In this paper, we consider the process of developing a simple game, such as searching for items, for mobile devices running on the Android OS using the MIT App Inventor. A game algorithm is developed, code blocks are given. The article is intended for schoolchildren who are fond of programming and will be useful for computer science teachers when used in additional classes or organizing project and research activities of computer science children.

Keywords: MIT App Inventor, mobile applications, training in the creation of mobile applications, additional education for children, hidden object

The article proposes a method of automatic recognition of the type of building for an environmental monitoring system. based on convolutional neural networks. To train the neural network, the Keras library was chosen, containing numerous implementations of the main components of neural networks, such as layers, target and transfer functions, optimizers, and many tools to simplify working with images and text. The processes of network implementation using the Google Colab cloud platform, the preparation of a training set, the training of a constructed neural network, and its testing during training are described. The result of this work is a convolutional neural network model, capable of determining with accuracy of the order of 90-92 percent what type of buildings is shown on the cartographic image, which allows us to automate this process and use it as a subsystem for the environmental monitoring system of atmospheric air.

Keywords: environmental monitoring system for air, building type recognition, convolutional neural networks, machine learning, computer vision

A large number of power receivers with non-linear current-voltage characteristics with a pulsed mode of operation appeared in residential buildings, which leads to the generation of 0.38 kV higher harmonic current components into the electric network, large values ​​of these harmonics lead to a deterioration in the shape of the network voltage curve. The purpose of the work is to study the harmonics of current generated by electrical receivers of residential buildings, and their influence on the coefficient of non-sinusoidality of the network voltage of 0.38 kV. It has been established that the greatest negative impact on the electric network is exerted by electronic devices with switching power supplies, such as PCs, laptops and netbooks, as well as dishwashers and LED lamps with a socle E14 and E27, whose total harmonic current component coefficient is 85% ≤ THDI ≤ 205%. In the Matlab Simulink program, a simulation model of a 0.38 kV network of a residential building is simulated, which allows the study of the total distortion coefficient of the current KI and voltage KU in the ASU. With the installed non-linear load power more than double the linear load, the coefficient of non-sinusoidality of the voltage in the network of 0.38 kV may exceed the values ​​established by GOST 32144-2013.

Keywords: power supply system, electric network, quality of electric energy, voltage harmonics, current harmonics, electromagnetic compatibility, power receiver

This article focuses on solving the urgent task of forecasting hazardous mining zones by determining the position of local centers of tension in a processed coal seam. The relevance of this task is confirmed by the fact that the intensification of mining processes inevitably leads to an increase in the risk of hazardous production situations, such as rock blows, sudden coal and rock emissions, etc. The most dangerous for the manifestation of rock strikes are the protrusions of the edge sections of the coal seam, intersection and pairing workings. Shockproof activities regulated by the normative documents, are not always sufficiently effective. To solve this problem, authors propose an approach that allows you to quickly determine the position of local centers of tension, taking into account the influence of the worked out space. The authors developed an integration grid, in the construction of which the division of the entire area into elementary sections is performed in such a way that the influence of the weight of the roof rocks over each section is the same. To implement this approach, the influence function of the worked out space is introduced in the form of the equation of the reference rock pressure diagram. Based on the results of numerical simulation of the stress-strain state of the geomassiv, an exponential dependence is obtained, which allows one to determine the concentration coefficient of vertical stresses for points on the plot of reference rock pressure. According to the values of vertical stresses calculated for each point of the integration grid, it is possible to predict the stress-strain state of the geomassiv and justify the need for shockproof measures. The application of the proposed approach will allow the rapid forecasting of hazardous areas and significantly reduce the cost of shockproof measures.

Keywords: modeling, geomassive, coal seam, integration grid, forecasting, vertical stresses

A method for remote determination of the angular velocity of rotation of the blades of a wind generator based on digital processing of the video stream of this wind generator is considered. The main problems that are encountered with this method of measuring angular velocity are analyzed. The considered method for determining the rotation speed of the blades of a wind generator is possible provided that the frame rate is several times greater than the determined rotation frequency. The minimum possible error of this measurement method was found; the real error of measuring the angular velocity was calculated on a specific example.

Keywords: digital processing of the video stream, image stabilization of the wind generator, finding the contours of the rotor blades, estimation of the angular speed of rotation of the rotor

The article describes an approximate analytical method for calculating the humidity regime of multi-layer building enclosing structures. The novelty of the proposed method consists in using an analytical dependence to determine the position of the possible condensation plane obtained as a result of the study of the function representing the difference between the partial pressure of water vapor in the considered section of the enclosure structure and the partial pressure of saturated water vapor at the extremum. The results of calculating the humidity regime of the external wall of a residential building under construction in the city of Samara, using a monolithic bespeschany expanded clay concrete with a density equal to 600 kg/m3, are presented. The assessment of moisture accumulation in the considered external wall both for the annual period of operation of the building, and for the period of months with negative temperatures, showed compliance with the regulatory requirements for heated rooms

Keywords: enclosing structure, humidity mode, moisture transfer, vapor penetration resistance, water vapor, condensation plane

The article presents theoretical calculations and studies of the possibility of parametric oscillations and parametric resonance arising in a polymer self-supporting thermoplastic pipe "Furanflex". The Furanflex thermoplastic, polymer liner is offered as a variant of a separate gas exhaust trunk during the reconstruction of boiler rooms and thermal power plants by heat generating companies.The article provides a detailed description and analysis of the occurrence of parametric oscillations. Examples of symmetric and asymmetric parametric oscillations are considered.Information and conclusions of the presented work are intended for a different range of readers, teachers, designers, students of construction specialties.This article should be of interest to utility managers and heat generating companies .

Keywords: chimney, ventilation duct, corrosion, repair, restoration of the chimney, condensate,protection of the chimney, lining, furanflex, thermoplastic liner,perimetric oscillation

The article presents a methodology for solving the problems of integrated quality management of production processes at enterprises for the production of food products. For a general assessment of product quality, it is advisable to calculate the criteria of correctness and accuracy with the subsequent determination of the G. Taguchi “signal-to-noise” ratio. To calculate the criteria of correctness and accuracy, a comparative assessment of product quality indicators was carried out in comparison with the standard sample.

Keywords: quality management, G. Taguchi methods, product quality, generalized indicator

The problem of creating semiconductor thermoresistors (PTR) capable of dissipating large amounts of heat is an urgent problem of semiconductor technology. The article presents a brief analysis of the possibilities of using high-power ATGM, the picture of the distribution of thermal fields in the mass of the thermistor under certain boundary and initial conditions. It is shown that when selecting a thermistor material, special attention should be paid to the specific thermal conductivity of the material.

Keywords: High power thermistors, current density, thermal conductivity, energy balance, similarity criteria

The paper considers the results of research on the use of various types of approximations of concrete deformation diagrams on the example of calculating a large-span reinforced concrete truss with a length of 18 m. calculations were performed taking into account the physical nonlinearity of concrete and reinforcement. The following concrete deformation diagrams were used : bilinear, trilinear , and curved with a descending branch. The result of the calculation was the forces in the truss rods, the displacement and the width of the crack opening. Conclusions were made about the influence of the choice of the concrete deformation diagram on the calculation results.

Keywords: concrete, deformation diagram, approximation, physical nonlinearity, stress-strain state, longitudinal force, bending moment, displacement, crack resistance , truss

On the basis of the proposed Timoshenko S. P. solution of the problem of pure bending of an elastic rectangular plate under the action of moments of constant intensity acting on its boundary, the theory of bending of viscoelastic plates fixed in the vertices is proposed for the first time. The proposed solution uses the hereditary theory taking into account the hypothesis of N. H. Harutyunyan about the constancy of the coefficient of transverse deformation. For the first time, a method of recalculation of the distributed transverse load applied on the surface of the plate at equivalent moments of constant intensity, time-dependent and applied at the edges, is proposed. For the first time with the help of this theory, the problem of bending a plate pinched at a single angular point distributed by a transverse load is solved. As examples, calculations of rectangular plates under the action of their own weight are given.

Keywords: roller blade, horizontal mixer, optimization, design, process, material procurement, machining, reduction of production costs

For the three main processes of the enterprise, identified in the decomposition of its activities, a mathematical model in the space of conditions is developed, taking into account their relationship and interaction in the quality management system. For the obtained system of differential equations, the structural composition of the operators included in it is disclosed. An example of the application of the created mathematical model in the study of the functioning of the quality management system using linear and non-linear operators and the action of random external disturbances is considered. A discussion of the simulation results at various parameter values from the point of view of the functioning of the selected processes is presented.

Keywords: differential equation, space of conditions, process, quality management system

Based on the cognitive methodology, the article considers the factors within and inter-regional migration process in the conditions of the regional community on the example of the Rostov region. Using the method of cognitive maps, the main factors of two forms of migration are visualized from the perspective of a systemic and structural approach. The structure of direct and reverse action factors that enhance / weaken the influence of structural and institutional elements on the processes of population displacement, their adaptation to new social conditions and integration into the host community is presented. Conclusions are made about the dominant factors of direct and reverse influence on the process of intra-regional (socio-economic, geographical, demographic) and inter-regional migration in the region (socio-psychological state of the population, the level of consolidation of the regional community, the activities of regional executive bodies).

Keywords: cognitive model, cognitive map, migration process, regional migration, interregional migration, direct action factors, reverse action factors, Rostov Region

The article presents the results of a study of the deflections of a monolithic flat floor with a different grid of columns with prestressed reinforcement without adhesion to concrete. To analyze the deflections, numerical studies of slabs with different rectangular columns and thicknesses were performed. The studies were performed using the LIRA CAD software package. The aspect ratio of rectangular cells of monolithic flat floors is determined, for which the application of prestressing is ineffective on the short side of the cell or most effective on the long side. It was revealed that the use of high-strength reinforcement of the "monostrand" type is most effective for a grid of columns 5x9m from the volume of the studied cell sides. It was found that the application of post-tension on the short side of the slab cell practically does not affect the total deflection of the cell - with the aspect ratio a / b> 1.2. The conclusion is drawn about the increase in the efficiency of using contour reinforcement with an increase in the deflections that affect the amount of rope repulsion. The results can be used in the design of slabs using prestressed reinforcement without adhesion to concrete of the "monostrand" type.

Keywords: rope, high-strength reinforcement, finite element, monostrand, repulse, prestressing, post-stressing, deflection

The article analyzes network traffic in WINDOWS operating systems, as well as a description of its tools to identify a certain redundancy of network activity. The authors also conduct a comparative analysis of the most common software products that perform the functions of monitoring network traffic.

Keywords: operating system, detection systems, network protocol, network traffic analysis, networks, sniffer, traffic, network activity

The trend of the transition of autonomous vehicles from internal combustion engines to electric drives leads to the need to find intermediate solutions. Hybrid transport is currently a fairly popular compromise. Improving its energy efficiency is possible in several ways. This article shows a software method based on dynamic programming, which allows you to optimize fuel consumption by separating the use of an internal combustion engine and an electric drive. Dynamic programming solves recursive optimization problems when sub-tasks are recounted several times. Also, in this work, mathematical modeling of the car’s movement pattern and determination of the optimal distribution of speed and battery charge depending on the number of fractional bits are carried out. The development of dynamic programming from the point of view of hardware implementation is possible using Field-Programmable Gate Array (FPGA).

Keywords: Hybrid transport, mathematical modeling, dynamic programming, programmable logic integrated circuits, internal combustion engine, electric drive

This article concentrates on the issues of radio wave propagation in forest conditions. The issue of representing the forest mass as a heterogeneous structure with a low dielectric constant is considered. Calculation and comparison of radio signal attenuation using several empirical models were carried out. It is shown that empirical models take into account the heterogeneous structure of the forest when moving from free space to the forest.

Keywords: radiowave propagation, wooded area, empirical model, radiowave attenuation, path loss, ground mobile communication, electrodynamic characteristics of a heterogeneous structure

The emergence of digital X-ray machines and the development of cloud storage technology has led to the accumulation of a huge number of medical X-rays, in particular, chest x-rays - fluorography. The accumulated image bases after high-quality preprocessing can be used to train the deep convolutional neural networks that have received the most development in recent years, the trained network performs preliminary binary classification of the incoming flow of images and can be used as a radiologist assistant. For this purpose, it is necessary to adequately train the neural net-work to minimize errors of the first and second kind. A possible approach to improving the efficiency of neural networks, reducing the computational complexity and quality of image classification by the criteria is the use of auxiliary approaches of image preprocessing and preliminary entropy calculation. The article presents an algorithm for the X-ray image preprocessing, its division into fragments and the calculation of the entropy of individual fragments. During the preprocessing, the region of interest with lungs and the spine is selected from the entire image, constituting about 30-40% of the entire image, then the image is divided into a fragment matrix and the entropy of individual fragments is calculated using the Shannon formula, by analyzing individual pixels. By determining the frequency of each of the 255 colors, the total entropy is calculated. The use of entropy for detecting pathologies is based on the assumption of dif-ferences in its values for individual fragments and the overall picture of its distribution between images with the norm and pathologies. Statistical indicators are analyzed: standard deviation of error, variance.

Keywords: image entropy, fragments, deep convolutional neural network, machine learning, x-rays images, computational experiment, matrix of elements, image preprocessing, statistical analysis, binary classification

The publication is devoted to the task of developing a demo-genetic model of the adaptation of pests to transgenic and hybrid agricultural crops, taking into account the type of taxis. An assumption is introduced that the dynamics of hybrid agricultural crops can be investigated using demo-genetic models. A description of the problem is given in accordance with the characteristics of the growth of biomass of agricultural crops and the dynamics of pests, as well as taxis species. The modeling of the processes of fast and slow taxis depending on the behavior of pests at a particular point in time is described in detail, taking into account the type of their genotypes that affect the acquisition of mutations. The paper describes the features of the physiological structure and life cycle of insect pests, affecting the prediction of their spatial concentration and, accordingly, the prediction of productivity; the possibilities of their application in mathematical modeling.

Keywords: demo-genetic model, taxis, transgenic agriculture, hybrid, pest, biomass, diffusion

The reliability of the solar heating system with solar collectors was studied using the logical-probabilistic method by building a fault tree. The fault tree was obtained by sequentially detailing the events associated with failures of the solar heating system, as well as its elements. Events were taken into account: conducting test diagnostics of elements of the power supply system, repairing failed elements, failure of elements, reducing the power of solar collectors due to a decrease in the intensity of the solar radiation. The events were divided into two groups: events in which there is sufficient intensity of solar radiation for the hot water supply from the solar collectors, as well as events when the heating supply cannot be provided only due to the solar collectors. The last group of events was divided into two subgroups, within events caused short-term downtimes (at the time of switching) and long-term downtimes (at the time of replacing or repairing a failed system element). Long shutdowns are associated with the coincidence of failures, repair or diagnosis of one or more elements of the solar heating system. Expressions are compiled to calculate the probability of long downtimes, the probability of short downtimes, the probability of failure due to a decrease in the intensity of the solar radiation, and the total probability of failures. As a result of substituting the values of the reliability indicators of the elements of the solar heating system, the value of the total probability of failure during the year is 4.03∙10-5.

Keywords: solar hot water supply, reliability, solar collector, failure cause, reliability modeling

To calculate the trajectory and coordinates of the droplets, the time of their flight, it is necessary to determine the parameters of droplet evaporation and their concentration in the stream. After the nozzle passes, the droplets move along different trajectories and form a fuel torch. The trajectory of the torch droplets is calculated according to the given initial parameters of the droplets, as well as the parameters of the nozzle and taking into account their influence on the movement of the droplet The aim of this work is to calculate the temperature of the evaporating droplet layer, which is necessary for calculating the trajectory and time of the droplet's motion depending on the thermodynamic parameters of the fuel. Based on the obtained air and fuel vapor parameters, the temperature of the evaporating droplet layer is found, which is necessary for calculating the trajectory, coordinates and time of movement of the fuel droplets after the nozzle.

Keywords: fuel, centrifugal nozzle, atomization spectrum, trajectory, evaporation temperature

This work outlines software packages that are capable of dealing with nonlinearity of the analyzing structure. Brief introduction of the software and its beginning in the history. Also explained the difference of linear and nonlinear analysis performed on the structure. Defined which software packages are for media and analyzing problem (structure). Similarly, descriptive study was done to understand advantages and disadvantages of main analyzing tools ANSYS, ABAQUS, SOLIDWORKS. In addition, the work looked into which one of the mentioned tools have its own distinguish functions. Finally, the results data of all three software were compared with each other.

Keywords: nonlinear analysis, numerical analysis, ANSYS, ABAQUS, SOLIDWORKS

The article discusses the most common schemes of direct integration of equations of motion in engineering practice, and gives basic formulas. An analysis of the accuracy of these methods is made on the example of solving a test problem

Keywords: structural dynamics, structural mechanics, direct methods for integrating equations of motion, Newmark's method, Habolt's method, Wilson's method

The article demonstrates the study of the processes of controlling the power system of an electric vehicle and the processes of energy distribution in it using pulse-width voltage converters. The general structure of the electric vehicle’s power system and elements of its subsystems are described. The pulse-width boost and buck DC-DC converters are considered. Based on the given mathematical model, the synthesis of controllers is carried out using the methods of the synergetic control theory. Mathematical modeling of the closed DC-DC converter control system, providing asymptotic stability and adaptability to parametric disturbances, is performed.

Keywords: electric vehicle, pulse-width converters, control system, ADAR, synergetic control theory, integral adaptation

The Minsk Motor Plant D-245 engines are the most widely used in automobiles and tractor manufacturing in Russia and neighboring countries. These engines are installed on cars of the GAZ and MAZ family, PAZ buses, special equipment manufactured by Amkodor, MTZ tractors, etc. A turbocharger is one of the engines units affects power and environmental performance. The presence of a large number of engines under consideration makes it important for repair enterprises to improve the technological process of repairing turbochargers. A large number of technologies for repair rotor shaft of the turbocharger have been developed to date. However, there is no technology to restore the outer surface of the rotor seal sleeve after they touch the hole of the middle housing. The article presents the results of calculating the stress-strain state of the rotor shaft of a turbocharger, taking into account the installation of an additional (repair) part as a turbine seal sleeve. The analysis of the created solid-state model was carried out using of the SolidWorks Simulation system. The calculation was carried out at various shaft diameters for bearings. The study found that the voltage in dangerous sections of the rotor shaft with the installed repair sleeve is higher than without it. However, they are much lower than the permissible torsional stresses. Therefore, the probability of destruction of the rotor shaft during normal operation of the turbocharger, due to the occurrence of a resonance phenomenon, even with the minimum allowable diameter, will be very small. The presented data allow the use of this repair method to restore the operability of the rotor shaft of the TKR-6 turbocharger.

Keywords: engine, turbocharger, defect, repair technology, additional part, repair sleeve, stress-strain state, solid-state model, dangerous section, permissible stress