胶体中布朗粒子简谐束缚下准直高斯光束的动态光散射

在将散射粒子间的相互作用看作简谐力、入射光为准直高斯光束、散射光为理想平面光波的模型下研究了胶体溶液中布朗粒子的统计特征并求解了动态光散射的散射光电场强度的自相关函数；     

一种基于数字图像自相关检测的改进算法

该文首先简要介绍了基于图像位平面分析的一种检测算法——转换函数法,并讨论了这种算法的优缺点。针对这种算法的不足,提出了一种区域自相关检测的方法,提高了检测的分辨率。根据检测到的结果,运用统计检验算法—t检验对图像最低位平面进行统计分析。最后通过试验验证了改进算法的有效性,并给出了相关的试验分析与结论。     

基于名义尺度的空间自相关指数测度方法研究*

从空间自相关的基本构成出发,提出了一种测度名义尺度的空间自相关指数——自邻接指数,给出了基于名义尺度下全局空间自相关和局部空间自相关的测度方法,并在ArcView平台下通过Avenue二次编程进行了算法实现。最后通过例子展示了自邻接指数在土地利用格局分析中发挥的重要作用。     

有色噪声背景下陆基导航接收机对信号的检测

针对我国典型海域干扰噪声的特点,提出了在有色噪声背景下直接序列扩频体制的无线电导航接收机对接收信号检测方法,即利用卡尔曼滤波技术对接收的信号进行建模从而得出自相关函数,根据单层神经网络对相关函数中的有色噪声协方差参数进行预测.同时,给出了系统的递推公式、预测自相关函数表达式、程序流程图和计算机仿真.计算机仿真结果表明,该方法不仅能够有效的逼近有色噪声,而且程序计算复杂度较低,从而提高了系统的稳定性.     

MATLAB在伪随机码的生成及仿真中的应用

主要介绍m序列、Gold序列、Kasami序列和JPL序列的生成原理及其MATLAB的实现，并介绍如何用MATLAB中Simulink对其进行硬件仿真，给出了相应自相关和互相关结果。     

Improved measure of workpiece surface deterioration during turning using non-contact vision method

The surface finish quality of a machined workpiece is commonly measured using the average roughness parameter, R_a. This parameter, however, is insensitive to the lateral changes undergone by the surface in the feed direction as a consequence of tool wear. In this work, the effectiveness of four methods of workpiece surface analysis, namely autocorrelation, cross-correlation, and two new methods, called lateral material shift (LMS) ratio and profile slope ratio (PSR) analyses are investigated. Dry machining experiments were carried out on 316 stainless steel. Images of tool nose and workpiece profiles were captured using digital camera, and the edges were extracted using sub-pixel edge detection. In the autocorrelation approach, each workpiece profile was correlated with a shifted version of the same profile. In the cross-correlation approach, the workpiece profiles at different stages of machining were correlated with a reference profile generated using the unworn tool edge. In the LMS ratio method, the material shift ratios were determined from each waveform on the workpiece profile at various stages of tool wear, while in the PSR method the slopes at the right and left part of the waveform were compared. Among the four methods, the LMS ratio method produced the best correlation with tool flank wear with the maximum R-squared value of 0.9461, while average roughness R_a showed no correlation at all with both major and nose flank wear.     

Voiceband data speed discrimination

Some results of research to discriminate voiceband data signals of different speeds are reported. A discrimination technique based upon the autocorrelation envelope and second order moment of the complex lowpass data signal is introduced. Under ideal channel conditions, the discriminator, within a window of 128 ms of PCM data samples, classifies whether the signal is at 9600 bit/s, 4800 bit/s, 2400 bit/s, 1200 bit/s or 300 bit/s. Performance of the discriminator for signals in the presence of various analog impairments shows that this method is quite robust.     

Analysis of the correlation structure of square time series

Abstract.  This paper analyses the asymptotic behaviour of the autocorrelation structure exhibited by squares of time series with a Wold expansion where the input error is a sequence of random variables with mean zero and finite kurtosis. Two important cases are discussed: (i) when the errors are independent and, (ii) when the errors are uncorrelated but their squares are correlated. Both situations are addressed when the process exhibits short or long memory. Consequences of these results on certain models widely used in many disciplines are also discussed.     

基于动态集成决策树的多类别时间序列分类模型

针对以往时间序列分类技术忽略了数据间自相关性对算法影响的不足,通过对传统决策树算法进行扩展,提出了序列熵和序列对信息增益的概念,并以此构建针对时间序列的决策树（Time Series Decision Tree,简称TSDT）。在此基础上,以TSDT为基分类器,通过动态分类器集成技术,提出了时间序列动态集成分类算法（En-TSDT）。在UCR数据集上的实验表明,与目前应用最广泛的1NN-DTW分类器相比,En-TSDT克服了时间序列数据的自相关性对分类算法的影响,具有更好的分类性能和鲁棒性。