Austin Matthews


2019

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Comparing Top-Down and Bottom-Up Neural Generative Dependency Models
Austin Matthews | Graham Neubig | Chris Dyer
Proceedings of the 23rd Conference on Computational Natural Language Learning (CoNLL)

Recurrent neural network grammars generate sentences using phrase-structure syntax and perform very well on both parsing and language modeling. To explore whether generative dependency models are similarly effective, we propose two new generative models of dependency syntax. Both models use recurrent neural nets to avoid making explicit independence assumptions, but they differ in the order used to construct the trees: one builds the tree bottom-up and the other top-down, which profoundly changes the estimation problem faced by the learner. We evaluate the two models on three typologically different languages: English, Arabic, and Japanese. While both generative models improve parsing performance over a discriminative baseline, they are significantly less effective than non-syntactic LSTM language models. Surprisingly, little difference between the construction orders is observed for either parsing or language modeling.

2018

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Using Morphological Knowledge in Open-Vocabulary Neural Language Models
Austin Matthews | Graham Neubig | Chris Dyer
Proceedings of the 2018 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Volume 1 (Long Papers)

Languages with productive morphology pose problems for language models that generate words from a fixed vocabulary. Although character-based models allow any possible word type to be generated, they are linguistically naïve: they must discover that words exist and are delimited by spaces—basic linguistic facts that are built in to the structure of word-based models. We introduce an open-vocabulary language model that incorporates more sophisticated linguistic knowledge by predicting words using a mixture of three generative processes: (1) by generating words as a sequence of characters, (2) by directly generating full word forms, and (3) by generating words as a sequence of morphemes that are combined using a hand-written morphological analyzer. Experiments on Finnish, Turkish, and Russian show that our model outperforms character sequence models and other strong baselines on intrinsic and extrinsic measures. Furthermore, we show that our model learns to exploit morphological knowledge encoded in the analyzer, and, as a byproduct, it can perform effective unsupervised morphological disambiguation.

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XNMT: The eXtensible Neural Machine Translation Toolkit
Graham Neubig | Matthias Sperber | Xinyi Wang | Matthieu Felix | Austin Matthews | Sarguna Padmanabhan | Ye Qi | Devendra Sachan | Philip Arthur | Pierre Godard | John Hewitt | Rachid Riad | Liming Wang
Proceedings of the 13th Conference of the Association for Machine Translation in the Americas (Volume 1: Research Track)

2016

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Synthesizing Compound Words for Machine Translation
Austin Matthews | Eva Schlinger | Alon Lavie | Chris Dyer
Proceedings of the 54th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

2015

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Transition-Based Dependency Parsing with Stack Long Short-Term Memory
Chris Dyer | Miguel Ballesteros | Wang Ling | Austin Matthews | Noah A. Smith
Proceedings of the 53rd Annual Meeting of the Association for Computational Linguistics and the 7th International Joint Conference on Natural Language Processing (Volume 1: Long Papers)

2014

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The CMU Machine Translation Systems at WMT 2014
Austin Matthews | Waleed Ammar | Archna Bhatia | Weston Feely | Greg Hanneman | Eva Schlinger | Swabha Swayamdipta | Yulia Tsvetkov | Alon Lavie | Chris Dyer
Proceedings of the Ninth Workshop on Statistical Machine Translation

2013

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The CMU Machine Translation Systems at WMT 2013: Syntax, Synthetic Translation Options, and Pseudo-References
Waleed Ammar | Victor Chahuneau | Michael Denkowski | Greg Hanneman | Wang Ling | Austin Matthews | Kenton Murray | Nicola Segall | Alon Lavie | Chris Dyer
Proceedings of the Eighth Workshop on Statistical Machine Translation