Results 111 to 120 of about 41,020 (249)
On directional derivatives of trace functionals of the form $A\mapsto\Tr(Pf(A))$
, 2018 Given a function $f:(0,\infty)\rightarrow\RR$ and a positive semidefinite $n\times n$ matrix $P$, one may define a trace functional on positive definite $n\times n$ matrices as $A\mapsto \Tr(Pf(A))$.
Girard, Mark W.
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Conjugate cone characterization of positive definite and semidefinite matrices [PDF]
, 1984 S.-P. Han, O. L. Mangasarian
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Mathematical Methods in the Applied Sciences, Volume 48, Issue 8, Page 9088-9097, 30 May 2025.ABSTRACT We suggest a modified version of the nonnegative matrix factorization problem, adding penalty terms to the model with the aim of taking control of the condition number of the decomposition elements. This measure is taken to reinforce computational stability in the solution path of the relevant optimization model.
Fatemeh Dargahi +3 more
wiley +1 more source
Positive semidefiniteness of estimated covariance matrices in linear models for sample survey data
Special 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
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On vector configurations that can be realized in the cone of positive matrices
, 2010 Let $v_1$,..., $v_n$ be $n$ vectors in an inner product space. Can we find a natural number $d$ and positive (semidefinite) complex matrices $A_1$,..., $A_n$ of size $d \times d$ such that ${\rm Tr}(A_kA_l)= $ for all $k,l=1,..., n$? For such matrices to
Frenkel, Péter E., Weiner, Mihály
core
Positive semidefinite matrices with a given sparsity pattern
Linear Algebra and its Applications, 1988 AbstractThis paper concerns the cone of positive semidefinite matrices which have zeros in prescribed entries. One of the main purposes is to obtain information and, if possible, describe the ranks of external matrices in such cones in terms of the pattern of prescribed zeros.
Leiba Rodman +4 more
openaire +2 more sources
Using distance on the Riemannian manifold to compare representations in brain and in models
NeuroImage, 2021 Representational similarity analysis (RSA) summarizes activity patterns for a set of experimental conditions into a matrix composed of pairwise comparisons between activity patterns.
Mahdiyar Shahbazi +3 more
doaj
Hyperbolic Polynomials and Generalized Clifford Algebras [PDF]
, 2012 We consider the problem of realizing hyperbolicity cones as spectrahedra, i.e. as linear slices of cones of positive semidefinite matrices. The generalized Lax conjecture states that this is always possible. We use generalized Clifford algebras for a new
Netzer, Tim, Thom, Andreas
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Mokslas: Lietuvos Ateitis, 2015 Semidefinite Programming (SDP) is a fairly recent way of solving optimization problems which are becoming more and more important in our fast moving world. It is a minimization of linear function over the intersection of the cone of positive semidefinite
Rasa Giniūnaitė
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On semidefinite representations of plane quartics
, 2008 This note focuses on the problem of representing convex sets as projections of the cone of positive semidefinite matrices, in the particular case of sets generated by bivariate polynomials of degree four.
Henrion, Didier
core +5 more sources