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Related papers: Space Upper Bounds for $\alpha$-Perfect Hashing

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Suppose we have n keys, n access probabilities for the keys, and n+1 access probabilities for the gaps between the keys. Let h_min(n) be the minimal height of a binary search tree for n keys. We consider the problem to construct an optimal…

Data Structures and Algorithms · Computer Science 2010-11-08 Peter Becker

Hashing is a basic tool for dimensionality reduction employed in several aspects of machine learning. However, the perfomance analysis is often carried out under the abstract assumption that a truly random unit cost hash function is used,…

Machine Learning · Statistics 2017-11-27 Søren Dahlgaard , Mathias Bæk Tejs Knudsen , Mikkel Thorup

We give a simple deterministic $O(\log K / \log\log K)$ approximation algorithm for the Min-Max Selecting Items problem, where $K$ is the number of scenarios. While our main goal is simplicity, this result also improves over the previous…

Data Structures and Algorithms · Computer Science 2013-04-30 Benjamin Doerr

Recently, supervised hashing methods have attracted much attention since they can optimize retrieval speed and storage cost while preserving semantic information. Because hashing codes learning is NP-hard, many methods resort to some form…

Machine Learning · Computer Science 2017-12-05 Zihao Hu , Xiyi Luo , Hongtao Lu , Yong Yu

Given an $n*n$ sparse symmetric matrix with $m$ nonzero entries, performing Gaussian elimination may turn some zeroes into nonzero values. To maintain the matrix sparse, we would like to minimize the number $k$ of these changes, hence…

Computational Complexity · Computer Science 2016-06-28 Yixin Cao , R. B. Sandeep

We study embedding a subset $K$ of the unit sphere to the Hamming cube $\{-1,+1\}^m$. We characterize the tradeoff between distortion and sample complexity $m$ in terms of the Gaussian width $\omega(K)$ of the set. For subspaces and several…

Machine Learning · Computer Science 2015-12-15 Samet Oymak , Ben Recht

This work focuses on representing very high-dimensional global image descriptors using very compact 64-1024 bit binary hashes for instance retrieval. We propose DeepHash: a hashing scheme based on deep networks. Key to making DeepHash work…

Computer Vision and Pattern Recognition · Computer Science 2016-02-17 Jie Lin , Olivier Morere , Vijay Chandrasekhar , Antoine Veillard , Hanlin Goh

We give a polynomial-time approximation algorithm for the (not necessarily metric) $k$-Median problem. The algorithm is an $\alpha$-size-approximation algorithm for $\alpha < 1 + 2 \ln(n/k)$. That is, it guarantees a solution having size at…

Data Structures and Algorithms · Computer Science 2025-11-18 Neal E. Young

Despite being one of the oldest data structures in computer science, hash tables continue to be the focus of a great deal of both theoretical and empirical research. A central reason for this is that many of the fundamental properties that…

Data Structures and Algorithms · Computer Science 2023-10-24 Michael A. Bender , Alex Conway , Martín Farach-Colton , William Kuszmaul , Guido Tagliavini

Approximate Nearest Neighbour (ANN) search is a fundamental problem in information retrieval, underpinning large-scale applications in computer vision, natural language processing, and cross-modal search. Hashing-based methods provide an…

Information Retrieval · Computer Science 2025-10-07 Sean Moran

We study the maximum set coverage problem in the massively parallel model. In this setting, $m$ sets that are subsets of a universe of $n$ elements are distributed among $m$ machines. In each round, these machines can communicate with each…

Data Structures and Algorithms · Computer Science 2024-11-26 Thai Bui , Hoa T. Vu

To get estimators that work within a certain error bound with high probability, a common strategy is to design one that works with constant probability, and then boost the probability using independent repetitions. Important examples of…

Data Structures and Algorithms · Computer Science 2020-04-03 Anders Aamand , Debarati Das , Evangelos Kipouridis , Jakob B. T. Knudsen , Peter M. R. Rasmussen , Mikkel Thorup

The classic way of computing a $k$-universal hash function is to use a random degree-$(k-1)$ polynomial over a prime field $\mathbb Z_p$. For a fast computation of the polynomial, the prime $p$ is often chosen as a Mersenne prime $p=2^b-1$.…

Data Structures and Algorithms · Computer Science 2021-05-07 Thomas Dybdahl Ahle , Jakob Tejs Bæk Knudsen , Mikkel Thorup

In this paper, we study the problem of designing prefix-free encoding schemes having minimum average code length that can be decoded efficiently under a decode cost model that captures memory hierarchy induced cost functions. We also study…

Data Structures and Algorithms · Computer Science 2021-10-22 Shashwat Banchhor , Rishikesh Gajjala , Yogish Sabharwal , Sandeep Sen

Empirical evidence suggests that hashing is an effective strategy for dimensionality reduction and practical nonparametric estimation. In this paper we provide exponential tail bounds for feature hashing and show that the interaction…

Artificial Intelligence · Computer Science 2010-02-27 Kilian Weinberger , Anirban Dasgupta , Josh Attenberg , John Langford , Alex Smola

We study the optimal memorization capacity of modern Hopfield models and Kernelized Hopfield Models (KHMs), a transformer-compatible class of Dense Associative Memories. We present a tight analysis by establishing a connection between the…

Machine Learning · Statistics 2024-11-04 Jerry Yao-Chieh Hu , Dennis Wu , Han Liu

Randomized algorithms are often enjoyed for their simplicity, but the hash functions employed to yield the desired probabilistic guarantees are often too complicated to be practical. Here we survey recent results on how simple hashing…

Data Structures and Algorithms · Computer Science 2017-01-04 Mikkel Thorup

Designing algorithms for balanced allocation of clients to servers in dynamic settings is a challenging problem for a variety of reasons. Both servers and clients may be added and/or removed from the system periodically, and the main…

Data Structures and Algorithms · Computer Science 2017-07-28 Vahab Mirrokni , Mikkel Thorup , Morteza Zadimoghaddam

Information retrieval with compact binary embeddings, also referred to as hashing, is crucial for scalable fast search applications, yet state-of-the-art hashing methods require expensive, scenario-specific training. In this work, we…

Machine Learning · Computer Science 2026-01-29 Ilyass Moummad , Kawtar Zaher , Lukas Rauch , Alexis Joly

Fully homomorphic encryption (FHE) enables private inference by evaluating neural networks on encrypted data. In this way, we can delegate the computation to a third party server without ever revealing the user's data. Currently, the CKKS…

Cryptography and Security · Computer Science 2026-05-25 Philipp Kern , Lorenzo Rovida , Samuel Teuber , Edoardo Manino , Carsten Sinz , Alberto Leporati