Bilingual Lexicon Extraction from Comparable Corpora Using Label Propagation
Akihiro Tamura, Taro Watanabe, Eiichiro Sumita · 2012
This paper proposes a novel method for lex-icon extraction that extracts translation pairs from comparable corpora by using graph-based label propagation. In previous work, it was established that performance drasti-cally decreases when the coverage of a seed lexicon is small. We resolve this problem by utilizing indirect relations with the bilin-gual seeds together with direct relations, in which each word is represented by a distri-bution of translated seeds. The seed distri-butions are propagated over a graph repre-senting relations among words, and transla-tion pairs are extracted by identifying word pairs with a high similarity in the seed dis-tributions. We propose two types of the graphs: a co-occurrence graph, representing co-occurrence relations between words, and a similarity graph, representing context sim-ilarities between words. Evaluations using English and Japanese patent comparable cor-pora show that our proposed graph propaga-tion method outperforms conventional meth-ods. Further, the similarity graph achieved im-proved performance by clustering synonyms into the same translation. 1