Updates
| 2026 |
RetroReasoner, our reasoning LLM for strategic retrosynthesis prediction, is accepted to
Findings of EMNLP 2026. |
| 2026 |
MolDesignBench, our benchmark for evaluating LLM agents on scenario-grounded molecular
design, is accepted to COLM 2026. |
| 2025 |
Our hierarchical decomposition framework for the Steiner tree packing problem received the
Best Paper Award at ICORES 2025. |
| 2025 |
ReactionReasoner and Mol-LLM are both accepted to the NeurIPS 2025 Workshop on AI for
Science, on chemical reaction reasoning and structure-grounded molecular LLMs. |
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Research
My research is on AI for Science, primarily large language models for chemistry.
Three lines of work: eliciting explicit reasoning for retrosynthesis and reaction prediction;
grounding multimodal LLMs in molecular structure so that molecular graphs are used rather than
ignored; and building the data pipelines and benchmarks needed to train and evaluate these models on
realistic tasks.
I also work on neural combinatorial optimization for industrial problems such as circuit routing and
truck-and-drone delivery. In both areas I work on settings with real-world constraints — feasible
solutions that are hard to find, semi-structured data, and evaluation that reflects how a model would
actually be used.
First-author works are highlighted below.
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RetroReasoner: A Reasoning LLM for Strategic Retrosynthesis Prediction
Hanbum Ko, Chanhui Lee, Ye Rin Kim, Rodrigo S. Hormazabal, Sehui Han,
Sungbin Lim,
Sungwoong Kim
Findings of EMNLP, 2026
paper
Trains an LLM to reason explicitly about strategic bond disconnections — which bond to
break, and why — before proposing precursors, so a retrosynthesis prediction can be
inspected rather than merely ranked.
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MolDesignBench: Evaluating LLM-based Agent for Scenario-grounded Molecular Design
Yongjun Jeong, Hanbum Ko, Ye Rin Kim, Chanhui Lee, Rodrigo S. Hormazabal,
Jaewan Lee, Sehui Han,
Sungbin Lim,
Sungwoong Kim
Conference on Language Modeling (COLM), 2026
A benchmark that places LLM agents in scenario-grounded design tasks — an objective and its
constraints — and measures whether the molecules they propose actually satisfy them.
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ReactionReasoner: Towards Reasoning LLM for Chemical Reaction Prediction
Hanbum Ko, Chanhui Lee, Ye Rin Kim, Rodrigo S. Hormazabal, Sehui Han,
Sungbin Lim,
Sungwoong Kim
NeurIPS Workshop on AI for Science, 2025
paper
Rather than mapping reactants to products in a single pass, the model works through the
transformation step by step, which helps most where pattern matching over SMILES fails.
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Mol-LLM: Multimodal Generalist Molecular LLM with Improved Graph Utilization
Chanhui Lee, Hanbum Ko, Yuheon Song, Yongjun Jeong, Rodrigo S. Hormazabal,
Sehui Han, Kyunghoon Bae,
Sungbin Lim,
Sungwoong Kim
NeurIPS Workshop on AI for Science, 2025
arXiv
/
openreview
Multimodal molecular LLMs are given molecular graphs but rarely use them. Molecular
structure Preference Optimization (MolPO) optimizes preferences between correct and
perturbed structures, so the model exploits structure and outperforms both generalist and
specialist models on property and reaction prediction.
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Hierarchical Decomposition Framework for Steiner Tree Packing Problem
Hanbum Ko, Minu Kim, Honglak Lee,
Sungbin Lim, Sungryull Sohn, et al.
ICML Workshop on Sampling and Optimization in Discrete Space (SODS), 2023
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ICORES, 2025 (Best Paper Award)
paper
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ICORES version
Rectilinear Steiner tree packing, the problem behind circuit routing, is hard even to find a
feasible solution for. Our hierarchical optimizer decomposes it into high- and
low-level sub-problems with far smaller search spaces, then composes their solutions.
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Filling in the Gaps: LLM-Based Structured Data Generation from Semi-Structured Scientific Data
Hanbum Ko, Hongjun Yang, Sehui Han,
Sungwoong Kim,
Sungbin Lim, Kyunghoon Bae, Rodrigo S. Hormazabal
ICML Workshop on AI for Science, 2024
paper
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talk
A framework for gathering, augmenting, and restructuring unstructured scientific documents
with LLMs, applied to chemical reactions for document augmentation and knowledge-graph
completion.
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A Deep Reinforcement Learning Approach for Solving the Traveling Salesman Problem with Drone
Aigerim Bogyrbayeva, Taehyun Yoon, Hanbum Ko,
Sungbin Lim, Hyokun Yun, Changhyun Kwon
Transportation Research Part C: Emerging Technologies, vol. 148, 2023
paper
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journal
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code
A hybrid attention-encoder / LSTM-decoder model for routing a truck and a drone in tandem,
improving both solution quality and computation time over purely attention-based models.
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ReSPack: A Large-Scale Rectilinear Steiner Tree Packing Data Generator and Benchmark
Kanghoon Lee, Youngjoon Park, Han-Seul Jeong, Sunghoon Hong, Deunsol Yoon, Sungryull Sohn,
Minu Kim, Hanbum Ko, et al.
NeurIPS Workshop on SyntheticData4ML, 2022
paper
A generator and benchmark producing rectilinear Steiner tree packing instances at scale,
with controllable size and difficulty, for training and comparing learned routing solvers.
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SwarmSense: Effective and Resilient Drone Swarm and Search for Disaster Response and Management Application
Cheolmin Jeon, Jeongsoo Ha, Hanbum Ko, Byeongman Lee, Bo Ryu
The World Congress on ANBRE, 2019
A drone-swarm sensing and search system for disaster response, resilient to the loss of
individual drones.
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Augmenting Structure for Noise Reduction in UAV
Hanbum Ko, Yeeun Lee, Suyeon Jin, Emma Kang, Nick Noonan, Minsun Lee,
Michael J. Hopmeier, Eric T. Matson
The World Congress on ANBRE, 2019
Structural augmentations to a UAV airframe that reduce the noise it radiates in flight.
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Education
| Sep 2023 – Present |
Ph.D. in Artificial Intelligence,
Korea University
Advisors: Prof. Sungwoong Kim, Prof. Sungbin Lim |
| Mar 2021 – Aug 2023 |
M.S. in Artificial Intelligence,
UNIST
Advisor: Prof. Sungbin Lim |
| Mar 2014 – Feb 2021 |
B.S. in Computer Science and Engineering, minor in Statistics,
Chungnam National University
Study abroad at Purdue University, Dec 2018 – Jan 2019 |
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Experience
| Sep 2023 – Present |
Research & Teaching Assistant,
AGI Laboratory, Korea University |
| Sep 2023 – Aug 2024 |
Research Intern, Materials Intelligence Lab.,
LG AI Research
(Mentors: Rodrigo S. Hormazabal, Sehui Han) |
| Mar 2022 – Dec 2022 |
Research Intern, Advanced ML Lab.,
LG AI Research
(Mentors: Sungryull Sohn, Moontae Lee) |
| Mar 2021 – Aug 2023 |
Research & Teaching Assistant, LIM Laboratory,
UNIST |
| Mar 2019 – Feb 2021 |
Research Intern, EpiSys Science, Inc., Poway, CA, USA |
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Selected Projects & Awards
| 2023 – Present |
EXAONE Discovery Development · LG AI Research |
| 2022 |
PCB Auto Routing · LG AI Research & LG Electronics |
| 2021 |
NeurIPS 2021 Competition — Machine Learning for Combinatorial Optimization
2nd on the global leaderboard, 1st on the student leaderboard |
| 2019 – 2020 |
AlphaDogFight Trials (hosted by DARPA) · EpiSys Science, Inc. |
| 2020 |
Patent: System for Increasing Resolution of JPEG Compressed Image and Method Thereof
KR Reg. No. 10-2098375, assigned to CNU Industry-Academic Cooperation Foundation |
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