Yota Otachi

Current Position and Address

Professor.
Department of Mathematical and Computing Science, School of Computing, Institute of Science Tokyo.
W8-54, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8552, Japan

Research Interests

Graph Algorithms, Fixed-Parameter Tractability, Algorithmic Graph Theory.

Occupation

October 2026 - present: Professor at Institute of Science Tokyo
March 2020 - September 2026: Associate Professor at Nagoya University
May 2017 - February 2020: Associate Professor at Kumamoto University
April 2012 - April 2017: Assistant Professor at JAIST
April 2011 - March 2012: Assistant Professor at Tohoku University
April 2010 - March 2011: JSPS Research Fellow (PD) at Tohoku University
April 2009 - March 2010: JSPS Research Fellow (DC2) at Gunma University

August 2015 - January 2016: Visiting Researcher at Simon Fraser University

Education

Ph.D. in Engineering, Gunma University, 2010.
M.E. in Computer Science, Gunma University, 2007.
B.E. in Computer Science, Gunma University, 2005.

Ph.D. thesis: Treewidth and related graph parameters
Supervised by Prof. Koichi Yamazaki

Research Activities

Publications

See journal papers and proceedings. See also my dblp, Google Scholar, and ORCID iD entries.

Awards

• Best Paper Award, WALCOM 2024, March 2024
  Title: Structural parameterizations of vertex integrity
  Authors: Tatsuya Gima, Tesshu Hanaka, Yasuaki Kobayashi, Ryota Murai, Hirotaka Ono, and Yota Otachi
• JSAI Incentive Award, June 2021
  Title: Algorithms for finding diverse subgraphs
  Authors: Tesshu Hanaka, Yasuaki Kobayashi, Kazuhiro Kurita, and Yota Otachi
• IPSJ Yamashita SIG Research Award, March 2019
  Title: Space-efficient algorithms for longest increasing subsequence
  Authors: Masashi Kiyomi, Hirotaka Ono, Yota Otachi, Pascal Schweitzer, and Jun Tarui
• The 16th EATCS/LA Presentation Award, February 2018
  Title: Space-efficient algorithms for longest increasing subsequence
  Authors: Masashi Kiyomi, Hirotaka Ono, Yota Otachi, Pascal Schweitzer, and Jun Tarui
• The 15th EATCS/LA Presentation Award, February 2017
  Title: A faster parameterized algorithm for Pseudoforest Deletion
  Authors: Hans L. Bodlaender, Hirotaka Ono, and Yota Otachi
• JAIST President Award, October 2015.
• IPSJ Computer Science Research Award for Young Scientists, September 2011
  Title: Spanning tree congestion of $k$-outerplanar graphs
  Authors: Hans L. Bodlaender, Kyohei Kozawa, Takayoshi Matsushima, and Yota Otachi

Student Awards

• Best Student Paper Award, IWOCA 2026, June 2026.
  Title: Minimum Clique Bicoloring.
  Authors: Shunsuke Hamada, Yuto Okada, Hirotaka Ono, Yota Otachi.
• Best Student Paper Award, WALCOM 2026, March 2026.
  Title: Forcing a unique minimum spanning tree and a unique shortest path.
  Authors: Tatsuya Gima, Yasuaki Kobayashi, Yota Otachi, Takumi Sato.
• Best Student Paper Award, SOFSEM 2023, January 2023.
  Title: Sequentially swapping tokens: Further on graph classes.
  Authors: Hironori Kiya, Yuto Okada, Hirotaka Ono, Yota Otachi.

Grants

• April 2025 - March 2030: JSPS Grant-in-Aid for Scientific Research (B)
  [25K03076] Practical Algorithm Generation through Diversification of Graph Decomposition Techniques and Problem Description Rules
• April 2021 - March 2026: JSPS Grant-in-Aid for Scientific Research (C)
  [21K11752] Refining the graph parameter hierarchy for fine-grained algorithms
• April 2019 - March 2021 March 2022 (extended): Bilateral Program (CNRS, France)
  [JPJSBP 120192912] PARAGA - Parameterized Approximation Graph Algorithms
• April 2018 - March 2021 March 2022 (extended): JSPS Grant-in-Aid for Scientific Research (C)
  [18K11168] Speeding up FPT algorithms with special tree decompositions
• September 2018: Bilateral Program Seminar (NWO, The Netherlands)
  Computations on Networks with a Tree-Structure: From Theory to Practice
• April 2017 - March 2019: Bilateral Program (MAEDI, Sakura Program, France)
  [38593YJ] GRAPA - Graph Algorithms for Parameterized Approximation
• April 2013 - March 2016: JSPS Grant-in-Aid for Young Scientists (B)
  [25730003] Fixed width parameter algorithms for the graph isomorphism problem
• September 2011 - March 2013: JSPS Grant-in-Aid for Research Activity Start-up
  [23800004] Designing low-congestion sparse networks
• April 2009 - March 2011: JSPS Research Fellowship for Young Scientists
  [21-6878] Treewidth and related graph parameters

Program Committee Member

• The 52nd International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2026). June 2-4, 2026 in Kortrijk, Belgium.
• The 20th International Symposium on Parameterized and Exact Computation (IPEC 2025). September 17-19, 2025, Warsaw, Poland.
• The 25th Japan-Korea Joint Workshop on Algorithms and Computation (WAAC 2025). August 19-20, 2025, in Sapporo, Japan.
• The 31st International Computing and Combinatorics Conference (COCOON 2025). August 15-17, 2025, in Chengdu, China.
• The 24th Korea-Japan Joint Workshop on Algorithms and Computation (WAAC 2024). August 2-3, 2024, in Seoul, Korea.
• The 19th Scandinavian Symposium on Algorithm Theory (SWAT 2024). June 12-14, 2024, in Helsinki, Finland.
• The 18th International Conference and Workshops on Algorithms and Computation (WALCOM 2024). March 18-20, 2024, in Kanazawa, Japan.
• The 23rd Japan-Korea Joint Workshop on Algorithms and Computation (WAAC 2023). June 24-25, 2023, in Nagoya, Japan.
• The 48th International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2022). June 22-24, 2022 in Tübingen, Germany.
• The 32nd International Symposium on Algorithms and Computation (ISAAC 2021). December 6-8, 2021 in Fukuoka, Japan.
• The 14th International Frontiers of Algorithmics Workshop (FAW 2020). May 29-31, 2020 in Haikou, China.
• The 14th International Symposium on Parameterized and Exact Computation (IPEC 2019). September 11-13, 2019 in Munich, Germany.
• The 11th International Conference on Algorithms and Complexity (CIAC 2019). May 27-29, 2019 in Rome, Italy.
• The 1st Computational Intelligence in Information Systems (CIIS 2016), Special Session on Computational Complexity and Algorithms (SoCCA). November 18-20, 2016 in Bandar Seri Begawan, Brunei Darussalam.
• The 42nd International Workshop on Graph-Theoretic Concepts in Computer Science (WG 2016). June 22-24, 2016 in İstanbul, Turkey.
• The 12th Annual Conference on Theory and Applications of Models of Computation (TAMC 2015). May 18-20, 2015 in Singapore.

Editorial Work

• Editor of IEICE Transactions (A) English and Japanese Editions. May 2013 - May 2017.

Membership

• IEICE - The Institute of Electronics, Information and Communication Engineers
• IPSJ - Information Processing Society of Japan
• LA Symposium