While symbolic parsers can be viewed as deduction systems, this view is less natural for probabilistic parsers. We present a view of parsing as directed hypergraph analysis which naturally covers both symbolic and probabilistic parsing. We illustrate the approach by showing how a dynamic extension of Dijkstra’s algorithm can be used to construct a probabilistic chart parser with an Ç Ò time bound for arbitrary PCFGs, while preserving as much of the flexibility of symbolic chart parsers as allowed by the inherent ordering of probabilistic dependencies. 1

We present a hierarchical phrase-based translation model which annotates and generalizes existing phrase translations with syntactic categories derived from parsing the target side of a parallel corpus. We associate target parse trees for each training sentence pair with a search lattice constructed from the existing phrase translations on the corresponding source sentence, and consider techniques to produce a syntactically motivated bilingual synchronous grammar. We describe refinements to a chart based decoder and k-best extraction techniques to effectively parse the resulting grammar, which contains up to 4000 syntax-derivated nonterminals, producing translations that achieve significant improvements over Pharaoh, a stateof-the-art phrase based system, on the Europarl French-to-English task (Koehn and Monz, 2005). 1

A lot of work remains to be done in the domain of a better integration of speech recognition and language processing systems. This paper gives an overview of several strategies for integrating linguistic models into speech understanding systems and investigates several ways of producing sets of hypotheses that include more "semantic" variability than usual language models. The main goal is to present and demonstrate by actual experiments that sequential coupling may be efficiently achieved by word-lattice syntactic analyzers, efficiently parsing the huge number of hypothesis (i.e. possible sentences) contained in the lattice produced by the speech recognizer. 1. Motivations The past decade has seen significant progress in speech recognition technology: word (recognition) error rates continue to drop by a factor of 2 every two years (Rabiner et al., 1996) and high performance systems are now becoming available. Several factors have contributed to this rapid progress: ffl Generalisati...

This paper presents an FPGA-based implementation of a co-processing unit able to parse context-free grammars of real-life sizes. The application fields of such a parser range from programming languages syntactic analysis to very demanding Natural Language Applications where parsing speed is an important issue.

While O(n³) methods for parsing probabilistic context-free grammars (PCFGs) are well known, a tabular parsing framework for arbitrary PCFGs which allows for botton-up, top-down, and other parsing strategies, has not yet been provided. This paper presents such an algorithm, and shows its correctness and advantages over prior work. The paper finishes by bringing out the connections between the algorithm and work on hypergraphs, which permits us to extend the presented Viterbi (best parse) algorithm to an inside (total probability) algorithm.

We describe refinements to hierarchical translation search procedures intended to reduce both search errors and memory usage through modifications to hypothesis expansion in cube pruning and reductions in the size of the rule sets used in translation. Rules are put into syntactic classes based on the number of non-terminals and the pattern, and various filtering strategies are then applied to assess the impact on translation speed and quality. Results are reported on the 2008 NIST Arabic-to-English evaluation task. 1

We present Jane, RWTH’s hierarchical phrase-based translation system, which has been open sourced for the scientific community. This system has been in development at RWTH for the last two years and has been successfully applied in different machine translation evaluations. It includes extensions to the hierarchical approach developed by RWTH as well as other research institutions. In this paper we give an overview of its main features. We also introduce a novel reordering model for the hierarchical phrase-based approach which further enhances translation performance, and analyze the effect some recent extended lexicon models have on the performance of the system. 1

This paper investigates the application of a probabilistic parser for natural language on the list of the Nbest sentences produced by an off-line recognition system for cursive handwritten sentences. For the generation of the N-best sentence list an HMM-based recognizer including a bigram language model is used. The parsing of the sentences is achieved by a bottom-up chart parser for stochastic context-free grammars which produces the parse tree of the input sentence as well as the word tags. From a collection of corpora we extract the linguistic resources to build the lexicon,a word bigram model and the stochastic context-free grammar. Results from experiments indicate an increase of the word and sentence recognition rate when using the proposed combination scheme.

We present the result of an experimental system aimed at performing a robust semantic analysis of analyzed speech input in the are of information system access. The goal of this experiment was to investigate the eectiveness of such a system in a pipelined architecture, where no control is possible over the morpho-syntactic analysis which precedes the semantic analysis and query formation. 1 Introduction The general applicative framework of the ISIS project 1 was to design an information system NLP interface for automated telephone-based phone-book inquiry. The objective of the project was to dene an architecture to improve speech recognition results by integrating higher level linguistic knowledge. The availability of a huge collection of annotated telephone calls for querying the Swiss phone-book database (i.e the Swiss French PolyPhone corpus [6]) allowed us to propose and evaluate a very rst functional prototype of software architecture for vocal access to database through...

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