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  • Development of an algorithm for identifying the parameters of object models using the example of a temperature control system

    The article discusses the main stages of identification of a control system for maintaining a given temperature, which includes an actuator, a control object and a temperature sensor. The initial data were experimental values ​​obtained under various setting influences on objects of the material world. To confirm the accuracy of the calculations and the selected methods for identifying parameters, mathematical modeling of the system in the Matlab / Simulink package is presented. At the end of the article, quantitative and qualitative assessments of the obtained mathematical models are given. The identification of the parameters of the control system for maintaining the set temperature was successful. The developed algorithm for describing material objects by mathematical models showed a low error, which indicates the applicability of this approach in real technological processes of production management.

    Keywords: identification, mathematical model, control object, control system, transient response, full-scale experiment, transfer function

  • Development of an AC voltage regulator

    An urgent scientific and technical task is the development of electric energy converters with high operational and energy characteristics. The use of modern methods for the development and analysis of power electronics circuits based on the use of computer equipment allows us to successfully solve this problem. In this article, a schematic diagram of an alternating voltage regulator has been developed, in which a control system based on a microcontroller implementing an algorithm for pulse-phase regulation of the variable output voltage is used to control a power thyristor key. The control system, a power thyristor key, is synchronized with the moments of transition through zero of the supply voltage of a sinusoidal shape. The controller circuit is adapted for computer modeling in the environment of the PROTEUS software product. In the article, a block diagram is also developed and a software implementation in assembly language of the microcontroller operation algorithm is performed. As a result of computer modeling, time diagrams of voltages on the main elements of the AC voltage regulator circuit are obtained. Time diagrams explain the features of electromagnetic processes occurring in the controller circuit. The results of computer modeling, the controller circuit, the developed algorithm and the microcontroller software can be used in the development of electric energy converters for automatic control systems of electrical equipment.

    Keywords: computer simulation, thyristor regulator, alternating voltage, microcontroller operation algorithm, time diagrams, transistor switch, control system, damping circuit, power thyristor, active-inductive load

  • Investigation of the heat transfer process in a cylindrical fuel element

    the presented work is devoted to the study of the temperature state of a fuel element (fuel element) – a cylindrical solid body with an internal heat source of constant power. Using the integral method of heat balance with the introduction of an additional desired function, an approximate analytical solution of the corresponding boundary value problem of thermal conductivity is obtained. The conditions of external heat transfer at the boundary of the studied region were set according to the Newton-Richman law (a boundary condition of the third kind). When obtaining the solution, trigonometric coordinate functions were used. Their use made it possible to reduce the number of terms in the desired solution due to the a priori fulfillment of the boundary condition in the center of the fuel element. It is shown that when using only three terms in the analytical solution (the first approximation), an accuracy sufficient for engineering applications is achieved. The error of the developed method was estimated by comparing the results obtained with a numerical solution based on the finite difference method. The article presents graphs of the temperature distribution at different power values of volumetric fuel element heat sources. The developed method can be used to determine the time of the system's exit to the stationary mode, estimate the maximum fuel element temperature at various values of the dimensionless Bio and Pomerantsev numbers, and determine temperature stresses.

    Keywords: internal heat sources, boundary conditions of the third kind, additional desired function, heat balance integral, heat-generating element, approximate analytical solution, numerical solution, heat conduction problem, Bio number, Pomerantsev number

  • Carbon fiber - as a good material for reinforcing reinforced concrete structures

    The work is devoted to a review of the study of a composite material based on CFRP in the field of reinforcing reinforced concrete structures. The main work on the study of the effectiveness of carbon fiber reinforced plastic in the reinforcement of bending elements along normal and inclined sections and compressed flexible elements are considered. The main achievements and conclusions are established, as well as the disadvantages of calculation methods and amplification technology are considered. The purpose of this paper is to review the areas already studied and identify promising topics for further study of composite material.

    Keywords: concrete, reinforced concrete, composite material, carbon fiber reinforced plastic, external reinforcement, deformations, compressed elements

  • Traffic control system using a fuzzy regulator at an intersection

    The growth in the number of vehicles on the streets of cities leads to adverse consequences: an increase in congestion, the occurrence of road accidents. In order to take measures for the efficient use of road transport roads in order to avoid unfavorable congestion situations, it is proposed to control traffic flows using a fuzzy regulator along the length of the queue in each of the conflicting directions. The optimization principle is based on minimizing the length of the queue of traffic flows, which allows the most efficient use of the transport bed, avoiding unwanted congestion situations. On the developed model of the intersection, a system with fuzzy regulation of traffic signals is proposed. The average idle time is estimated with a fixed traffic light cycle and with a fuzzy control. With the use of a fuzzy regulator, the average queue at the intersection decreased by 11%.

    Keywords: fuzzy regulator, traffic flow, intersection, traffic control system, control algorithm, vehicle intensity

  • Technology for the construction of special-purpose winter roads for the transportation of oversized cargo using a combined machine

    The design of a mobile complex for the construction of winter roads with the selection of the main working units has been developed, an analysis of the effectiveness of the application has been carried out and the ways of further development have been considered. An assessment and a detailed analysis of existing mobile snow-melting machines was carried out, the problem of the quality of winter roads was analyzed, ways to improve the quality of temporary winter roads were considered and the most effective was identified, the principle of operation of the proposed design, advantages were described, the main parameters of equipment were calculated, the calculation and selection of working units were made, and the power balance of the mobile complex is also calculated.

    Keywords: snow transfer, autowinter areas, cleared, extended, temporary, regular, humidification, technology, category, carriageway, roadside, compacted snow

  • Mathematical models of the measurement error of the main magnetization curve of electrical steel sheet

    The paper considers mathematical models obtained on the basis of experimental studies of electrical sheet steel. The models reflect the error in determining the main magnetization curve of electrical steel. The magnetic properties are determined in the center and at the edge of the cut of sheet samples with a size of 150 × 150 mm, made by cutting with guillotine shears and laser cutting. The choice of scale factors for calculating the main magnetization curve with an error of ± 5% according to the measured Weber-ampere characteristic has been substantiated. The study was carried out using a device for express control of the magnetic characteristics of electrical sheet steel. The main curve of magnetization of the sample material from sheet electrical steel was determined in an alternating magnetic field with a frequency of 50 Hz, along the direction of rolling. Investigated samples of isotropic sheet electrical steel grade 2212.

    Keywords: mathematical model, electrical steel, magnetic properties, magnetization curve

  • Predictive analysis of the state of objects as a new strategy for the technical operation of electrified railways

    Stable reliability characteristics are a guarantee of non-emergency operation of electrified railways, undoubtedly, the profitability of transportation processes is growing. The article proposes an innovative method for determining the characteristics of reliability, with a decrease in the risk of failure or emergency. Electric traction used in most of the railroad landfill. It is necessary to consider the issues of reliability of the power supply system to predict the state of the system and study the patterns of interaction that affect system and non-system communications. Therefore, we will pay special attention to the reliability of the power supply system; in order to predict failures, first of all, it is necessary to know the patterns of interaction and patterns that affect system and non-system communications. The danger of risk directly depends on the number and duration of failures. In the power supply system, a huge number of heterogeneous and differently distributed objects, nodes and elements operate in different modes and are susceptible to different operational influences.Therefore, the work summarizes the existing methods of probabilistic forecasting, and gives recommendations on their application to solve the existing problematic of the issue. Further, the paper shows a method for determining the probability of failure of a constituent structural element of any, arbitrarily complex, stochastic system, to which the contact network of electrified railways belongs. In the conclusion of the work, an elementary method-oriented software tool with the functional purpose of automating statistical methods for solving problems of primary data processing and calculating elementary statistics in the process of risk management is proposed, as well as loading and maintaining a database that is subsequently oriented to the principles of machine learning.

    Keywords: electrified railways, predictive analysis, operational reliability, probability of failure, forecasting

  • Construction of a regression model of a device for measuring the impedance of a biological object

    it is known that the human body consists of water, proteins, minerals and adipose tissue, the sum of which is body weight. An important condition for maintaining health is the balance of the main components found in the internal organs of a person. Currently, the development of modern technologies allows you to find out the exact composition of your body, as well as internal organs, without complicated analyzes, using special devices that are based on measuring the bioimpedance of living tissue. Absolutely all tissues can conduct electric current, while the more water in the tissues, the more electrical conductivity and less resistance., The opposite is also true. Bioimpedance analysis measures the reactance of parts of the human body at different frequencies. On the basis of which the characteristics of the composition of the body or internal organs are calculated. Meanwhile, the measurement of the impedance of a person or his internal organs is associated with certain problems. So distorting factors can be the position of a person in space, improperly prepared areas of the body from which data are taken, improper placement of electrodes, poor contact. The aim of this work was to construct a regression model of a device for measuring the impedance of a biological object (BO), reflecting the contribution of the BO impedance to the total impedance of the entire measurement section.

    Keywords: distributed information processing system, self-similar flow, average response time of the system, simulation, object-oriented concept, agent-based and discrete-event modeling

  • Correction of training samples taking into account errors in measuring the characteristics of objects when constructing classifiers according to the methodology of teaching with a teacher

    Noise in training samples, the main part of which is made up of outliers and novelty, is considered. The analysis of the main causes of outliers in training samples is given. The essence of the main existing approaches to determining outliers in training samples is considered. Based on the use of the nearest neighbors method, a modified method for comparing generalized distances from objects to classes is proposed. For the main types of metrics used in the spaces of feature values, the justified values ​​of the safety factors used in this technique are found. For a programmatic assessment of the quality of the training sample and a reasonable choice of the method for correcting outliers, it is proposed to use the permissible fractions of corrected and removed outliers in it. An algorithm for analyzing the presence of outliers in a set of training examples is given. An estimate of the complexity of the algorithm by the length of the input of the problem is given. An algorithm for evaluating and correcting training samples has been developed.

    Keywords: classification problem, classifier, decision function, training sample, precedent, erroneous data, analysis, correction, artificial intelligence, compactness hypothesis, novelty, learningg

  • Planning and natural frameworks the region as a basis for the formation of tourist and recreational areas

    The article analyzes the urban planning documents of the constituent entity of the Russian Federation, establishing the boundaries of the planned tourist and recreational zones of regional significance on the territory. The author gives proposals for the creation and development of planning frameworks for the region: ecological, tourist-recreational and natural water, contributing to the balanced socio-economic development of the territory of the Leningrad region. The classification of recreation and tourism objects for a particular region is formulated, as a basis for the formation of tourist and recreational zones of the constituent entity of the Russian Federation.

    Keywords: Planning framework, ecological framework, tourist and recreational framework, natural water framework, forest park green belt, specially protected natural area, tourist and recreational zone, objects of recreation and tourism

  • Application of energy-efficient and green technologies in the construction of a multi-storey residential building

    The analysis of the use of renewable energy sources in Russia is carried out. The main features of the use of energy-efficient technologies in construction are considered. On the example of the construction of a 9-storey residential building, a comprehensive analysis of the construction area is performed. Solutions with the use of energy-efficient and green technologies are proposed.

    Keywords: construction, energy-efficient technologies, green technologies, renewable energy sources, energy saving, energy efficiency

  • Behavioral features of a virtual personality on the web

    This article provides information that there are different categories of users with different groups of behavioral features. All this data is separated from each other. In the course of this work, it was found that if all data on user models are combined into one method, then the analysis by which information about a virtual person is obtained can lead to improved adaptability of web resources using new technologies.

    Keywords: usability, virtual reality, types of virtual personalities, segmentation, socialization, user, Internet

  • Automatic segmentation of subretinal fluid boundaries in retinal macular layers to improve the analysis quality of optical coherence tomography scans of retinal patients with wet AMD

    This paper proposes an algorithm for automatic segmentation of subretinal fluids in the macular retinal layers of the retina. The proposed algorithm is implemented in an integrated development environment - PyCharm, a high-level general-purpose programming language (GPL) - Python was chosen. The proposed algorithm together with other methods of analysis of morphometric parameters of the human retina, which are still under development, will be used for more accurate diagnosis of the stage and degree of retinal damage in age-related macular degeneration.

    Keywords: software, image processing, diagnostics, automatic segmentation, macula, retina, age-related macular degeneration, optical coherence tomography

  • A model for assessing the timeliness and completeness of the exchange of information resources in corporate systems with a distributed registry

    The article considers a model for evaluating the performance indicators of information resource exchange in corporate systems, designed to analyze the ability of systems with a distributed registry to ensure the timeliness and completeness of information exchange. As the main indicator, it is proposed to take into account the probability of failure of a segment of the corporate system for each epoch. To find this indicator, we use probabilistic estimates of sums bounded from above by hypergeometric and binomial distributions with probability boundaries of Chebyshev, Heffding, and Schwatal. A numerical and comparative analysis of the proposed estimates is carried out.

    Keywords: distributed registry technology, information system, segmentation, block chain