English
Related papers

Related papers: PFO: A Parallel Friendly High Performance System f…

200 papers

We show that approximate near neighbor search in high dimensions can be solved in a Las Vegas fashion (i.e., without false negatives) for $\ell_p$ ($1\le p\le 2$) while matching the performance of optimal locality-sensitive hashing.…

Data Structures and Algorithms · Computer Science 2018-07-20 Alexander Wei

The Jaccard index is an important similarity measure for item sets and Boolean data. On large datasets, an exact similarity computation is often infeasible for all item pairs both due to time and space constraints, giving rise to faster…

Data Structures and Algorithms · Computer Science 2021-03-09 Marc Bury , Chris Schwiegelshohn , Mara Sorella

Locality-sensitive hashing (LSH) is a fundamental technique for similarity search and similarity estimation in high-dimensional spaces. The basic idea is that similar objects should produce hash collisions with probability significantly…

Computational Geometry · Computer Science 2017-09-25 Joachim Gudmundsson , Rasmus Pagh

Retrieving the most similar objects in a large-scale database for a given query is a fundamental building block in many application domains, ranging from web searches, visual, cross media, and document retrievals. State-of-the-art…

Machine Learning · Computer Science 2018-03-15 Muge Li , Liangyue Li , Feiping Nie

Due to the compelling efficiency in retrieval and storage, similarity-preserving hashing has been widely applied to approximate nearest neighbor search in large-scale image retrieval. However, existing methods have poor performance in…

Multimedia · Computer Science 2020-04-27 Xingbo Liu , Xiushan Nie , Qi Dai , Yupan Huang , Yilong Yin

Similarity search in high-dimentional spaces is a pivotal operation found a variety of database applications. Recently, there has been an increase interest in similarity search for online content-based multimedia services. Those services,…

Multimedia · Computer Science 2012-09-04 George Teodoro , Eduardo Valle , Nathan Mariano , Ricardo Torres , Wagner Meira , Joel H. Saltz

Proximal Policy Optimization (PPO) is central to aligning Large Language Models (LLMs) in reasoning tasks with verifiable rewards. However, standard token-level PPO struggles in this setting due to the instability of temporal credit…

Artificial Intelligence · Computer Science 2026-04-13 Tianyi Wang , Yixia Li , Long Li , Yibiao Chen , Shaohan Huang , Yun Chen , Peng Li , Yang Liu , Guanhua Chen

In this paper we present two versions of a parallel finger structure FS on p processors that supports searches, insertions and deletions, and has a finger at each end. This is to our knowledge the first implementation of a parallel search…

Data Structures and Algorithms · Computer Science 2019-10-11 Seth Gilbert , Wei Quan Lim

This paper describes a novel approach to neighbour-finding in Smoothed Particle Hydrodynamics (SPH) simulations with large dynamic range in smoothing length. This approach is based on hierarchical cell decompositions, sorted interactions,…

Instrumentation and Methods for Astrophysics · Physics 2013-09-17 Pedro Gonnet , Matthieu Schaller , Tom Theuns , Aidan B. G. Chalk

We present a set of parallel algorithms for computing exact k-nearest neighbors in low dimensions. Many k-nearest neighbor algorithms use either a kd-tree or the Morton ordering of the point set; our algorithms combine these approaches…

Data Structures and Algorithms · Computer Science 2021-11-09 Magdalen Dobson , Guy Blelloch

The Nearest Neighbor Search (NNS) problem asks to design a data structure that preprocesses an $n$-point dataset $X$ lying in a metric space $\mathcal{M}$, so that given a query point $q \in \mathcal{M}$, one can quickly return a point of…

Data Structures and Algorithms · Computer Science 2026-03-24 Robert Krauthgamer , Nir Petruschka

Scalar field comparison is a fundamental task in scientific visualization. In topological data analysis, we compare topological descriptors of scalar fields -- such as persistence diagrams and merge trees -- because they provide succinct…

Computational Geometry · Computer Science 2024-09-18 Weiran Lyu , Raghavendra Sridharamurthy , Jeff M. Phillips , Bei Wang

We study the problem of approximate near neighbor (ANN) search and show the following results: - An improved framework for solving the ANN problem using locality-sensitive hashing, reducing the number of evaluations of locality-sensitive…

Data Structures and Algorithms · Computer Science 2019-06-25 Tobias Christiani

We develop methods for accelerating metric similarity search that are effective on modern hardware. Our algorithms factor into easily parallelizable components, making them simple to deploy and efficient on multicore CPUs and GPUs. Despite…

Databases · Computer Science 2016-11-15 Lawrence Cayton

$\newcommand{\ball}{\mathbb{B}}\newcommand{\dsQ}{{\mathcal{Q}}}\newcommand{\dsS}{{\mathcal{S}}}$In this work we study a fair variant of the near neighbor problem. Namely, given a set of $n$ points $P$ and a parameter $r$, the goal is to…

Machine Learning · Computer Science 2019-11-25 Sariel Har-Peled , Sepideh Mahabadi

This paper investigates the usage of FPGA devices for energy-efficient exact kNN search in high-dimension latent spaces. This work intercepts a relevant trend that tries to support the increasing popularity of learned representations based…

Information Retrieval · Computer Science 2025-10-21 Patrizio Dazzi , William Guglielmo , Franco Maria Nardini , Raffaele Perego , Salvatore Trani

Approximate Nearest neighbor search (ANNS) is fundamental and essential operation in applications from many domains, such as databases, machine learning, multimedia, and computer vision. Although many algorithms have been continuously…

Databases · Computer Science 2016-10-11 Wen Li , Ying Zhang , Yifang Sun , Wei Wang , Wenjie Zhang , Xuemin Lin

Residential demand response programs aim to activate demand flexibility at the household level. In recent years, reinforcement learning (RL) has gained significant attention for these type of applications. A major challenge of RL algorithms…

Systems and Control · Electrical Eng. & Systems 2024-03-13 Thijs Peirelinck , Chris Hermans , Fred Spiessens , Geert Deconinck

Approximate Nearest Neighbor Search (ANNS) is a core primitive in modern AI systems, and graph-based methods currently offer the best accuracy-efficiency trade-off at scale. The workload is fundamentally memory-bound: graph traversal…

Hardware Architecture · Computer Science 2026-05-26 Sitian Chen , Yusen Li , Yao Chen , Minwen Deng , Jintao Meng , Amelie Chi Zhou

Direct Preference Optimization (DPO) improves the alignment of large language models (LLMs) with human values by training directly on human preference datasets, eliminating the need for reward models. However, due to the presence of…

Artificial Intelligence · Computer Science 2024-06-11 Biqing Qi , Pengfei Li , Fangyuan Li , Junqi Gao , Kaiyan Zhang , Bowen Zhou