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Vincent Liu

6 accepted papers

2024

Exploiting Action Impact Regularity and Exogenous State Variables for Offline Reinforcement Learning (Abstract Reprint)

AAAI 2024technical

Offline reinforcement learning—learning a policy from a batch of data—is known to be hard for general MDPs. These results motivate the need to look at specific classes of MDPs where offline reinforcement learning might be feasible. In this work, we explore a restricted class of MDPs to obtain guaran…

Cited by 0SourcePDFScholar
2024

Switching the Loss Reduces the Cost in Batch Reinforcement Learning

ICML 2024poster

We propose training fitted Q-iteration with log-loss (FQI-LOG) for batch reinforcement learning (RL). We show that the number of samples needed to learn a near-optimal policy with FQI-LOG scales with the accumulated cost of the optimal policy, which is zero in problems where acting optimally achieve…

Cited by 6SourcePDFScholar
2023

Asymptotically Unbiased Off-Policy Policy Evaluation when Reusing Old Data in Nonstationary Environments

AISTATS 2023poster

In this work, we consider the off-policy policy evaluation problem for contextual bandits and finite horizon reinforcement learning in the nonstationary setting. Reusing old data is critical for policy evaluation, but existing estimators that reuse old data introduce large bias such that we can not…

Cited by 2SourcePDFScholar
2022

DABS 2.0: Improved Datasets and Algorithms for Universal Self-Supervision

NeurIPS 2022accept

Universal self-supervised (SSL) algorithms hold enormous promise for making machine learning accessible to high-impact domains such as protein biology, manufacturing, and genomics. We present DABS 2.0: a set of improved datasets and algorithms for advancing research on universal SSL. We extend the r…

2021

DABS: a Domain-Agnostic Benchmark for Self-Supervised Learning

NeurIPS 2021poster

Self-supervised learning algorithms, including BERT and SimCLR, have enabled significant strides in fields like natural language processing, computer vision, and speech processing. However, these algorithms are domain-specific, meaning that new self-supervised learning algorithms must be developed f…

Cited by 43SourcecodeScholar
2020

Training Recurrent Neural Networks Online by Learning Explicit State Variables

ICLR 2020poster

Recurrent neural networks (RNNs) allow an agent to construct a state-representation from a stream of experience, which is essential in partially observable problems. However, there are two primary issues one must overcome when training an RNN: the sensitivity of the learning algorithm's performance…

Cited by 6SourceScholar