← Search

Alistair Stewart

8 accepted papers

2021

Statistical Query Lower Bounds for List-Decodable Linear Regression

NeurIPS 2021spotlight

We study the problem of list-decodable linear regression, where an adversary can corrupt a majority of the examples. Specifically, we are given a set $T$ of labeled examples $(x, y) \in \mathbb{R}^d \times \mathbb{R}$ and a parameter $0< \alpha <1/2$ such that an $\alpha$-fraction of the points in $…

Cited by 26SourcePDFScholar
2019

A Polynomial Time Algorithm for Log-Concave Maximum Likelihood via Locally Exponential Families

NeurIPS 2019poster

We consider the problem of computing the maximum likelihood multivariate log-concave distribution for a set of points. Specifically, we present an algorithm which, given $n$ points in $\mathbb{R}^d$ and an accuracy parameter $\eps>0$, runs in time $\poly(n,d,1/\eps),$ and returns a log-concave dist…

Cited by 12SourcePDFScholar
2019

Outlier-Robust High-Dimensional Sparse Estimation via Iterative Filtering

NeurIPS 2019poster

We study high-dimensional sparse estimation tasks in a robust setting where a constant fraction of the dataset is adversarially corrupted. Specifically, we focus on the fundamental problems of robust sparse mean estimation and robust sparse PCA. We give the first practically viable robust estimators…

2019

Sever: A Robust Meta-Algorithm for Stochastic Optimization

ICML 2019oral

In high dimensions, most machine learning methods are brittle to even a small fraction of structured outliers. To address this, we introduce a new meta-algorithm that can take in a base learner such as least squares or stochastic gradient descent, and harden the learner to be resistant to outliers.…

2018

Robust Learning of Fixed-Structure Bayesian Networks

NeurIPS 2018poster

We investigate the problem of learning Bayesian networks in a robust model where an $\epsilon$-fraction of the samples are adversarially corrupted. In this work, we study the fully observable discrete case where the structure of the network is given. Even in this basic setting, previous learning a…

Cited by 37SourcePDFScholar
2018

Testing for Families of Distributions via the Fourier Transform

NeurIPS 2018poster

We study the general problem of testing whether an unknown discrete distribution belongs to a specified family of distributions. More specifically, given a distribution family P and sample access to an unknown discrete distribution D , we want to distinguish (with high probability) between the case…

Cited by 6SourcePDFScholar
2017

Being Robust (in High Dimensions) Can Be Practical

ICML 2017poster

Robust estimation is much more challenging in high-dimensions than it is in one-dimension: Most techniques either lead to intractable optimization problems or estimators that can tolerate only a tiny fraction of errors. Recent work in theoretical computer science has shown that, in appropriate distr…