Results 11 to 20 of about 564,115 (361)

On matrix valued square integrable positive definite functions [PDF]

Monatshefte für Mathematik, 2015
In this paper, we study matrix valued positive definite functions on a unimodular group. We generalize two important results of Godement on square integrable positive definite functions to matrix valued square integrable positive definite functions.
He, Hongyu
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Solutions and Improved Perturbation Analysis for the Matrix Equation X-A*X-pA=Q   (p>0) [PDF]

Abstract and Applied Analysis, 2013
The nonlinear matrix equation X-A*X-pA=Q with p>0 is investigated.
Jing Li
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Positive definite matrix functions on spheres defined by hypergeometric functions

Integral transforms and special functions, 2019
Positive definite matrix functions on spheres arise naturally in multivariate approximation and spatial statistics. The construction of strictly positive definite models has become one of the most important goals for the analysis and study of vector ...
Jean Carlo Guella, V‎. ‎A‎. Menegatto   +1 more
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Weighted spectral geometric means and matrix equations of positive definite matrices involving semi-tensor products

AIMS Mathematics
We characterized weighted spectral geometric means (SGM) of positive definite matrices in terms of certain matrix equations involving metric geometric means (MGM) $ \sharp $ and semi-tensor products $ \ltimes $. Indeed, for each real number $ t $ and two
Arnon Ploymukda , Kanjanaporn Tansri, Pattrawut Chansangiam   +2 more
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A Simple, Positive Semi-Definite, Heteroskedasticity and AutocorrelationConsistent Covariance Matrix [PDF]

, 1986
Whitney K. Newey, Kenneth D. West
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Positive definite solution of non-linear matrix equations through fixed point technique

AIMS Mathematics, 2022
The goal of this study is to solve a non-linear matrix equation of the form $ \mathcal{X} = \mathcal{Q} + \sum\limits_{i = 1}^{m} \mathcal{B}_{i}^{*}\mathcal{G} (\mathcal{X})\mathcal{B}_{i} $, where $ \mathcal{Q} $ is a Hermitian positive definite ...
Sourav Shil, Hemant Kumar Nashine
doaj   +1 more source

mbend: an R package for bending non-positive-definite symmetric matrices to positive-definite

BMC Genetics, 2020
Background R package mbend was developed for bending symmetric non-positive-definite matrices to positive-definite (PD). Bending is a procedure of transforming non-PD matrices to PD.
Mohammad Ali Nilforooshan
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Positive Definiteness of Symmetric Rank 1 (H-Version) Update for Unconstrained Optimization

مجلة بغداد للعلوم, 2022
Several attempts have been made to modify the quasi-Newton condition in order to obtain rapid convergence with complete properties (symmetric and positive definite) of the inverse of  Hessian matrix (second derivative of the objective function).
Saad Shakir Mahmood, Jaafer Hmood Eidi, Jinan Adel Jasem   +2 more
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Modified BFGS Update (H-Version) Based on the Determinant Property of Inverse of Hessian Matrix for Unconstrained Optimization

مجلة بغداد للعلوم, 2020
The study presents the modification of the Broyden-Flecher-Goldfarb-Shanno (BFGS) update (H-Version) based on the determinant property of inverse of Hessian matrix (second derivative of the objective function), via updating of the vector s ( the ...
Saad Shakir Mahmood
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