4,405 research outputs found
On Norm-Based Estimations for Domains of Attraction in Nonlinear Time-Delay Systems
For nonlinear time-delay systems, domains of attraction are rarely studied
despite their importance for technological applications. The present paper
provides methodological hints for the determination of an upper bound on the
radius of attraction by numerical means. Thereby, the respective Banach space
for initial functions has to be selected and primary initial functions have to
be chosen. The latter are used in time-forward simulations to determine a first
upper bound on the radius of attraction. Thereafter, this upper bound is
refined by secondary initial functions, which result a posteriori from the
preceding simulations. Additionally, a bifurcation analysis should be
undertaken. This analysis results in a possible improvement of the previous
estimation. An example of a time-delayed swing equation demonstrates the
various aspects.Comment: 33 pages, 8 figures, "This is a pre-print of an article published in
'Nonlinear Dynamics'. The final authenticated version is available online at
https://doi.org/10.1007/s11071-020-05620-8
Efficient Approaches for Enclosing the United Solution Set of the Interval Generalized Sylvester Matrix Equation
In this work, we investigate the interval generalized Sylvester matrix
equation and develop some
techniques for obtaining outer estimations for the so-called united solution
set of this interval system. First, we propose a modified variant of the
Krawczyk operator which causes reducing computational complexity to cubic,
compared to Kronecker product form. We then propose an iterative technique for
enclosing the solution set. These approaches are based on spectral
decompositions of the midpoints of , , and
and in both of them we suppose that the midpoints of and
are simultaneously diagonalizable as well as for the midpoints of
the matrices and . Some numerical experiments are given to
illustrate the performance of the proposed methods
Maximal-entropy-production-rate nonlinear quantum dynamics compatible with second law, reciprocity, fluctuation-dissipation, and time-energy uncertainty relations
In view of the recent quest for well-behaved nonlinear extensions of the
traditional Schroedinger-von Neumann unitary dynamics that could provide
fundamental explanations of recent experimental evidence of loss of quantum
coherence at the microscopic level, in this paper, together with a review of
the general features of the nonlinear quantum (thermo)dynamics I proposed in a
series of papers [see references in G.P. Beretta, Found.Phys. 17, 365 (1987)],
I show its exact equivalence with the maximal-entropy-production
variational-principle formulation recently derived in S.
Gheorghiu-Svirschevski, Phys.Rev. A 63, 022105 (2001). In addition, based on
the formalism of general interest I developed for the analysis of composite
systems, I show how the variational derivation can be extended to the case of a
composite system to obtain the general form of my equation of motion, that
turns out to be consistent with the demanding requirements of strong
separability. Moreover, I propose a new intriguing fundamental ansatz: that the
time evolution along the direction of steepest entropy ascent unfolds at the
fastest rate compatible with the time-energy Heisenberg uncertainty relation.
This ansatz provides a possible well-behaved general closure of the nonlinear
dynamics, compatible with the nontrivial requirements of strong separability,
and with no need of new physical constants. In any case, the time-energy
uncertainty relation provides lower bounds to the internal-relaxation-time
functionals and, therefore, upper bounds to the rate of entropy production.Comment: RevTeX; 19 pages; submitted to Phys.Rev.A on Feb.9, 2001; revised
version submitted on Sept.14, 2001 with slightly modified derivation in
Section III, improved discussion on strong separability in Sections X and IX,
added Eqs. 64b, 64c and 11
A Small-Gain Theorem with Applications to Input/Output Systems, Incremental Stability, Detectability, and Interconnections
A general ISS-type small-gain result is presented. It specializes to a
small-gain theorem for ISS operators, and it also recovers the classical
statement for ISS systems in state-space form. In addition, we highlight
applications to incrementally stable systems, detectable systems, and to
interconnections of stable systems.Comment: 16 pages, no figure
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