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Ashkan Norouzi-Fard

18 accepted papers

2026

A General Framework for Dynamic Consistent Submodular Maximization

ICML 2026poster

Consistency is an important property in dynamic submodular maximization and entails maintaining a near-optimal solution at all times, making only a small number of adjustments to the solution in each step. Prior work has explored this question for the insertion-only case, where the algorithm faces a…

Cited by 0SourceScholar
2026

Resilient Coresets and Consistent Clustering

ICML 2026poster

Many machine learning problems are geometric at their core, relying on metric representations of data for tasks such as clustering, prototype selection, nearest-neighbor search, and graph-based learning. Furthermore, data is constantly evolving and it is routinely transformed through dimensionality …

Cited by 0SourceScholar
2024

Consistent Submodular Maximization

ICML 2024poster

Maximizing monotone submodular functions under cardinality constraints is a classic optimization task with several applications in data mining and machine learning. In this paper, we study this problem in a dynamic environment with consistency constraints: elements arrive in a streaming fashion, and…

2024

Fairness in Submodular Maximization over a Matroid Constraint

AISTATS 2024poster

Submodular maximization over a matroid constraint is a fundamental problem with various applications in machine learning. Some of these applications involve decision-making over datapoints with sensitive attributes such as gender or race. In such settings, it is crucial to guarantee that the selecte…

Cited by 6SourcePDFScholar
2023

Fairness in Streaming Submodular Maximization over a Matroid Constraint

ICML 2023poster

Streaming submodular maximization is a natural model for the task of selecting a representative subset from a large-scale dataset. If datapoints have sensitive attributes such as gender or race, it becomes important to enforce fairness to avoid bias and discrimination. This has spurred significant i…

2023

Fully Dynamic Submodular Maximization over Matroids

ICML 2023poster

Maximizing monotone submodular functions under a matroid constraint is a classic algorithmic problem with multiple applications in data mining and machine learning. We study this classic problem in the fully dynamic setting, where elements can be both inserted and deleted in real-time. Our main resu…

Cited by 15SourcePDFScholar
2022

Deletion Robust Submodular Maximization over Matroids

ICML 2022oral

Maximizing a monotone submodular function is a fundamental task in machine learning. In this paper we study the deletion robust version of the problem under the classic matroids constraint. Here the goal is to extract a small size summary of the dataset that contains a high value independent set eve…

2022

Near-Optimal Correlation Clustering with Privacy

NeurIPS 2022accept

Correlation clustering is a central problem in unsupervised learning, with applications spanning community detection, duplicate detection, automated labeling and many more. In the correlation clustering problem one receives as input a set of nodes and for each node a list of co-clustering preference…

Cited by 18SourcePDFScholar
2021

Correlation Clustering in Constant Many Parallel Rounds

ICML 2021oral

Correlation clustering is a central topic in unsupervised learning, with many applications in ML and data mining. In correlation clustering, one receives as input a signed graph and the goal is to partition it to minimize the number of disagreements. In this work we propose a massively parallel comp…

Cited by 48SourcePDFScholar
2021

Parallel and Efficient Hierarchical k-Median Clustering

NeurIPS 2021poster

As a fundamental unsupervised learning task, hierarchical clustering has been extensively studied in the past decade. In particular, standard metric formulations as hierarchical $k$-center, $k$-means, and $k$-median received a lot of attention and the problems have been studied extensively in diffe…

Cited by 8SourcePDFScholar
2021

Streaming Belief Propagation for Community Detection

NeurIPS 2021poster

The community detection problem requires to cluster the nodes of a network into a small number of well-connected ‘communities’. There has been substantial recent progress in characterizing the fundamental statistical limits of community detection under simple stochastic block models. However, in re…

Cited by 6SourcePDFScholar
2020

Fairness in Streaming Submodular Maximization: Algorithms and Hardness

NeurIPS 2020poster

Submodular maximization has become established as the method of choice for the task of selecting representative and diverse summaries of data. However, if datapoints have sensitive attributes such as gender or age, such machine learning algorithms, left unchecked, are known to exhibit bias: under- o…

2020

Fast and Accurate $k$-means++ via Rejection Sampling

NeurIPS 2020poster

$k$-means++ \cite{arthur2007k} is a widely used clustering algorithm that is easy to implement, has nice theoretical guarantees and strong empirical performance. Despite its wide adoption, $k$-means++ sometimes suffers from being slow on large data-sets so a natural question has been to obtain more…

Cited by 27SourcePDFScholar
2020

Fully Dynamic Algorithm for Constrained Submodular Optimization

NeurIPS 2020oral

The task of maximizing a monotone submodular function under a cardinality constraint is at the core of many machine learning and data mining applications, including data summarization, sparse regression and coverage problems. We study this classic problem in the fully dynamic setting, where elements…

Cited by 30SourcePDFScholar
2018

Beyond 1/2-Approximation for Submodular Maximization on Massive Data Streams

ICML 2018oral

Many tasks in machine learning and data mining, such as data diversification, non-parametric learning, kernel machines, clustering etc., require extracting a small but representative summary from a massive dataset. Often, such problems can be posed as maximizing a submodular set function subject to…

Cited by 112SourcePDFScholar
2017

Streaming Robust Submodular Maximization: A Partitioned Thresholding Approach

NeurIPS 2017poster

We study the classical problem of maximizing a monotone submodular function subject to a cardinality constraint k, with two additional twists: (i) elements arrive in a streaming fashion, and (ii) m items from the algorithm’s memory are removed after the stream is finished. We develop a robust submod…

Cited by 63SourcePDFScholar
2016

An Efficient Streaming Algorithm for the Submodular Cover Problem

NeurIPS 2016poster

We initiate the study of the classical Submodular Cover (SC) problem in the data streaming model which we refer to as the Streaming Submodular Cover (SSC). We show that any single pass streaming algorithm using sublinear memory in the size of the stream will fail to provide any non-trivial approxima…

Cited by 27SourcePDFScholar