Département d'Informatique, Université de Montréal, Montréal, QC H3C 3J7, Canada.
Neural Comput. 2011 Jul;23(7):1661-74. doi: 10.1162/NECO_a_00142. Epub 2011 Apr 14.
Denoising autoencoders have been previously shown to be competitive alternatives to restricted Boltzmann machines for unsupervised pretraining of each layer of a deep architecture. We show that a simple denoising autoencoder training criterion is equivalent to matching the score (with respect to the data) of a specific energy-based model to that of a nonparametric Parzen density estimator of the data. This yields several useful insights. It defines a proper probabilistic model for the denoising autoencoder technique, which makes it in principle possible to sample from them or rank examples by their energy. It suggests a different way to apply score matching that is related to learning to denoise and does not require computing second derivatives. It justifies the use of tied weights between the encoder and decoder and suggests ways to extend the success of denoising autoencoders to a larger family of energy-based models.
去噪自动编码器此前已被证明是受限玻尔兹曼机的一种有竞争力的替代方法,可用于深度架构的每一层的无监督预训练。我们表明,一个简单的去噪自动编码器训练准则等同于匹配特定基于能量模型的得分(相对于数据)与数据的非参数 Parzen 密度估计器的得分。这产生了几个有用的见解。它为去噪自动编码器技术定义了一个合适的概率模型,这使得从它们中进行采样或根据它们的能量对示例进行排序在原则上成为可能。它提出了一种应用得分匹配的不同方法,与学习去噪有关,并且不需要计算二阶导数。它证明了在编码器和解码器之间使用绑定权重的合理性,并提出了将去噪自动编码器的成功扩展到更大的基于能量模型家族的方法。