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Morteza Ibrahimi

5 accepted papers

2023

Approximate Thompson Sampling via Epistemic Neural Networks

UAI 2023poster

Thompson sampling (TS) is a popular heuristic for action selection, but it requires sampling from a posterior distribution. Unfortunately, this can become computationally intractable in complex environments, such as those modeled using neural networks. Approximate posterior samples can produce effec…

2023

Epistemic Neural Networks

NeurIPS 2023spotlight

Intelligence relies on an agent's knowledge of what it does not know. This capability can be assessed based on the quality of joint predictions of labels across multiple inputs. In principle, ensemble-based approaches can produce effective joint predictions, but the computational costs of large ense…

Cited by 144SourcePDFScholar
2022

The Neural Testbed: Evaluating Joint Predictions

NeurIPS 2022accept

Predictive distributions quantify uncertainties ignored by point estimates. This paper introduces The Neural Testbed: an open source benchmark for controlled and principled evaluation of agents that generate such predictions. Crucially, the testbed assesses agents not only on the quality of their ma…

2020

Hypermodels for Exploration

ICLR 2020poster

We study the use of hypermodels to represent epistemic uncertainty and guide exploration. This generalizes and extends the use of ensembles to approximate Thompson sampling. The computational cost of training an ensemble grows with its size, and as such, prior work has typically been limited to ense…

Cited by 58SourceScholar
2020

On Efficiency in Hierarchical Reinforcement Learning

NeurIPS 2020spotlight

Hierarchical Reinforcement Learning (HRL) approaches promise to provide more efficient solutions to sequential decision making problems, both in terms of statistical as well as computational efficiency. While this has been demonstrated empirically over time in a variety of tasks, theoretical results…

Cited by 53SourcePDFScholar