The purpose of the study is to establish the regularities of a stable hydrodynamic regime by applying a fluoroplastic–containing composite polymer material to the support profile. Research methods: new models have been proposed describing the movement of a lubricant with truly viscous rheological properties in the laminar motion mode in the approximation for a "thin layer", in the working gap of a radial bearing with a support profile having a polymer coating with a groove, the continuity equation. A comparative analysis of the obtained results is carried out, confirming the approximation of the obtained model to practice. As a result of the study, a significant expansion of the possibilities for assessing the operational characteristics of the bearing has been achieved: the magnitude of hydrodynamic pressure, load capacity and coefficient of friction.

Keywords: radial bearing, increased wear resistance, antifriction polymer composite coating, groove, hydrodynamic mode, verification

The article considers the problem of optimizing the scheme of portages in a cutting area. The mathematical model of the cutting area is a polygon - a bounded closed broken part of the plane. The portage scheme corresponds to a root graph (forest, tree) of a special type. We have introduced the concept of covering a polygon with a rooted forest. The cover is interpreted as the possibility of cutting and collecting all the trees in the cutting area while moving the harvester and forwarder along the trails. The trails are laid according to the found covering root forest. Two variants of the algorithm for solving the problem are proposed, which are a modification of the local search. The first algorithm uses the greedy method we described earlier[18] to find the underlying solution. The second algorithm uses the branch and bound method to find the basic solution. Comparative experiments were carried out on polygons sized 12x12 and 18x18. Experimental results show that both modifications of the algorithm improve the basic solution. The first algorithm improves the solution by an average of 11% for a 12x12 polygon and by 24% for a 18x18 polygon.

Keywords: portage schemes, cutting area, polygon covering the root forest, local search, coverage

This paper presents the results of a study of the nature of lifting the tail lift of a truck with a hydraulic drive that supplies the working fluid to the cylinders in series for two positions of the center of gravity of the load on the lifting platform. A diagram of a hydraulic drive is presented, which supplies the working fluid to the hydraulic cylinders in series. Mathematical models describing the operation of the hydraulic drive are compiled according to the scheme. Simulation modeling was carried out using the MATLAB Simulink environment.

Keywords: wheel tyre, suspension module, wheeled vehicle, MATLAB Simulink, mathematical model, modeling

The paper presents the properties and nomenclature of products made of ceramic fiber used for insulating lining in steam reforming furnaces. On the example of the lining of the radiant chamber, the technology of mounting ceramic blankets on anchor studs, which is currently used in the construction and repair of reforming furnaces, is considered. The shortcomings of the existing technology are noted. These include the complexity of the process, the complexity of installation control and the high probability of uneven thermal conductivity of the lining surface due to hidden defects, as well as the spraying of ceramic fiber particles in the air that cause diseases. The nomenclature and technology of installation of insulating lining with ceramic blocks along guide tubes with subsequent resistance welding with the camera body is proposed. The technology will reduce the repair time, improve the thermal conductivity of the camera, reduce the risk of diseases.

Keywords: gas reforming, radiant chamber, insulation lining, ceramic fiber, thermal conductivity of the furnace

This article is devoted to the study of the effect of photocatalytic oxidation together with successive layers of sorbents (shungite, celite) on the efficiency of cleaning the supply air of premises from pollutants of motor vehicles. The studies were carried out with the help of a developed supply ventilation valve with air purification.

Keywords: intensity of ultraviolet radiation, shungite, zeolite, titanium dioxide, adsorption limit, supply air, ventilation valve

Bottom sediments (UP to) are media in which both longitudinal and shear acoustic vibrations can be present. The presence of several velocity components in bottom sediments makes it possible to excite various types of waves, both longitudinal and shear. In this paper, methods of excitation, generation and reception of difference frequency shear waves (RF) created by parametric systems in (DO) in location modes are analyzed. The analysis of their work in the DO is presented, and their comparative characteristics are given in comparison with the excitation, formation and propagation of the field of longitudinal RFCs in the DO. Prerequisites are given for the creation of a parametric profiler working using the method of excitation, generation and location of shear waves in a complex multiphase medium ""water-DO"". A block diagram is presented and the principle of operation of a parametric profiler on shear waves is described. The advantages and disadvantages of this method of location are shown. The conclusion is made about the possibility of creating and ration.

Keywords: parametric antenna, bottom sediments, shear waves, difference frequency waves, parametric profilogaf

Yemeni cities are distinguished by their ancient history and rich traditions in terms of the organization of urban recreation, which are not well studied and therefore are not used in modern city planning. The developed concept of the recreational framework of Sana'a was developed on the basis of data from a comprehensive system analysis of the planning structure of the city, the identification of the national identity of the Yemeni landscaping structure, the integration of climatic, dendrological and landscape conditions, as well as social factors influencing the organization of urban recreations of Sana'a. Based on the analysis data and identified architectural and planning opportunities, the key principles for organizing the "green" recreational frame of the city of Sana'a were proposed.

Keywords: urban planning, urban greening, sustainable development of the city, landscape design, urban environment, reconstruction

The regulation of the stress-strain state of the floor slab is considered in order to choose the optimal design solution for the frame of a unique building. Three variants of design solutions with varying reinforcement of the plate and cross sections of the vertical elements of the frame are proposed. The numerical experiment was performed by the finite element method using the Lira-CAD software package. To improve the accuracy of the results obtained, calculations were made taking into account the nonlinear operation of materials. The computational model of the floor slab includes physically nonlinear shell finite elements. Nonlinear loading was modeled taking into account the creep of concrete. Based on the results of the calculations, the analysis of the deflections of the floor slab and the consumption of materials was performed. The numerical experiment allowed us to propose an optimal design solution for the frame of a unique building.

Keywords: stress-strain state, finite element method, unique building, physical nonlinearity, deformation law, building frame

This article proposes a method for determining the emotional state of a person using a chatbot. The article defines a chat bot, justifies the choice of the type of chat bot, and defines the basic principles of their work. Based on the identified differences in the work of algorithms for determining text by chat bots, the most suitable technology for solving the task is described - working with neural networks.

Keywords: chatbot, neural network, text tone, emotions, augmented reality

A computer simulator for training operators of the technological process of granulating ammophos in a drum granulator dryer is considered. The technological object and the requirements for controlling the granulation process are briefly described. The functions of the simulator, the structure of its mathematical and algorithmic support are given. The software implementation of the simulator is made in the Visual Basic environment.

Keywords: computer simulator, mathematical model, algorithmic support, training of process operators, pelletizing, drum granulator dryer, granule diameter, ammophos pulp

The study of the problem of fretting damage to a mechanical assembly bolted in three dimensions requires the analysis of stress fields in Cartesian coordinates along the angle and radius of contact pads. It also requires determining the location of the crack initiation and propagation. In this study, we will focus on numerical simulation using ANSYS. The results obtained in the form of nodal solutions show in detail the positions of stress concentrations and the formation of the bolted assembly. The contact surface between plates (or contact elements) is characterized by contact pressure, adhesion and clearance. The results obtained made it possible to determine the stress that caused the initiation and propagation of a crack, as well as the position of the damaged area by fretting.

Keywords: bolt assembly, contact modeling, damage zone, fretting, Ramberg-Osgood law, Von Mises stresses

The paper discusses the use of machine learning in relation to natural language processing (sentiment analysis, semantic proximity analysis) to build a recommendation system for the choice of perfumery products. The topic of the work is relevant in view of the growth of the range of manufactured perfumery products and the complexity of its choice by consumers and promotion by manufacturers. The proposed approaches are relevant for solving this problem due to the accumulated textual reviews and reviews of perfumery products on various websites, including online stores.

Keywords: machine learning, natural language, sentiment analysis, distributive semantics, word2vec, recommender systems

The paper considers the problem of bringing vibrations of a flat membrane to rest, controlled by forces applied to the entire area of the membrane and limited in absolute value. Sufficient conditions are given for the initial data of the deviation and velocity of the membrane, under which a complete stop of motion in a finite time is possible. The resting time is also evaluated. The theorem on estimating the eigenfunctions of the Dirichlet problem for the Laplace equation used in the work makes it possible to refine the mentioned sufficient condition in comparison with the work of F.L. Chernousko. In this work, a similar problem is considered, and the method of expanding the unknown control and the corresponding solution in terms of eigenfunctions of the Dirichlet problem for the Laplace equation is also applied. In this paper, the problem of bringing various elastic oscillatory systems with distributed parameters (membrane, rod, plate, etc.) to a state of rest in a finite time is reduced by means of expansion into a Fourier series in the corresponding system of eigenfunctions to the study of the problem of stopping a counting system of pendulums, connected with each other only through the values of external control actions, the sum of the values of which should not exceed in absolute value some given constant. In order to fulfill this limitation, it is necessary to use estimates for the absolute values of the eigenfunctions, normalized in the mean square. In this paper, we use some estimates for the absolute values of eigenfunctions, previously obtained by Eidus D.M. This allows us to refine the results of F.L. Chernousko for sufficient conditions on the initial functions of the oscillatory system, under which we must dampen the oscillations. These conditions consist in the fact that the initial functions belong to Sobolev spaces with certain indices and in the fulfillment of some additional boundary conditions on the boundary of the domain in which the system is defined.

Keywords: control, wave equation, limited distributed force, Fourier method, counting system of harmonic oscillators

The problem of atmospheric air pollution in the regions is considered. Attention is paid to the development and implementation of automated air pollution control systems. The developed information and analytical system has a two-level system and consists of two subsystems: a city information system and a regional information system. The proposed software allows you to perform calculations of surface concentrations of pollutants with the formation of a data bank, as well as the construction of maps of pollution in the region and histograms of the distribution of the level of adverse effects of atmospheric pollution on humans.

Keywords: atmospheric air, pollution, monitoring, information and analytical system, maps of the pollution of the region

The article discusses the stages of entity allocation for constructing an ANN description language that simplifies the exchange of ANN between people. The developed language reduces the task of migrating the ANN between different hardware and software technologies to the task of converting a text description to the required platform, which is much easier to develop intelligent models. As a result of minimizing the set of entities, a language consisting of a dozen and a half tags was obtained that allow describing the most popular ANN models used for classification and pattern recognition tasks.

Keywords: artificial neural networks, neuron, synapse, multilayer perceptron, INSML, forward calculation, mathematical modeling