IZUMI Tomonari
Keywords
Algorithm Theory, Graph Theory, Mathematical Optimization, Bandit Problems, Artificial Intelligence, Front-end Engineering, Cybersecurity, UI/UX Design
Hobbies
Cooking, Drawing, MathematicsSkills
Python, C, Java, Scheme, JavaScript, Ruby, PHP, Swift, HTML, CSS, Docker, Google Cloud, Google Apps Script, Microsoft Graph API, MySQL, LaTeX, Figma
Career
| 2002 | Born in Aomori City, Aomori Prefecture |
| Mar. 2015 | Graduated from Ryouun Elementary School Asahikawa City, Hokkaido |
| Mar. 2018 | Graduated from Niiza Daini Junior High School, Saitama Prefecture |
| Mar. 2023 | Graduated from the Course in the Field of Information Engineering, Smart Mechanics Course, Department of Creative Engineering, National Institute of Technology (KOSEN), Kushiro College |
| Mar. 2023 | Completed the Advanced Course of Electronic and Information Systems Engineering, National Institute of Technology (KOSEN), Kushiro College |
| Apr. 2025 | Enrolled in the Graduate School of Information Science and Technology, Hokkaido University |
Part-time Work Experience
| Aug.-Dec. 2022 | Shika Holdings Inc. | Software Engineer |
| Jun. 2023-Apr. 2024 | K-HACK Inc. | Software Engineer |
| Nov. 2023-Current | Sigma-i Co., Ltd. | Researcher |
Activities
| Sep. 2018 | Participated in the Doto × IoT Hackathon | Proposed an SMS (Shelter Management System) utilizing Kintone and motion sensors |
| Sep. 2018 | Competed in the U-16 Programming Contest Kushiro Tournament | Placed 4th with a Ruby-based agent competition program |
| Oct. 2021 | Participated in Micro Hardening for Youth 2021 | Engaged in hands-on exercises defending a virtual e-commerce site against cyberattacks |
| Dec. 2021 | Attended the K-SEC Security Winter School 2021 | Studied cyberattacks and defense in a virtual environment |
| Feb. 2022 | Participated in the Cybersecurity “Top Gun Training” | Engaged in hands-on exercises on CSIRT incident response and cyberattack log analysis |
| Jun. 2022 | Participated in Startup Weekend Kushiro | Awarded 3rd place for proposing a business model for a bereavement notification app |
| Jan.–May 2023 | Participated in "Quantum Annealing for You 2nd Party!" | Developed a home care shift optimization app using quantum annealing |
| Mar. 2023 | Participated in Hakodate KOSEN Global Seminar 2023 | Received the Best Presentation Award for proposing an online shop for recyclable food waste addressing food loss issues |
| 2024–2025 | Participated in the KIC (KOSEN Incubate Committee) Project | Contributed to a project developing an add-on device for small snowplows using FM-CW radar to detect obstacles in snow |
| Sep.–Dec. 2024 | Studied abroad at Turku University of Applied Sciences, Finland | Took courses in ICT and Industrial Management, ICT Projects, and Cybersecurity |
| Mar. 2025 | Participated in the Hokkaido University × KOSEN Ideathon | Worked on building a DX system to centralize diverse and complex support for crime victims across institutions |
| Apr.–Aug. 2025 | Participated in the Global Consumer Intelligence (GCI) 2025 Summer | Studied the basics of AI and business problem-solving through data science |
| Jul. 2025–Present | Participating in DGM Summer 2025 (Deep Generative Models) | An intensive hands-on course covering generative models, from fundamentals to advanced diffusion models |
| Jul. 2025–Present | Participating in RL Summer 2025 (Deep Reinforcement Learning) | A short-term intensive course on deep reinforcement learning, covering theory and applications (robotics, game AI, finance) |
| Aug. 2025–Present | Participating in Finance Summer 2025 (Financial Markets and Machine Learning) | An intensive course covering the foundations of financial markets and applications of machine learning in finance |
| Sep. 6–20, 2025 | Participated in Engineer Guild Hackathon | Awarded 3rd place for the the development of “holo” — a new walking map app powered by an AI camera and user questions |
| Nov. 2025 | Exhibiting at Geekten 2025 (Tech-Youth Exhibition) | Participation in the preliminary competition and the development of “holo” — a new walking map app powered by an AI camera and user questions |
Awards
| Mar. 2023 | Received the Excellent Academic Award at Advanced Technologies for SDGs |
Conference Presentations
- Development of an Efficient Algorithm for Identifying the Maximum Detour Hinge Vertex in Networks with Trapezoid Graph Structures, Tomonari Izumi*, Yoko Nakajima, Hirotoshi Honma, The Operations Research Society of Japan 2024 Spring Conference, pp.96-97, Tsukuba City, Mar. 2024.
- Development of an Efficient Algorithm for Identifying the Maximum Detour Hinge Vertex in Trapezoid Graphs, Tomonari Izumi*, Yoko Nakajima, Hirotoshi Honma, Toshihiro Fujito, Hyper Interdisciplinary Conference Hokkaido Forum 2023, Sapporo City, Sep. 2023.
- Development of a Graph Algorithm Aimed at Reducing Maintenance Costs in Lifeline Networks with Intersection Graph Structures, Tomonari Izumi*, Hirotoshi Honma, Yoko Nakajima, Toshihiro Fujito, Advanced Technologies for SDGs, Toyohashi University of Technology, Mar. 2023.
- Algorithm for Maximum Detour Hinge Vertices problem of Trapezoid Graphs, Tomonari Izumi*, Hirotoshi Honma, Yoko Nakajima, The 7th International Conference on Science of Technology Innovation (STI-Gigaku202), STI-9-9, pp.81, Nagaoka, Nov., 2022.
- Algorithm for Detour Hinge Vertex Problem of Circular-arc Graphs, Tomonari Izumi*, Syoma Nameki, Yoko Nakajima, Hirotoshi Honma, Toshihiro Fujito, The 41st JSST Annual International Conference on Simulation Technology (JSST2022), Student Session, pp.29-32, Iizuka, Sep., 2022.
Publications
- An Efficient Algorithm for the Detour Hinge Vertex Problem on Trapezoid Graphs, Tomonari Izumi, Yoko Nakajima, Tomoyosi Akiba, Takashi Yukawa, Hirotoshi Honma, IEICE Trans. Fundamentals, 2026, Accepted for publication.
- Algorithm for Solving the Detour Hinge Vertex Problem on Circular-arc Graphs, Yoko Nakajima, Shoma Nameki, Tomonari Izumi, Hirotoshi Honma, Journal of Engineering and Digital Technology, Vol.11, No.1, pp.1-7, 2023.