Results 91 to 100 of about 71,699 (272)

Certain Positive Semidefinite Matrices of Special Functions [PDF]

open access: yes, 2018
Special functions are often defined as a Fourier or Laplace transform of a positive measure, and the positivity of the measure manifests as positive definiteness of certain matrices. The purpose of this expository note is to give a sample of such positive definite matrices to demonstrate this connection for some well-known special functions such as ...
openaire   +2 more sources

Multi‐Objective Robust Controller Synthesis With Integral Quadratic Constraints in Discrete‐Time

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This article presents a novel framework for the robust controller synthesis problem in discrete‐time systems using dynamic Integral Quadratic Constraints (IQCs). We present an algorithm to minimize closed‐loop performance measures such as the ℋ∞$$ {\mathscr{H}}_{\infty } $$‐norm, the energy‐to‐peak gain, the peak‐to‐peak gain, or a ...
Lukas Schwenkel   +4 more
wiley   +1 more source

A generalization and an application of the arithmetic–geometric mean inequality for the Frobenius norm

open access: yesJournal of Inequalities and Applications, 2018
Recently, Kittaneh and Manasrah (J. Math. Anal. Appl. 361:262–269, 2010) showed a refinement of the arithmetic–geometric mean inequality for the Frobenius norm. In this paper, we shall present a generalization of Kittaneh and Manasrah’s result. Meanwhile,
Xuesha Wu
doaj   +1 more source

Separability of symmetric states and vandermonde decomposition

open access: yesNew Journal of Physics, 2020
Symmetry is one of the central mysteries of quantum mechanics and plays an essential role in multipartite entanglement. In this paper, we consider the separability problem of quantum states in the symmetric space.
Lilong Qian, Lin Chen, Delin Chu
doaj   +1 more source

On directional derivatives of trace functionals of the form $A\mapsto\Tr(Pf(A))$

open access: yes, 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.
core   +1 more source

Hanner's Inequality For Positive Semidefinite Matrices

open access: yes, 2021
Error in Theorem 3.1 requires significant ...
openaire   +2 more sources

On Positive Semidefinite Matrices with Known Null Space [PDF]

open access: yesSIAM Journal on Matrix Analysis and Applications, 2002
We show how the zero structure of a basis of the null space of a positive semidefinite matrix can be exploited to determine a positive definite submatrix of maximal rank. We discuss consequences of this result for the solution of (constrained) linear systems and eigenvalue problems.
Arbenz, Peter, Drmac, Zlatko
openaire   +3 more sources

Data‐Based Refinement of Parametric Uncertainty Descriptions

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT We consider dynamical systems with a linear fractional representation involving parametric uncertainties which are either constant or varying with time. Given a finite‐horizon input‐state or input‐output trajectory of such a system, we propose a numerical scheme which iteratively improves the available knowledge about the involved constant ...
Tobias Holicki, Carsten W. Scherer
wiley   +1 more source

Homogeneous Observer‐Based Affine Formation Tracking

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This article addresses the control of mobile agents, termed followers, to track a time‐varying affine formation specified by a set of leaders. We present a distributed hierarchical method composed of a homogeneous high‐order sliding mode observer and a tracking controller. The observer estimates the followers' target trajectories from neighbor
Rodrigo Aldana‐López   +3 more
wiley   +1 more source

Dynamic Event‐Triggered Robust Model Predictive Control for Quadrotor Trajectory Tracking

open access: yesInternational Journal of Robust and Nonlinear Control, EarlyView.
ABSTRACT This paper addresses the trajectory tracking problem for a full‐state quadrotor subject to physical model constraints and unknown external disturbances. A robust tube‐based model predictive control (MPC) approach is successfully applied to the system, which is subject to bounded disturbances and hard constraints.
Ali Can Erüst   +2 more
wiley   +1 more source

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