1,338 research outputs found
Exact decoding for phrase-based statistical machine translation
© 2014 Association for Computational Linguistics. The combinatorial space of translation derivations in phrase-based statistical machine translation is given by the intersection between a translation lattice and a target language model. We replace this intractable intersection by a tractable relaxation which incorporates a low-order upperbound on the language model. Exact optimisation is achieved through a coarseto- fine strategy with connections to adaptive rejection sampling. We perform exact optimisation with unpruned language models of order 3 to 5 and show searcherror curves for beam search and cube pruning on standard test sets. This is the first work to tractably tackle exact optimisation with language models of orders higher than 3
Planning in the imagination: High-level planning on learned abstract search spaces
We propose a new method, called PiZero, that gives an agent the ability to
plan in an abstract search space of its own creation that is completely
decoupled from the real environment. Unlike prior approaches, this enables the
agent to perform high-level planning at arbitrary timescales and reason in
terms of compound or temporally-extended actions, which can be useful in
environments where large numbers of base-level micro-actions are needed to
perform relevant macro-actions. In addition, our method is more general than
comparable prior methods because it handles settings with continuous action
spaces and partial observability. We evaluate our method on multiple domains,
including navigation tasks and Sokoban. Experimentally, it outperforms
comparable prior methods without assuming access to an environment simulator
Graph Transformer for Graph-to-Sequence Learning
The dominant graph-to-sequence transduction models employ graph neural
networks for graph representation learning, where the structural information is
reflected by the receptive field of neurons. Unlike graph neural networks that
restrict the information exchange between immediate neighborhood, we propose a
new model, known as Graph Transformer, that uses explicit relation encoding and
allows direct communication between two distant nodes. It provides a more
efficient way for global graph structure modeling. Experiments on the
applications of text generation from Abstract Meaning Representation (AMR) and
syntax-based neural machine translation show the superiority of our proposed
model. Specifically, our model achieves 27.4 BLEU on LDC2015E86 and 29.7 BLEU
on LDC2017T10 for AMR-to-text generation, outperforming the state-of-the-art
results by up to 2.2 points. On the syntax-based translation tasks, our model
establishes new single-model state-of-the-art BLEU scores, 21.3 for
English-to-German and 14.1 for English-to-Czech, improving over the existing
best results, including ensembles, by over 1 BLEU.Comment: accepted by AAAI202
Exact Decoding for Phrase-Based Statistical Machine Translation
Abstract The combinatorial space of translation derivations in phrase-based statistical machine translation is given by the intersection between a translation lattice and a target language model. We replace this intractable intersection by a tractable relaxation which incorporates a low-order upperbound on the language model. Exact optimisation is achieved through a coarseto-fine strategy with connections to adaptive rejection sampling. We perform exact optimisation with unpruned language models of order 3 to 5 and show searcherror curves for beam search and cube pruning on standard test sets. This is the first work to tractably tackle exact optimisation with language models of orders higher than 3
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