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In-Order Transition-based Constituent Parsing

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TLDR
A novel parsing system based on in-order traversal over syntactic trees, designing a set of transition actions to find a compromise between bottom-up constituent information and top-down lookahead information is proposed.
Abstract
Both bottom-up and top-down strategies have been used for neural transition-based constituent parsing. The parsing strategies differ in terms of the order in which they recognize productions in the derivation tree, where bottom-up strategies and top-down strategies take post-order and pre-order traversal over trees, respectively. Bottom-up parsers benefit from rich features from readily built partial parses, but lack lookahead guidance in the parsing process; top-down parsers benefit from non-local guidance for local decisions, but rely on a strong encoder over the input to predict a constituent hierarchy before its construction. To mitigate both issues, we propose a novel parsing system based on in-order traversal over syntactic trees, designing a set of transition actions to find a compromise between bottom-up constituent information and top-down lookahead information. Based on stack-LSTM, our psycholinguistically motivated constituent parsing system achieves 91.8 F1 on WSJ benchmark. Furthermore, the system achieves 93.6 F1 with supervised reranking and 94.2 F1 with semi-supervised reranking, which are the best results on the WSJ benchmark.

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Investigating Non-local Features for Neural Constituency Parsing.

TL;DR: In this article, non-local features are injected into the training process of a local span-based parser, by predicting constituent n-gram nonlocal patterns and ensuring consistency between nonlocal pattern and local constituents.
Journal ArticleDOI

Discontinuous grammar as a foreign language

TL;DR: The authors extended the framework of sequence-to-sequence models for constituent parsing, not only by providing a more powerful neural architecture for improving their performance, but also enlarging their coverage to handle the most complex syntactic structures.
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A Span-based Linearization for Constituent Trees

TL;DR: This paper proposed a novel linearization of a constituent tree, together with a new locally normalized model for each split point in a sentence, computes the normalizer on all spans ending with that split point, and then predicts a tree span from them.
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Dependency Language Models for Transition-based Dependency Parsing

TL;DR: This article presented an approach to improve the accuracy of a strong transition-based dependency parser by exploiting dependency language models that are extracted from a large parsed corpus, which achieved state-of-the-art accuracy on Chinese data.
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Head-driven Phrase Structure Parsing in O($n^3$) Time Complexity.

TL;DR: This article proposed an improved head scorer that helps achieve a novel performance-preserved parser in $O$($n^3$) time complexity and explored the general method of training an HPSG-based parser from only a constituent or dependency annotations in multilingual scenario.
References
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ReportDOI

Building a large annotated corpus of English: the penn treebank

TL;DR: As a result of this grant, the researchers have now published on CDROM a corpus of over 4 million words of running text annotated with part-of- speech (POS) tags, which includes a fully hand-parsed version of the classic Brown corpus.
Journal ArticleDOI

Head-Driven Statistical Models for Natural Language Parsing

TL;DR: Three statistical models for natural language parsing are described, leading to approaches in which a parse tree is represented as the sequence of decisions corresponding to a head-centered, top-down derivation of the tree.
Proceedings ArticleDOI

A Fast and Accurate Dependency Parser using Neural Networks

TL;DR: This work proposes a novel way of learning a neural network classifier for use in a greedy, transition-based dependency parser that can work very fast, while achieving an about 2% improvement in unlabeled and labeled attachment scores on both English and Chinese datasets.
Proceedings Article

A maximum-entropy-inspired parser

TL;DR: A new parser for parsing down to Penn tree-bank style parse trees that achieves 90.1% average precision/recall for sentences of length 40 and less and 89.5% when trained and tested on the previously established sections of the Wall Street Journal treebank is presented.
Proceedings Article

Parsing with Compositional Vector Grammars

TL;DR: A Compositional Vector Grammar (CVG), which combines PCFGs with a syntactically untied recursive neural network that learns syntactico-semantic, compositional vector representations and improves performance on the types of ambiguities that require semantic information such as PP attachments.
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