Porous Lattice Transformer Encoder for Chinese NER

Xue Mengge, Bowen Yu, Tingwen Liu, Yue Zhang, Erli Meng, Bin Wang


Abstract
Incorporating lexicons into character-level Chinese NER by lattices is proven effective to exploitrich word boundary information. Previous work has extended RNNs to consume lattice inputsand achieved great success. However, due to the DAG structure and the inherently unidirectionalsequential nature, this method precludes batched computation and sufficient semantic interaction.In this paper, we propose PLTE, an extension of transformer encoder that is tailored for ChineseNER, which models all the characters and matched lexical words in parallel with batch process-ing. PLTE augments self-attention with positional relation representations to incorporate latticestructure. It also introduces a porous mechanism to augment localness modeling and maintainthe strength of capturing the rich long-term dependencies. Experimental results show that PLTEperforms up to 11.4 times faster than state-of-the-art methods while realizing better performance.We also demonstrate that using BERT representations further substantially boosts the performanceand brings out the best in PLTE.
Anthology ID:
2020.coling-main.340
Volume:
Proceedings of the 28th International Conference on Computational Linguistics
Month:
December
Year:
2020
Address:
Barcelona, Spain (Online)
Venue:
COLING
SIG:
Publisher:
International Committee on Computational Linguistics
Note:
Pages:
3831–3841
Language:
URL:
https://aclanthology.org/2020.coling-main.340
DOI:
10.18653/v1/2020.coling-main.340
Bibkey:
Cite (ACL):
Xue Mengge, Bowen Yu, Tingwen Liu, Yue Zhang, Erli Meng, and Bin Wang. 2020. Porous Lattice Transformer Encoder for Chinese NER. In Proceedings of the 28th International Conference on Computational Linguistics, pages 3831–3841, Barcelona, Spain (Online). International Committee on Computational Linguistics.
Cite (Informal):
Porous Lattice Transformer Encoder for Chinese NER (Mengge et al., COLING 2020)
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PDF:
https://aclanthology.org/2020.coling-main.340.pdf