The article is devoted to the possibility of applying the methods of successive approximations in the analysis of the instantaneous scheme of the traction network. The described approach allows to improve the accuracy of modeling dynamic modes of operation of traction power supply sections, and also allows to significantly improve the process of modeling diagnostics and control systems of electric rolling stock at the design stage based on a more accurate model of dynamically changing input parameters of the traction network, depending on their required level.
Keywords: traction network, instantaneous circuit, diagnostics, simulation, recruitment model
The paper is focused on research of an access control system based on the analysis of the thermal radiation of the user's palms using common components, it is shown that the use of multifactor biometric authentication based on the thermal image of the palms and infrared images of the user's veins allows to reduce the errors of the first and second kind during biometric authentication.
Keywords: biometric authentication, thermal palm print, access control system, infrared vein imaging
The article considered the propagation of a long impulse signal in a hydroacoustic waveguide. A solution is given for a replica of a impulse signal in the second approximation of the dispersion theory. The propagation of a single-mode and multimode impulse in a Pekeris waveguide with a bottom in the form of an absorbing half-space is simulated. The acoustic properties of the half-space correspond to medium sand with an average grain size 0,3 mm. The result of the solution in the second approximation of the dispersion theory is compared with the result of the simulation of the impulse replica obtained as a convolution of the input signal with the impulse response of the waveguide. The disadvantages of the solution in the second approximation of the dispersion theory are shown and analyzed. It is shown that the theory of dispersion incorrectly reproduces the transients when the signal is switched on and off in cases where the signal frequency lies near the critical frequency of the first or second mode. It is shown that the theory of dispersion correctly reproduces the envelope of a multimode impulse signal.
Keywords: impulse signal, normal modes, group velocity, dispersion theory, intramode dispersion, intermode dispersion
For a decision maker, the problem is to choose the best franchise on a wide variety of existing Russian and foreign alternatives in the face of uncertainty. For a successful business, a decision maker needs to analyze the data on all the criteria among the selected franchises. In this paper, 5 alternatives- franchises of linguistic centers were considered. To calculate the weights of the importance of the criteria, the hierarchy analysis method was used. By fuzzy criteria using the Fuzzy VICOR method, a comparative analysis of several franchises was conducted. As a result, the best franchise for doing business was revealed. The Fuzzy VICOR method allows to get an effective result even in the conditions of uncertainty of input data.
Keywords: decision making, franchising, fuzzy decision making method, hierarchy analysis, defuzzification, Fuzzy VICOR
It is necessary to study the mechanisms of supporting the sustainability and reproduction of professional dynasties in order to better understand the relationship between the constructive and destructive effects of professional dynasties on the development of professional spheres. The most convenient tools for this purpose can serve as a cognitive and simulation modeling. The purpose of this article is to build cognitive models that demonstrate the mechanisms of supporting the stability and maintaining the stability of professional dynasties. The main research method is cognitive modeling. The models are based on the idea of the dual potential of professional dynasties, which is expressed in a deeper and earlier primary professional adaptation and in the formation of a social monopoly. The article presents 4 cognitive models: model of professional self-preservation dynasties through the monopolization of the professional sphere, model resist external destruction of the system, model to reduce the level of prioritization and conflicts with the institutional environment, a general model of the sustainability and development of professional dynasties. Professional dynasties, due to the desire for leaktightness, develop mechanisms that are aimed at the development of dynasties. These mechanisms also serve to support conservation and enhance sustainability. Also, it is necessary to understand the succession strategies of children from professional dynasties by using simulation models. They are based on some factors that are involved in the transmission of the statuses and practices of professional dynasties and were considered in the cognitive models from the article.
Keywords: professional dynasties, cognitive modeling, stability of professional dynasties, sustainable development of professional models
Solid particles (PM) contaminate the filter surfaces and enter the pores, as well as settle on the surfaces of catalysts and deactivate them. Therefore, this article discusses the filter system and the cleaning system. The paper describes the requirements for what they should contain and provide, what properties and parameters the filter material should have, as well as catalytic converters that contribute to an increased level of cleaning. It is also shown that the system that filters exhaust gases must be resistant to vibrations of up to 150 Hz at an acceleration of up to 4 g. The filter system and cleaning system must be equipped with devices that ensure the regeneration of catalysts at the site of dismantling. The purification system must ensure that the emissions of the following harmful substances are reduced.
Keywords: solid particle, filter system, purification system, catalytic Converter, oxide, external environment, diesel engine
Piezoceramics based on the lead zirconate-titanate (PZT) system is the basis of most transducers operating on the piezoelectric effect and are used in various electronic devices operating in the sections of electrical and hydroacoustics, ultrasonic technology, etc. In turn, piezoceramic materials created in the last century have substantially exhausted their potential for use in modern devices, and it is rather difficult to develop new compositions and is not economically efficient. In connection with the above, an urgent task is to find modern ways to increase the parameters of piezoceramic materials.
Keywords: piezoceramics, piezophase, piezomaterial, ceramic technology, microstructure
Space grid structures are widely used for covering large-span public and industrial buildings and allow for a wide variety of structural and architectural forms. The article presents and solves the problem of finding a design solution for a space grid coating structure of minimum mass for a given steel class, element cross-section type, and loading conditions. The location of the supports is considered as a variable parameter, which leads to a different stress-strain state of the structure, and, accordingly, different cross-sections of the supporting elements.The change in the stress-strain state of the roof space structure when changing the location of the supports was studied. In total, 10 options for the arrangement of supports of a space structure with a size of 24x24 m and 7 options for a space structure with a size of 30x30 m were considered. After the load was applied, the VAT of the structure was determined numerically, the cross-section of the elements was selected and their mass was calculated. Then a comparison of the various options for supporting by the weight of the structure was made. In the article, the optimization problem was solved according to the optimality criterion of metal consumption, restrictions in the form of overall dimensions, topology and strength conditions.
Keywords: space grid structures, optimization, metal consumption, control parameter
According to regulatory requirements, the Khakassia Republic is characterized by high seismicity, and therefore reliability and safety requirements are imposed on buildings and structures in accordance with SP 14.13330.2014 “Construction in seismic regions”. It is necessary to significantly reduce or eliminate the likelihood of an emergency, to ensure the necessary margin of safety and durability of buildings. It is possible to achieve such a multifaceted effect, including through the introduction of construction technologies using fiber-reinforced concrete. The experience of Russian and foreign researchers shows that the use of fiber-reinforced concrete in various structures makes it possible to achieve higher tensile strength, no shrinkage and resistance to cracking, as well as high impact strength and plasticity. In this regard, the study of the possibility of using fiber-reinforced concrete in the conditions of the Khakassia Republic is relevant. The purpose of this work is to study structures using fiber-reinforced concrete based on basalt fiber, which has increased strength, as well as to analyze the stress-strain state of models of various structures. The article presents the results of determining the optimal percentage of concrete reinforcement with basalt fiber based on the study of the kinetics of changes in strength in compression and bending. The paper presents the dependences of changes in strength and shrinkage deformations on the percentage of reinforcement. It is shown that concretes with 2% fiber content are characterized by the best performance. It is noted that an increase in the percentage of fiber reinforcement does not always lead to an increase in strength due to the uneven distribution of fiber throughout the volume. The authors investigated the stress-strain state of bending elements (slabs, beams) based on fiber-reinforced concrete. It is shown that when using basalt fiber, there is a decrease in the percentage of reinforcement with working reinforcement of reinforced concrete elements to 26–57 %.
Keywords: Fiber concrete, basalt fiber, percentage of reinforcement, bending element, shrinkage, deformation, stress-strain state, compressive strength, flexural strength, steel economy
The synthesis of phase-locked frequency systems is based on a two-stage optimization procedure. This makes it possible to apply the combined maximum principle to construct a model of the signal phase dynamics under conditions of structural uncertainty of regular effects. The estimation equations in the form of a two-point boundary value problem are obtained using the discrete maximum principle Of L. S. Pontryagin, and a recurrent estimation algorithm is obtained using the invariant immersion method. The efficiency of the synthesized phase-locked frequency system was evaluated on the basis of mathematical modeling in comparison with the traditional one by the criteria of convergence rate and accuracy.
Keywords: synthesis, phase auto-tuning of frequency, the maximum principle of L. S. Pontryagin, the maximum condition of the generalized power function
The article discusses the concept of a system for automatic identification and traceability of pipe production at the stage of hot rolling. The main stages of pipe production are presented. A table of selection of technological parameters has been compiled. The structure of the database for the system of automatic identification and traceability of pipe products has been developed.
Keywords: raceability, automatic identification, pipe production, hot rolled products, quality management system
A mathematical model of the surface of deformation zones as a set of flat cross-section described on the basis of spline functions for profiling pipes in rollers with subsequent calibration is proposed.
Keywords: Mathematical model, deformation zone surface, flat cross-section, spline functions, рipe profiling
Recently, the issues of improving the environmental situation in the urban environment have become more relevant than ever. "Green architecture" gets popularity not only in Russia but over the world as well. The necessity of this type of architecture causes the need to improve air quality and environmental factors of urban conditions. Most often, greening the roof of a building or greening the facades is used for ecologization, so-called the element of wall greening and also greening of vertical surfaces of buildings (phyto facade).
Keywords: green architecture, vertical greening, green wall, waving plants, green screens, phyto facades
The article is devoted to improving the processing of radon flux density measurement data using mathematical processing. The article considers the influence of construction works on the radon flux density (RDP) indicators. for the purpose of the study, real measurements were taken at a mining and processing plant in the volgograd region. The article presents the construction of histograms and frequency polygons for measurements performed at different stages, as well as graphs of the empirical distribution function of a random variable. They clearly showed the impact of construction, the hypothesis of the influence of clay soils on the radon output from the soil was confirmed, namely, it was proved that the permeability of the near-surface layer of soil is one of the key factors determining the spatial PPR within homogeneous areas, that is, the permeability of near-surface deposits is one of the leading factors determining the distribution of PPR. analysis of the obtained results allows us to conclude that there is a correlation between the calculated data obtained and the data obtained at the measurement input, i.e. relationship of two or more random variables.
Keywords: radon, pollution, ionizing radiation, engineering surveys, random variable, histogram and frequency polygon, empirical distribution
Currently, there is a rapid development of computing systems, including systems that include various types of devices. Such systems are called heterogeneous or heterogeneous. In addition to traditional processors, such a system may include graphics processing units, programmable gate arrays, and other devices. One of the most pronounced problems of such systems is the complexity of distributing the computational load between the nodes of the computing system. This paper describes the types of balancing and methods for distributing computational load in heterogeneous computing systems. An example of load balancing in a real heterogeneous computing system is described.
Keywords: heterogeneous system, heterogeneous system, load balancing, load distribution, computing cluster