Hierarchical Text Categorization Using Level Based Neural Networks of Word Embedding Sequences with Sharing Layer Information
Mongkud Klungpornkun, Peerapon Vateekul · Walailak Journal of Science and Technology (WJST) · 2018
In text corpora, it is common to categorize each document to a predefined class hierarchy, which is usually a tree. One of the most widely-used approaches is a level-based strategy that induces a multiclass classifier for each class level independently. However, all prior attempts did not utilize information from its parent level and employed a bag of words rather than considered a sequence of words. In this paper, we present a novel level-based hierarchical text categorization with a strategy called “sharing layer information” For each class level, a neural network is constructed, where its input is a sequence of word embedding vectors generated from Convolutional Neural Networks (CNN). Also, a training strategy to avoid imbalance issues is proposed called “the balanced resampling with mini-batch training” Furthermore, a label correction strategy is proposed to conform the predicted results from all networks on different class levels. The experiment was conducted on 2 standard benchmarks: WIPO and Wiki comparing to a top-down based SVM framework with TF-IDF inputs called “HR-SVM.” The results show that the proposed model can achieved the highest accuracy in terms of micro F1 and outperforms the baseline in the top levels in terms of macro F1.