Results 81 to 90 of about 6,682,316 (219)

Norm inequalities for functions of matrices

Heliyon
In this paper, we prove several spectral norm and unitarily invariant norm inequalities for matrices in which the special cases of our results present some known inequalities. Also, some of our results give interpolating inequalities which are related to
Ahmad Al-Natoor
doaj   +1 more source

Proximal Alternating Direction Method with Relaxed Proximal Parameters for the Least Squares Covariance Adjustment Problem

Abstract and Applied Analysis, 2014
We consider the problem of seeking a symmetric positive semidefinite matrix in a closed convex set to approximate a given matrix. This problem may arise in several areas of numerical linear algebra or come from finance industry or statistics and thus has
Minghua Xu, Yong Zhang, Qinglong Huang, Zhenhua Yang   +3 more
doaj   +1 more source

Positive semidefinite matrix completion, universal rigidity and the Strong Arnold Property

Linear Algebra and its Applications, 2014
This paper addresses the following three topics: positive semidefinite (psd) matrix completions, universal rigidity of frameworks, and the Strong Arnold Property (SAP). We show some strong connections among these topics, using semidefinite programming as unifying theme.
M. Laurent (Monique), A. Varvitsiotis (Antonios)   +1 more
openaire   +4 more sources

The Unintended Consequences of Sugar‐Sweetened Beverage Taxes on Sales and Prices of Beer Beverages

Health Economics, Volume 35, Issue 12, Page 1814-1834, December 2026.
ABSTRACT This paper estimates the causal effect of Berkeley's sugar‐sweetened beverage (SSB) tax on beer purchases and prices using retail scanner data from 2014 to 2015. Applying both synthetic control and difference‐in‐differences (DID) approaches, we find that the tax reduced beer purchases within Berkeley by 8.9%, while having a negligible effect ...
Lei Pan, Xiaoyong Zheng
wiley   +1 more source

Optimal Experimental Design for Fast and Accurate Relaxation Time Measurements in Magnetic Resonance

Magnetic Resonance in Chemistry, Volume 64, Issue 12, Page 1001-1012, December 2026.
We apply D‐optimal experimental design to relaxation constant estimation in NMR relaxometry. The resulting sampling schedules concentrate measurements where the signal is most sensitive to the relaxation constant. Compared with conventional linear or logarithmic spacing, D‐optimal designs achieve better estimation accuracy and precision with fewer ...
Natalie E. Klein, Adam R. Altenhof, Amber J. Day, Michelle A. Espy, Michael W. Malone   +4 more
wiley   +1 more source

Advanced p-numerical radius bounds through partitioned matrix methodologies

Results in Applied Mathematics
The present investigation develops novel upper limits for the p-numerical radius of linear transformations through sophisticated partitioned matrix methodologies.
Raja’a Al-Naimi
doaj   +1 more source

A new approach for handling missing correlation values for meta‐analytic structural equation modeling: Corboundary R package

Campbell Systematic Reviews, 2020
With increased use of multivariate meta‐analysis in numerous disciplines, where structural relationships among multiple variables are examined, researchers often encounter a particular challenge due to missing information.
Soyeon Ahn, John M. Abbamonte
doaj   +1 more source

Symplecticity‐Preserving Prediction of Parameter‐Dependent Hamiltonian Dynamics by Generalized Kernel Interpolation

Proceedings in Applied Mathematics and Mechanics, Volume 26, Issue 4, December 2026.
ABSTRACT We extend the kernel‐based symplectic predictor introduced by Herkert et al. (2026) to a parameter‐augmented setting in which the learned flow‐map surrogate depends not only on the state, but also on additional variables such as physical parameters and macro time‐step sizes. The method uses a product kernel ansatz on a parameter and macro step
Robin Herkert, Tobias Ehring, Bernard Haasdonk   +2 more
wiley   +1 more source

Positive semidefinite germs in real analytic surfaces.

, 2002
We find all real analytic surface germs in R3 on which every positive semidefinite function germ is a sum of squares (in fact, of two squares) of analytic function germs.Ministerio de Educación y Ciencia (España)Depto.
Fernando Galván, José Francisco
core   +1 more source

A new generalization of two refined Young inequalities and applications

Moroccan Journal of Pure and Applied Analysis, 2020
In this paper, we prove that if a, b > 0 and 0 ≤ α ≤ 1, then for m = 1, 2, 3, . . . ,
Ighachane M. A., Akkouchi M.
doaj   +1 more source