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Alexandru Tifrea

6 accepted papers

2025

Learning Pareto manifolds in high dimensions: How can regularization help?

AISTATS 2025poster

Simultaneously addressing multiple objectives is becoming increasingly important in modern machine learning. At the same time, data is often high-dimensional and costly to label. For a single objective such as prediction risk, conventional regularization techniques are known to improve generalizatio…

Cited by 0SourceScholar
2024

FRAPPÉ: A Group Fairness Framework for Post-Processing Everything

ICML 2024poster

Despite achieving promising fairness-error trade-offs, in-processing mitigation techniques for group fairness cannot be employed in numerous practical applications with limited computation resources or no access to the training pipeline of the prediction model. In these situations, post-processing i…

Cited by 8SourcePDFScholar
2023

Can semi-supervised learning use all the data effectively? A lower bound perspective

NeurIPS 2023spotlight

Prior theoretical and empirical works have established that semi-supervised learning algorithms can leverage the unlabeled data to improve over the labeled sample complexity of supervised learning (SL) algorithms. However, existing theoretical work focuses on regimes where the unlabeled data is suff…

Cited by 0SourcePDFScholar
2023

Margin-based sampling in high dimensions: When being active is less efficient than staying passive

ICML 2023poster

It is widely believed that given the same labeling budget, active learning (AL) algorithms like margin-based active learning achieve better predictive performance than passive learning (PL), albeit at a higher computational cost. Recent empirical evidence suggests that this added cost might be in va…

Cited by 2SourcePDFScholar
2022

Semi-supervised novelty detection using ensembles with regularized disagreement

UAI 2022poster

Deep neural networks often predict samples with high confidence even when they come from unseen classes and should instead be flagged for expert evaluation. Current novelty detection algorithms cannot reliably identify such near OOD points unless they have access to labeled data that is similar to…

2021

Interpolation can hurt robust generalization even when there is no noise

NeurIPS 2021poster

Numerous recent works show that overparameterization implicitly reduces variance for min-norm interpolators and max-margin classifiers. These findings suggest that ridge regularization has vanishing benefits in high dimensions. We challenge this narrative by showing that, even in the absence of noi…