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We address functional uncertainty quantification for ill-posed inverse problems where it is possible to evaluate a possibly rank-deficient forward model, the observation noise distribution is known, and there are known parameter…

Methodology · Statistics 2025-02-06 Michael Stanley , Pau Batlle , Pratik Patil , Houman Owhadi , Mikael Kuusela

A passive approximation problem is formulated where the target function is an arbitrary complex valued continuous function defined on an approximation domain consisting of a finite union of closed and bounded intervals on the real axis. The…

Mean-field Langevin dynamics (MFLD) minimizes an entropy-regularized nonlinear convex functional defined over the space of probability distributions. MFLD has gained attention due to its connection with noisy gradient descent for mean-field…

Machine Learning · Computer Science 2024-10-31 Atsushi Nitanda

Upcoming wide field surveys will have many overlapping epochs of the same region of sky. The conventional wisdom is that in order to reduce the errors sufficiently for systematics-limited measurements, like weak lensing, we must do…

The shifted boundary method (SBM) is an approximate domain method for boundary value problems, in the broader class of unfitted/embedded/immersed methods. It has proven to be quite efficient in handling problems with complex geometries,…

Numerical Analysis · Mathematics 2020-06-02 Nabil M. Atallah , Claudio Canuto , Guglielmo Scovazzi

Some variant of the Frank-Wolfe method for convex optimization problems with adaptive selection of the step parameter corresponding to information about the smoothness of the objective function (the Lipschitz constant of the gradient).…

Optimization and Control · Mathematics 2023-08-01 G. V. Aivazian , F. S. Stonyakin , D. A. Pasechnyuk , M. S. Alkousa , A. M. Raigorodskii

Data observed at high sampling frequency are typically assumed to be an additive composite of a relatively slow-varying continuous-time component, a latent stochastic process or a smooth random function, and measurement error. Supposing…

Statistics Theory · Mathematics 2018-12-21 Jinyuan Chang , Aurore Delaigle , Peter Hall , Cheng Yong Tang

Time warping function provides a mathematical representation to measure phase variability in functional data. Recent studies have developed various approaches to estimate optimal warping between functions and provide non-Euclidean models.…

Methodology · Statistics 2022-04-15 Yijia Ma , Xinyu Zhou , Wei Wu

Spatial regression of random fields based on potentially biased sensing information is proposed in this paper. One major concern in such applications is that since it is not known a-priori what the accuracy of the collected data from each…

Signal Processing · Electrical Eng. & Systems 2020-09-04 Qikun Xiang , Ido Nevat , Gareth W. Peters

Data analysis and interpretation often relies on an approximation of an empirical dataset by some analytic functions or models. Actual implementations usually rely on a non-linear multi-dimensional optimization algorithm, typically…

Instrumentation and Methods for Astrophysics · Physics 2025-01-29 Igor Chilingarian , Kirill Grishin

In this paper we analyze the asymptotic properties of l1 penalized maximum likelihood estimation of signals with piece-wise constant mean values and/or variances. The focus is on segmentation of a non-stationary time series with respect to…

Statistics Theory · Mathematics 2014-01-22 Cristian R. Rojas , Bo Wahlberg

This survey hinges on the interplay between regularity and approximation for linear and quasi-linear fractional elliptic problems on Lipschitz domains. For the linear Dirichlet integral Laplacian, after briefly recalling H\"older regularity…

Numerical Analysis · Mathematics 2023-01-02 Juan Pablo Borthagaray , Wenbo Li , Ricardo H. Nochetto

This paper proposes an adaptive near-field beam training method to enhance performance in multi-user and multipath environments. The approach identifies multiple strongest beams through beam sweeping and linearly combines their received…

Signal Processing · Electrical Eng. & Systems 2025-05-14 Zijun Wang , Rama Kiran , Jinesh Nair , Chien-Hua Chen , Tzu-Han Chou , Shawn Tsai , Rui Zhang

For consistency (even oracle properties) of estimation and model prediction, almost all existing methods of variable/feature selection critically depend on sparsity of models. However, for ``large $p$ and small $n$" models sparsity…

Methodology · Statistics 2010-08-10 Lu Lin , Lixing Zhu , Yujie Gai

We consider the problem of minimizing a difference of (smooth) convex functions over a compact convex feasible region $P$, i.e., $\min_{x \in P} f(x) - g(x)$, with smooth $f$ and Lipschitz continuous $g$. This computational study builds…

Optimization and Control · Mathematics 2025-08-05 Sebastian Pokutta

We study nonasymptotic minimax estimation of the linear functional $L(\theta)=\eta^\top \theta$ for a high-dimensional $s$-sparse mean vector with an arbitrary loading vector $\eta$. For symmetric noise with exponentially decaying tails, we…

Statistics Theory · Mathematics 2026-04-29 Jie Xie , Dongming Huang

We consider the class of convex minimization problems, composed of a self-concordant function, such as the $\log\det$ metric, a convex data fidelity term $h(\cdot)$ and, a regularizing -- possibly non-smooth -- function $g(\cdot)$. This…

Machine Learning · Statistics 2014-05-14 Anastasios Kyrillidis , Rabeeh Karimi Mahabadi , Quoc Tran-Dinh , Volkan Cevher

In this paper, we provide a generalization of the forward-backward splitting algorithm for minimizing the sum of a proper convex lower semicontinuous function and a differentiable convex function whose gradient satisfies a locally…

Optimization and Control · Mathematics 2023-06-29 Luis M. Briceno-Arias , Francisco José Silva , Xianjin Yang

We consider the problem of providing optimal uncertainty quantification (UQ) --- and hence rigorous certification --- for partially-observed functions. We present a UQ framework within which the observations may be small or large in number,…

Probability · Mathematics 2016-05-20 T. J. Sullivan , M. McKerns , D. Meyer , F. Theil , H. Owhadi , M. Ortiz

In this article we present a modification of classical Radial Basis Function (RBF) interpolation techniques aimed at reducing oscillations near discontinuities in one and two dimensions. Our approach introduces an adaptive mechanism by…

Numerical Analysis · Mathematics 2026-03-25 José Kuruc , David Levin , Pep Mulet , Juan Ruiz-Álvarez , Dionisio F. Yáñez