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在高维特征协方差开发在线学习

Exploiting feature covariance in high-dimensional online learning
课程网址: http://videolectures.net/aistats2010_ma_efcih/  
主讲教师: Justin Ma
开课单位: 加利福尼亚大学
开课时间: 2010-06-03
课程语种: 英语
中文简介:
一些在线分类的在线算法模拟了学习过程中其权重的不确定性。对权重的完全协方差结构建模可以为分类提供显着的优势。然而,对于高维,大规模数据,即使可能存在许多二阶特征相互作用,维持该协方差结构在计算上也是不可行的。为了将二阶方法扩展到高维数据,我们开发了协方差结构的低秩近似。我们使用置信度加权在线学习框架评估我们在合成和现实数据集上的方法。我们对低维和高维数据的对角协方差矩阵进行了改进。
课程简介: Some online algorithms for linear classification model the uncertainty in their weights over the course of learning. Modeling the full covariance structure of the weights can provide a significant advantage for classification. However, for high-dimensional, large-scale data, even though there may be many second-order feature interactions, it is computationally infeasible to maintain this covariance structure. To extend second-order methods to high-dimensional data, we develop low-rank approximations of the covariance structure. We evaluate our approach on both synthetic and real-world data sets using the confidence-weighted online learning framework. We show improvements over diagonal covariance matrices for both low and high-dimensional data.
关 键 词: 线性分类模型; 全协方差结构建模; 对角协方差矩阵
课程来源: 视频讲座网
最后编审: 2020-07-17:yumf
阅读次数: 57