基于约束满足理论,通过分析中继卫星调度问题的特点与约束条件,建立了中继卫星调度问题的CSP模型。利用卫星工具箱STK进行模拟仿真,对CSP模型进行了求解。结果表明,所建立的CSP模型是合理的。     

复杂系统评估的综合层次分析法

针对现今多样的复杂系统评估问题,在原来传统层次分析法的基础上作了进一步的改进和扩展,形成了综合层次分析法———CAHP.该方法可运用于多类型属性并存的复杂系统评估中,并能对单个评价对象给出量化评估值.实践证明,该方法具有可行性和有效性.     

平流层飞艇抗风场干扰CUKF算法设计与应用

为了提高风场干扰环境下飞艇的导航精度,研究飞艇抗风场干扰导航算法。在建立风场干扰条件下飞艇速度误差约束模型的基础上,设计抗风场干扰的约束Unscented卡尔曼滤波算法。首先确定风场干扰条件下飞艇的速度误差约束量,将该约束与Unscented卡尔曼滤波算法相结合,对速度误差进行估计和补偿,以减小风场对飞艇定位精度的影响;然后证明该算法的状态估计量不仅是无偏的,而且协方差小于标准UKF的协方差;最后将提出的算法应用于捷联惯导/天文/合成孔径雷达组合导航系统中进行仿真验证,并与自适应扩展卡尔曼滤波和抗差自适应UKF算法进行比较,结果表明：提出的约束UKF算法的滤波性能明显优于自适应EKF和抗差自适应UKF算法,能够有效抑制风场对飞艇定位精度的影响,提高飞艇的导航定位精度。