经典DBSCAN(density based spatial clustering of applications with noise)算法需要人工指定邻域半径(Eps)和点数阈值(Minpts),且均为全局参数,导致聚类准确率低。针对此问题,为了提高经典DBSCAN聚类算法的聚类准确率,基于网格划分思...经典DBSCAN(density based spatial clustering of applications with noise)算法需要人工指定邻域半径(Eps)和点数阈值(Minpts),且均为全局参数,导致聚类准确率低。针对此问题,为了提高经典DBSCAN聚类算法的聚类准确率,基于网格划分思想,提出了一种局部自适应DBSCAN聚类算法。根据数据集自身特征生成网格空间,将特征数据映射至相应的网格空间;利用高斯核函数估计每个网格区间的局部密度;联合多维度网格密度分布信息,寻找无连接或弱连接高密度网格之间的区域,同时统计同区域的波峰数量,从而自适应确定各区域的Eps及Minpts参数;使用每个区域独有的参数作为DBSCAN算法输入,并进行聚类。实验结果表明,该算法能够在聚类过程中自适应确定每个局部区域的Eps和Minpts参数,聚类准确率高且耗时较低。展开更多
This paper presents a classifier named kernel-based nonlinear representor (KNR) for optimal representation of pattern features. Adopting the Gaussian kernel, with the kernel width adaptively estimated by a simple tech...This paper presents a classifier named kernel-based nonlinear representor (KNR) for optimal representation of pattern features. Adopting the Gaussian kernel, with the kernel width adaptively estimated by a simple technique, it is applied to eigenface classification. Experimental results on the ORL face database show that it improves performance by around 6 points, in classification rate, over the Euclidean distance classifier.展开更多
文摘经典DBSCAN(density based spatial clustering of applications with noise)算法需要人工指定邻域半径(Eps)和点数阈值(Minpts),且均为全局参数,导致聚类准确率低。针对此问题,为了提高经典DBSCAN聚类算法的聚类准确率,基于网格划分思想,提出了一种局部自适应DBSCAN聚类算法。根据数据集自身特征生成网格空间,将特征数据映射至相应的网格空间;利用高斯核函数估计每个网格区间的局部密度;联合多维度网格密度分布信息,寻找无连接或弱连接高密度网格之间的区域,同时统计同区域的波峰数量,从而自适应确定各区域的Eps及Minpts参数;使用每个区域独有的参数作为DBSCAN算法输入,并进行聚类。实验结果表明,该算法能够在聚类过程中自适应确定每个局部区域的Eps和Minpts参数,聚类准确率高且耗时较低。
文摘This paper presents a classifier named kernel-based nonlinear representor (KNR) for optimal representation of pattern features. Adopting the Gaussian kernel, with the kernel width adaptively estimated by a simple technique, it is applied to eigenface classification. Experimental results on the ORL face database show that it improves performance by around 6 points, in classification rate, over the Euclidean distance classifier.
