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子空间正则化:一种新的半监督学习方法

Subspace Regularization: A New Semi-Supervised Learning Method
课程网址: http://videolectures.net/ecmlpkdd09_zhang_srnsslm/  
主讲教师: Yan-Ming Zhang
开课单位: 中国科学院
开课时间: 2009-10-20
课程语种: 汉简
中文简介:
大多数现有的半监督学习方法基于平滑度假设,即相同高密度区域中的数据点应具有相同的标签。尽管这种假设在许多情况下运作良好,但仍具有局限性。为了克服这个问题,我们在半监督学习中引入经典的低维嵌入假设,指出高维数据的大多数几何信息嵌入在低维流形中。在此基础上,我们将半监督学习的问题制定为在子空间上寻找子空间和决策函数的任务,使得投影数据被很好地分离并且尽可能地保留原始几何信息。在此框架下,通过投影寻踪程序迭代地找到最优子空间和决策函数。所提出方法的低计算复杂性使其适用于大规模数据集。实验结果证明了我们的方法的有效性。
课程简介: Most existing semi-supervised learning methods are based on the smoothness assumption that data points in the same high density region should have the same label. This assumption, though works well in many cases, has limitations. To overcome this problems, we introduce into semi-supervised learning the classic low-dimensionality embedding assumption, stating that most geometric information of high dimensional data is embedded in a low dimensional manifold. Based on this, we formulate the problem of semi-supervised learning as a task of finding a subspace and a decision function on the subspace such that the projected data are well separated and the original geometric information is preserved as much as possible. Under this framework, the optimal subspace and decision function are iteratively found via a projection pursuit procedure. The low computational complexity of the proposed method lends it to applications on large scale data sets. Experimental results demonstrates the effectiveness of our method.
关 键 词: 半监督学习方法; 平滑度假设; 低维嵌入假设
课程来源: 视频讲座网
最后编审: 2019-03-27:lxf
阅读次数: 64