Weapon effectiveness and the shapes of damage functions

This paper provides a review of methods of assessing a fragmentation weapon's effectiveness against a point target or an area target with keeping the focus on the necessity of using the Carleton damage function with the correct shape factor.First,cookie-cutter damage functions are redefined to preserve the shape factor of and to have the same lethal area as the corresponding Carleton damage function.Then,closed-form solutions of the effectiveness methods are obtained by using those cookie-cutter damage functions and the Carleton damage function.Finally,the closed-form solutions are applied to calculate the probability of damaging a point target and the expected fractional damage to an area target for several attack scenarios by using cookie-cutter damage functions and the Carleton damage functions with different shape factors.The comparison of the calculation results shows that using cookie-cutter damage functions or the Carleton damage function with a wrong shape factor results in quite signifi-cant differences from using the original Carleton damage function with a correct shape factor when weapon's delivery error deviations are less than or comparable to the lengths of the lethal area and the aim point is far from a target.The effectiveness methods improved in this paper will be useful for mission planning utilizing the precision-guided munitions in circumstances where the collateral damage should be reduced.     

基于结构加权的海面编队预定目标选择方法

海面目标运动和编队阵型的约束特性,使得通过对装订阵型和末制导探测阵型进行点集匹配来选择预定目标成为一种有效途径。但当编队目标释放干扰时,会引起阵型结构发生局部变化,导致目标选择性能恶化。本文基于反舰导弹目标选择需求,分析了传感器导航和探测误差、装订信息误差、编队目标运动和释放干扰等因素所引起的位置点集变形,通过利用阵型中未污染的结构信息,提出了基于几何散列法和结构加权平均Hausdorff距离的编队预定目标选择方法。理论分析和实验结果表明,该方法不受传感器导航误差和编队目标整体运动的影响,在编队存在冲淡干扰时能有效提高目标选择能力。     

Deterring ‘Able Archer’: Comments Arising from Adamsky’s ‘Lessons for Deterrence Theory and Practice’

This is a short commentary on Dmitry Adamsky’s recent article ‘The 1983 Nuclear Crisis – Lessons for Deterrence Theory and Practice’. First, it teases out nuances in the relationship between deterrence and strategy and considers deterrence to be both a strategy and an effect. Second, it explores the culminating point of deterrence in theory and considers it untenable, as it does not conform to the logic of, or to any logic analogous to, Clausewitz’s culminating point of victory. Deterrence logically cannot culminate. Moreover, any culminating point of deterrence would ignore why the potential deteree should perceive the actions of his deterrer in such a way as to render strengthened strategies of deterrence counterproductive. It is the deteree who is the only strategic actor to determine whether the deterrer is actually practising a successful strategy of deterrence or not.     

基于粒子群优化的点云场景拼接算法

多视点三维点点云场景拼接是解决激光三维主动成像目标自遮挡或被遮挡情况下目标数据不完全问题的一种有效方法,它将直接影响到后续的目标检测与识别处理。本文提出了一种基于粒子群优化（PSO）的点云拼接算法,该方法通过投影分布熵对待拼接场景姿态进行估计,由此获取场景拼接的初值,然后利用PSO实现多视点场景的精确拼接。仿真实验结果表明,本文方法是一种有效可行的方法。     

复合假设下导弹可靠性指标Bayes检验方法

在用Bayes方法对海防战术导弹可靠性指标进行假设检验时,原假设和对立假设均采用简单假设的形式,而此种方法可能导致使用方Bayes风险增大。从理论上阐述了简单假设Bayes检验方法可能导致使用方Bayes风险增大的原因,同时给出了用于取代简单假设的复合假设Bayes检验方法,并用实例证明了它比简单假设Bayes检验方法科学、合理。     

基于跑道平面结构化线特征的固定翼无人机视觉导航算法

针对固定翼无人机在着陆阶段的位姿估计的问题，提出了一种基于跑道平面结构化线特征的无人机视觉导航方法。结构化线特征包括跑道平面上的跑道边缘及共面的垂直于跑道边缘的单条合作标志线。利用单台固连在无人机上的前视相机对跑道区域进行成像，自动提取结构化线特征。在无人机降落前期利用完整的结构化线特征配置解算出无人机的六自由度位姿参数(偏航角、俯仰角、滚转角、纵向位置、横向位置、高度)，并在无人机降落到较低高度时，利用退化的结构化线特征(跑道边缘)解算出无人机的关键位姿参数(偏航角、俯仰角、横向位置、高度)。三维实景仿真实验证明，在距离机场距离为200m处，无人机的距离参数精度为<0.5m，角度参数精度为<0.1°。本文的方法充分考虑到无人机自主着陆过程中的成像特点，具有自动化程度高、工程实用性好的优点。     

红外警戒系统点目标检测距离理论分析

给出了红外警戒系统点目标探测距离的计算模型与公式,分析了影响点目标探测距离的参数间关系,并得出有关目标提取算法及传感器参数选择的几点重要结论.     

多系统组合精密单点定位性能分析

文章提出在数据预处理之前进行钟跳探测与修复以避免周跳探测误判,而后对非差无电离层组合载波相位观测值进行星间单差,避免接收机钟差解算,有效降低了对伪距观测值随机模型建模精度的要求,最后给出了抗差Kalman滤波PPP解算模型。利用GPS、GLONASS、BDS数据,对单、双、三系统PPP定位精度和收敛时间进行了分析,得出了以下结论：三系统PPP技术无论定位精度还是收敛速度均是最优的,加强多系统组合导航定位有利于提高导航定位精度。     

自由曲面慢刀伺服车削及刀具参数确定方法

自由曲面光学元件具有优越的光学性能,在现代光学系统中得到越来越广泛的应用。慢刀伺服是单点金刚石车削自由曲面的新技术。由于自由曲面面形的复杂性以及慢刀伺服车削技术的特殊性,刀具与工件的相对位置关系也更加复杂,必须对刀具与工件表面的相对几何关系深入研究,从而确定合适的刀具参数。从原理上对慢刀伺服车削技术的特殊性进行了分析。分别基于过轴心截面曲线特性和基于NURBS曲面整体特性研究了刀具参数确定方法。以正弦阵列表面工件为例,验证了这两种分析方法。     

Markovian approximation for manufacturing systems of unreliable machines in tandem

This paper studies production planning of manufacturing systems of unreliable machines in tandem. The manufacturing system considered here produces one type of product. The demand is assumed to be a Poisson process and the processing time for one unit of product in each machine is exponentially distributed. A broken machine is subject to a sequence of repairing processes. The up time and the repairing time in each phase are assumed to be exponentially distributed. We study the manufacturing system by considering each machine as an individual system with stochastic supply and demand. The Markov Modulated Poisson Process (MMPP) is applied to model the process of supply. Numerical examples are given to demonstrate the accuracy of the proposed method. We employ (s, S) policy as production control. Fast algorithms are presented to solve the average running costs of the machine system for a given (s, S) policy and hence the approximated optimal (s, S) policy. © 2001 John Wiley & Sons, Inc. Naval Research Logistics 48: 65–78, 2001