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Afshin Rostamizadeh

15 accepted papers

2025

Analyzing Similarity Metrics for Data Selection for Language Model Pretraining

NeurIPS 2025poster

Measuring similarity between training examples is critical for curating high-quality and diverse pretraining datasets for language models. However, similarity is typically computed with a generic off-the-shelf embedding model that has been trained for tasks such as retrieval. Whether these embeddi…

Cited by 0SourceScholar
2025

This Time is Different: An Observability Perspective on Time Series Foundation Models

NeurIPS 2025poster

We introduce Toto, a time series forecasting foundation model with 151 million parameters. Toto uses a modern decoder-only architecture coupled with architectural innovations designed to account for specific challenges found in multivariate observability time series data. Toto's pre-training corpus…

Cited by 0SourcecodeScholar
2024

DistillSpec: Improving Speculative Decoding via Knowledge Distillation

ICLR 2024poster

Speculative decoding~(SD) accelerates large language model inference by employing a faster {\em draft} model for generating multiple tokens, which are then verified in parallel by the larger {\em target} model, resulting in the text generated according to the target model distribution. However, iden…

Cited by 86SourcePDFScholar
2023

Leveraging Importance Weights in Subset Selection

ICLR 2023poster

We present a subset selection algorithm designed to work with arbitrary model families in a practical batch setting. In such a setting, an algorithm can sample examples one at a time but, in order to limit overhead costs, is only able to update its state (i.e. further train model weights) once a lar…

Cited by 3SourcePDFScholar
2022

Churn Reduction via Distillation

ICLR 2022spotlight

In real-world systems, models are frequently updated as more data becomes available, and in addition to achieving high accuracy, the goal is to also maintain a low difference in predictions compared to the base model (i.e. predictive churn). If model retraining results in vastly different behavior,…

Cited by 25SourcePDFScholar
2021

Active Covering

ICML 2021spotlight

We analyze the problem of active covering, where the learner is given an unlabeled dataset and can sequentially label query examples. The objective is to label query all of the positive examples in the fewest number of total label queries. We show under standard non-parametric assumptions that a cla…

Cited by 3SourcePDFScholar
2021

Batch Active Learning at Scale

NeurIPS 2021poster

The ability to train complex and highly effective models often requires an abundance of training data, which can easily become a bottleneck in cost, time, and computational resources. Batch active learning, which adaptively issues batched queries to a labeling oracle, is a common approach for addres…

Cited by 189SourcePDFScholar
2021

Federated Learning via Posterior Averaging: A New Perspective and Practical Algorithms

ICLR 2021poster

Federated learning is typically approached as an optimization problem, where the goal is to minimize a global loss function by distributing computation across client devices that possess local data and specify different parts of the global objective. We present an alternative perspective and formul…

2020

An Analysis of SVD for Deep Rotation Estimation

NeurIPS 2020poster

Symmetric orthogonalization via SVD, and closely related procedures, are well-known techniques for projecting matrices onto O(n) or SO(n). These tools have long been used for applications in computer vision, for example optimal 3D alignment problems solved by orthogonal Procrustes, rotation averagin…

2020

Understanding the Effects of Batching in Online Active Learning

AISTATS 2020poster

Online active learning (AL) algorithms often assume immediate access to a label once a query has been made. However, due to practical constraints, the labels of these queried examples are generally only available in “batches”. In this work, we present an analysis for a generic class of batch online…

Cited by 9SourcePDFScholar
2019

Categorical Feature Compression via Submodular Optimization

ICML 2019oral

In the era of big data, learning from categorical features with very large vocabularies (e.g., 28 million for the Criteo click prediction dataset) has become a practical challenge for machine learning researchers and practitioners. We design a highly-scalable vocabulary compression algorithm that se…

Cited by 23SourcePDFScholar
2019

Learning a Compressed Sensing Measurement Matrix via Gradient Unrolling

ICML 2019oral

Linear encoding of sparse vectors is widely popular, but is commonly data-independent – missing any possible extra (but a priori unknown) structure beyond sparsity. In this paper we present a new method to learn linear encoders that adapt to data, while still performing well with the widely used $\e…

2017

Hyperband: Bandit-Based Configuration Evaluation for Hyperparameter Optimization

ICLR 2017poster

Performance of machine learning algorithms depends critically on identifying a good set of hyperparameters. While recent approaches use Bayesian Optimization to adaptively select configurations, we focus on speeding up random search through adaptive resource allocation. We present Hyperband, a no…

Cited by 196SourceScholar
2016

Greedy Column Subset Selection: New Bounds and Distributed Algorithms

ICML 2016poster

The problem of column subset selection has recently attracted a large body of research, with feature selection serving as one obvious and important application. Among the techniques that have been applied to solve this problem, the greedy algorithm has been shown to be quite effective in practice. H…

Cited by 90SourcePDFScholar