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The purpose of this paper is to study the approximation of vector valued mappings defined on a subset of a normed space. We investigate Korovkin-type conditions under which a given sequence of linear operators becomes a so-called…

Functional Analysis · Mathematics 2007-05-23 Lorenzo D'Ambrosio

In this paper we introduce the Stancu type generalization of the q-Bernstein-Schurer-Kantorovich operators and examine their approximation properties. We investigate the convergence of our operators with the help of the Korovkin's…

Classical Analysis and ODEs · Mathematics 2016-02-23 M. Mursaleen , Taqseer Khan

The main result of the present theoretical paper is an original decomposition formula for the proximal operator of the sum of two proper, lower semicontinuous and convex functions $f$ and $g$. For this purpose, we introduce a new operator,…

Optimization and Control · Mathematics 2018-06-13 Samir Adly , Loïc Bourdin , Fabien Caubet

Probabilistic conditioning is concerned with the identification of a distribution of a random variable $X$ given a random variable $Y$. It is a cornerstone of scientific and engineering applications where modeling uncertainty is key. This…

Machine Learning · Statistics 2026-05-13 Panos Tsimpos , Edoardo Calvello , Ayoub Belhadji , Nicholas H. Nelsen

In this paper, we consider optimizing a smooth, convex, lower semicontinuous function in Riemannian space with constraints. To solve the problem, we first convert it to a dual problem and then propose a general primal-dual algorithm to…

Machine Learning · Computer Science 2020-05-20 Shijun Wang , Baocheng Zhu , Lintao Ma , Yuan Qi

This technical note studies a class of distributed nonsmooth convex consensus optimization problem. The cost function is a summation of local cost functions which are convex but nonsmooth. Each of the local cost functions consists of a…

Optimization and Control · Mathematics 2018-08-17 Yue Wei , Hao Fang , Xianlin Zeng , Jie Chen , Panos M. Pardalos

In \cite{cheung2019optimally}, the authors presented two finite element methods for approximating second order boundary value problems on polytopial meshes with optimal accuracy without having to utilize curvilinear mappings. This was done…

Numerical Analysis · Mathematics 2023-01-11 James Cheung

This paper studies bilinear saddle point problems $\min_{\bf{x}} \max_{\bf{y}} g(\bf{x}) + \bf{x}^{\top} \bf{A} \bf{y} - h(\bf{y})$, where the functions $g, h$ are smooth and strongly-convex. When the gradient and proximal oracle related to…

Machine Learning · Computer Science 2021-03-16 Guangzeng Xie , Yuze Han , Zhihua Zhang

In this paper, we introduce the new construction of fractional derivatives and integrals with respect to a function, based on a matrix approach. We believe that this is a powerful tool in both analytical and numerical calculations. We begin…

Numerical Analysis · Mathematics 2025-12-12 V. N. Kolokoltsov , E. L. Shishkina

We consider a regularized least squares problem, with regularization by structured sparsity-inducing norms, which extend the usual $\ell_1$ and the group lasso penalty, by allowing the subsets to overlap. Such regularizations lead to…

Optimization and Control · Mathematics 2012-09-04 Silvia Villa , Lorenzo Rosasco , Sofia Mosci , Alessandro Verri

This work concerns the zeroth-order global minimization of continuous nonconvex functions with a unique global minimizer and possibly multiple local minimizers. We formulate a theoretical framework for inexact proximal point (IPP) methods…

Optimization and Control · Mathematics 2025-06-03 Minxin Zhang , Fuqun Han , Yat Tin Chow , Stanley Osher , Hayden Schaeffer

We present a numerical iterative optimization algorithm for the minimization of a cost function consisting of a linear combination of three convex terms, one of which is differentiable, a second one is prox-simple and the third one is the…

Optimization and Control · Mathematics 2024-10-04 Ignace Loris , Simone Rebegoldi

We propose a new random sketching approach for embedding high-dimensional Hilbert-Schmidt operators, using random input-output pairs. Such operator can then be approximated in a low-dimensional subspace of operators by solving a small…

Numerical Analysis · Mathematics 2026-04-15 Oleg Balabanov , Anthony Nouy , Alexandre Pasco

We consider a bilevel problem involving two monotone equilibrium bifunctions and we show that this problem can be solved by a proximal point method with generalized proximal distances. We propose a framework for the convergence analysis of…

Optimization and Control · Mathematics 2014-07-09 G. C. Bento , J. X. Cruz Neto , J. O. Lopes , P. A. Soares , A. Soubeyran

We propose a new primal-dual splitting method for solving composite inclusions involving Lipschitzian, and parallel-sum-type monotone operators. Our approach extends the framework in \cite{Siopt4} to a more general class of monotone…

Optimization and Control · Mathematics 2015-07-28 Quoc Tran-Dinh , Bang Cong Vu

We give a new algorithm for the construction of the unique superoptimal analytic approximant of a given continuous matrix-valued function on the unit circle, making use of exterior powers of operators in preference to spectral or {\em…

Functional Analysis · Mathematics 2021-08-06 Dimitrios Chiotis , Zinaida Lykova , Nicholas Young

We propose a new first-order optimisation algorithm to solve high-dimensional non-smooth composite minimisation problems. Typical examples of such problems have an objective that decomposes into a non-smooth empirical risk part and a…

Optimization and Control · Mathematics 2015-07-07 Niao He , Zaid Harchaoui

We provide the first nearly-linear time algorithm for approximating $\ell_{q \rightarrow p}$-norms of non-negative matrices, for $q \geq p \geq 1$. Our algorithm returns a $(1-\varepsilon)$-approximation to the matrix norm in time…

Data Structures and Algorithms · Computer Science 2025-03-26 Étienne Objois , Adrian Vladu

In this paper we develop proximal methods for statistical learning. Proximal point algorithms are useful in statistics and machine learning for obtaining optimization solutions for composite functions. Our approach exploits closed-form…

Machine Learning · Statistics 2015-06-02 Nicholas G. Polson , James G. Scott , Brandon T. Willard

In this paper we deal with the connection of frames with the class of Hilbert Schmidt operators. First we give an easy criteria for operators being in this class using frames. It is the equivalent to the criteria using orthonormal bases.…

Functional Analysis · Mathematics 2008-04-09 Peter Balazs