Using Subword Sequence BiLSTM-CRF Model for Compound Name Extraction

Abstract

In this paper, we investigate of using subword sequences for compound name extraction problem. Five variety of subword sequence generators (SYMBOL, SP, BPE, BPE-DICT, and BPE-PMI) were used in the investigation. Last two of these, BPE-DICT and BPE-PMI, are originally proposed in this work. BPE-DICT is a variation of BPE which has a dictionary-based restriction. BPE-PMI introduces the PMI measure instead of word frequency count. The experimental results showed that subword sequence information improved the extraction performance. The F-measure value of BPE-DICT is 86.74 which is best score in all conditions of our experiments.