200 research outputs found
Linguistic knowledge-based vocabularies for Neural Machine Translation
This article has been published in a revised form in Natural Language Engineering https://doi.org/10.1017/S1351324920000364. This version is free to view and download for private research and study only. Not for re-distribution, re-sale or use in derivative works. © Cambridge University PressNeural Networks applied to Machine Translation need a finite vocabulary to express textual information as a sequence of discrete tokens. The currently dominant subword vocabularies exploit statistically-discovered common parts of words to achieve the flexibility of character-based vocabularies without delegating the whole learning of word formation to the neural network. However, they trade this for the inability to apply word-level token associations, which limits their use in semantically-rich areas and prevents some transfer learning approaches e.g. cross-lingual pretrained embeddings, and reduces their interpretability. In this work, we propose new hybrid linguistically-grounded vocabulary definition strategies that keep both the advantages of subword vocabularies and the word-level associations, enabling neural networks to profit from the derived benefits. We test the proposed approaches in both morphologically rich and poor languages, showing that, for the former, the quality in the translation of out-of-domain texts is improved with respect to a strong subword baseline.This work is partially supported by Lucy Software / United Language Group (ULG) and the Catalan Agency for Management of University and Research Grants (AGAUR) through an Industrial PhD Grant. This work is also supported in part by the Spanish Ministerio de Economa y Competitividad, the European Regional Development Fund and the Agencia Estatal de Investigacin, through the postdoctoral senior grant Ramn y Cajal, contract TEC2015-69266-P (MINECO/FEDER,EU) and contract PCIN-2017-079 (AEI/MINECO).Peer ReviewedPostprint (author's final draft
End-to-End Simultaneous Speech Translation with Differentiable Segmentation
End-to-end simultaneous speech translation (SimulST) outputs translation
while receiving the streaming speech inputs (a.k.a. streaming speech
translation), and hence needs to segment the speech inputs and then translate
based on the current received speech. However, segmenting the speech inputs at
unfavorable moments can disrupt the acoustic integrity and adversely affect the
performance of the translation model. Therefore, learning to segment the speech
inputs at those moments that are beneficial for the translation model to
produce high-quality translation is the key to SimulST. Existing SimulST
methods, either using the fixed-length segmentation or external segmentation
model, always separate segmentation from the underlying translation model,
where the gap results in segmentation outcomes that are not necessarily
beneficial for the translation process. In this paper, we propose
Differentiable Segmentation (DiSeg) for SimulST to directly learn segmentation
from the underlying translation model. DiSeg turns hard segmentation into
differentiable through the proposed expectation training, enabling it to be
jointly trained with the translation model and thereby learn
translation-beneficial segmentation. Experimental results demonstrate that
DiSeg achieves state-of-the-art performance and exhibits superior segmentation
capability.Comment: Accepted at ACL 2023 finding
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