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The purpose of this work is to apply a model of interaction between thalamocortical system modules to control brain neuroplasticity. Methods. Psychophysiological experiments on neurofeedback are being carried out, which consist of light stimulation of the eyes with monofrequency light pulses in the range of 4...20 Hz and recording the bioelectrical activity of the brain. As a characteristic of maturity, brain rhythms use the combination of the presence or absence in the bioelectrical activity of the brain of a dominant peak frequency in the alpha range of the EEG, the effect of assimilation of the rhythms imposed by stimulation, and the presence of a multiplying effect from the rhythms imposed by stimulation. Solutions to the model of an elementary thalamocortical cell, which is described by a system of differential equations, corresponding to a psychophysiological experiment are considered. The model is implemented using the Python. Results. The model parameters are selected in such a way as to achieve a qualitative correspondence of the spectral characteristics of the obtained solutions with the bioelectrical activity of the subject’s brain. Rhythmic maturity is assessed based on the parameters of the thalamocortical cell model. The brightness and frequency characteristics of light stimuli are selected based on the prediction of the model, the input of which is supplied with various variants of pulse sequences. Conclusion. A method has been developed for digital diagnostics of the level of brain rhythm maturity based on a comparison of modeling results and data from a psychophysiological experiment on neurofeedback. The evolution of model solutions depending on its parameters simulates the process of biocontrol of brain neuroplasticity, taking into account the initial level of rhythmic maturity and stress-induced distortions of neurodynamics. Experiments on the model with different parameters of the model and external signal can be used in the development of new neurofeedback protocols.

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This study systematizes and analyzes the legal aspects of changes in the deployment of international peacekeeping forces over the past 50 years. The article deals with topical political and legal problems facing the peacekeeping activities of the United Nations (UN) and regional international organizations. These problems emanate from both natural institutional and artificially created factors. Overcoming the challenges ahead is possible only through the development of multilateral diplomacy, the aim of which is to achieve long-term and realizable agreements to resolve conflicts and establish lasting and sustainable peace. The study analyzes the role, effect, and potential of peacekeeping operations under the auspices of the UN and other regional international organizations to ensure international security as a timely response to legal and institutional challenges related to the interests of certain players in the world arena, where Russia and some countries in Europe and Asia have been affected. [ABSTRACT FROM AUTHOR]

The development of modern production systems is taking place in the context of the transition to the concept of Industry 4.0. In these conditions, the competitiveness of production systems is determined by the volume and depth of implementation of digital technologies. These technologies include the digital twin. Recently, a lot of research has been devoted to digital twins. The use of digital twins by modern production systems offers many advantages, both technical and economic. This article provides a systematization of the concept of "digital twin", and also describes the organizational aspects of the development and use of digital twins in production systems designed in the form of a model.

The present-day compressors development is a labor-intensive problem, because compressor structure should meet different requirements to the design characteristics. It’s reasonable to find optimal combination of compressor design parameters using the mathematical optimization resources. In this paper the multi-criteria optimization of the rotor and stator blades of the experimental compressor stage NASA Rotor 37 is carried out. The goal of this work is the analysis of different blade parameterization schemes and determination of optimum number of variable parameters for compressor stage aerodynamic characteristics improvement. As an optimization criterions efficiency of compressor stage was used. Flow rate and pressure ratio values should not exceed base values more than ±0.5%. In order to research an effect of the number of variables to the optimization results, the four parameterized models were created. The optimization of the NASA Rotor 37 was carried out using all created parametric models. The models are characterized by number of variables, which describe the blade pressure and suction sides. As a result of optimization the NASA Rotor 37 version was found, which provide the efficiency increasing by approximately 2% while all aerodynamic and requirements are satisfied. It was also found, that increasing of the blade profile number of variables more than 14 is not rational.

The current level of numerical methods of gas dynamics makes it possible to optimize compressors using 3D CFD models. However, the methods and means are not sufficiently developed for their wide application. This paper describes a new method for the optimization of multistage axial compressors based on 3D CFD modeling and summarizes the experience of its application. The developed method is a complex system of interconnected components (an effective mathematical model, a parameterizer, and an optimum search algorithm). The use of the method makes it possible to improve or provide the necessary values of the main gas-dynamic parameters of the compressor by changing the shape of the blades and their relative position. The method was tested in solving optimization problems for multistage axial compressors of gas turbine engines (the number of stages from 3 to 15). As a result, an increase in efficiency, pressure ratio, and stability margins was achieved. The presented work is a summary of a long-years investigation of the research team and aims at creating a complete picture of the obtained results for the reader. A brief description of the results of industrial compresses optimization contained in the paper is given as an illustration of the effectiveness of the developed methods. [ABSTRACT FROM AUTHOR]