Research
On-device research index

arXiv research

A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.

169,051 papers · 148 categories

Trend · papers per month

3.0%6.1%9.1%12.1% · May 202619922001200920172026
48 results for nearest neighbor matching

Paper studies L2L_2-consistency of nearest neighbor matching for biased samples.

problem Biased sampling and missing data in statistical problems.
method Nearest neighbor matching (NNM) to estimate population quantities from biased samples.
result NNM is L2L_2-consistent in finite dimensions without smoothness and boundedness assumptions.

New methods use vector search and nearest-neighbor matching for policy learning in causal inference.

problem Learning optimal policies in causal inference with limited data.
method RAG-based policy learning with vector search and nearest-neighbor matching.
result The methods bound the within-candidate choice regret and evaluate the one-step method directly as a policy.

Nonasymptotic error bounds and strong consistency rates for survival analysis methods.

problem Establishing reliable error bounds and consistency rates for survival analysis methods.
method Nonasymptotic error bounds for Kaplan-Meier-based nearest neighbor and kernel survival probability estimators in metric spaces.
result Rates of strong consistency match existing lower bounds for conditional CDF estimation.

Optimizes sample reweighting to match laws under covariate shift using Wasserstein distance.

problem Matching laws of samples with different distributions under covariate shift.
method Minimizes Wasserstein distance between empirical measures of samples using Nearest Neighbors weights.
result Consistent reweighting leads to asymptotic convergence of empirical measures.

The article proposes modified Gower's coefficients for handling mixed type variables in nearest neighbor methods.

problem Handling mixed type variables in nearest neighbor methods, especially imputation and statistical matching.
method Suggests modifications to the Gower's distance for interval and ratio scaled variables to address unbalanced contributions and outlier sensitivity.
result Improved distance calculations reduce the unbalanced contribution of different variable types and attenuate outlier effects.

Study nearest-neighbor radii under dependent sampling, finding they remain informative.

problem Analyzing nearest-neighbor radii under dependent sampling.
method Consider strong mixing dependent observations, establish distribution-free almost sure convergence and sharp non-asymptotic moment bounds.
result Nearest-neighbor geometry remains informative under dependence sampling.

Generative models use kernel smoothing for conditioning on small example sets.

problem Improving generative models' performance with limited conditioning examples.
method Showed that cross-attention conditioning is equivalent to kernel smoothing, specifically a Nadaraya--Watson kernel smoother.
result The approach predicts and confirms three failure regimes for kernel-based conditioning.

Characterizes Lebesgue points using nearest neighbor methods.

problem Consistency of classification algorithms based on nearest neighbors.
method Characterization of Lebesgue points via 1-Nearest Neighbor regression.
result Proves convergence of 1-Nearest Neighbor classification algorithms in metric spaces.

The paper explains how nearest neighbor methods succeed in prediction.

problem Explaining the success of nearest neighbor methods in prediction.
method The paper covers both theoretical and practical aspects of nearest neighbor methods, including statistical guarantees and practical algorithms.
result The paper provides nonasymptotic statistical guarantees and practical algorithms for nearest neighbor methods.

AWNN improves matrix completion by adaptively weighting nearest neighbors.

problem Matrix completion with optimal nearest neighbor weights and radii selection.
method Adaptively weighted nearest neighbor method for matrix completion.
result Theoretical guarantees and synthetic experiments support the effectiveness of AWNN.

This paper compares FAISS and FENSHSES for nearest neighbor search in Hamming space.

problem Comparing nearest neighbor search systems in Hamming space.
method Comprehensive evaluations of indexing speed, search latency, and RAM consumption.
result Better understanding of trade-offs between main memory and secondary memory systems.

Nearest neighbor methods are a popular class of nonparametric estimators with several desirable properties, such as adaptivity to different distance scales in different regions of space. Prior work on convergence rates for nearest neighbor classification has not fully reflected these subtle properties. We analyze the b…

2014-06-30abs ↗pdf ↗

The estimation of optimal treatment regimes is of considerable interest to precision medicine. In this work, we propose a causal kk-nearest neighbor method to estimate the optimal treatment regime. The method roots in the framework of causal inference, and estimates the causal treatment effects within the nearest neig…

2017-11-22abs ↗pdf ↗

BigNN classifier improves nearest neighbor classification for large datasets.

problem Classification of large datasets that cannot fit into a single machine's memory.
method Divide and conquer scheme with majority voting for final decision; pre-training acceleration technique.
result Rates of convergence for bigNN classifier under minimal assumptions, proving it as optimal.

Paper improves full-text search engines for fast exact NNS in binary codes.

problem Efficient nearest neighbor search in Hamming space for full-text search engines.
method Revisits and combines three techniques from information retrieval: bit operation, subs-code filtering, and data preprocessing with permutation.
result Significant speed-ups for NNS in binary codes over state-of-the-art term match approach.

The paper tackles time series data by applying conformal prediction with nearest neighbors.

problem Time series data violates the exchangeability assumption required for conformal prediction.
method The approach uses the nearest neighbors method with fast parameter tuning and weighted nearest neighbors (FPTO-WNN) to construct reliable prediction intervals.
result Data analysis shows the effectiveness of the proposed approach.

New matching estimators correct bias in multivariate settings without smoothing parameters.

problem Bias in nearest-neighbor and matching estimators in multiple dimensions.
method Polynomial least squares fits on Voronoi tessellations.
result Novel estimators converge at n\sqrt{n} rate under mild smoothness assumptions.

A new multilabel classification framework improves ANN search performance.

problem Efficiently finding approximate nearest neighbors in large datasets.
method Formulated ANN search as a multilabel classification problem, using partitioning classifiers.
result Natural classifier leads to strictly improved performance in ANN search.

K-Nearest neighbor classifier (k-NNC) is simple to use and has little design time like finding k values in k-nearest neighbor classifier, hence these are suitable to work with dynamically varying data-sets. There exists some fundamental improvements over the basic k-NNC, like weighted k-nearest neighbors classifier (wh…

2013-01-27abs ↗pdf ↗

The paper studies empirical processes from nearest neighbors in regression.

problem Estimating conditional cumulative distribution functions and local linear regression.
method Uniform central limit theorem and non-asymptotic bound under local bracketing entropy and uniform entropy numbers.
result Gaussian limit of empirical process with simple covariance.

This paper proposes a new hashing-based KNN technique for faster nearest neighbor selection.

problem Slowness of KNN in big datasets due to searching entire dataset.
method Divide data space into subcells, use hashing to map data points, and select nearest neighbors layer by layer.
result The proposed technique offers competitive performance with KNN and KDtree while significantly improving time efficiency.

In this paper, we propose deep learning techniques for econometrics, specifically for causal inference and for estimating individual as well as average treatment effects. The contribution of this paper is twofold: 1. For generalized neighbor matching to estimate individual and average treatment effects, we analyze the …

2018-03-01abs ↗pdf ↗

Sublinear memory sketch finds nearest neighbors in streaming data.

problem Finding nearest neighbors in large datasets with limited memory.
method Combines LSH, online kernel density estimation, and compressed sensing to achieve sublinear memory.
result Achieves sublinear memory performance on stable queries, reporting nearest neighbors efficiently.

The nearest neighbor problem is defined as follows: Given a set PP of nn points in some metric space (X,D)(X,D), build a data structure that, given any point qq, returns a point in PP that is closest to qq (its "nearest neighbor" in PP). The data structure stores additional information about the set PP, which is th…

2018-06-26abs ↗pdf ↗

New method speeds up k-means clustering for large k by improving nearest-neighbor search.

problem Efficiently clustering large datasets with high-dimensional points.
method Seeded Approximate Nearest-Neighbor Search methods to improve Lloyd's algorithm.
result Significantly faster k-means clustering for large k values.

The Soft Nearest Neighbor Loss improves representation quality and generalization.

problem Improving the quality of representations in machine learning models.
method Explored and expanded the Soft Nearest Neighbor Loss to measure class entanglement.
result Maximizing the entanglement of different class representations leads to better generalization and uncertainty estimation.

Random forest improves nearest neighbor estimation of information-theoretic quantities.

problem Estimating information-theoretic quantities in high-dimensional and scale-different settings.
method Decision forest-based adaptive nearest neighbor estimators.
result Forest-based estimators effectively estimate posterior probabilities and mutual information.

This paper presents a simple but effective density-based outlier detection approach with the local kernel density estimation (KDE). A Relative Density-based Outlier Score (RDOS) is introduced to measure the local outlierness of objects, in which the density distribution at the location of an object is estimated with a …

2016-06-28abs ↗pdf ↗

The stability of statistical analysis is an important indicator for reproducibility, which is one main principle of scientific method. It entails that similar statistical conclusions can be reached based on independent samples from the same underlying population. In this paper, we introduce a general measure of classif…

2014-05-26abs ↗pdf ↗

Adaptive NN method improves matrix completion for non-smooth data.

problem Matrix completion with non-smooth non-linear functions under high missingness.
method Two-sided nearest neighbors with \Holder function class non-linearity.
result NN error rate matches oracle's for latent factors, non-trivial for wide range of missingness.

In many scientific disciplines structures in high-dimensional data have to be found, e.g., in stellar spectra, in genome data, or in face recognition tasks. In this work we present a novel approach to non-linear dimensionality reduction. It is based on fitting K-nearest neighbor regression to the unsupervised regressio…

2011-07-19abs ↗pdf ↗