Hi! I am Jaeyong Ko, an M.S. student in Industrial Engineering at Seoul National University, advised by Prof. Pilsung Kang in the Data Science & Business Analytics Lab.
My research interests are in large language models, with a focus on mathematical reasoning, latent reasoning, and evaluation in the financial domain. I am currently interested in latent reasoning in vision-language models, especially how models reason beyond text-token reasoning traces.
Education
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Seoul National UniversityM.S. in Industrial EngineeringSep. 2025 - Present -
Seoul National UniversityB.S. in Industrial EngineeringMar. 2019 - Aug. 2025
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Cliff Tokens: Identifying Single-Token Failure Triggers in LLM Mathematical Reasoning
Jaeyong Ko, Pilsung Kang, Yukyung Lee
arXiv preprint arXiv:2606.25524 2026
Identifies single-token triggers that can sharply change the success or failure of LLM mathematical reasoning, supporting fine-grained analysis of reasoning reliability.
Cliff Tokens: Identifying Single-Token Failure Triggers in LLM Mathematical Reasoning
Jaeyong Ko, Pilsung Kang, Yukyung Lee
arXiv preprint arXiv:2606.25524 2026
Identifies single-token triggers that can sharply change the success or failure of LLM mathematical reasoning, supporting fine-grained analysis of reasoning reliability.
All publications
Research Experience
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Data Science & Business Analytics Lab, SNUMaster's StudentSep. 2025 - PresentAdvisor: Prof. Pilsung Kang
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Ecole Polytechnique de MontrealResearch InternApr. 2024 - Aug. 2024Advisor: Prof. Walid Jomaa- Human-centric smart manufacturing workcells for Industry 5.0 applications.
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Financial Engineering Lab, KAISTResearch InternDec. 2023 - Feb. 2024Advisor: Prof. Woo Chang Kim- Reinforcement learning applications for goal-based wealth management.
Projects
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Duo 2.0: Evaluating LLM Reliability in Long Financial ConversationsFinancial-domain conversational reliability benchmark and LLM-as-a-Judge evaluation.Granted by KakaobankDec. 2025 - Present -
Development of Advanced Integrated Monitoring Technologies for Laser WeldingLaser welding anomaly detection with time-series and image multi-modal data.Granted by LG ElectronicsJul. 2025 - Dec. 2025
Other Experience
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EXGRAMProduct Manager InternJul. 2022 - Oct. 2022Planned app configurations and push notifications for Veloo. -
SNU Startup Consulting Group (ACT)President & Team MemberMar. 2023 - Dec. 2023Led student consulting engagements and developed GTM strategies for startup clients. -
Republic of Korea ArmyCorporalJan. 2021 - Jul. 2022
Teaching
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Peer Tutoring, SNUCourse: Production Control (406.310)Sep. 2024 - Dec. 2024
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Peer Tutoring, SNUCourse: Human Factors Engineering (406.304)Sep. 2023 - Dec. 2023