Natural language processing and computational linguistics research group at the Tokyo Metropolitan University. We aim at creating a research hub for natural language processing in Tokyo.


natural language processing (error correction, machine translation, information extraction, semantic analysis), web mining, machine learning (deep learning, representation learning)


  • 2017/03/20 We published following paper on arXiv.
    • Yuya Sakaizawa and Mamoru Komachi. Construction of a Japanese Word Similarity Dataset. In arXiv e-prints, 1703.05916 (5 pages). March 2017.
  • 2017/03/16 We published following paper on arXiv.
    • Ai Hirata and Mamoru Komachi. Sparse Named Entity Classification using Factorization Machines. In arXiv e-prints, 1703.04879 (5 pages). March 2017.
  • 2016/10/22 Our papers will be presented at COLING 2016 main conference and workshops. See you in Osaka!
    • Tomoyuki Kajiwara and Mamoru Komachi. Building a Monolingual Parallel Corpus for Text Simplification Using Sentence Similarity Based on Alignment between Word Embeddings. The 26th International Conference on Computational Linguistics (COLING 2016): Poster presentation.
    • Yasunobu Asakura, Masatsugu Hangyo and Mamoru Komachi. Disaster Analysis using User-Generated Weather Report. The 2nd Workshop on Noisy User-generated Text.
    • Takayuki Sato, Jun Harashima and Mamoru Komachi. Japanese-English Machine Translation of Recipe Texts. The 3rd Workshop on Asian Translation (WAT): Scientific papers (refereed).
    • Shin Kanouchi, Katsuhito Sudoh and Mamoru Komachi. Neural Reordering Model Considering Phrase Translation and Word Alignment for Phrase-based Translation. The 3rd Workshop on Asian Translation (WAT): Scientific papers (refereed).
    • Hayahide Yamagishi, Shin Kanouchi, Takayuki Sato and Mamoru Komachi. Controlling Voice in Japanese to English Neural Machine Translation. The 3rd Workshop on Asian Translation (WAT): System description papers (non-refereed).
  • 2016/05/27 Our paper has been accepted at ACL 2016 Student Research Workshop.
    • Tomonori Kodaira, Tomoyuki Kajiwara and Mamoru Komachi. Controlled and Balanced Dataset for Japanese Lexical Simplification. ACL SRW 2016.
  • 2016/04/04 New members joined our lab!
    • PhD student: Erika Ochiai (part-time)
    • Masters students: Masahiro Kaneko and Gaku Kuriu
    • Undergraduates: Yukio Matsumura, Tomoya Ogata, Hiraku Omori, Ayaha Osaki and Hayahide Yamagishi
    • Research student: Aizhan Imankulova (MEXT scholarship student)
  • 2016/03/10 One of our lab members (Ai Hirata) was awarded the Young Researcher Award of the 22th Annual Meeting of the Association for Natural Language Processing. Congratulations!
  • 2016/02/01 Our paper about gamification is accepted as poster (demo) at LREC.
    • Ryuichi Tachibana and Mamoru Komachi. Extraction of English Spelling Errors using a Word Typing Game. In Proceedings of The 10th Edition of the Language Resources and Evaluation Conference (LREC). Portoro┼ż, Slovenia, May 2016. (to appear)
  • 2015/10/16 Our poster paper about Japanese-English machine translation is up.
    • Junki Matsuo, Kenichi Ohwada and Mamoru Komachi. Source Phrase Segmentation and Translation for Japanese-English Translation Using Dependency Structure. In Proceedings of the 2nd Workshop on Asian Translation (WAT2015), pp.99-104. Kyoto, Japan, October 2015. (poster)
  • 2015/09/13 Our paper about sentiment classification using deep neural network has been accepted for oral presentation at PACLIC.
    • Peinan Zhang and Mamoru Komachi. Japanese Sentiment Classification with Stacked Denoising Auto-Encoder using Distributed Word Representation. The 29th Pacific Asia Conference on Language, Information and Computation (PACLIC 29).
  • 2015/08/01 Presented our work at ACL-IJCNLP 2015, one of the top conferences in the natural language processing.
    • Shin Kanouchi, Mamoru Komachi, Naoaki Okazaki (Tohoku University), Eiji ARAMAKI (Kyoto University) and Hiroshi Ishikawa. Who caught a cold? - Identifying the subject of a symptom. In Proceedings of the ACL-IJCNLP 2015 (long papers), pp.1660-1670. Beijing, China, July 2015. (acceptance rate = 25%)
    • Yoshiaki Kitagawa, Mamoru Komachi, Eiji ARAMAKI (Kyoto University), Naoaki Okazaki (Tohoku University) and Hiroshi Ishikawa. Disease Event Detection based on Deep Modality Analysis. In Proceedings of the ACL-IJCNLP 2015 Student Research Workshop, pp.28-34. Beijing, China, July 2015. (acceptance rate = 31%)
    • Tomoyuki Kajiwara and Kazuhide Yamamoto (Nagaoka University of Technology). Evaluation Dataset and System for Japanese Lexical Simplification. In Proceedings of the ACL-IJCNLP 2015 Student Research Workshop, pp.35-40. Beijing, China, July 2015. *This work was done while the first author was affiliated with Nagaoka University of Technology. (acceptance rate = 31%)
    • Yinchen Zhao, Mamoru Komachi and Hiroshi Ishikawa. Improving Chinese Grammatical Error Correction with Corpus Augmentation and Hierarchical Phrase-based Statistical Machine Translation. In Proceedings of the 2nd Workshop on Natural Language Processing Techniques for Educational Applications (NLP-TEA-2): Shared Task on Chinese Grammatical Error Diagnosis (CGED), pp.111-116. Beijing, China, July 2015.
  • 2015/04/01 New members joined are lab!
    • PhD students: Tomoyuki Kajiwara and Yui Suzuki (part-time)
    • Masters students: Yasunobu Asakura, Kanako Ikeda, Junki Matsuo and Takayuki Sato
    • Undergrad students: Tomonori Kodaira, Mahito Noguchi, Kento Shioda and Yuki Sekizawa
  • 2014/11/04 Welcomed two visiting students from National Chi Nan University, Taiwan.
  • 2014/10/21 Set up a GitHub organization for TMU-NLP Group. https://github.com/tmu-nlp
  • 2014/10/04 Presented a poster at the 1st Workshop on Asian Translation.
    • Kenichi Ohwada, Ryosuke Miyazaki and Mamoru Komachi. Predicate-Argument Structure-based Preordering for Japanese-English Statistical Machine Translation. In Proceedings of the 1st Workshop on Asian Translation (WAT), pp.44-49. Tokyo, Japan, October 2014.