Denoising Autoencoder as an Effective Dimensionality Reduction and Clustering of Text Data

Deep learning methods are widely used in vision and face recognition, however there is a real lack of application of such methods in the field of text data. In this context, the data is often represented by a sparse high dimensional document-term matrix. Dealing with such data matrices, we present, in this paper, a new denoising auto-encoder for dimensionality reduction, where each document is not only affected by its own information, but also affected by the information from its neighbors according to the cosine similarity measure. It turns out that the proposed auto-encoder can discover the low dimensional embeddings, and as a result reveal the underlying effective manifold structure. The visual representation of these embeddings suggests the suitability of performing the clustering on the set of documents relying on the Expectation-Maximization algorithm for Gaussian mixture models. On real-world datasets, the relevance of the presented auto-encoder in the visualisation and document clustering field is shown by a comparison with five widely used unsupervised dimensionality reduction methods including the classic auto-encoder.