collaborators

7 papers

cs.LG2026

Neglected Free Lunch from Post-training: Progress Advantage for LLM Agents

Changdae Oh, Wendi Li, Seongheon Park +3

Process reward models enable fine-grained, step-level evaluation of LLMs, yet building them for agentic settings remains prohibitively difficult: long-horizon interactions, irrever…

cs.RO2026

Hide-and-Seek in Trajectories: Discovering Failure Signals for VLA Runtime Monitoring

Seongheon Park, Wendi Li, Changdae Oh +4

Vision-Language-Action (VLA) models enable robots to follow natural language instructions and generalize across diverse tasks, but they remain vulnerable to execution failures that…

cs.CL2026

How Do Transformers Learn to Associate Tokens: Gradient Leading Terms Bring Mechanistic Interpretability

Shawn Im, Changdae Oh, Zhen Fang +1

Semantic associations such as the link between "bird" and "flew" are foundational for language modeling as they enable models to go beyond memorization and instead generalize and g…

cs.AI2026

Uncertainty Quantification in LLM Agents: Foundations, Emerging Challenges, and Opportunities

Changdae Oh, Seongheon Park, To Eun Kim +8

Uncertainty quantification (UQ) for large language models (LLMs) is a key building block for safety guardrails of daily LLM applications. Yet, even as LLM agents are increasingly d…

cs.LG2026

General Exploratory Bonus for Optimistic Exploration in RLHF

Wendi Li, Changdae Oh, Sharon Li

Optimistic exploration is central to improving sample efficiency in reinforcement learning with human feedback, yet existing exploratory bonus methods to incentivize exploration of…

cs.LG2026

Understanding Language Prior of LVLMs by Contrasting Chain-of-Embedding

Lin Long, Changdae Oh, Seongheon Park +1

Large vision-language models (LVLMs) achieve strong performance on multimodal tasks, yet they often default to their language prior (LP) -- memorized textual patterns from pre-trai…