Hajime Kiyama / 木山 朔 

Research interests

• Computational Linguistic / Natural Language Processing

  • Language Change

  • Resources and Evaluation

• Machine Learning

  • Embedding Representation

Selected Publications

Jounal

• Hajime Kiyama, Taichi Aida, Mamoru Komachi, Toshinobu Ogiso, Hiroya Takamura, Daichi Mochihashi
  Analyzing Word Semantic Shifts with Diachronic Similarity Matrices.
  Journal of Natural Language Processing (In Japanese), Vol.32, No.4, December, 2025. [paper] [poster] [slide] [article] [Best Paper Award]

International conference

• Mio Ohashi, Hajime Kiyama, Zhidong Ling, Mamoru Komachi.
  LLM-based Literal Example Generation for Japanese Multiword Expressions.
  The 64th Annual Meeting of the Association for Computational Linguistics Student Research Workshop (ACL SRW 2026). July, 2026. (130/402, 34.7%) [paper] [Oral, 12/130]

• Mao Shimada, Hajime Kiyama, Zhidong Ling, Mamoru Komachi, Toshinobu Ogiso, Hiroya Takamura, Daichi Mochihashi.
  Neural KWIC: Inducing Contextualized Word Embeddings from KWIC Concordance Examples.
  The 64th Annual Meeting of the Association for Computational Linguistics Student Research Workshop (ACL SRW 2026). July, 2026. (130/402, 34.7%, non-archival) [Oral, 12/130]

• Iori Yamashita, Hikari Tanaka, Hajime Kiyama, Kexin Bian, Zhousi Chen, Mamoru Komachi.
  Evaluation of Document-Level Text Simplification in Japanese.
  Proceedings of the Fifteenth Language Resources and Evaluation Conference (LREC 2026). May, 2026. (944/1786, 52.9%) [paper]

• Hajime Kiyama, Taichi Aida, Mamoru Komachi, Toshinobu Ogiso, Hiroya Takamura, Daichi Mochihashi.
  Analyzing Continuous Semantic Shifts with Diachronic Word Similarity Matrices.
  Proceedings of the 31th International Conference on Computational Linguistics (COLING 2025). January, 2025. (853/2723, 31.3%) [arXiv] [paper] [slide]

Selected Awards

• 2026.06 Outstanding Paper Award (1/12) 

  • The 268nd Special Interest Group on Natural Language Processing of the Information Processing Society of Japan [link]

• 2026.03 Best Paper Award (3/33)

  • Journal of Natural Language Processing in FY2025  [link] [comment] [atricle] [selection]

• 2024.12 Outstanding Paper Award (2/18) 

  • The 262nd Special Interest Group on Natural Language Processing of the Information Processing Society of Japan [link]

• 2023.03 Best Student Award (GPA:3.66/4.00,  146/128 credit) 

  • Tokyo Metropolitan University, Faculty of System Design, Department of Computer Science [link] [grade]

• 2022.03 Young Researcher Encouragement Award (12/280) 

  • The 28th Annual Meeting of the Association for Natural Language Processing (Japan) [link]

Experience

• 2026.08 - 2026.09：Future Corporation, Research Camp Intern

  • Project of NLP research

• 2026.05 - 2026.08：University of Liverpool, Visiting Research Student

  • Natural Language Processing Group

  • Advisor: Prof. Danushka Bollegala

• 2025.09 -  Present：Shogakukan Inc. ,  Contract Research

  • Project of Nihon Kokugo Daijiten 3rd edition

• 2025.07 -  2026.03：Hitotsubashi University, Research Assistant 

  • Research Assistant in a Laboratory

• 2025.04 - Present：National Institute for Japanese Language and Linguistics, Collaborative Researcher

  • Extending the Diachronic Corpus through an Open Co-construction Environment

• 2025.04 - 2025.05：Hitotsubashi University, Teaching Assistant 

  • Teaching Assistant at Programming 1

• 2024.11 - 2025.06 ：Hitotsubashi University, Contract Research

  • Research Assistant in a Laboratory

• 2024.04 - 2024.07：Tokyo Metropolitan University, Teaching Assistant

  • Teaching Assistant at NLP 100 Knock  

• 2023.08 - 2024.02：Hitotsubashi University, Contract Research  

  • Evidence-Based Survey and Analysis of Important Scientific and Technological Fields

• 2023.09 - 2023.10：Recruit Co., Data Specialist Intern 

  • Project of Recommendation System

• 2023.09  ( 2weeks )：Chura DATA Inc, Data Scientist Intern 

  • Project of LLM based Grammatical Error Correction

• 2023.04 - 2023.07：Tokyo Metropolitan University, Teaching Assistant 

  • Teaching Assistant at NLP 100 Knock  

Academic Activities

Scholarship/Grant

• 2026.04 - 2028.03. Japan Society for the Promotion of Science "Research Fellowship for Young Scientists" (JSPS DC2)

  • 227,000 yen / month (Scholarship)

  • 1,500,000 yen (Grant)

• 2025.04 - 2026.03.  “The Bridge to the Future” Doctoral Innovation Human Resource Development Project, Hitotsubashi University (JST SPRING)

  • 180,000 yen / month (Scholarship)

  • 300,000 yen / year (Grant)

Committee

• 2025.01 - 2026.12.  YANS Symposium

• 2025.10 - Present.  CL Nomadic

• 2026.03.  NLP2026 theme session "Computational Linguistics at the tug of war"