Hirofumi Yamamoto

Also published as: Hirohumi Yamamoto


2009

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On the Importance of Pivot Language Selection for Statistical Machine Translation
Michael Paul | Hirofumi Yamamoto | Eiichiro Sumita | Satoshi Nakamura
Proceedings of Human Language Technologies: The 2009 Annual Conference of the North American Chapter of the Association for Computational Linguistics, Companion Volume: Short Papers

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Reordering Model Using Syntactic Information of a Source Tree for Statistical Machine Translation
Kei Hashimoto | Hirohumi Yamamoto | Hideo Okuma | Eiichiro Sumita | Keiichi Tokuda
Proceedings of the Third Workshop on Syntax and Structure in Statistical Translation (SSST-3) at NAACL HLT 2009

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Two methods for stabilizing MERT
Masao Utiyama | Hirofumi Yamamoto | Eiichiro Sumita
Proceedings of the 6th International Workshop on Spoken Language Translation: Evaluation Campaign

This paper describes the NICT SMT system used in the International Workshop on Spoken Language Translation (IWSLT) 2009 evaluation campaign. We participated in the Challenge Task. Our system was based on a fairly common phrase-based machine translation system. We used two methods for stabilizing MERT.

2008

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Method of Selecting Training Data to Build a Compact and Efficient Translation Model
Keiji Yasuda | Ruiqiang Zhang | Hirofumi Yamamoto | Eiichiro Sumita
Proceedings of the Third International Joint Conference on Natural Language Processing: Volume-II

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The NICT/ATR speech translation system for IWSLT 2008.
Masao Utiyama | Andrew Finch | Hideo Okuma | Michael Paul | Hailong Cao | Hirofumi Yamamoto | Keiji Yasuda | Eiichiro Sumita
Proceedings of the 5th International Workshop on Spoken Language Translation: Evaluation Campaign

This paper describes the National Institute of Information and Communications Technology/Advanced Telecommunications Research Institute International (NICT/ATR) statistical machine translation (SMT) system used for the IWSLT 2008 evaluation campaign. We participated in the Chinese–English (Challenge Task), English–Chinese (Challenge Task), Chinese–English (BTEC Task), Chinese–Spanish (BTEC Task), and Chinese–English–Spanish (PIVOT Task) translation tasks. In the English–Chinese translation Challenge Task, we focused on exploring various factors for the English–Chinese translation because the research on the translation of English–Chinese is scarce compared to the opposite direction. In the Chinese–English translation Challenge Task, we employed a novel clustering method, where training sentences similar to the development data in terms of the word error rate formed a cluster. In the pivot translation task, we integrated two strategies for pivot translation by linear interpolation.

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Multilingual Mobile-Phone Translation Services for World Travelers
Michael Paul | Hideo Okuma | Hirofumi Yamamoto | Eiichiro Sumita | Shigeki Matsuda | Tohru Shimizu | Satoshi Nakamura
Coling 2008: Companion volume: Demonstrations

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Imposing Constraints from the Source Tree on ITG Constraints for SMT
Hirofumi Yamamoto | Hideo Okuma | Eiichiro Sumita
Proceedings of the ACL-08: HLT Second Workshop on Syntax and Structure in Statistical Translation (SSST-2)

2007

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Introducing translation dictionary into phrase-based SMT
Hideo Okuma | Hirofumi Yamamoto | Eiichiro Sumita
Proceedings of Machine Translation Summit XI: Papers

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Method of selecting training sets to build compact and efficient language model
Keiji Yasuda | Hirofumi Yamamoto | Eiichiro Sumita
Proceedings of the Workshop on Using corpora for natural language generation

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Bilingual Cluster Based Models for Statistical Machine Translation
Hirofumi Yamamoto | Eiichiro Sumita
Proceedings of the 2007 Joint Conference on Empirical Methods in Natural Language Processing and Computational Natural Language Learning (EMNLP-CoNLL)

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The NICT/ATR speech translation system for IWSLT 2007
Andrew Finch | Etienne Denoual | Hideo Okuma | Michael Paul | Hirofumi Yamamoto | Keiji Yasuda | Ruiqiang Zhang | Eiichiro Sumita
Proceedings of the Fourth International Workshop on Spoken Language Translation

This paper describes the NiCT-ATR statistical machine translation (SMT) system used for the IWSLT 2007 evaluation campaign. We participated in three of the four language pair translation tasks (CE, JE, and IE). We used a phrase-based SMT system using log-linear feature models for all tracks. This year we decoded from the ASR n-best lists in the JE track and found a gain in performance. We also applied some new techniques to facilitate the use of out-of-domain external resources by model combination and also by utilizing a huge corpus of n-grams provided by Google Inc.. Using these resources gave mixed results that depended on the technique also the language pair however, in some cases we achieved consistently positive results. The results from model-interpolation in particular were very promising.

2006

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The NiCT-ATR statistical machine translation system for IWSLT 2006
Ruiqiang Zhang | Hirofumi Yamamoto | Michael Paul | Hideo Okuma | Keiji Yasuda | Yves Lepage | Etienne Denoual | Daichi Mochihashi | Andrew Finch | Eiichiro Sumita
Proceedings of the Third International Workshop on Spoken Language Translation: Evaluation Campaign

2005

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Graph-based Retrieval for Example-based Machine Translation Using Edit-distance
Takao Doi | Hirofumi Yamamoto | Eiichiro Sumita
Workshop on example-based machine translation

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A decoding algorithm for word lattice translation in speech translation
Ruiqiang Zhang | Genichiro Kikui | Hirofumi Yamamoto | Wai-Kit Lo
Proceedings of the Second International Workshop on Spoken Language Translation

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Using multiple recognition hypotheses to improve speech translation
Ruiqiang Zhang | Genichiro Kikui | Hirofumi Yamamoto
Proceedings of the Second International Workshop on Spoken Language Translation

2004

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Multi-lingual speech recognition system for speech-to-speech translation
Satoshi Nakamura | Konstantin Markov | Takatoshi Jitsuhiro | Jin-Song Zhang | Hirofumi Yamamoto | Genichiro Kikui
Proceedings of the First International Workshop on Spoken Language Translation: Papers

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A Unified Approach in Speech-to-Speech Translation: Integrating Features of Speech recognition and Machine Translation
Ruiqiang Zhang | Genichiro Kikui | Hirofumi Yamamoto | Frank Soong | Taro Watanabe | Wai Kit Lo
COLING 2004: Proceedings of the 20th International Conference on Computational Linguistics

2003

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Adaptation Using Out-of-Domain Corpus within EBMT
Takao Doi | Eiichiro Sumita | Hirofumi Yamamoto
Companion Volume of the Proceedings of HLT-NAACL 2003 - Short Papers

2002

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Toward a Broad-coverage Bilingual Corpus for Speech Translation of Travel Conversations in the Real World
Toshiyuki Takezawa | Eiichiro Sumita | Fumiaki Sugaya | Hirofumi Yamamoto | Seiichi Yamamoto
Proceedings of the Third International Conference on Language Resources and Evaluation (LREC’02)

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Language Model Adaptation with Additional Text Generated by Machine Translation
Hideharu Nakajima | Hirofumi Yamamoto | Taro Watanabe
COLING 2002: The 19th International Conference on Computational Linguistics

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Finding Translation Pairs from English-Japanese Untokenized Aligned Corpora
Genichiro Kikui | Hirofumi Yamamoto
Proceedings of the ACL-02 Workshop on Speech-to-Speech Translation: Algorithms and Systems

2001

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Multi-Class Composite N-gram Language Model for Spoken Language Processing Using Multiple Word Clusters
Hirofumi Yamamoto | Shuntaro Isogai | Yoshinori Sagisaka
Proceedings of the 39th Annual Meeting of the Association for Computational Linguistics