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We consider the problem of estimating an unknown function f* and its partial derivatives from a noisy data set of n observations, where we make no assumptions about f* except that it is smooth in the sense that it has square integrable…

Machine Learning · Statistics 2024-05-17 Eunji Lim

We provide general adaptive upper bounds for estimating nonparametric functionals based on second order U-statistics arising from finite dimensional approximation of the infinite dimensional models. We then provide examples of functionals…

Statistics Theory · Mathematics 2021-06-07 Lin Liu , Rajarshi Mukherjee , James Robins , Eric Tchetgen Tchetgen

Modern neural networks are very powerful predictive models, but they are often incapable of recognizing when their predictions may be wrong. Closely related to this is the task of out-of-distribution detection, where a network must…

Machine Learning · Statistics 2018-02-15 Terrance DeVries , Graham W. Taylor

This paper describes three methods for carrying out non-asymptotic inference on partially identified parameters that are solutions to a class of optimization problems. Applications in which the optimization problems arise include estimation…

Methodology · Statistics 2022-12-02 Joel L. Horowitz , Sokbae Lee

Given noisy data, function estimation is considered when the unknown function is known apriori to consist of a small number of regions where the function is either convex or concave. When the regions are known apriori, the estimate is…

Methodology · Statistics 2020-02-18 Kurt S. Riedel

We revisit the classical problem of estimating an unknown distribution from its samples by fitting a mixture model that minimizes cross-entropy loss. Framing the task as a stochastic convex optimization problem over the space of $ M…

Machine Learning · Statistics 2026-05-26 Mohammadreza Ahmadypour , Tara Javidi , Farinaz Koushanfar

The empirical distribution function assigns mass $1/n$ to each of the $n$ observations in a sample. As these are highly variable, estimation error may be reduced by replacing them with estimated observations that are asymptotically less…

Methodology · Statistics 2026-05-26 Tommaso Lando , Lorenzo Tedesco

This paper focuses on the study of semilinear fractional diffusion-wave equations in the context of critical nonlinearities. Firstly, we address the issue of local well-posedness for the problem, examine spatial regularity, and the…

Analysis of PDEs · Mathematics 2026-02-09 Masterson Costa , Claudio Cuevas , Bruno de Andrade

We study the Cauchy problem for one-dimensional dispersive equations posed on $\mathbb{R} $, under the hypotheses that the dispersive operator behaves, for high frequencies, as a Fourier multiplier by $ i |\xi|^\alpha \xi $ with $ 1 \le…

Analysis of PDEs · Mathematics 2025-11-03 Luc Molinet , Tomoyuki Tanaka

This study presents new estimates for fractional derivatives without singular kernels defined by some specific functions. Based on obtained inequalities, we give a useful method to establish the global stability of steady states for…

Dynamical Systems · Mathematics 2022-04-21 Adnane Boukhouima , Houssine Zine , El Mehdi Lotfi , Marouane Mahrouf , Delfim F. M. Torres , Noura Yousfi

We study the semiparametric efficient estimation of a class of linear functionals in settings where a complete multivariate dataset is supplemented by additional datasets recording subsets of the variables of interest. These datasets are…

Statistics Theory · Mathematics 2025-06-19 Thomas B. Berrett

The three dimensional cubic defocusing nonlinear wave equation is known to be ill-posed for general low regularity initial data. However, well-posedness can be recovered globally in time on a probabilistic level when considering random…

Analysis of PDEs · Mathematics 2026-04-08 Wandrille Ruffenach , Nikolay Tzvetkov

The notion of well-posedness has drawn the attention of many researchers in the field of nonlinear analysis, as it allows to explore problems in which exact solutions are not known and/or computationally hard to compute. Roughly speaking,…

Optimization and Control · Mathematics 2023-05-04 Soumitra Dey , Aviv Gibali , Simeon Reich

Fractional calculus provides a rigorous mathematical framework to describe anomalous stochastic processes by generalizing the notion of classical differential equations to their fractional-order counterparts. By introducing the fractional…

Numerical Analysis · Mathematics 2018-06-04 Ehsan Kharazmi , Mohsen Zayernouri

Recent work has shown that the performance of machine learning models can vary substantially when models are evaluated on data drawn from a distribution that is close to but different from the training distribution. As a result, predicting…

Machine Learning · Computer Science 2021-08-23 Devin Guillory , Vaishaal Shankar , Sayna Ebrahimi , Trevor Darrell , Ludwig Schmidt

Distributed minimax estimation and distributed adaptive estimation under communication constraints for Gaussian sequence model and white noise model are studied. The minimax rate of convergence for distributed estimation over a given Besov…

Statistics Theory · Mathematics 2021-07-02 T. Tony Cai , Hongji Wei

This article considers nonparametric regression models with multivariate covariates and with responses missing at random. We estimate the regression function with a local polynomial smoother. The residual-based empirical distribution…

Methodology · Statistics 2016-10-27 Justin Chown , Ursula U. Müller

Reliable predictive uncertainty estimation plays an important role in enabling the deployment of neural networks to safety-critical settings. A popular approach for estimating the predictive uncertainty of neural networks is to define a…

Machine Learning · Statistics 2023-12-29 Tim G. J. Rudner , Zonghao Chen , Yee Whye Teh , Yarin Gal

Low-dimensional embedding, manifold learning, clustering, classification, and anomaly detection are among the most important problems in machine learning. The existing methods usually consider the case when each instance has a fixed,…

Machine Learning · Computer Science 2012-02-20 Barnabas Poczos , Liang Xiong , Jeff Schneider

A new formalism is presented for finding equilibrium distribution functions for axisymmetric systems. The formalism, obtainded by using the concept of fractional derivatives, generalizes the methods of Fricke (1952), Kalnajs (1972) and…

Astrophysics · Physics 2009-06-14 Juan F. Pedraza , Javier Ramos-Caro , Guillermo A. Gonzalez