← Search

Chi-Guhn Lee

11 accepted papers

2026

Diverse and Sparse Mixture-of-Experts for Causal Subgraph–Based Out-of-Distribution Graph Learning

ICLR 2026poster

Current state-of-the-art methods for out-of-distribution (OOD) generalization lack the ability to effectively address datasets with heterogeneous causal subgraphs at the instance level. Existing approaches that attempt to handle such heterogeneity either rely on data augmentation, which risks alteri…

Cited by 0SourceScholar
2023

Recursive Time Series Data Augmentation

ICLR 2023poster

Time series observations can be seen as realizations of an underlying dynamical system governed by rules that we typically do not know. For time series learning tasks we create our model using available data. Training on available realizations, where data is limited, often induces severe over-fittin…

Cited by 18SourcePDFScholar
2022

Multi-policy Grounding and Ensemble Policy Learning for Transfer Learning with Dynamics Mismatch

IJCAI 2022poster

We propose a new transfer learning algorithm between tasks with different dynamics. The proposed algorithm solves an Imitation from Observation problem (IfO) to ground the source environment to the target task before learning an optimal policy in the grounded environment. The learned policy is deplo…

2021

A Marginal Log-Likelihood Approach for the Estimation of Discount Factors of Multiple Experts in Inverse Reinforcement Learning

IROS 2021poster

We focus on multiple experts performing a task in a Markov decision process (MDP) environment. A probabilistic assignment of trajectories to clusters and a mathematical framework which leverages the utility function are employed to jointly estimate the discount factor and reward. We treat the number…

Cited by 4SourceScholar
2021

Contextual policy transfer in reinforcement learning domains via deep mixtures-of-experts

UAI 2021poster

In reinforcement learning, agents that consider the context or current state when transferring source policies have been shown to outperform context-free approaches. However, existing approaches suffer from limitations, including sensitivity to sparse or delayed rewards and estimation errors in valu…

Cited by 10SourcePDFScholar
2021

Risk-Aware Transfer in Reinforcement Learning using Successor Features

NeurIPS 2021poster

Sample efficiency and risk-awareness are central to the development of practical reinforcement learning (RL) for complex decision-making. The former can be addressed by transfer learning, while the latter by optimizing some utility function of the return. However, the problem of transferring skills…

Cited by 26SourcePDFScholar
2019

Epsilon-BMC: A Bayesian Ensemble Approach to Epsilon-Greedy Exploration in Model-Free Reinforcement Learning

UAI 2019poster

Resolving the exploration-exploitation trade-off remains a fundamental problem in the design and implementation of reinforcement learning (RL) algorithms. In this paper, we focus on model-free RL using the epsilon-greedy exploration policy, which despite its simplicity, remains one of the most frequ…

Cited by 28SourcePDFScholar
2018

Reinforcement Learning with Multiple Experts: A Bayesian Model Combination Approach

NeurIPS 2018poster

Potential based reward shaping is a powerful technique for accelerating convergence of reinforcement learning algorithms. Typically, such information includes an estimate of the optimal value function and is often provided by a human expert or other sources of domain knowledge. However, this informa…

Cited by 32SourcePDFScholar