On uniform exponential stability for skew-evolution semiflows on Banach spaces

The aim of this paper is to give several characterizations for the property of stability for skew-evolution semiflows on Banach spaces. Thus, we obtain generalizations of some well known results due to Barbashin, Datko and Rolewicz in the case of evolution equations in Banach spaces. A unified treatment in the uniform setting is provided.     

Uniform attractors for non-autonomous Brinkman-Forchheimer equations with delay

In this paper, we prove the existence of a uniform attractor for non-autonomous Brinkman-Forchheimer equations with general delay and time-dependent external force.     

Stability of uniform attractors of impulsive multi-valued semiflows

In this paper we investigate stability of uniformly attracting sets for semiflows generated by impulsive infinite-dimensional dynamical systems without uniqueness. Obtained abstract results are applied to weakly nonlinear parabolic system, whose trajectories have jumps at moments of intersection with certain surface in the phase space.     

Strong continuity implies uniform sequential continuity

Uniform sequential continuity, a property classically equivalent to sequential continuity on compact sets, is shown, constructively, to be a consequence of strong continuity on a metric space. It is then shown that in the case of a separable metric space, uniform sequential continuity implies strong continuity if and only if one adopts a certain boundedness principle that, although valid in the classical, recursive and intuitionistic setting, is independent of Heyting arithmetic.     

Uniform solution for uniform polyhedra

An arbitrary precision solution of uniform polyhedra and their duals is presented. The solution is uniform for all polyhedra given by their kaleidoscopic construction, with no need to examine each polyhedron separately.In memoriam of my father, Gershon Har'El, who introduced me to spatial structures.     

Finitely determined implies very weak Bernoulli

It is shown that if a process is finitely determined then it is very weak Bernoulli (VWB). Combined with known results this says that a process is isomorphic to a Bernoulli shift if and only if it satisfies an asymptotic independence condition, namely that of being VWB.     

Uniform attractors for non-autonomous motion equations of viscoelastic medium

Sufficient conditions for existence of minimal uniform trajectory attractors and uniform global attractors of non-autonomous evolution equations in Banach spaces are obtained. It is not assumed that the symbol space of an equation is a compact metric space and that the family of trajectory spaces corresponding to this symbol space is translation-coordinated or closed in any sense. Using these results, existence of minimal uniform trajectory attractors and uniform global attractors for weak solutions of the boundary value problem for motion equations of an incompressible viscoelastic medium with the Jeffreys constitutive law is shown.     

The strong persistence property and symbolic strong persistence property

Czechoslovak Mathematical Journal - Let I be an ideal in a commutative Noetherian ring R. Then the ideal I has the strong persistence property if and only if (Ik+1: RI) = Ik for all k, and I has...     

Continuous and discrete characterizations for the uniform exponential stability of linear skew-evolution semiflows

In this paper, we will consider the concept “linear skew-evolution semiflows” and extend theorems of R. Datko, S. Rolewicz, Zabczyk and J.M.A.M van Neerven for this case [15].     

Uniform exponential attractors for second order non-autonomous lattice dynamical systems

In this paper, the existence of a uniform exponential attractor for a second order non-autonomous lattice dynamical system with quasiperiodic symbols acting on a closed bounded set is considered. Firstly, the existence and uniqueness of solutions for the considered systems which generate a family of continuous processes is shown, and the existence of a uniform bounded absorbing sets for the processes is proved. Secondly, a semigroup defined on a extended space is introduced, and the Lipschitz continuity, α-contraction and squeezing property of this semigroup are proved. Finally, the existence of a uniform exponential attractor for the family of processes associated with the studied lattice dynamical systems is obtained.     

Uniform exponential attractors for first order non-autonomous lattice dynamical systems

In Abdallah (2008, 2009) [2] and [3], we have investigated the existence of exponential attractors for first and second order autonomous lattice dynamical systems. Within this work, in l², we carefully study the existence of a uniform exponential attractor for the family of processes associated with an abstract family of first order non-autonomous lattice dynamical systems with quasiperiodic symbols acting on a closed bounded set.     

Nonuniform exponential dichotomy for linear skew-product semiflows over semiflows

The aim of this paper is to obtain necessary and sufficient conditions for the existence of a nonuniform exponential dichotomy over a general class of linear skew-product semiflows (over semiflows) on a Banach space. We extend Datko’s classical result to the case of the exponential nonuniform dichotomy of linear skew-product semiflows over semiflows on a Banach space, by using Lyapunov norms.     

Schäffer spaces and uniform exponential stability of linear skew-product semiflows

We study the exponential stability of linear skew-product semiflows on locally compact metric space with Banach fibers. Our main tool is the admissibility of a pair of the so-called Schäffer spaces. This characterization is a very general one, it includes as particular cases many interesting situations among them we can mention some results due to Clark, Datko, Latushkin, van Minh, Montgomery-Smith, Randolph, Räbiger, Schnaubelt.     

Structural reducts and the full implies strong problem

Let be a finite algebra. We show that if there exists a particular dualising alter ego that satisfies a weak form of injectivity, then the notions of full duality and strong duality for are equivalent. Presented by R. Willard. Received August 30, 2005; accepted in final form August 1, 2006.     

A strong uniform time for random transpositions

A random permutation ofN items generated by a sequence ofK random transpositions is considered. The method of strong uniform times is used to give an upper bound on the variation distance between the distributions of the random permutation generated and a uniformly distributed permutation. The strong uniform time is also used to find the asymptotic distribution of the number of fixed points of the generated permutation. This is used to give a lower bound on the same variation distance. Together these bounds give a striking demonstration of the threshold phenomenon in the convergence of rapidly mixing Markov chains to stationarity.     

Global existence,asymptotic behavior and uniform attractors for non-autonomous thermoelastic systems

In this paper, we first establish the global existence and asymptotic behavior of solutions by using the semigroup method and multiplicative techniques, then further prove the existence of a uniform attractor for a non-autonomous thermoelastic system by using the method of uniform contractive functions. The main advantage of this method is that we need only to verify compactness condition with the same type of energy estimates as that for establishing absorbing sets. Moreover, we also investigate an alternative result of solutions to the semilinear thermoelastic systems by virtue of the semigroup method.