Spiral attractors as the root of a new type of "bursting activity" in the Rosenzweig-MacArthur model

We study the peculiarities of spiral attractors in the Rosenzweig-MacArthur model, that describes dynamics in a food chain "prey-predator-superpredator". It is well-known that spiral attractors having a "teacup" geometry are typical for this model at certain values of parameters for which the system can be considered as slow-fast system. We show that these attractors appear due to the Shilnikov scenario, the first step in which is associated with a supercritical Andronov-Hopf bifurcation and the last step leads to the appearance of a homoclinic attractor containing a homoclinic loop to a saddle-focus equilibrium with two-dimension unstable manifold. It is shown that the homoclinic spiral attractors together with the slow-fast behavior give rise to a new type of bursting activity in this system. Intervals of fast oscillations for such type of bursting alternate with slow motions of two types: small amplitude oscillations near a saddle-focus equilibrium and motions near a stable slow manifold of a fast subsystem. We demonstrate that such type of bursting activity can be either chaotic or regular

ANALYSIS OF THE CAUSES OF INCONSISTENCIES IN THE ELECTRICAL PRODUCTS MANUFACTURING

This article discusses methods suitable for analyzing the causes of nonconforming products, an example of their application at an enterprise for the production of electrical products, as well as a way to document the described activities.В настоящей статье рассмотрены методы, подходящие для проведения анализа причин возникновения несоответствующей продукции, пример их применения на предприятии по производству электротехнической продукции, а также способ документирования описанной деятельности

Rationing of the Process of Interaction with Consumers in the Conditions of Industrial Enterprises

В настоящей статье рассмотрены стандарты, которые содержат рекомендации по достижению удовлетворенности потребителя, траектории потребителя в рыночных взаимоотношениях, какие методы управления качеством подходят для выделенных траекторий и для чего они нужны.This article discusses standards that contain recommendations for achieving customer satisfaction, consumer trajectories in market relations, which quality management methods are suitable for the selected trajectories and what they are needed for

Sequential switching activity in ensembles of inhibitory coupled oscillators

The heteroclinic cycles and channels are mathematical images of a sequential switching activity in neural ensembles. In this paper we present a phenomenological model of such activity. The model is based on coupled Poincaré systems. The existence of heteroclinic cycles and channels is shown

Characteristics of bifidobacteria biological properties in gut microflora disorders in HIV-infected children

Aim is to evaluate the biological properties of bifidobacteria in HIV-infected children with different degrees of gut microflora disorders to determine the direction for correction of bifidobacterium in HIV infection.Materials and methods. 58 selected cultures of bifidobacteria from HIV-infected children, 45 children in the comparison group. In bifidobacteria studied adhesion index of microorganisms (IAM), hydrophobicity (H), acid formation, antioxidant activity (AOA), delayed antagonism to opportunistic microorganisms.Results. In HIV-infected children at I degree of gut microflora disorders biological properties of bifidobacteria did not differ from the comparison group (p>0.05). At II degree of gut microflora disorders hydrophobicity of bifidobacteria was 45,75% (33; 58.8), IaM — 2.5 (2,0; 2.9), acid formation 67,30 T (53,0; 97,4), AOA — 0.8 Eaoa (0,6; 1.0). At III degree of gut microflora disorders H — 22,7% (15.8; 46,6), iAm — 2.4 (1,92; 3,69), acid formation — 66,3 T (48,9; 94,9), AOA-0.4 Eaoa (0,3; 0,6). Value biological properties at II and III degrees of gut microflora disorders were lower than in bifidoflora from HIV-negative children (p<0.01).Conclusion. At the I degree of gut microflora disorders in HIV infection it is necessary to correct the quantitative level of bifidobacteria. At II and III degree it is necessary to correct the surface properties, antioxidant and fermentation of carbohydrates activity of bifidobacteria