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


Effect of nonlinearity on coupling estimations between oscillators using partial directed coherence approach

The purpose of this work is to determine the ability of the partial directed coherence method to identify directed interactions between nonlinear systems correctly in presence of nonlinear couplings between systems, as well as in the
case of measured signals generated by objects of high dimension. The other purpose is to determine the dependence of the coupling estimation results on the parameters: series length, sampling rate, model dimension and coupling architecture.

Влияние нелинейности на оценки связанности осцилляторов методом частной направленной когерентности

Цель настоящего исследования — определить, может ли метод частной направленной когерентности правильно определять направленное взаимодействие между нелинейными системами, при нелинейных связях между системами, а также в случае, когда измеренные сигналы порождены объектами высокой размерности (ансамблями). Также определить зависимость результатов оценки связанности методом частной направленной когерентности от параметров: длины реализации, частоты дискретизации, размерности модели и от архитектуры связей в системах.

Nonlinear models of blood supply dynamics in tissue area

A continual model of tissue blood supply has been suggested in this paper providing the existence of autostructures in the inhomogeneous blood distribution. Theoretical analysis including both analytical and numerical calculations has been carried out on the base of this model. The filtration variations of blood flow caused by medium activity (chemical reactions, nerve excitation) have been studied as well as self­organization processes accounting mechanisms of microvessel regulation.

Radial patterns in a vibrated granular layer

Laboratory experiments were conducted for a sand layer placed in the vertically­oscillated containers of various shapes. Radial patterns on the sand surface were observed; experimental investigations of such structures have never been described in scientific literature. The waveform, amplitude and frequency of vibrations and the depth of the vibrated layer could be varied, allowing study the dependence of the shape and scale of radial structures upon these parameters.