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Changyeol Lee

Graduate student studying Computer Science at Yonsei Univ.
Combinatorial Optimization Lab (Advisor - Prof. Hyung-Chan An)
Email - changyeollee_at_yonsei.ac.kr or 777john_at_yonsei.ac.kr

RESEARCH INTERESTS

  • Approximation Algorithm
  • Online Algortihm
  • Learning-augmented Algorithm
  • Combinatorial Optimization
  • Miscellaneous (Theoretical Computer Science, Game Theory and Mechanism Design, Quantum algorithms)

EDUCATION

  • Ph.D student at Yonsei Univserity (advised by Prof. Hyung-Chan An)
  • B.S. in Computer Science, Yonsei Univ. (2017.03-2021.02)

TEACHING EXPERIENCE

  • Teaching Assistent @ Yonsei Univ. Algorithm Analysis CSI3108 (Fall 2021, Fall 2023)
  • Teaching Assistent @ Yonsei Univ. Data Structures (Spring 2021, Spring 2023)
  • Tutor @ Yonsei Univ. Algorithm Analysis CSI3108 (Fall 2019, Fall 2020)
  • Tutor @ Yonsei Univ. Linear Algebra MAT2011 (Spring 2019)
  • Peer Mentor (Head Mentor) @ Yonsei-Nexon RC Creative Platform (2018-2020)

AWARDS

  • High honors at (B.S.) graduation @ Yonsei Univ. (2021.02)
  • RC Creative Platform Grand Prize, Yonsei Univ. & NEXON Co., Ltd. (2017.11)

RESEARCH EXPERIENCE

  • 2025.12.13 – 2025.12.18

    Gave a talk at FOCS 2025 (The 66th Annual Symposium on Foundations of Computer Science, Session 10A)

  • 2025.12.2 – 2025.12.7

    Presented a poster at NeurIPS 2025 (The 39th Annual Conference on Neural Information Processing Systems)

  • 2025.6.15 – 2025.6.21

    Visited University of Wrocław, Poland, and gave a talk on LP rounding algorithm for hierarchical correlation clustering and ultrametric violation distance at C⚙G seminar
    Invited by professor Jarosław Byrka

  • 2025.1.2 – 2025.1.4

    Co-organized Workshop on Algorithm for Students (WAS 2025)
    (See - link)

  • 2024.10.23 – 2024.10.26

    Visited National Yang-Ming Chiao-Tung University (NYCU), Taiwan
    Invited by professor Mong-Jen Kao

  • 2024.8.2 – 2024.8.3

    Speaker at WAAC 2024 (The 24th Korea-Japan Joint Workshop on Algorithms and Computation)
    Talk on learning-augmented algorithms for multi-option ski-rental (See - link)

  • 2024.03. – current

    Co-organizer of Yonsei CS Theory Student Group(link)
    (with Sungmin Kim)

  • 2023.10.27 – 2023.10.28

    Speaker at FWAC 2023 (3rd Fall Workshop on Algorithms and Computation)
    Talk on learning-augmented algorithms for multi-option ski-rental (See the program book - link)

  • 2023.10.27 – 2023.10.28

    Presented a poster at ICML 2023 (The 40th International Conference on Machine Learning)

  • 2022.09. – 2022.10.

    Visiting Research Intern, Cornell University, advised by professor David Shmoys

  • 2018.12. – 2021.02.

    Research Intern, Yonsei University, advised by professor Hyung-Chan An

RECENT PUBLICATIONS

[All Publications]
  1. Handling LP-Rounding for Hierarchical Clustering and Fitting Distances by Ultrametrics
    An, Hyung-Chan, Kao, Mong-Jen,  Lee, Changyeol, and Lee, Mu-Ting
    In IEEE 66th Annual Symposium on Foundations of Computer Science (FOCS), Dec, 2025
  2. Improved Algorithms for Overlapping and Robust Clustering of Edge-Colored Hypergraphs: An LP-Based Combinatorial Approach
    Lee, Changyeol, Shin, Yongho, and An, Hyung-Chan
    In The Thirty-ninth Annual Conference on Neural Information Processing Systems (NeurIPS), Dec, 2025
  3. Improved Learning-Augmented Algorithms and (Tight) Lower Bounds for Multi-Option Ski Rental Problem
    Shin, Yongho,  Lee, Changyeol, Lee, Gukryeol, and An, Hyung-Chan
    ACM Transactions on Algorithms (TALG), vol. 22, Nov, 2025
  4. Chromatic correlation clustering via cluster LP
    Abbasi, Fateme, An, Hyung-Chan, Byrka, Jarosław,  Lee, Changyeol, and Shin, Yongho
    arXiv preprint arXiv:2510.13446, Oct, 2025
  5. Improved Learning-Augmented Algorithms for the Multi-Option Ski Rental Problem via Best-Possible Competitive Analysis
    Shin, Yongho,  Lee, Changyeol, Lee, Gukryeol, and An, Hyung-Chan
    In Proceedings of the 40th International Conference on Machine Learning (ICML), vol. 202, pp. 31539–31561, Jul, 2023
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