Results 61 to 70 of about 1,468 (179)
Extremal positive semidefinite doubly stochastic matrices
Linear Algebra and its Applications, 1991 This paper continues the investigation initiated by \textit{J. P. R. Christensen} and \textit{P. Fischer} [ibid. 82, 123-132 (1986; Zbl 0599.15011)] on the extreme points of \(K_ n=H_ n\cap \Omega_ n\), the intersection set of the closed convex cone \(H_ n\) of all real \(n\times n\) symmetric positive semidefinite matrices and the compact convex set \(
Grone, Bob, Pierce, Steve
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International Journal of Adaptive Control and Signal Processing, Volume 40, Issue 3, Page 544-564, March 2026.This paper proposes two projector‐based Hopfield neural network (HNN) estimators for online, constrained parameter estimation under time‐varying data, additive disturbances, and slowly drifting physical parameters. The first is a constraint‐aware HNN that enforces linear equalities and inequalities (via slack neurons) and continuously tracks the ...
Miguel Pedro Silva
wiley +1 more source
A Geometric Mean of Parameterized Arithmetic and Harmonic Means of Convex Functions
Abstract and Applied Analysis, 2012 The notion of the geometric mean of two positive reals is extended by Ando (1978) to the case of positive semidefinite matrices A and B. Moreover, an interesting generalization of the geometric mean A # B of A and B to convex functions was introduced by ...
Sangho Kum, Yongdo Lim
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Log-Determinant Divergences Revisited: Alpha-Beta and Gamma Log-Det Divergences
Entropy, 2015 This work reviews and extends a family of log-determinant (log-det) divergences for symmetric positive definite (SPD) matrices and discusses their fundamental properties.
Andrzej Cichocki +2 more
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Rank inequalities for positive semidefinite matrices
Linear Algebra and its Applications, 1996 Several inequalities relating the rank of a positive semidefinite matrix with the ranks of various principal submatrices are presented. These inequalities are analogous to known determinantal inequalities for positive definite matrices, such as Fischer's inequality, Koteljanskii's inequality, and extensions of these associated with chordal graphs.
Lundquist, Michael, Barrett, Wayne
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Simulating Quantum State Transfer Between Distributed Devices Using Noisy Interconnects
Advanced Quantum Technologies, Volume 9, Issue 3, March 2026.Noisy connections challenge future networked quantum computers. This work presents a practical method to address this by simulating an ideal state transfer over noisy interconnects. The approach reduces the high sampling cost of previous methods, an advantage that improves as interconnect quality gets better.
Marvin Bechtold +3 more
wiley +1 more source
ON THE SET-SEMIDEFINITE REPRESENTATION OF NONCONVEX QUADRATIC PROGRAMS WITH CONE CONSTRAINTS
Croatian Operational Research Review, 2010 The well-known result stating that any non-convex quadratic problem over the non-negative orthant with some additional linear and binary constraints can be rewritten as linear problem over the cone of completely positive matrices (Burer, 2009) is ...
Gabriele Eichfelder, Janez Povh
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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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From ƒ-Divergence to Quantum Quasi-Entropies and Their Use
Entropy, 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
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Journal of Numerical Analysis and Approximation Theory, 2010 In this paper, we obtain new results concerning the generalizations of additive and multiplicative majorizations by means of exponential convexity. We prove positive semi-definiteness of matrices generated by differences deduced from majorization type ...
Naveed Latif, Josip Pečarić
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