一种基于参考点和密度的快速聚类算法

数据的规模越来越大,要求数据挖掘算法有很高的执行效率.基于密度的聚类是聚类分析中的一种,其主要优点是发现任意形状的聚类和对噪音数据不敏感.提出了一种新的基于参考点和密度的CURD(clustering using references and density)聚类算法,其创新点在于,通过参考点来准确地反映数据的空间几何特征,然后基于参考点对数据进行分析处理.CURD算法保持了基于密度的聚类算法的上述优点,而且CURD算法具有近似线性的时间复杂性,因此CURD算法适合对大规模数据的挖掘.理论分析和实验结果也证明了CURD算法具有处理任意形状的聚类、对噪音数据不敏感的特点,并且其执行效率明显高于传统的基于R*-树的DBSCAN算法.     

Robust matrix 𝒟U‐stability analysis

In this paper, the problem of robust matrix root‐clustering is addressed. The studied matrices are subject to both polytopic and unstructured uncertainties. An original point is the large choice of clustering regions enabled by the proposed approach since these regions can be unions of possibly disjoint and non‐symmetric subregions of the complex plane. The precise purpose is, considering a specified polytope, to determine the greatest robustness bound on the unstructured uncertainty such that robust matrix root‐clustering is ensured. To reduce conservatism in the derivation of the bound, the reasoning relies on a framework based upon parameter‐dependent Lyapunov functions. The bound value is computed by solving an ?? ?? ? problem. Copyright © 2003 John Wiley & Sons, Ltd.     

基于运动轨迹聚类的运动分割

文中提出了一种基于子空间聚类的运动分割算法。针对基于因式分解的运动分割方法对噪声敏感的问题，引入一个基于形状相关矩阵的相似矩阵，然后将特征点映射到一个由相似矩阵决定的低维子空间中。在这个子空间中，可以通过光谱图聚类方法对特征点进行聚类。为提高光谱图聚类方法的分段常数特征向量条件，文中计算了一个相关的概率矩阵的较大特征值相对于边权重变化的敏感度，来切断类之间的连接。通过实验，可以看到文中的方法有较好的鲁棒性。     

Comparative analysis of different approaches to target differentiation and localization with sonar

This study compares the performances of different methods for the differentiation and localization of commonly encountered features in indoor environments. Differentiation of such features is of interest for intelligent systems in a variety of applications such as system control based on acoustic signal detection and identification, map building, navigation, obstacle avoidance, and target tracking. Different representations of amplitude and time-of-flight measurement patterns experimentally acquired from a real sonar system are processed. The approaches compared in this study include the target differentiation algorithm, Dempster-Shafer evidential reasoning, different kinds of voting schemes, statistical pattern recognition techniques (k-nearest neighbor classifier, kernel estimator, parameterized density estimator, linear discriminant analysis, and fuzzy c-means clustering algorithm), and artificial neural networks. The neural networks are trained with different input signal representations obtained using pre-processing techniques such as discrete ordinary and fractional Fourier, Hartley and wavelet transforms, and Kohonen's self-organizing feature map. The use of neural networks trained with the back-propagation algorithm, usually with fractional Fourier transform or wavelet pre-processing results in near perfect differentiation, around 85% correct range estimation and around 95% correct azimuth estimation, which would be satisfactory in a wide range of applications.     

基于正交最小二乘和UD分解的模糊建模方法

通过改进模糊聚类方法确定模糊模型的前件结构，并对模糊推理关系矩阵进行正交最小二乘估计。通过分析正交向量在模型中贡献的大小确定聚类规则的有效性，然后采用基于UD分解的最小二乘确定模糊模型的后件参数，实现模糊模型的结构和参数的优化。该方法已成功地应用于Box-Jenkins煤气炉的数据系统建模。     

一种基于纹理的图像分割方法

提出了一种基于多进制小波变换的纹理特征提取方法，通过对小波系数的标准差作为纹理测度以生成特征向量，利用模糊c-均值聚类算法进行纹理分割，获得了较好实验结果。     

利用多进制小波变换和模糊c-均值聚类进行纹理分割

提出了一种基于多进制小波变换的多纹理特征提取方法,通过对小波系数的标准差作为纹理测度以生成特征向量,利用模糊c-均值聚类算法进行纹理分割,获得了较好的实验结果。     

基于新型的竞争型神经网络的Web日志挖掘

提出了一种基于竞争的自激励神经网络学习算法SIN，该算法综合了自适应谐振理论和竞争型神经网络的特点，并在隐含层采用了Hebb学习规则，既能保证原有记忆不受影响，又能对新的信息加以记忆，同时又克服了ART网络对噪音敏感的缺点，学习速度快，分类性能好，具有在线学习的功能．将该算法应用于Web日志挖掘能够有效地剔除噪音，得到很好的用户聚类和页面聚类的结果，为网站的管理者设计个性化的商务网站提供了有效的决策依据．     

Experience with a Hybrid Processor: K-Means Clustering

We discuss hardware/software co-processing on a hybrid processor for a compute- and data-intensive multispectral imaging algorithm, k-means clustering. The experiments are performed on two models of the Altera Excalibur board, the first using the soft IP core 32-bit NIOS 1.1 RISC processor, and the second with the hard IP core ARM processor. In our experiments, we compare performance of the sequential k-means algorithm with three different accelerated versions. We consider granularity and synchronization issues when mapping an algorithm to a hybrid processor. Our results show that speedup of 11.8X is achieved by migrating computation to the Excalibur ARM hardware/software as compared to software only on a Gigahertz Pentium III. Speedup on the Excalibur NIOS is limited by the communication cost of transferring data from external memory through the processor to the customized circuits. This limitation is overcome on the Excalibur ARM, in which dual-port memories, accessible to both the processor and configurable logic, have the biggest performance impact of all the techniques studied.