Results 41 to 50 of about 277,976 (316)

A Note on Quaternion Skew-Symmetric Matrices [PDF]

open access: yesarXiv, 2021
The product of a complex skew-symmetric matrix and its conjugate transpose is a positive semi-definite Hermitian matrix with nonnegative eigenvalues, with a property that each distinct positive eigenvalue has even multiplicity. This property plays a key role for Professor Loo-Keng Hua to establish the unitary equivalence theorem for complex skew ...
arxiv  

Constrained Solutions of a System of Matrix Equations

open access: yesJournal of Applied Mathematics, 2012
We derive the necessary and sufficient conditions of and the expressions for the orthogonal solutions, the symmetric orthogonal solutions, and the skew-symmetric orthogonal solutions of the system of matrix equations AX=B and XC=D, respectively. When the
Qing-Wen Wang, Juan Yu
doaj   +1 more source

Sufficient conditions for symmetric matrices to have exactly one positive eigenvalue

open access: yesSpecial Matrices, 2020
Let A = [aij] be a real symmetric matrix. If f : (0, ∞) → [0, ∞) is a Bernstein function, a sufficient condition for the matrix [f (aij)] to have only one positive eigenvalue is presented.
Al-Saafin Doaa, Garloff Jürgen
doaj   +1 more source

Unsupervised non‐small cell lung cancer tumor segmentation using cycled generative adversarial network with similarity‐based discriminator

open access: yesJournal of Applied Clinical Medical Physics, EarlyView.
Abstract Background Tumor segmentation is crucial for lung disease diagnosis and treatment. Most existing deep learning‐based automatic segmentation methods rely on manually annotated data for network training. Purpose This study aims to develop an unsupervised tumor segmentation network smic‐GAN by using a similarity‐driven generative adversarial ...
Chengyijue Fang   +2 more
wiley   +1 more source

Claustrum Volume Is Reduced in Multiple Sclerosis and Predicts Disability

open access: yesAnnals of Clinical and Translational Neurology, EarlyView.
ABSTRACT Objective The claustrum is a small, thin structure of predominantly gray matter with broad connectivity and enigmatic function. Little is known regarding the impact of claustrum pathology in multiple sclerosis (MS). Methods This study assessed whether claustrum volume was reduced in MS and whether reductions were associated with specific ...
Nicole Shelley   +5 more
wiley   +1 more source

The quantum marginal problem for symmetric states: applications to variational optimization, nonlocality and self-testing

open access: yesNew Journal of Physics, 2021
In this paper, we present a method to solve the quantum marginal problem for symmetric d -level systems. The method is built upon an efficient semi-definite program that uses the compatibility conditions of an m -body reduced density with a global n ...
Albert Aloy, Matteo Fadel, Jordi Tura
doaj   +1 more source

A matrix subadditivity inequality for symmetric norms [PDF]

open access: yesProceedings of the American Mathematical Society, 2009
Well-known subadditivity results for positive operators (of Brown-Kosaki and Rotfeld/Ando-Zhan types) are extended to Hermitian and normal ones. Applications to Cartesian decomposition and block-matrices are given.
openaire   +5 more sources

The Orbit Rigidity Matrix of a Symmetric Framework [PDF]

open access: yesDiscrete & Computational Geometry, 2010
41 pages, 12 ...
Schulze, Bernd, Whiteley, Walter
openaire   +4 more sources

Random Learning Leads to Faster Convergence in ‘Model‐Free’ ILC: With Application to MIMO Feedforward in Industrial Printing

open access: yesInternational Journal of Adaptive Control and Signal Processing, EarlyView.
The cost as a function of the number of experiments for a non‐symmetric 21×21$$ 21\times 21 $$ system. Four approaches are shown: the proposed stochastic conjugate gradient ILC (SCGILC) method (), deterministic conjugate gradient ILC (), stochastic gradient descent ILC () and deterministic gradient descent ILC ().
Leontine Aarnoudse, Tom Oomen
wiley   +1 more source

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