Hajime Tsukada


2015

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Improvement of word alignment models for Vietnamese-to-English translation
Takahiro Nomura | Hajime Tsukada | Tomoyoshi Akiba
Proceedings of the 12th International Workshop on Spoken Language Translation: Evaluation Campaign

2013

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Shift-Reduce Word Reordering for Machine Translation
Katsuhiko Hayashi | Katsuhito Sudoh | Hajime Tsukada | Jun Suzuki | Masaaki Nagata
Proceedings of the 2013 Conference on Empirical Methods in Natural Language Processing

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NTT-NAIST SMT systems for IWSLT 2013
Katsuhito Sudoh | Graham Neubig | Kevin Duh | Hajime Tsukada
Proceedings of the 10th International Workshop on Spoken Language Translation: Evaluation Campaign

This paper presents NTT-NAIST SMT systems for English-German and German-English MT tasks of the IWSLT 2013 evaluation campaign. The systems are based on generalized minimum Bayes risk system combination of three SMT systems: forest-to-string, hierarchical phrase-based, phrasebased with pre-ordering. Individual SMT systems include data selection for domain adaptation, rescoring using recurrent neural net language models, interpolated language models, and compound word splitting (only for German-English).

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Adaptation Data Selection using Neural Language Models: Experiments in Machine Translation
Kevin Duh | Graham Neubig | Katsuhito Sudoh | Hajime Tsukada
Proceedings of the 51st Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

2012

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Head Finalization Reordering for Chinese-to-Japanese Machine Translation
Dan Han | Katsuhito Sudoh | Xianchao Wu | Kevin Duh | Hajime Tsukada | Masaaki Nagata
Proceedings of the Sixth Workshop on Syntax, Semantics and Structure in Statistical Translation

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Learning to Translate with Multiple Objectives
Kevin Duh | Katsuhito Sudoh | Xianchao Wu | Hajime Tsukada | Masaaki Nagata
Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)

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A Comparative Study of Target Dependency Structures for Statistical Machine Translation
Xianchao Wu | Katsuhito Sudoh | Kevin Duh | Hajime Tsukada | Masaaki Nagata
Proceedings of the 50th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers)

2011

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Automatic Error Analysis Based on Grammatical Questions
Tomoki Nagase | Hajime Tsukada | Katsunori Kotani | Nobutoshi Hatanaka | Yoshiyuki Sakamoto
Proceedings of the 25th Pacific Asia Conference on Language, Information and Computation

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Extracting Pre-ordering Rules from Predicate-Argument Structures
Xianchao Wu | Katsuhito Sudoh | Kevin Duh | Hajime Tsukada | Masaaki Nagata
Proceedings of 5th International Joint Conference on Natural Language Processing

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Generalized Minimum Bayes Risk System Combination
Kevin Duh | Katsuhito Sudoh | Xianchao Wu | Hajime Tsukada | Masaaki Nagata
Proceedings of 5th International Joint Conference on Natural Language Processing

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Alignment Inference and Bayesian Adaptation for Machine Translation
Kevin Duh | Katsuhito Sudoh | Tomoharu Iwata | Hajime Tsukada
Proceedings of Machine Translation Summit XIII: Papers

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Extracting Pre-ordering Rules from Chunk-based Dependency Trees for Japanese-to-English Translation
Xianchao Wu | Katsuhito Sudoh | Kevin Duh | Hajime Tsukada | Masaaki Nagata
Proceedings of Machine Translation Summit XIII: Papers

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Post-ordering in Statistical Machine Translation
Katsuhito Sudoh | Xianchao Wu | Kevin Duh | Hajime Tsukada | Masaaki Nagata
Proceedings of Machine Translation Summit XIII: Papers

2010

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Head Finalization: A Simple Reordering Rule for SOV Languages
Hideki Isozaki | Katsuhito Sudoh | Hajime Tsukada | Kevin Duh
Proceedings of the Joint Fifth Workshop on Statistical Machine Translation and MetricsMATR

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N-Best Reranking by Multitask Learning
Kevin Duh | Katsuhito Sudoh | Hajime Tsukada | Hideki Isozaki | Masaaki Nagata
Proceedings of the Joint Fifth Workshop on Statistical Machine Translation and MetricsMATR

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Divide and Translate: Improving Long Distance Reordering in Statistical Machine Translation
Katsuhito Sudoh | Kevin Duh | Hajime Tsukada | Tsutomu Hirao | Masaaki Nagata
Proceedings of the Joint Fifth Workshop on Statistical Machine Translation and MetricsMATR

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NTT statistical MT system for IWSLT 2010
Katsuhito Sudoh | Kevin Duh | Hajime Tsukada
Proceedings of the 7th International Workshop on Spoken Language Translation: Evaluation Campaign

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Analysis of translation model adaptation in statistical machine translation
Kevin Duh | Katsuhito Sudoh | Hajime Tsukada
Proceedings of the 7th International Workshop on Spoken Language Translation: Papers

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Automatic Evaluation of Translation Quality for Distant Language Pairs
Hideki Isozaki | Tsutomu Hirao | Kevin Duh | Katsuhito Sudoh | Hajime Tsukada
Proceedings of the 2010 Conference on Empirical Methods in Natural Language Processing

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Hierarchical Phrase-based Machine Translation with Word-based Reordering Model
Katsuhiko Hayashi | Hajime Tsukada | Katsuhito Sudoh | Kevin Duh | Seiichi Yamamoto
Proceedings of the 23rd International Conference on Computational Linguistics (Coling 2010)

2009

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A Succinct N-gram Language Model
Taro Watanabe | Hajime Tsukada | Hideki Isozaki
Proceedings of the ACL-IJCNLP 2009 Conference Short Papers

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Structural support vector machines for log-linear approach in statistical machine translation
Katsuhiko Hayashi | Taro Watanabe | Hajime Tsukada | Hideki Isozaki
Proceedings of the 6th International Workshop on Spoken Language Translation: Papers

Minimum error rate training (MERT) is a widely used learning method for statistical machine translation. In this paper, we present a SVM-based training method to enhance generalization ability. We extend MERT optimization by maximizing the margin between the reference and incorrect translations under the L2-norm prior to avoid overfitting problem. Translation accuracy obtained by our proposed methods is more stable in various conditions than that obtained by MERT. Our experimental results on the French-English WMT08 shared task show that degrade of our proposed methods is smaller than that of MERT in case of small training data or out-of-domain test data.

2008

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NTT statistical machine translation system for IWSLT 2008.
Katsuhito Sudoh | Taro Watanabe | Jun Suzuki | Hajime Tsukada | Hideki Isozaki
Proceedings of the 5th International Workshop on Spoken Language Translation: Evaluation Campaign

The NTT Statistical Machine Translation System consists of two primary components: a statistical machine translation decoder and a reranker. The decoder generates k-best translation canditates using a hierarchical phrase-based translation based on synchronous context-free grammar. The decoder employs a linear feature combination among several real-valued scores on translation and language models. The reranker reorders the k-best translation candidates using Ranking SVMs with a large number of sparse features. This paper describes the two components and presents the results for the evaluation campaign of IWSLT 2008.

2007

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Online Large-Margin Training for Statistical Machine Translation
Taro Watanabe | Jun Suzuki | Hajime Tsukada | Hideki Isozaki
Proceedings of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL)

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Larger feature set approach for machine translation in IWSLT 2007
Taro Watanabe | Jun Suzuki | Katsuhito Sudoh | Hajime Tsukada | Hideki Isozaki
Proceedings of the Fourth International Workshop on Spoken Language Translation

The NTT Statistical Machine Translation System employs a large number of feature functions. First, k-best translation candidates are generated by an efficient decoding method of hierarchical phrase-based translation. Second, the k-best translations are reranked. In both steps, sparse binary features — of the order of millions — are integrated during the search. This paper gives the details of the two steps and shows the results for the Evaluation campaign of the International Workshop on Spoken Language Translation (IWSLT) 2007.

2006

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Incorporating Speech Recognition Confidence into Discriminative Named Entity Recognition of Speech Data
Katsuhito Sudoh | Hajime Tsukada | Hideki Isozaki
Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics

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Left-to-Right Target Generation for Hierarchical Phrase-Based Translation
Taro Watanabe | Hajime Tsukada | Hideki Isozaki
Proceedings of the 21st International Conference on Computational Linguistics and 44th Annual Meeting of the Association for Computational Linguistics

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NTT System Description for the WMT2006 Shared Task
Taro Watanabe | Hajime Tsukada | Hideki Isozaki
Proceedings on the Workshop on Statistical Machine Translation

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NTT statistical machine translation for IWSLT 2006
Taro Watanabe | Jun Suzuki | Hajime Tsukada | Hideki Isozaki
Proceedings of the Third International Workshop on Spoken Language Translation: Evaluation Campaign

2005

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The NTT Statistical Machine Translation System for IWSLT2005
Hajime Tsukada | Taro Watanabe | Jun Suzuki | Hideto Kazawa | Hideki Isozaki
Proceedings of the Second International Workshop on Spoken Language Translation

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Instance-Based Generation for Interactive Restricted Domain Question Answering Systems
Matthias Denecke | Hajime Tsukada
Second International Joint Conference on Natural Language Processing: Full Papers

2004

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Efficient Decoding for Statistical Machine Translation with a Fully Expanded WFST Model
Hajime Tsukada | Masaaki Nagata
Proceedings of the 2004 Conference on Empirical Methods in Natural Language Processing

2003

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Spoken Interactive ODQA System: SPIQA
Chiori Hori | Takaaki Hori | Hajime Tsukada | Hideki Isozaki | Yutaka Sasaki | Eisaku Maeda
The Companion Volume to the Proceedings of 41st Annual Meeting of the Association for Computational Linguistics