弹道导弹威胁估计模型构建

简要分析了弹道导弹飞行3个阶段的不同特点及各阶段导弹预警探测手段的侧重点,结合威胁估计的特征构建了弹道导弹威胁估计模型结构框架,运用多阶段贝叶斯网络理论,构造了主动段、自由段和再入段威胁估计模型,并明确了三阶段间的转换时机。采用动态贝叶斯方法对弹道导弹作战全过程进行威胁估计仿真推理,仿真结果能够反映导弹在飞行过程中威胁程度的变化特点,为反导指挥员作出辅助决策提供智力支持。     

高动态GNSS信号多普勒模拟任意阶直接数字合成器设计

为高精度模拟高动态条件下GNSS信号的多普勒特性,提出一种任意阶直接数字合成信号合成器的设计方法。设计任意阶直接数字合成信号合成器的结构;通过理论分析,推导各级累加器相位初值的计算公式;给出字长选择方法。经仿真验证,该方法能精确模拟GNSS信号的多普勒特性。此外,提出的直接数字合成器设计方法不受阶数的限制,可普遍应用于各类信号模拟器的设计。     

基于CISE环境的导弹武器仿真系统

数字仿真研究是导弹武器设计验证的有效手段,基于CISE环境设计了导弹武器仿真系统,介绍了CISE环境的特点,给出了仿真系统的模块组成、系统方案、软件界面,设计了系统工作流程和仿真系统各组成模块间信息交互定义及关系,介绍了仿真系统中的中末制导交班流程、攻击区计算流程。该平台各模块间具有良好的独立性和封装性,基于此系统开展了系统建模、作战模式、战技指标论证、逃逸方式等方面研究工作。     

On efficient algorithms for finding efficient salvo policies

We consider the salvo policy problem, in which there are k moments, called salvos, at which we can fire multiple missiles simultaneously at an incoming object. Each salvo is characterized by a probability p_i: the hit probability of a single missile. After each salvo, we can assess whether the incoming object is still active. If it is, we fire the missiles assigned to the next salvo. In the salvo policy problem, the goal is to assign at most n missiles to salvos in order to minimize the expected number of missiles used. We consider three problem versions. In Gould's version, we have to assign all n missiles to salvos. In the Big Bomb version, a cost of B is incurred when all salvo's are unsuccessful. Finally, we consider the Quota version in which the kill probability should exceed some quota Q. We discuss the computational complexity and the approximability of these problem versions. In particular, we show that Gould's version and the Big Bomb version admit pseudopolynomial time exact algorithms and fully polynomial time approximation schemes. We also present an iterative approximation algorithm for the Quota version, and show that a related problem is NP-complete.     

Technical note: Finite-time regret analysis of Kiefer-Wolfowitz stochastic approximation algorithm and nonparametric multi-product dynamic pricing with unknown demand

We consider the problem of nonparametric multi-product dynamic pricing with unknown demand and show that the problem may be formulated as an online model-free stochastic program, which can be solved by the classical Kiefer-Wolfowitz stochastic approximation (KWSA) algorithm. We prove that the expected cumulative regret of the KWSA algorithm is bounded above by where κ₁, κ₂ are positive constants and T is the number of periods for any T = 1, 2, … . Therefore, the regret of the KWSA algorithm grows in the order of , which achieves the lower bounds known for parametric dynamic pricing problems and shows that the nonparametric problems are not necessarily more difficult to solve than the parametric ones. Numerical experiments further demonstrate the effectiveness and efficiency of our proposed KW pricing policy by comparing with some pricing policies in the literature.     

基于3D打印的可移植人体外耳支架关键技术研究*

耳廓缺损是临床常见疾病，使用患者自体肋软骨雕刻为耳支架并植入缺损耳皮下是目前的主要治疗方法。该方法对手术者提出很高的技术要求，雕刻的外耳支架无法精确还原患者耳廓形状，同时肋软骨的切除会对患者带来并发症。本文探索使用医用硅胶制作患者个体外耳支架的关键技术，使用CT和逆向建模技术得到对应患者个体的外耳数字模型，利用3D打印技术制造人体外耳支架模具，并使用医用硅胶MED 4735完成人体外耳支架的制作成型。动物实验验证了其生物相容性，证明了该方法的可行性。通过该技术制作的硅胶人体外耳支架可以高度模仿患者特定的耳廓形状，支架精度高，制造周期短，无生物排异，可为替代肋软骨雕刻人体外耳支架进行耳廓缺损治疗提供依据。     

基于ANSYS／LS—DYNA的电子装备爆炸冲击振动损伤建模研究

针对电子装备爆炸冲击振动损伤问题，设计了损伤模拟的基本方案；采用ANSYS／LS—DYNA建立了二维“爆炸源-地面-弹性体-电子装备”模型；通过模型试验，获得了与实际爆炸冲击振动特性相吻合的加速度、位移和应力等数据。     

分形理论在装备保障组织设计中的应用研究

基于分形理论，提出了一种适应敏捷化要求的分形装备保障系统组织模型，能够通过快速的重构以响应战场环境的变化。阐明了其层次性、自相似、自组织和自优化的组织结构特点，分析了其运行模式。     

自由漂浮柔性机械臂系统的动力学建模与仿真

动量矩守恒约束使自由漂浮柔性机械臂系统成为非完整系统,其动力学模型通常是难以求解的微分—代数方程,因此提出将机械臂系统等效为一个完整系统进行建模。假设载体存在姿态控制力矩,此时由于不存在动量矩守恒约束,系统变成一个完整系统,采用Lagrange方法建立其动力学方程;令方程中载体的姿态控制力矩为零,即得到自由漂浮机械臂系统的动力学方程;采用数值方法求解动力学方程,并将动力学分析的结果与ADAMS中仿真的结果进行对比,验证了模型能够有效模拟自由漂浮柔性机械臂系统的动力学特性。