Results 61 to 70 of about 4,272 (299)

On a Factorisation of Positive Definite Matrices [PDF]

Canadian Mathematical Bulletin, 1963
All our matrices are square with real elements. The Schur product of two n × n matrices B = (bij) and C = (cij) (i, j, = 1, 2, …, n), is an n × n matrix A = (aij) with aij = bij cij, (i, j = 1, 2, …, n).A result due to Schur [1] states that if B and C are symmetric positive definite matrices then so is their Schur product A. A question now a rises. Can
openaire   +1 more source

Triangular Index Ratio as an Alternative Method to the Alpha Angle for Defining the Presence of Cam Morphology: A Prospective Cohort Study

Arthritis Care &Research, EarlyView.
Objective Cam morphology, which is a significant risk factor for hip osteoarthritis, is commonly quantified by the alpha angle (AA). This study aims to explore the potential of the triangular index ratio (TIR) to quantify cam morphology on anteroposterior radiographs by assessing the association between TIR‐defined cam morphology and the development of
Jinchi Tang, Fleur Boel, Michiel M. A. van Buuren, Noortje S. Riedstra, Myrthe A. van den Berg, Jos Runhaar, Sita Bierma‐Zeinstra, Rintje Agricola   +7 more
wiley   +1 more source

From Adult to Adolescent: Alignment in Clinical Trials and Outcomes in Axial Spondyloarthritis

Arthritis Care &Research, Accepted Article.
Spondyloarthritis (SpA) is a group of chronic inflammatory diseases encompassing axial and peripheral forms, with up to 20% of patients developing symptoms before age 16. Despite this substantial pediatric burden, treatment options for juvenile‐onset SpA (JSpA), particularly those with axial disease (axJSpA), remain limited.
Pamela F. Weiss, Judith A. Smith, Robert A. Colbert, Erin Treemarcki, Michael H. Weisman, Walter P. Maksymowych, Hermine I. Brunner, for the CARRA, SPARTAN, and PRCSG Advisory Council   +9 more
wiley   +1 more source

Checking positive definiteness or stability of symmetric interval matrices is NP-hard [PDF]

, 1994
summary:It is proved that checking positive definiteness, stability or nonsingularity of all [symmetric] matrices contained in a symmetric interval matrix is NP ...
Rohn, Jiří
core  

Symmetry and Positive Definiteness in Oriented Matroids [PDF]

, 1988
We show the properties of a class of oriented matroids that properly generalizes the class of oriented matroids that can be represented by matrices of the form (I, − A), where A is a real n × n symmetric matrix and I is the n × n identity matrix. Several
Todd, Michael J., Morris, Walter D.
core   +1 more source

The Dirichlet problem successive upper relaxation numerical method convergence relaxation parameters influence investigations

Karpatsʹkì Matematičnì Publìkacìï, 2013
The relaxation parameters values to definite sequential upper relaxation block method convergence optimal velocity have been determined for the Dirichlet's problem in two-dimensional rectangle spatial region, the iteration procedure convergence and ...
A. P. Oliynyk, L. O. Shtayer
doaj   +1 more source

New lower bounds for the minimum M-eigenvalue of elasticity M-tensors and applications

Journal of Inequalities and Applications, 2020
M-eigenvalues of elasticity M-tensors play an important role in nonlinear elasticity and materials. In this paper, we present several new lower bounds for the minimum M-eigenvalue of elasticity M-tensors and propose numerical examples to illustrate the ...
Haitao Che, Haibin Chen, Na Xu, Qingni Zhu   +3 more
doaj   +1 more source

On the Stabilization of the Solution to the Initial Boundary Value Problem for One-Dimensional Isothermal Equations of Viscous Compressible Multicomponent Media Dynamics

Mathematics, 2023
An initial boundary value problem is considered for one-dimensional isothermal equations of the dynamics of viscous compressible multicomponent media, which are a generalization of the Navier–Stokes equations.
Dmitriy Prokudin
doaj   +1 more source

A Q‐Learning Algorithm to Solve the Two‐Player Zero‐Sum Game Problem for Nonlinear Systems

International Journal of Adaptive Control and Signal Processing, Volume 39, Issue 3, Page 566-581, March 2025.
A Q‐learning algorithm to solve the two‐player zero‐sum game problem for nonlinear systems. ABSTRACT This paper deals with the two‐player zero‐sum game problem, which is a bounded L2$$ {L}_2 $$‐gain robust control problem. Finding an analytical solution to the complex Hamilton‐Jacobi‐Issacs (HJI) equation is a challenging task.
Afreen Islam, Anthony Siming Chen, Guido Herrmann   +2 more
wiley   +1 more source

Sage–Husa Algorithm Based on Adaptive Double Forgetting Factors

Applied Sciences
In order to address the issues of insufficient filtering accuracy and filtering divergence that have been observed in the Sage–Husa algorithm when applied to nonlinear system state estimation, an adaptive double forgetting factor-based Sage–Husa ...
Wenjuan Li, Mingjing Zhan, Hui Feng
doaj   +1 more source