We consider a population consisting of two species whose dynamics is determined by quadratic stochastic operator with variable coefficients, which makes it discontinuous at points. This depends on three parameters. The set these parameters divided into seven subsets. For each subset parameters, we find fixed points, periodic and the limit points trajectories generated respective operators.

We describe a data-driven approach to optimize periodic maintenance policies for heterogeneous portfolio with different machine profiles. When insufficient data are available per profile assess failure intensities and costs accurately, we pool the of all profiles evaluate effect (observable) characteristics by calibrating appropriate statistical models. This reduces compared stratified that spl...

In this note we consider multi-dimensional Hartman almost periodic functions and sequences, defined with respect to different averaging sequences of subsets in R or Z. We consider the behavior of their Fourier-Bohr coefficients and their spectrum, depending on the particular averaging sequence, and we demonstrate this dependence by several examples. Extensions to compactly generated, locally co...

We investigate the nontrivial solutions for a class of the systems of the superquadratic nonlinear wave equations with Dirichlet boundary condition and periodic condition with a superquadratic nonlinear terms at infinity which have continuous derivatives. We approach the variational method and use the critical point theory on the manifold, in terms of the limit relative category of the sublevel...

This paper gives localization and nonexistence conditions of periodic orbits in some subsets of the state space. Mainly, our approach is based on high-order extremum conditions, on high-order tangency conditions of a nonsingular solution of a polynomial system with an algebraic surface, and on some ideas related to algebraically-dependent polynomials. Examples of the localization analysis of pe...

This paper presents evidence for a conjecture concerning the structure of the set of braid types of periodic orbits of Smale’s horseshoe map, partially ordered by Boyland’s forcing order. The braid types are partitioned into totally ordered subsets, which are defined by parsing the symbolic code of a periodic orbit into two segments, the prefix and the decoration: the set of braid types of orbi...

The method of periodic projections consists in iterating projections onto m closed convex subsets of a Hilbert space according to a periodic sweeping strategy. In the presence ofm ≥ 3 sets, a long-standing question going back to the 1960s is whether the limit cycles obtained by such a process can be characterized as the minimizers of a certain functional. In this paper we answer this question i...

Let (X, d) be a nonempty metric space, and let (2X , Hd) be the hyperspace of all nonempty compact subsets of X with the Hausdorff metric. Let F :X → 2X be an ε-contractive map. A general condition is given that guarantees the existence of a periodic point of F (the theorem extends a result of Edelstein to multi-valued maps). The condition holds when X is compact; hence, F has a periodic point ...

[2] J. Bourgain, Fourier Transform Restriction Phenomena for Certain Lattice Subsets and Applications to Nonlinear Evolution Equations, Geometric and Functional Analysis 3 (1993), 107–156. [3] M. Christ, J. Colliander and T. Tao, Instability of the periodic nonlinear Schrödinger equation, Preprint, 2003. [4] M. Hochbruck, A. Ostermann, Explicit exponential Runge-Kutta methods for semilinear par...

peripheral blood t lymphocytes and their subsets were studied in 31 patients with beta thalassemia major (age 2-12years) and compared with 14 age-arid sex-matched healthy controls. three monoclonal antibodies (anti-cd3, anti cd-f, unti-cds) were simultaneously applied for detection of th (cd3-, cd4^), tsk (cd3+, cd8+) and th/ts ratio by flow-cytometry respectively. the results of this study sho...