Results 81 to 90 of about 5,889,360 (355)

Structural Dynamics Model Updating with Positive Definiteness and No Spillover

, 2014
Model updating is a common method to improve the correlation between structural dynamics models and measured data. In conducting the updating, it is desirable to match only the measured spectral data without tampering with the other unmeasured and ...
Yongxin Yuan
semanticscholar   +1 more source

On Positive Definiteness of Some Functions

Journal of Multivariate Analysis, 2000
Let \(E\) be a linear space over \(\mathbb{R}\) and let \(\rho(x)\) be the \(\ell^n_p\)-norm in \(\mathbb{R}^n\). A function \(f: E\to\mathbb{C}\) is called definite if \(\sum^n_{k,j=1} c_k\overline c_jf(x_k- x_j)\geq 0\) for all \(n\in\mathbb{N}\), \(x_k\in E\), \(c_k\in\mathbb{C}\) for \(k= 1,2,\dots, n\).
openaire   +5 more sources

Extension of positive definite functions

Journal of Mathematical Analysis and Applications, 2015
Let $ \subset\mathbb{R}^n$ be an open, connected subset of $\mathbb{R}^n$, and let $F\colon - \to\mathbb{C}$, where $ - =\{x-y\colon x,y\in \}$, be a continuous positive definite function. We give necessary and sufficient conditions for $F$ to have an extension to a continuous positive definite function defined on the entire Euclidean space ...
Jorgensen, Palle, Niedzialomski, Robert
openaire   +3 more sources

Exploring patients’ profiles associated with the resolution of acute calcium pyrophosphate arthritis treatedwith colchicine and prednisone: post hoc analysis of a randomized controlled trial

Arthritis Care &Research, Accepted Article.
Objective The objective was to identify factors determining acute arthritis resolution and safety with colchicine and prednisone in acute calcium pyrophosphate (CPP) crystal arthritis. Methods We conducted a post hoc analysis of the COLCHICORT trial, which compared colchicine and prednisone for the treatment of acute CPP crystal arthritis, using a ...
Tristan Pascart, Laurène Norberciak, Pascal Richette, Pierre Robinet, Aurore Pacaud, Gauthier Marchasson, Thibault Rabin, Hélène Luraschi, Pierre Maciejasz, Anne‐France Georgel, Augustin Latourte, Hang‐Korng Ea, Sébastien Ottaviani, Charlotte Jauffret, Vincent Ducoulombier   +14 more
wiley   +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

Trajectory-Free Control of Lower-Limb Exoskeletons Through Underactuated Total Energy Shaping

IEEE Access, 2021
Kinematic control approaches for exoskeletons replicate normative joint kinematics associated with one specific task and user at a time, which makes it difficult to adjust to continuously-varying activities during gait training.
Ge Lv, Jianping Lin, Robert D. Gregg
doaj   +1 more source

On means of positive definite matrices [PDF]

Czechoslovak Mathematical Journal, 1987
\textit{E. Lutwak} [J. Linear Algebra Appl. 57, 13-19 (1984; Zbl 0529.15012)] defined \(\Phi_ p(A)\), the power mean of a positive definite \(n\times n\) symmetric matrix A, as \[ \Phi_ p(A) = [1/n\omega_ n\int_{S^{n-1}}(u,Au)^{p/2} dS(u)]^{2/p},\quad -\infty
openaire   +3 more sources

Operator equations and Moyal products -- metrics in quasi-hermitian quantum mechanics

, 2005
The Moyal product is used to cast the equation for the metric of a non-hermitian Hamiltonian in the form of a differential equation. For Hamiltonians of the form $p^2+V(ix)$ with $V$ polynomial this is an exact equation.
Bender, Bender, Bender, Bender, Bratteli, Curtright, Dobaczewski, Dobaczewski, Dobaczewski, F.G. Scholtz, Fairlie, Fairlie, Geyer, Geyer, H.B. Geyer, Jones, Mostafazadeh, Mostafazadeh, Mostafazadeh, Mostafazadeh, Moyal, Scholtz, Swanson, Wigner   +23 more
core   +1 more source

Ultrasound compared to Computed Tomography in identifying thoracic aortic aneurysms in patients with Giant Cell Arteritis

Arthritis Care &Research, Accepted Article.
Objectives The objectives of this study were to evaluate the correlation and agreement between ultrasound and computed tomography (CT) in measuring ascending aorta diameter in patients with giant cell arteritis (GCA) and to investigate the development of new ascending aortic aneurysms in patients with newly diagnosed GCA. Methods To achieve the primary
Anne C Bull Haaversen, Lene K Brekke, Tanaz A Kermani, Øyvind Molberg, Andreas P Diamantopoulos   +4 more
wiley   +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