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Nikos Arechiga

3 accepted papers

2022

Second-Order Sensitivity Analysis for Bilevel Optimization

AISTATS 2022poster

In this work we derive a second-order approach to bilevel optimization, a type of mathematical programming in which the solution to a parameterized optimization problem (the “lower” problem) is itself to be optimized (in the “upper” problem) as a function of the parameters. Many existing approaches…

2021

Heteroskedastic and Imbalanced Deep Learning with Adaptive Regularization

ICLR 2021poster

Real-world large-scale datasets are heteroskedastic and imbalanced --- labels have varying levels of uncertainty and label distributions are long-tailed. Heteroskedasticity and imbalance challenge deep learning algorithms due to the difficulty of distinguishing among mislabeled, ambiguous, and rare…

2019

Learning Imbalanced Datasets with Label-Distribution-Aware Margin Loss

NeurIPS 2019poster

Deep learning algorithms can fare poorly when the training dataset suffers from heavy class-imbalance but the testing criterion requires good generalization on less frequent classes. We design two novel methods to improve performance in such scenarios. First, we propose a theoretically-principled la…