In this article it is shown that for specific initial conditions an input beam injected in a Multimode Periodic Segmented Waveguides (MPSW) does not diffract and remains collimated all along the waveguide whereas a speckle like pattern is expected at the output of a multimode structure. This nonintuitive behavior can be explained with the help of ray and wave chaos properties. A modal analysis ...

Periodic autoregressive moving average (PARMA) models are indicated for time series whose mean, variance and covariance function vary with the season. In this study, we develop and implement forecasting procedures for PARMA models. Forecasts are developed using the innovations algorithm, along with an idea of Ansley. A formula for the asymptotic error variance is provided, so that Gaussian pred...

This paper discusses a discrete multispecies Gilpin-Ayala mutualism system. We first study the permanence and global attractivity of the system. Assume that the coefficients in the system are almost periodic sequences, we obtain the sufficient conditions for the existence of a unique almost periodic solution which is globally attractive and uniformly asymptotically stable by constructing a suit...

The paper is concerned with conditions for the existence of almost periodic solutions of the following abstract functional differential equation u̇(t) = Au(t)+[Bu](t)+f(t), where A is a closed operator in a Banach space X, B is a general bounded linear operator in the function space of all X-valued bounded and uniformly continuous functions that satisfies a so-called autonomous condition. The ob...

The paper studies different variants of almost periodicity notion. We introduce the class of eventually strongly almost periodic sequences where some suffix is strongly almost periodic (=uniformly recurrent). The class of almost periodic sequences includes the class of eventually strongly almost periodic sequences, and we prove this inclusion to be strict. We prove that the class of eventually ...

We establish an abstract infinite dimensional KAM theorem dealing with unbounded perturbation vector-field, which could be applied to a large class of Hamiltonian PDEs containing the derivative ∂x in the perturbation. Especially, in this range of application lie a class of derivative nonlinear Schrödinger equations with Dirichlet boundary conditions and perturbed Benjamin-Ono equation with peri...

Several collaborations have employed O(a) improved Wilson fermions, following the nonperturbative determination of the clover coefficient csw for Nf = 2 flavours in the range β ≥ 5.2 [1]. UKQCD, QCDSF and JLQCD perform simulations on physically large volumes (L ∼ 1.5 fm) using periodic boundary conditions [2–4], whereas ALPHA use Schrödinger functional (SF) boundary conditions on small volumes ...

In this paper, we consider second order differential inclusions with periodic boundary conditions. We obtain the existence of positive solutions and of continuous branches of positive solutions.

I derive a general set of boundary conditions for quasiclassical transport theory of metals and superconductors that is valid for equilibrium and nonequilibrium situations and includes multiband systems, weakly and strongly spin-polarized systems, and disordered systems. The formulation is in terms of the normal state scattering matrix. Various special cases for boundary conditions are known in...

We study controllability of 2D defocusing cubic Schroedinger equation under periodic boundary conditions and control applied via source term (additively). The source term is a linear combination of few complex exponentials (modes) with time-variant coefficients controls. We manage to prove that controlling just 4 modes one can achieve controllability of this equation in any finite-dimensional p...