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改良Nystrom低秩逼近及其误差分析

Improved Nystrom Low-Rank Approximation and Error Analysis
课程网址: http://videolectures.net/icml08_zhang_inl/  
主讲教师: Kai Zhang
开课单位: 天普大学
开课时间: 2008-08-05
课程语种: 英语
中文简介:
低秩矩阵近似是减轻核方法和采样的记忆和计算负担的有效工具,作为这类算法的主流,在理论和实践中都引起了相当大的关注。本文介绍了Nystrom采样方案的详细研究,特别是在总结数据时直接将Nystrom逼近质量与地标点的编码能力相关联的误差分析。得到的误差界限表明了一种简单有效的采样方案,即k均值聚类算法,用于Nystrom低秩近似。我们将其与从贪婪计划到概率抽样的最新方法进行比较。我们的算法在许多监督/无监督学习任务中实现了显着的性能提升,包括内核PCA和最小二乘SVM。
课程简介: Low-rank matrix approximation is an effective tool in alleviating the memory and computational burdens of kernel methods and sampling, as the mainstream of such algorithms, has drawn considerable attention in both theory and practice. This paper presents detailed studies on the Nystrom sampling scheme and in particular, an error analysis that directly relates the Nystrom approximation quality with the encoding powers of the landmark points in summarizing the data. The resultant error bound suggests a simple and efficient sampling scheme, the k-means clustering algorithm, for Nystrom low-rank approximation. We compare it with state-of-the-art approaches that range from greedy schemes to probabilistic sampling. Our algorithm achieves significant performance gains in a number of supervised/unsupervised learning tasks including kernel PCA and least squares SVM.
关 键 词: 矩阵低秩; Nystrom抽样方案; 奈斯特龙
课程来源: 视频讲座网
最后编审: 2020-06-27:yumf
阅读次数: 87