二维阻尼／无阻尼谐波的状态空间复合描述与参数估计

本文提出了二维阻尼／无阻尼谐波的一种状态空间复合描述方法。在此基础上，通过了辨识状态间模型的参数获得了二维谐波的参数估计，这种新的估计方法既实现了分维处理，又避免了配对问题，仿真结果表明了该方法的有效性。     

Modular realization of multi-dimensional filters

A method is proposed for the exact decomposition of a general multi-dimensional (m-d) rational transfer function in terms of order one, each one of which is a function of only one of the m variables. This method is used for the realization of general, linear m-d filters, with great modularity, and high parallelism. By using known nonsingular matrices, the coefficients of the decomposed filter can be expressed in terms of the coefficients of the given transfer function and the elements of these matrices. An algorithm for the determination of these coefficients is given and a class of matrices is proposed which leads to simple realizations.     

白噪声中二维谐波的二维ARMA建模

本文研究了白噪声中二维谐波的二维ＡＲＭＡ建模问题，并从理论上探讨了利用所建立的二维ＡＲＭＡ模型进行二维谐波信号频率估计的方法。     

A new algorithm for non-linear mapping with applications to dimension and cluster analyses

In this paper, a new non-linear mapping method suitable for dimension and cluster analysis is proposed. In order to obtain a flexible and powerful method, the non-metric multidimensional scaling of Kruskal type is extended by introducing the concept of k-nearest neighbor. Some simulation results supporting the efficiency of our new method are given along with a detailed discussion.     

沸腾的动态建筑——迈向多维的城市空间

自从工业革命发生以后,现代主义设计以崭新的面貌展现在世人面前,并且给工业革命以前的设计以毁灭性的打击。在人类社会出现了近100年的现代主义也开始被更多的各具特色的风格和流派所覆盖。动态建筑的出现,以破竹之势冲击着正统的现代主义设计原则和形式,为建筑创作带来了新的气象,使城市景观视觉形象呈现多元之维。     

富营养化评价中数据分析的研究进展

数据处理方法是富营养化评价的关键因素。简要阐述富营养化的定义,比较详细地评述富营养化评价过程中数据处理方法的研究现状及国内外常用的几种富营养化评价方法。重点介绍几种定量评价水质富营养化的方法:综合指数法、统计分析方法(主成分、聚类和判别分析),以及遥感技术、多标准评价分析、模型分析等。指出富营养评价技术的发展将为水质管理提供可靠的依据,并对富营养化评价技术的研究做出了展望。     

Robust H∞ filtering for 2D continuous systems with finite frequency specifications

This paper investigates the design problem of robust H_∞ filtering for uncertain two-dimensional (2D) continuous systems described by Roesser model with polytopic uncertainties and frequency domain specifications. Our aim is to design a new filter guaranteeing an H_∞ performance level in specific finite frequency (FF) domains. Using the well-known generalised Kalman Yakubovich Popov lemma and homogeneous polynomially parameter-dependent matrices of arbitrary degrees, sufficient conditions for the existence of H_∞ filters for different FF ranges are proposed and then unified in terms of solving a set of linear matrix inequalities. Illustrative examples are provided to show the usefulness and potential of the proposed results.     

Multi-dimensional spectral analysis of the noise contribution from a drum washer with a dehydrating condition

Recently, there has been a growing consumer interest in the amount of noise produced by household electrical appliances. The designer of the product must determine the source of the noise, in order to eliminate the source. In the case of a household electric appliance such as the washing machine, the consumer’s complaint was about the noise that is generated during the dehydrating condition. However, in the case of the washing machine, it is difficult to identify the noise source when the washing machine uses the dehydrating condition. Several noise sources combine making it difficult to determine the key factor that contributes to the noise output. Multi-Dimensional Spectral Analysis (MDSA) is a method that can remove the correlation between different noise sources, and it expresses the key contributing factor as a unique output. This study utilized MDSA to analyze the contribution of each noise source in the output during the dehydrating condition.     

基于多维金字塔表达和AdaBoost的高分辨率SAR图像城区场景分类算法

提出了多维金字塔表达算法, 并使用基于多维金字塔表达的AdaBoost实现了高分辨率合成孔径雷达(Synthetic aperture radar, SAR)图像的城区场景分类. 多维金字塔表达算法首先在局部特征的各维计算金字塔表达矢量, 再将所有的金字塔表达矢量连接起来构成多维金字塔表达矢量. 多维金字塔表达算法克服了金字塔表达算法在处理高维局部特征时, 遇到的输出金字塔表达矢量的区分力受计算效率制约的问题. 本文分别在一个TerraSAR-X图像库和一张大幅TerraSAR-X图像上比较基于金字塔表达的AdaBoost和基于多维金字塔表达的AdaBoost的分类性能. 实验结果表明, 与前者相比, 后者显著提高了计算效率同时保证了分类精度.     

Three-dimensional MHD high-resolution computations with CWENO employing adaptive mesh refinement

Until recently, numerical simulations of discontinuities in highly super-Alfvénic plasmas have been severely limited by comparatively crude resolution and accuracy. Significant progress in the numerical simulation of such plasmas was achieved with the recently implemented Central Weighted Essentially Non-Oscillatory (CWENO) scheme. Combining this technique with that of adaptive mesh refinement (AMR), we have developed a third-order numerical scheme, which is able to efficiently capture strong gradients on spatial scales being small compared to the overall scale of the plasma system considered. Here, we first describe important algorithmic aspects of the scheme as well as the physics included in it. Second, we present the results of various performance tests. And, third, we illustrate its application to ‘real world problems’ using the example of the dynamics of a Sedov-type explosion.