Two Facets of Learning Robust Models: Fundamental Limits and Generalization to Natural Out-of-Distribution Inputs

November 06, 2020, Zoom

Hamed Hassani

UPenn, Electrical Engineering

Abstract

In this talk, we will focus on the recently-emerged field of (adversarially) robust learning. The talk will be self-contained and no particular background on robust learning will be needed. The field began by the observation that modern learning models, despite the breakthrough performance, remain fragile to seemingly innocuous changes in the data such as small, norm-bounded perturbations of the input data. In response, various training methodologies have been developed for enhancing robustness. However, it is fair to say that our understanding in this field is still at its infancy and several key questions remain widely open. We will consider two such questions. In this talk, we will focus on the recently-emerged field of (adversarially) robust learning. The talk will be self-contained and no particular background on robust learning will be needed. The field began by the observation that modern learning models, despite the breakthrough performance, remain fragile to seemingly innocuous changes in the data such as small, norm-bounded perturbations of the input data. In response, various training methodologies have been developed for enhancing robustness. However, it is fair to say that our understanding in this field is still at its infancy and several key questions remain widely open. We will consider two such questions. (2) Robustness to other types of out-of-distribution inputs: There are other sources of fragility for deep learning that are arguably more common and less studied. Indeed, natural variation such as lighting or weather conditions or device imperfections can significantly degrade the accuracy of trained neural networks, proving that such natural variation presents a significant challenge. To this end, in the second part of the talk we propose a paradigm shift from perturbation-based adversarial robustness toward a new framework called "model-based robust deep learning". Using this framework, we will provide general training algorithms that improve the robustness of neural networks against natural variation in data. We will show the success of this framework to improve robustness of modern learning models consistently against many types of natural out-of-distribution inputs and across a variety of commonly-used datasets. (2) Robustness to other types of out-of-distribution inputs: There are other sources of fragility for deep learning that are arguably more common and less studied. Indeed, natural variation such as lighting or weather conditions or device imperfections can significantly degrade the accuracy of trained neural networks, proving that such natural variation presents a significant challenge. To this end, in the second part of the talk we propose a paradigm shift from perturbation-based adversarial robustness toward a new framework called "model-based robust deep learning". Using this framework, we will provide general training algorithms that improve the robustness of neural networks against natural variation in data. We will show the success of this framework to improve robustness of modern learning models consistently against many types of natural out-of-distribution inputs and across a variety of commonly-used datasets.

Speaker's Bio

Hamed Hassani is currently an assistant professor of Electrical and Systems Engineering department at the University of Pennsylvania. Prior to that, he was a research fellow at Simons Institute for the Theory of Computing (UC Berkeley) affiliated with the program of Foundations of Machine Learning, and a post-doctoral researcher in the Institute of Machine Learning at ETH Zurich. He received a Ph.D. degree in Computer and Communication Sciences from EPFL, Lausanne. He is the recipient of the 2014 IEEE Information Theory Society Thomas M. Cover Dissertation Award, 2015 IEEE International Symposium on Information Theory Student Paper Award, 2017 Simons-Berkeley Fellowship, 2018 NSF-CRII Research Initiative Award, 2020 Air Force Office of Scientific Research (AFOSR) Young Investigator Award, and 2020 National Science Foundation (NSF) CAREER Award.

Video URL: