activity
20242026
most citedLasso Bandit with Compatibility Condition on Optimal Arm

1 citations · 2 across the 15 of their papers we have counts for

collaborators

16 papers

cs.LG2026

Latent Representation Alignment for Offline Goal-Conditioned Reinforcement Learning

Hyungkyu Kang, Byeongchan Kim, Min-hwan Oh

Offline goal-conditioned reinforcement learning (GCRL) provides a practical framework for obtaining goal-reaching policies from fixed datasets. However, learning a reliable goal-co…

stat.ML2026

Nonstationary Generalized Linear Bandits with Discounted Online Mirror Descent

Joongkyu Lee, Min-hwan Oh

We study nonstationary generalized linear bandits (GLBs), where the expected reward is modeled through a nonlinear link function with an unknown time-varying parameter. This framew…

cs.LG2026

Multi-Step Likelihood-Ratio Correction for Reinforcement Learning with Verifiable Rewards

Deokgyu Yoon, Hyungkyu Kang, Joongkyu Lee +4

Reinforcement learning with verifiable rewards (RLVR) plays a pivotal role in improving the reasoning ability of large language models. However, widely used PPO surrogate objective…

cs.LG2026

Block-Sphere Vector Quantization

Heesang Ann, Joongkyu Lee, Min-hwan Oh

Vector quantization is a fundamental primitive for scalable machine learning systems, enabling memory-efficient storage, fast retrieval, and compressed inference. Recent rotation-b…

cs.LG2026

Peng's Q() for Conservative Value Estimation in Offline Reinforcement Learning

Byeongchan Kim, Min-hwan Oh

We propose a model-free offline multi-step reinforcement learning (RL) algorithm, Conservative Peng's Q() (CPQL). Our algorithm adapts the Peng's Q() (PQL) operator for conse…

cs.LG2026

RelFlexformer: Efficient Attention 3D-Transformers for Integrable Relative Positional Encodings

Byeongchan Kim, Arijit Sehanobish, Avinava Dubey +2

We present a new class of efficient attention mechanisms applying universal 3D Relative Positional Encoding (RPE) methods given by arbitrary integrable modulation functions . Th…

stat.ML2026

Optimal Design for Multinomial Logit Model with Applications to Best Assortment Identification

Joongkyu Lee, Min-hwan Oh

We study optimal experimental design for multinomial logit (MNL) bandits, where an agent repeatedly selects a subset of items from a ground set of size and observes single-…

cs.LG2025

Exploration via Feature Perturbation in Contextual Bandits

Seouh-won Yi, Min-hwan Oh

We propose feature perturbation, a simple yet effective exploration strategy for contextual bandits that injects randomness directly into feature inputs, instead of randomizing unk…

cs.LG2025

Preference-based Reinforcement Learning beyond Pairwise Comparisons: Benefits of Multiple Options

Joongkyu Lee, Seouh-won Yi, Min-hwan Oh

We study online preference-based reinforcement learning (PbRL) with the goal of improving sample efficiency. While a growing body of theoretical work has emerged-motivated by PbRL'…

stat.ML2025

Combinatorial Reinforcement Learning with Preference Feedback

Joongkyu Lee, Min-hwan Oh

In this paper, we consider combinatorial reinforcement learning with preference feedback, where a learning agent sequentially offers an action--an assortment of multiple items to--…

stat.ML2025

Improved Online Confidence Bounds for Multinomial Logistic Bandits

Joongkyu Lee, Min-hwan Oh

In this paper, we propose an improved online confidence bound for multinomial logistic (MNL) models and apply this result to MNL bandits, achieving variance-dependent optimal regre…

stat.ML2024

Demystifying Linear MDPs and Novel Dynamics Aggregation Framework

Joongkyu Lee, Min-hwan Oh

In this work, we prove that, in linear MDPs, the feature dimension is lower bounded by in order to aptly represent transition probabilities, where is the size of the…

stat.ML2024★ 1 cited

Lasso Bandit with Compatibility Condition on Optimal Arm

Harin Lee, Taehyun Hwang, Min-hwan Oh

We consider a stochastic sparse linear bandit problem where only a sparse subset of context features affects the expected reward function, i.e., the unknown reward parameter has a…

stat.ML2024

Randomized Exploration for Reinforcement Learning with Multinomial Logistic Function Approximation

Wooseong Cho, Taehyun Hwang, Joongkyu Lee +1

We study reinforcement learning with multinomial logistic (MNL) function approximation where the underlying transition probability kernel of the Markov decision processes (MDPs) is…

stat.ML2024

Nearly Minimax Optimal Regret for Multinomial Logistic Bandit

Joongkyu Lee, Min-hwan Oh

In this paper, we study the contextual multinomial logit (MNL) bandit problem in which a learning agent sequentially selects an assortment based on contextual information, and user…

cs.LG2024★ 1 cited

Learning Uncertainty-Aware Temporally-Extended Actions

Joongkyu Lee, Seung Joon Park, Yunhao Tang +1

In reinforcement learning, temporal abstraction in the action space, exemplified by action repetition, is a technique to facilitate policy learning through extended actions. Howeve…