Logistic label propagation

Abstract

In this paper, we propose a novel method for semi-supervised learning, called logistic label propagation (LLP). The proposed method employs the logistic function to classify input pattern vectors, similarly to logistic regression. To cope with unlabeled samples as well as labeled ones in the semi-supervised learning framework, the logistic functions are learnt by using similarities between samples in a manner similar to label propagation. In the proposed method, these two methods of logistic regression and label propagation are effectively incorporated in terms of posterior probabilities. LLP estimates the labels of input samples by using the learnt logistic function, whereas the method of label propagation has to optimize the whole labels whenever an input sample comes. In addition, we suggest the way to provide proper parameter setting and initialization, which frees the users from determining a parameter value in trial and error. In experiments on classification (estimating labels) in the semi-supervised learning framework, the proposed method exhibits favorable performances compared to the other methods.