基于粗集和最大熵的模式识别方法

用基于属性约简的粗集理论找出条件属性的最小属性集。对属性间为不确定因果关系的模式,计算在最大熵情况下发生的概率,通过比较概率来进行模式识别,实例分析和结论部分说明这种方法是有效的。     

排烟口设计对排烟效果影响的研究

排烟口是火灾发生时烟气排出的出口,排烟口高度和位置对排烟效果具有重要影响。运用FDS数值模拟方法,以实验台为依据建立数值模型,针对排烟口高度和排烟口位置的改变对排烟效果的影响进行分析,结果表明:随着排烟口高度的升高,各种排烟风速下的排烟效果都得到了改善。在排烟口风速较高的情况下,排烟口的高度变化对烟气溢出厚度的影响更大,采用大风速的控烟效果要优于小风速。侧排方式的排烟效果低于顶排方式,远壁排烟方式要优于近壁排烟方式。     

最大生存概率下的编队防空目标分配研究

为研究编队目标武器分配方法,分析了编队防空体系在作战过程中武器系统火力单元状态、分配决策矩阵和目标序列状态的动态更新形式,建立了以编队生存概率最大为最优函数的动态目标分配优化模型。描述了仿真环境,运用不确定目标序列对分配过程进行了仿真。结果表明,所建立的模型能够反映实际情况,得到的关于集火、转火射击和优先分配策略对模型的工程应用具有实际指导意义。     

密集目标有偏航迹整体匹配关联方法

针对密集目标和传感器探测存在较大系统偏差的复杂条件下的分布式融合中航迹关联问题,设计了一种整体匹配航迹关联方法,首先将所有航迹划分成若干个关联聚,对各传感器都有多个目标航迹的关联聚采用多目标点图整体匹配,对某传感器只有单目标航迹的关联聚采用航迹段整体匹配,从而获得关联聚内所有航迹的关联关系。在仿真分析中,随机产生态势,分别计算新算法在不同情形下的漏关联、正确关联率、错误关联率。仿真验证结果表明该算法在不同目标密集程度、系统误差情形下都有较好的适应性。     

Rectangles algorithm for generating normal variates

We propose an algorithm for generating normal random variates that is based on the acceptance–rejection method and uses a piecewise majorizing function. The piecewise function has 2048 equal‐area pieces, 2046 of which are constant, and the two extreme pieces are curves that majorize the tails. The proposed algorithm has not only good performance from correlation induction perspective, but also works well from a speed perspective. It is faster than the inversion method by Odeh and Evans and most other methods. © 2011 Wiley Periodicals, Inc. Naval Research Logistics, 2011     

Double Mover–Stayer model on customer switching in telecommunications industry

Customer acquisition and customer retention are the most important challenges in the increasingly competitive telecommunications industry. Traditional studies of customer switching always assume that customers are homogeneous, and thus that model customer switching behavior follows a Markov formulation. However, this postulation is obviously inappropriate in most instances. Blumen et al. (Cornell Studies of Industrial and Labor Relations, Cornell University Press, Ithaca, NY, 1955) developed the Mover–Stayer (MS) model, a generalization of the Markov chain model, to relax the requirement of homogeneity and allow the presence of heterogeneity with two different types of individuals—“stayers,” who purchase the same kinds of products or services throughout the entire observation period; and “movers,” who look for variety in products or services over time. There are two purpose of this article. First, we extend the MS model to a Double Mover‐Stayer (DMS) model by assuming the existence of three types of individuals in the market: (1) stable and loyal customers, who have stable usage within the same company; (2) instable but loyal customers, whose usage varies within the same company over time; and (3) disloyal customers, who switch from one company to another to seek for new experiences or/and benefits. We also propose an estimation method for the DMS model. Second, we apply the DMS model to telecommunications data and demonstrate how it can be used for pattern identification, hidden knowledge discovery, and decision making. © 2012 Wiley Periodicals, Inc. Naval Research Logistics, 2012     

多源信息的验前分布融合方法研究

验前分布的获取和表示是B ayes理论应用中的一个关键问题。针对目前多源验前信息融合中存在的过分依赖专家信息的问题,提出了一种基于第2类极大似然估计原理(M L-II)确定验前分布权重的方法,该方法将现场试验数据看作是由其边缘分布产生的样本,然后根据不同验前分布下现场样本似然性的大小来确定其在验前分布融合中的作用,并以此进一步确定不同验前分布的权重因子。最后通过算例证明了该方法比基于专家信息的融合方法更为合理和有效。     

微波超视距条件下舰船目标RCS分层计算方法

针对微波超视距条件下海面舰船目标的散射特性,提出了一种舰船目标雷达散射截面(RCS)的分层计算方法.首先,研究并给出了随机摆动状态下舰船目标各局部散射体的非相干叠加条件;在此基础上,提出了微波超视距条件下舰船目标RCS的计算流程,针对目标的几何建模、模型划分、遮挡面判定、平均RCS计算等进行了详细阐述;最后,以某型舰船...     

关联维数在齿轮箱振动信号特征提取中的应用

论述了关联维数的基本概念和性质,给出了定量描述分形特征的重要参数———关联维数的计算方法,分析了齿轮箱故障时振动的特点.通过对试验获取的齿轮故障振动信号进行分析计算,确定了关联维数与齿轮箱故障程度之间的联系.结果表明,齿轮箱的不同运行情况对应的关联维数有明显不同.因此,可用关联维数作为区分齿轮箱工作状态的特征参数.     

机载雷达与地面雷达的最大似然配准算法

空、地多雷达配准是空地一体化预警的前提。通过建立空中运动雷达与地面静止雷达的配准模型,以最大似然算法为基础,导出其空间系统误差配准参数及目标运动状态估计的具体公式,并对系统误差估计值的卡拉美-罗界进行了讨论。仿真结果表明,该算法具有较快的迭代收敛速度和较好的配准效果。