Harmonizable processes with spectral mass concentrated on a number of straight lines are considered. The asymptotic behavior of the bias and covariance of a number of spectral estimates is described. The results generalize those obtained for periodic and almost periodic processes.

In this paper, we consider a time-delayed periodic system which describes the competition among mature populations. By appealing to theories of monotone dynamical systems, periodic semiflows and uniform persistence, we analyze the evolutionary behavior of the system and establish sufficient conditions for competitive coexistence and exclusion.  2005 Elsevier Inc. All rights reserved.

We consider a deterministic realization of Parrondo games, and use periodic orbit theory to analyze their asymptotic behavior.

Data summarization is an important technique to understand large datasets and discover useful patterns. In this paper we formulate a problem of summarizing network flow data to discover periodic communication behavior. An efficient implementation method for discovering periodic patterns is described in this paper and it has successfully discovered such patterns in a simulated and real

We study the long time behavior of the solution X(t, s, x) of a 2D-Navier-Stokes equation subjected to a periodic time dependent forcing term. We prove in particular that as t → ∞, E[φ(X(t, s, x))] approaches a periodic orbit independently of s and x for any continuous and bounded real function φ. 2000 Mathematics Subject Classification AMS: 76D05, 60H15,37A25

We consider stochastic dynamics for a spin system with mean field interaction, in which the interaction potential is subject to noisy and dissipative stochastic evolution. We show that, in the thermodynamic limit and at sufficiently low temperature, the magnetization of the system has a time periodic behavior, despite of the fact that no periodic force is applied.

This article concerns the behavior of the solutions to periodic linear neutral delay differential equations as well as to periodic linear neutral delay difference equations. Some new results are obtained via two appropriate distinct roots of the corresponding (so called) characteristic equation.

Using the periodic unfolding method we construct the homogenization theory for the quasistatic initial boundary value problems with internal variables, which model the deformation behavior of viscoplastic materials with a periodic microstructure. The free energy associated with models is assumed to be positive semi-definite only.

We have expressed in E. coli a series of periodic polypeptides represented by sequence 1. Our objective has been an understanding of the role of chemical sequence in determining the chain folding behavior of periodic macromolecules. Molecular organization has been examined by infrared spectroscopy and IH and l 3 ~ NMR methods and a preliminary model of the folded structure has been developed.

Analysis of nonlinear autonomous systems has been a popular field of study in recent decades. As an interesting nonlinear behavior, chaotic dynamics has been intensively investigated since Lorenz discovered the first physical evidence of chaos in his famous equations. Although many chaotic systems have been ever reported in the literature, a systematic and qualitative approach for chaos generat...