This paper is concerned about studying modeling-based methods in cluster analysis to classify data elements into clusters and thus dealing with time series in view of this classification to choose the appropriate mixe...This paper is concerned about studying modeling-based methods in cluster analysis to classify data elements into clusters and thus dealing with time series in view of this classification to choose the appropriate mixed model. The mixture-model cluster analysis technique under different covariance structures of the component densities is presented. This model is used to capture the compactness, orientation, shape, and the volume of component clusters in one expert system to handle Gaussian high dimensional heterogeneous data set. To achieve flexibility in currently practiced cluster analysis techniques. The Expectation-Maximization (EM) algorithm is considered to estimate the parameter of the covariance matrix. To judge the goodness of the models, some criteria are used. These criteria are for the covariance matrix produced by the simulation. These models have not been tackled in previous studies. The results showed the superiority criterion ICOMP PEU to other criteria.<span> </span><span>This is in addition to the success of the model based on Gaussian clusters in the prediction by using covariance matrices used in this study. The study also found the possibility of determining the optimal number of clusters by choosing the number of clusters corresponding to lower values </span><span><span><span>for the different criteria used in the study</span></span></span><span><span><span>.展开更多
空间信号源数检测是阵列信号处理的关键问题之一,该文针对低信噪比下传统检测方法的性能差的问题,提出了一种基于近似特征向量的检测新方法DTAE(Detection Technique based on Approximate Eigenvectors)来改善低信噪比下传感器阵列的...空间信号源数检测是阵列信号处理的关键问题之一,该文针对低信噪比下传统检测方法的性能差的问题,提出了一种基于近似特征向量的检测新方法DTAE(Detection Technique based on Approximate Eigenvectors)来改善低信噪比下传感器阵列的信源数检测性能。该方法首先利用波束形成器在空间做预扫描来估计信号群中心的位置,以这些位置作为参考方向计算接收数据协方差矩阵的特征向量的近似值,然后使用特征向量的近似值对阵列输出数据加权,最后计算加权输出数据的频域峰值-平均功率比值从而估计信号源的个数。仿真结果表明,提出的新方法在低信噪比下的检测性能显著优于AIC(Akaike Information Criterion)等方法,有一定的工程应用价值。展开更多
Mixture regression is a regression problem with mixed data. Specifically, in the observations, some data are from one model, while others from other models. Only after assuming the quantity of the model is given, EM o...Mixture regression is a regression problem with mixed data. Specifically, in the observations, some data are from one model, while others from other models. Only after assuming the quantity of the model is given, EM or other algorithms can be used to solve this problem. We propose an information criterion for mixture regression model in this paper. Compared to ordinary information citizen by data simulations, results show our citizen has better performance on choosing the correct quantity of models.展开更多
文摘This paper is concerned about studying modeling-based methods in cluster analysis to classify data elements into clusters and thus dealing with time series in view of this classification to choose the appropriate mixed model. The mixture-model cluster analysis technique under different covariance structures of the component densities is presented. This model is used to capture the compactness, orientation, shape, and the volume of component clusters in one expert system to handle Gaussian high dimensional heterogeneous data set. To achieve flexibility in currently practiced cluster analysis techniques. The Expectation-Maximization (EM) algorithm is considered to estimate the parameter of the covariance matrix. To judge the goodness of the models, some criteria are used. These criteria are for the covariance matrix produced by the simulation. These models have not been tackled in previous studies. The results showed the superiority criterion ICOMP PEU to other criteria.<span> </span><span>This is in addition to the success of the model based on Gaussian clusters in the prediction by using covariance matrices used in this study. The study also found the possibility of determining the optimal number of clusters by choosing the number of clusters corresponding to lower values </span><span><span><span>for the different criteria used in the study</span></span></span><span><span><span>.
文摘空间信号源数检测是阵列信号处理的关键问题之一,该文针对低信噪比下传统检测方法的性能差的问题,提出了一种基于近似特征向量的检测新方法DTAE(Detection Technique based on Approximate Eigenvectors)来改善低信噪比下传感器阵列的信源数检测性能。该方法首先利用波束形成器在空间做预扫描来估计信号群中心的位置,以这些位置作为参考方向计算接收数据协方差矩阵的特征向量的近似值,然后使用特征向量的近似值对阵列输出数据加权,最后计算加权输出数据的频域峰值-平均功率比值从而估计信号源的个数。仿真结果表明,提出的新方法在低信噪比下的检测性能显著优于AIC(Akaike Information Criterion)等方法,有一定的工程应用价值。
文摘Mixture regression is a regression problem with mixed data. Specifically, in the observations, some data are from one model, while others from other models. Only after assuming the quantity of the model is given, EM or other algorithms can be used to solve this problem. We propose an information criterion for mixture regression model in this paper. Compared to ordinary information citizen by data simulations, results show our citizen has better performance on choosing the correct quantity of models.
