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Weichao Zhou

8 accepted papers

2025

Constraint-Conditioned Actor-Critic for Offline Safe Reinforcement Learning

ICLR 2025poster

Offline safe reinforcement learning (OSRL) aims to learn policies with high rewards while satisfying safety constraints solely from data collected offline. However, the learned policies often struggle to handle states and actions that are not present or out-of-distribution (OOD) from the offline dat…

Cited by 0SourcePDFScholar
2025

Semantic Consistency-Based Uncertainty Quantification for Factuality in Radiology Report Generation

NAACL 2025findings

Radiology report generation (RRG) has shown great potential in assisting radiologists by automating the labor-intensive task of report writing. While recent advancements have improved the quality and coherence of generated reports, ensuring their factual correctness remains a critical challenge. Alt…

2024

HyQE: Ranking Contexts with Hypothetical Query Embeddings

EMNLP 2024finding

In retrieval-augmented systems, context ranking techniques are commonly employed to reorder the retrieved contexts based on their relevance to a user query. A standard approach is to measure this relevance through the similarity between contexts and queries in the embedding space. However, such simi…

2024

REGLO: Provable Neural Network Repair for Global Robustness Properties

AAAI 2024technical

We present REGLO, a novel methodology for repairing pretrained neural networks to satisfy global robustness and individual fairness properties. A neural network is said to be globally robust with respect to a given input region if and only if all the input points in the region are locally robust. Th…

2024

Rethinking Inverse Reinforcement Learning: from Data Alignment to Task Alignment

NeurIPS 2024poster

Many imitation learning (IL) algorithms use inverse reinforcement learning (IRL) to infer a reward function that aligns with the demonstration. However, the inferred reward functions often fail to capture the underlying task objectives. In this paper, we propose a novel framework for IRL-based IL th…

2024

Temporal Logic Specification-Conditioned Decision Transformer for Offline Safe Reinforcement Learning

ICML 2024poster

Offline safe reinforcement learning (RL) aims to train a constraint satisfaction policy from a fixed dataset. Current state-of-the-art approaches are based on supervised learning with a conditioned policy. However, these approaches fall short in real-world applications that involve complex tasks wit…

Cited by 2SourcePDFScholar
2022

A Hierarchical Bayesian Approach to Inverse Reinforcement Learning with Symbolic Reward Machines

ICML 2022spotlight

A misspecified reward can degrade sample efficiency and induce undesired behaviors in reinforcement learning (RL) problems. We propose symbolic reward machines for incorporating high-level task knowledge when specifying the reward signals. Symbolic reward machines augment existing reward machine for…