单静止站纯方位系统的可观测性与目标参数估计算法

分析了目标参数Vmx/Do,Vmy/Do 可观测的条件 ,给出了估计这对参数的一种递推算法 .     

局部放电在线监测电流传感器的等效电路及其参数计算

局部放电在线监测是保证电力设备正常工作的重要手段。从变压器理论出发 ,提出了局放脉冲电流传感器等效电路及其参数计算方法 ,所提出的方法已成功地应用于实际局放在线监测传感器的设计中     

核反应堆非能动系统物理过程敏感参数识别的迭代法

核反应堆非能动系统参数敏感性分析是系统可靠性不确定性分析的重要组成部分。相关系数在刻画系统物理过程的成功准则参数敏感性方面存在缺陷,针对此问题提出迭代法,其综合了输入参数与成功准则的相关系数、偏相关系数以及输入参数之间的相关系数三方面信息,通过实例验证方法的正确性和实用性。迭代法适合分析参数对成功准则的偏相关性,能识别出更为精确的敏感参数,为进一步提高非能动系统物理过程的可靠性提供参考依据。     

介电谱快速测定汽油研究法辛烷值

根据汽油的介电性质与其组成、结构之间存在的相关关系,研制了用介电谱快速测定汽油研究法辛烷值的专用检测装置,采用偏最小二乘法建立数学模型,用全交互验证法对68个不同汽油样品的研究法辛烷值进行了分析。研究结果表明,汽油研究法辛烷值分析结果能够满足国家标准的再现性和重复性误差要求。该方法具有快速、简便的特点,适用于现场快速检测。     

Maintaining systems with heterogeneous spare parts

We consider the problem of optimally maintaining a stochastically degrading, single‐unit system using heterogeneous spares of varying quality. The system's failures are unannounced; therefore, it is inspected periodically to determine its status (functioning or failed). The system continues in operation until it is either preventively or correctively maintained. The available maintenance options include perfect repair, which restores the system to an as‐good‐as‐new condition, and replacement with a randomly selected unit from the supply of heterogeneous spares. The objective is to minimize the total expected discounted maintenance costs over an infinite time horizon. We formulate the problem using a mixed observability Markov decision process (MOMDP) model in which the system's age is observable but its quality must be inferred. We show, under suitable conditions, the monotonicity of the optimal value function in the belief about the system quality and establish conditions under which finite preventive maintenance thresholds exist. A detailed computational study reveals that the optimal policy encourages exploration when the system's quality is uncertain; the policy is more exploitive when the quality is highly certain. The study also demonstrates that substantial cost savings are achieved by utilizing our MOMDP‐based method as compared to more naïve methods of accounting for heterogeneous spares.     

一类偶数阶非线性中立型偏微分方程组的振动判据

讨论一类偶数阶非线性中立型偏微分方程组的振动性,利用Green公式和边值条件将这类非线性中立型偏微分方程组的振动问题转化为中立型微分不等式不存在最终正解的问题,并利用最终正解的定义和微分不等式方法,获得了该类方程组在两类不同边值条件下所有解振动的若干充分性条件。所得结果为解决物理学、生物学、工程学等学科领域中的实际问题提供了数学理论基础。     

A sequential partial information bomber-defender shooting problem

A bomber carrying homogenous weapons sequentially engages ground targets capable of retaliation. Upon reaching a target, the bomber may fire a weapon at it. If the target survives the direct fire, it can either return fire or choose to hold fire (play dead). If the former occurs, the bomber is immediately made aware that the target is alive. If no return fire is seen, the true status of the target is unknown to the bomber. After the current engagement, the bomber, if still alive, can either re-engage the same target or move on to the next target in the sequence. The bomber seeks to maximize the expected cumulative damage it can inflict on the targets. We solve the perfect and partial information problems, where a target always fires back and sometimes fires back respectively using stochastic dynamic programming. The perfect information scenario yields an appealing threshold based bombing policy. Indeed, the marginal future reward is the threshold at which the control policy switches and furthermore, the threshold is monotonic decreasing with the number of weapons left with the bomber and monotonic nondecreasing with the number of targets left in the mission. For the partial information scenario, we show via a counterexample that the marginal future reward is not the threshold at which the control switches. In light of the negative result, we provide an appealing threshold based heuristic instead. Finally, we address the partial information game, where the target can choose to fire back and establish the Nash equilibrium strategies for a representative two target scenario.     

惯性平台自标定中惯性仪表安装误差可观测性分析

针对惯性平台自标定中惯性仪表安装误差可观测性问题,深入研究了系统模型与平台坐标系对惯性仪表安装误差可观测性的影响。根据不同系统动力学模型和观测量构建四种系统模型。从可观测性定义出发,分析与判断惯性仪表安装误差在不同系统模型和不同平台坐标系下的可观测性。理论分析和仿真结果均表明惯性仪表安装误差在以下两种情况完全可观:观测量为平台框架角和加速度计输出,系统动力学模型为框架角模型,平台坐标系以平台六面体为基准定义;观测量为加速度输出,系统动力学模型为姿态角或失准角模型,平台坐标系以加速度计敏感轴为基准定义。     

基于局部评估的分布式图模式匹配算法

为了在分布式存储的大规模数据图上进行快速图模式匹配,提出了基于局部评估的分布式图模式匹配算法disGPM-PE。首先各计算节点并行地执行本地匹配,然后协调器节点收集局部匹配结果、计算边界点的匹配状态并发送给相应的计算节点,接着计算节点根据边界点的匹配状态确定与边界点相连的节点的匹配情况,最后协调器节点组合得出最大匹配集。实验结果表明：与已有的分布式图模式匹配算法相比,disGPM-PE算法都能够在不显著增加通信量的前提下避免数据片段间的依赖关系对执行时间的影响,减少了图模式匹配的时间。     

利用局部评估的分布式图模式匹配算法

为了在分布式存储的大规模数据图上进行快速图模式匹配,提出利用局部评估的分布式图模式匹配算法。各计算节点并行地执行本地匹配;协调器节点收集局部匹配结果、计算边界点的匹配状态并发送给相应的计算节点;计算节点根据边界点的匹配状态确定与边界点相连的节点的匹配情况;协调器节点组合得出最大匹配集。实验结果表明:与已有的分布式图模式匹配算法相比,dis GPM-PE算法都能够在不显著增加通信量的前提下避免数据片段间的依赖关系对执行时间的影响,从而减少图模式匹配的时间。