← Search

Sungjin Im

10 accepted papers

2025

A Beyond-Worst-Case Analysis of Greedy k-means++

NeurIPS 2025poster

$k$-means++ and the related greedy $k$-means++ algorithm are celebrated algorithms that efficiently compute seeds for Lloyd's algorithm. Greedy $k$-means++ is a generalization of $k$-means++ where, in each iteration, a new seed is greedily chosen among multiple $\ell \geq 2$ points sampled, as oppos…

Cited by 0SourceScholar
2024

Binary Search with Distributional Predictions

NeurIPS 2024poster

Algorithms with (machine-learned) predictions is a powerful framework for combining traditional worst-case algorithms with modern machine learning. However, the vast majority of work in this space assumes that the prediction itself is non-probabilistic, even if it is generated by some stochastic pr…

2024

Sampling for Beyond-Worst-Case Online Ranking

AAAI 2024technical

The feedback arc set problem is one of the most fundamental and well-studied ranking problems where n objects are to be ordered based on their pairwise comparison. The problem enjoys several efficient approximation algorithms in the offline setting. Unfortunately, online there are strong lower boun…

Cited by 0SourcePDFScholar
2023

Min-Max Submodular Ranking for Multiple Agents

AAAI 2023technical

In the submodular ranking (SR) problem, the input consists of a set of submodular functions defined on a ground set of elements. The goal is to order elements for all the functions to have value above a certain threshold as soon on average as possible, assuming we choose one element per time. The pr…

2022

Algorithms with Prediction Portfolios

NeurIPS 2022accept

The research area of algorithms with predictions has seen recent success showing how to incorporate machine learning into algorithm design to improve performance when the predictions are correct, while retaining worst-case guarantees when they are not. Most previous work has assumed that the algori…

2021

Faster Matchings via Learned Duals

NeurIPS 2021oral

A recent line of research investigates how algorithms can be augmented with machine-learned predictions to overcome worst case lower bounds. This area has revealed interesting algorithmic insights into problems, with particular success in the design of competitive online algorithms. However, the q…

Cited by 30SourcePDFScholar
2020

Fast Noise Removal for k-Means Clustering

AISTATS 2020poster

This paper considers k-means clustering in the presence of noise. It is known that k-means clustering is highly sensitive to noise, and thus noise should be removed to obtain a quality solution. A popular formulation of this problem is called k-means clustering with outliers. The goal of k-means clu…

Cited by 37SourcePDFScholar
2020

Unconditional Coresets for Regularized Loss Minimization

AISTATS 2020poster

We design and mathematically analyze sampling-based algorithms for regularized loss minimization problems that are implementable in popular computational models for large data, in which the access to the data is restricted in some way. Our main result is that if the regularizer’s effect does not bec…

Cited by 11SourcePDFScholar