ISSN 0869-6632 (Print)
ISSN 2542-1905 (Online)


nonlinear dynamics

Equations with the Fermi–Pasta–Ulam and dislocations nonlinearity

Issue. The class of Fermi–Pasta–Ulam equations and equations describing dislocations are investigated. Being a bright representative of integrable equations, they are of interest both in theoretical constructions and in applied research. Investigation methods. In the present work, a model combining these two equations is considered, and local dynamic properties of solutions are investigated. An important feature of the model is the fact that the infinite set of characteristic numbers of the equation linearized at zero consists of purely imaginary values.

Dynamics of weakly dissipative self-oscillatory system at external pulse influence, which amplitude is depending polynomially on the dynamic variable

Topic and aim. In this work, we study the dynamics of the kicked van der Pol oscillator with the amplitude of kicks depending nonlinearly on the dynamic variable. We choose the expansions of the function cos x in a Taylor series near zero, as functions describing this dependence.

Complex structure and nonlinear behavior of very low frequency of heart rate variability: model of analysis, and practical applications

Researched the structure of Very Low Frequency (VLF) spectrum of heart rate variability (HRV)  and its nonlinear behavior in a relationship with the energy of oscillations, baroreflex and parasympathetic activity at functional tests of low intensity in 100 subjects (seven-test, deep breathing), including active orthostatic test of 32 subjects with orthostatic tachycardia in comparison to the control group of 20 subjects. There were three stages of research. The first  stage: created the method of spectral analysis of separate components of VLF.

From theory of oscillations to nonlinear dynamics

The paper deals with the retrospective consideration of course lectures on theory of oscillations in Nizhny Novgorod university and its evolution during more then 70 years.

The suppression of the excitation of the active medium with a weak external action

This paper presents two new methods of suppressing an impulse in one-dimensional and two-dimensional excitable media using an external influence. In the proposed methods, we used short-impulseinfluence, leading to a change in velocity of the front , which in turn led to the destabilization of  the propagating impulse and transition medium unexcited state. The studies were conducted on the Zykov model that a certain set of parameters is a model of an excitable medium.

About the history of econophysics, nonlinear and evolutionary economics

The paper is devoted to the history of physics and evolutionary biology to economics. This influence began with the birth of economics as a separate field of scientific knowledge and changed  with the development of physics and biology. Strengthening the role of statistical methods in the  physics of the twentieth century, the birth of nonlinear physics, biology, evolution is reflected in the  economy and finance, resulting in the appearance of such area as econophysics, nonlinear and  evolutionary economics.

Using arduino platform in the measurements and the physical experiment

This paper discusses the possibility of a hardware­software platform Arduino, as a relatively simple and flexible tool that could occupy a niche in the research tools. Radiophysical chaotic oscillator with delayed feedback was created on the base of Arduino.

Synergetics of mathematical models for analysis of composite materials

The authors propose a complex approach for the analysis of composite materials, including the fundamental models of the nonlinear dynamics, model of effective medium and the theory of electrical circuits. The composite consisting of spherical inclusions in the matrix is considered. The simulation of composite material is carried out by various methods. Download full version

Rotational dynamics in the system of two coupled pendulums

We consider dynamics in a pair of nonlinearly coupled pendulums. With existence of dissipation and constant torque such system can demonstrate in-phase periodical rotation in addition to the stable state. We have shown in numerical simulations that such in- phase rotation becomes unstable at certain values of coupling strength. In the limit of small dissipation we have created an asymptotic theory that explains instability of the in-phase cycle. Found analytical equations for coupling strength values corresponding to the boundaries of the instability area.

About influence of the changed harmonics on dynamics of self-oscillations in discrete time

  The effect arising in discrete time at interaction of self-oscillations with higher harmonics of the main frequency is described. It is shown that it is similar to effect of capture of the frequency (synchronization) of self-oscillations by an external harmonic signal. As the discrete oscillator formally is autonomous system, the effect is classified as self-capture of frequency or self-synchronization. Self-capture is analysed by method of slow-changing amplitudes.