Buscar recursos académicos

"It is shown that impulsive systems of nonlinear, time-varying and/or switched form that allow a stable global state weak linearization are jointly input-to-state stable (ISS) under small inputs and integral ISS (iISS). ...

"Very recently, it has been shown that the standard notion of stability for impulsive systems, whereby the state is ensured to approach the equilibrium only as continuous time elapses, is too weak to allow for any meanin...

"In this paper we study the stability of nonlinear and time-varying switched systems under restricted switching. We approach the problem by decomposing the system dynamics into a nominal-like part and a perturbationlike ...

"Stability results for time-varying systems with inputs are relatively scarce, as opposed to the abundant literature available for time-invariant systems. This paper extends to time-varying systems existing results that ...

"In this paper, it is shown that an algorithm for the stabilisation of switched systems introduced by the authors is robust with respect to perturbations which are unbounded in the supremum norm, but bounded in a power-l...

"This paper is concerned with the study of both, local and global, uniform asymptotic stability for switched nonlinear time-varying (NLTV) systems through the detectability of outputmaps. With this aim the notion of redu...

"In this paper we present a criterion for the uniform global asymptotic stability of switched nonlinear systems with time/state-dependent switching constraints but with no dwell-time assumptions. This criterion is based ...

"We provide novel sufficient conditions for stability of nonlinear and time-varying impulsive systems. These conditions generalize, extend, and strengthen many existing results. Different types of input-to-state stabilit...

"Characterizations of various uniform stability properties of switched systems described by differential inclusions, and whose switchings are governed by a digraph, are developed. These characterizations are given in t...

"Most of the existing characterizations of the integral input-to-state stability (iISS) property are not valid for time-varying or switched systems in cases where converse Lyapunov theorems for stability are not availabl...

"For time-invariant systems, the property of input-to-state stability (ISS) is known to be strictly stronger than integral-ISS (iISS). Known proofs of the fact that ISS implies iISS employ Lyapunov characterizations of b...

Objective. The aim of this study was to determine the prevalence of asymptomatic nasopharyngeal carriage of Streptococcus pneumoniae , which is a major factor in the transmission of this bacterium. Material and Meth...

Objective. To analyze the results of a stool work-up protocolin a series of infants and preschoolers with acute diarrhea.Material and Methods. A cross-sectional descriptive studywas conducted between April 1999 and March...

For large classes of infinite-dimensional time-varying control systems, the equivalence between integral input-to-state stability (iISS) and the combination of global uniform asymptotic stability under zero input (0-GUAS...

"In this paper we address invariance principles for nonlinear switched systems with otherwise arbitrary compact index set and with constrained switchings. We present an extension of LaSalle's invariance principle for the...

We present here a deciduous tooth recovered from the Blancan (Pliocene) Río Tomayate locality (Republic of El Salvador) and assign it to cf. Arctotherium (South American short-faced bears) based on its morphology and si...

"Most of the existing characterizations of the integral input-to-state stability (iISS) property are not suitable for time varying or switched (nonlinear) systems. Previous work by the authors has shown that in such case...

Anthraquinones-rich extracts of Heterophyllaea pustulata Hook f. (Rubiaceae) exhibited in vitro antiviral activity against Herpes Simplex Virus Type I, from which several anthraquinones (AQs) were isolated and identified...

"How to bound the state vector trajectory of a nonlinear system in a way so that the obtained bound be of practical value is an open problem. If some norm is employed for bounding the state vector trajectory, then this n...