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随机游走的图形内核和合理的内核

Random walk graph kernels and rational kernels
课程网址: http://videolectures.net/sicgt07_vishwanathan_rwgk/  
主讲教师: S.V.N. Vishwanathan
开课单位: 加利福尼亚大学
开课时间: 2007-09-07
课程语种: 英语
中文简介:
随机游走图核 (gartner 等人, 2003 [5];borgwardt 等人, 2005 [1]) 计数匹配随机游走, 并使用张量乘积图定义。简单地说, 理性内核 (cortes 等人, 2004年, 2003年, 2002年 [4, 3, 2]) 使用传感器分配的重量来定义内核。当传感器可以写为两个相同的传感器的组合时, 内核被证明是正半确定的。在我们的谈话中, 我们将在随机游走图核和理性内核之间建立明确的联系。更具体地说, 我们表明, 传感器的组成类似于计算产品图, 而加权传感器上的合理核可以看作是随机游走核对加权自动机的推广。为了使这些连接变得清晰, 我们对加权传感器采用了稍微非标准的表示法, 尽可能广泛地使用矩阵和张量。我们证明了在一定条件下, 合理的内核是正半确定的。我们的证明只使用基本的线性代数, 比 cortes 等人2004年提出的方法更简单。
课程简介: Random walk graph kernels (Gartner et al., 2003 [5]; Borgwardt et al., 2005 [1]) count matching random walks, and are defined using the tensor product graph. Loosely speaking, rational kernels (Cortes et al., 2004, 2003, 2002 [4, 3, 2]) use the weight assigned by a transducer to define a kernel. The kernel is shown to be positive semi-definite when the transducer can be written as a composition of two identical transducers. In our talk we will establish explicit connections between random walk graph kernels and rational kernels. More concretely, we show that composition of transducers is analogous to computing product graphs, and that rational kernels on weighted transducers may be viewed as generalizations of random walk kernels to weighted automata. In order to make these connections explicit we adapt slightly non-standard notation for weighted transducers, extensively using matrices and tensors wherever possible. We prove that under certain conditions rational kernels are positive semi-definite. Our proof only uses basic linear algebra and is simpler than the one presented in Cortes et al., 2004[4].
关 键 词: 内核; 计算产品图形; 随机游走
课程来源: 视频讲座网
最后编审: 2020-07-29:yumf
阅读次数: 236