Results 111 to 120 of about 49,764 (200)

Uniqueness of size-2 positive semidefinite matrix factorizations

open access: yes
We characterize when a size-2 positive semidefinite (psd) factorization of a positive matrix of rank 3 and psd rank 2 is unique. The characterization is obtained using tools from rigidity theory. In the first step, we define s-infinitesimally rigid psd factorizations and characterize 1- and 2-infinitesimally rigid size-2 psd factorizations.
Dawson, Kristen   +3 more
openaire   +2 more sources

From ƒ-Divergence to Quantum Quasi-Entropies and Their Use

open access: yesEntropy, 2010
Csiszár’s ƒ-divergence of two probability distributions was extended to the quantum case by the author in 1985. In the quantum setting, positive semidefinite matrices are in the place of probability distributions and the quantum generalization is called ...
Dénes Petz
doaj   +1 more source

Positive Semidefinite Metric Learning with Boosting

open access: yes, 2009
The learning of appropriate distance metrics is a critical problem in image classification and retrieval. In this work, we propose a boosting-based technique, termed \BoostMetric, for learning a Mahalanobis distance metric.
Hengel, Anton van den   +3 more
core  

General Zagreb adjacency matrix [PDF]

open access: yesContributions to Mathematics, 2022
Zhen Lin
doaj   +1 more source

Optimal Pilot Design for MIMO Broadcasting Systems Based on the Positive Definite Matrix Manifold

open access: yesIEEE Access, 2019
In the MIMO broadcasting system, channel state information (CSI) is often used for data detection at the receiver or preprocessing techniques such as the power control and user scheduling at the transmitter and hence, the study of its acquisition is ...
Wen Zhou   +4 more
doaj   +1 more source

Positive semidefiniteness of estimated covariance matrices in linear models for sample survey data

open access: yesSpecial Matrices, 2016
Descriptive analysis of sample survey data estimates means, totals and their variances in a design framework. When analysis is extended to linear models, the standard design-based method for regression parameters includes inverse selection probabilities ...
Haslett Stephen
doaj   +1 more source

Semidefinite geometry of the numerical range

open access: yes, 2008
The numerical range of a matrix is studied geometrically via the cone of positive semidefinite matrices (or semidefinite cone for short). In particular it is shown that the feasible set of a two-dimensional linear matrix inequality (LMI), an affine ...
Henrion, Didier
core   +1 more source

A Framework for Coxeter Spectral Classification of Finite Posets and Their Mesh Geometries of Roots

open access: yesInternational Journal of Mathematics and Mathematical Sciences, 2013
Following our paper [Linear Algebra Appl. 433(2010), 699–717], we present a framework and computational tools for the Coxeter spectral classification of finite posets J≡(J,⪯).
Daniel Simson, Katarzyna Zając
doaj   +1 more source

Gaussian mixtures closest to a given measure via optimal transport

open access: yesComptes Rendus. Mathématique
Given a determinate (multivariate) probability measure $\mu $, we characterize Gaussian mixtures $\nu _\phi $ which minimize the Wasserstein distance $W_2(\mu ,\nu _\phi )$ to $\mu $ when the mixing probability measure $\phi $ on the parameters $(\mathbf{
Lasserre, Jean B.
doaj   +1 more source

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