空间目标RCS序列的R/S分析

RCS包含了目标丰富的信息.分析了空间目标RCS序列产生混沌的机理,并非线性理论中的功率谱法引入空间目标RCS序列的分析中,用重整标度分析法(R/S)分析了空间目标RCS序列的混沌特性,仿真结果表明,与旋转目标相比,三轴稳定目标RCS序列较复杂和不规则,这与实际分析的情况相符合,证明了该方法的有效性.     

确定重构相空间维数的方法

计算混沌统计特征量前必须先获得重构相空间的维数,因此给出了最大特征值不变法、几何不变量法、虚假邻点法、预测误差最小法、最小Shannon熵法、经验赋值法六种确定方法,得出了应用最大特征值不变法和最小Shannon熵法的工程案例计算结果。     

子母式穿甲弹子弹发射过程研究

对子母式穿甲弹子弹的发射过程进行详细的分析,得出了子弹长度与子弹飞离母弹速度的关系、子弹长度与火药燃烧率的关系、子弹长度与母弹弹头部发射孔内最大压力的关系以及子弹的长度与子弹发射所需时间的关系,为子母式穿甲弹设计提供了依据。     

基于ADC模型的数据链系统作战效能评估

从数据链系统的信息支持能力出发,结合指标体系的选取和确立原则,建立了数据链系统作战效能指标体系。提出并建立了数据链系统作战效能评估的ADC模型,针对模型中能力矩阵C计算繁杂的问题,考虑到某些指标在分析过程中定量化的需要,综合运用幂指数法和层次分析法对能力矩阵C子模型及体系指标进行定量化分析和计算。对于运用幂指数法中涉及各指标的加权系数采用层次分析法来确定,进一步分析了层次分析法的原理及步骤。最后给出实例,结果表明该模型具有一定的合理性且计算简单、易于理解、结论可靠等优点。     

Two‐stage component test plans for testing the reliability of a series system

A system reliability is often evaluated by individual tests of components that constitute the system. These component test plans have advantages over complete system based tests in terms of time and cost. In this paper, we consider the series system with n components, where the lifetime of the i‐th component follows exponential distribution with parameter λ_i. Assuming test costs for the components are different, we develop an efficient algorithm to design a two‐stage component test plan that satisfies the usual probability requirements on the system reliability and in addition minimizes the maximum expected cost. For the case of prior information in the form of upper bounds on λ_i's, we use the genetic algorithm to solve the associated optimization problems which are otherwise difficult to solve using mathematical programming techniques. The two‐stage component test plans are cost effective compared to single‐stage plans developed by Rajgopal and Mazumdar. We demonstrate through several numerical examples that our approach has the potential to reduce the overall testing costs significantly. © 2002 John Wiley & Sons, Inc. Naval Research Logistics, 49: 95–116, 2002; DOI 10.1002/nav.1051     

精密磨床主轴回转误差补偿技术的研究

本文在分析精密磨床主轴回转误差运动特点的基础上,提出了基于时序建模理论的随机运动误差补偿方案,并介绍了采用信号处理器TMS32010实现高速补偿控制的方法及初步实验结果。     

GPS定位误差分析及建模

采用时间序列分析方法,根据大量的实测数据分析了ＧＰＳ定位误差的统计特征,建立了ＧＰＳ定位误差模型。     

小波边界元法

将边界上的函数展成小波级数,利用循环矩阵方法,从核函数边界上的值,得到离散的积分方程系数矩阵,求解未知的小波级数系数,从而得到边界积分方程近似解,文中计算了一个二维拉普拉斯方程的解。     

加拿大山猫数据的几种时序模型分析

本文利用四种时间序列模型,即自回归模型、组合模型、疏系数自回归模型、门限自回归模型,分别对时间序列分析中一组有名数据,即加拿大山猫数据,进行模型拟合,并对得到的四个模型及预报结果进行了分析和比较。     

Call center arrival modeling: A Bayesian state‐space approach

In this article, we introduce three discrete time Bayesian state‐space models with Poisson measurements, each aiming to address different issues in call center arrival modeling. We present the properties of the models and develop their Bayesian inference. In so doing, we provide sequential updating and smoothing for call arrival rates and discuss how the models can be used for intra‐day, inter‐day, and inter‐week forecasts. We illustrate the implementation of the models by using actual arrival data from a US commercial bank's call center and provide forecasting comparisons. © 2011 Wiley Periodicals, Inc. Naval Research Logistics 58: 28–42, 2011