Spatially Localized Models of Extended Systems

We investigate the construction of low-dimensional spatiallylocalized models of extended systems. Specifically, theKuramoto–Sivashinsky (KS) equation on large one-dimensional domainsdisplays spatiotemporally complex dynamics that are remarkablywell-localized in both real and Fourier space, as demonstrated by a(spline) wavelet representation. We show how wavelet projectionsmay be used to construct various localized, relativelylow-dimensional models of KS spatiotemporal chaos. There ispersuasive evidence that short, periodized systems, internally forcedat their largest scales, form minimal models for chaotic dynamics inarbitrarily large domains. Such models assist in the understandingof extended systems.     

隐马尔可夫模型在被动声信号分类中的应用

为了提高被动声目标识别率，该文研究了隐马尔可夫模型在被动声信号分类中的应用问题，然后，又提出了２种混合分类器：特征矢量混合的ＨＭＭ分类器和ＨＭＭ／ＭＬＰＮＮ（多层感知机神经网络）混合模型分类器。结果表明，这２种混合分类器在性能上都优于单个特定的分类器，它们在被动声信号分类中具有良好的应用前景。     

分块半相依线性回归模型的参数估计

考虑一般的分块半相依线性回归（SUR）模型及其相应的简约模型，给出简约模型下未知回归系数及其可估函数的协方差改进估计仍是分块SUR模型下相应参数的协方差改进估计的一个充要条件．     

Discrete Velocity Models Without Nonphysical Invariants

Models for mixtures of discrete velocity gases have been recently introduced by the authors and have produced unexpected results, particularly with regard to the possible existence of nonphysical collision invariants. Here we discuss a method to construct models without spurious invariants. The method can be extended to very general models, including polyatomic gases, chemical reactions, etc.     

有线电视的邻频传输技术

对有线电视传输系统的邻频传输技术以及增补频道等电视扩容技术进行分析和研究.     

中文科技期刊线性增长模型

在描述文献增长的诸多模型中，线性增长模型更适合于某一特定文献类型的短期预测。本文依据我国７８至９６年各年间中文科技期刊的种数，利用最小平方法，拟合出中文科技期刊种数随时间增长的线性方程。针对各年间科技期刊种数存在着自相关的现象，建立了剔除序列相关后的预测模型。     

SETAR model selection-A bootstrap approach

Summary  The aim of this paper is to propose new selection criteria for the orders of selfexciting threshold autoregressive (SETAR) models. These criteria use bootstrap methodology; they are based on a weighted mean of the apparent error rate in the sample and the average error rate obtained from bootstrap samples not containing the point being predicted. These new criteria are compared with the traditional ones based on the Akaike information criterion (AIC). A simulation study and an example on a real data set end the paper.     

Modelling population growth vialaguerre-type exponentials

We use the Laguerre-type exponentials, i.e., eigenfunctions of the Laguerre-type derivatives, in order to construct new models for population growth. Relevant modifications of the classical exponential, logistic, and Volterra-Lotka models are investigated.     

单体液压支柱设计的优化方法

本文讨论了单体液压支柱设计的优化方法。首先,按重量最轻原则建立了优化设计的数学模型,然后分析了数学模型的解法,并利用电子计算机求解。     

地物杂波特性的分析及抑制

本文讨论杂波的频谱分布,目标特性。FFT分析指出杂波频谱的数学模型及杂波频谱截止频率与风速的关系。设计一实用的抑制杂波系统,利用其正,负多卜勒分别处理为正、负电平,长时间积分可检测强杂波中的慢速目标。对CW雷达回波振幅统计特性作了理论探讨。