Search

The paper examines the heat supply system of the building of the educational building of the National University "Odesa Polytechnic" in intermittent mode. Intermittent heating mode is quite widely used to save costs mainly for autonomous building heating systems. The application of Pontryagin's maximum principle to solving the problem of the optimal load of the heating system during the morning on-top of the room is considered. At the same time, a corresponding optimality criterion is also added. With regard to the intermittent-frequent heating mode, the task of optimal control is formulated as the determination of the optimal control effect during the period of morning heat to achieve a comfortable air temperature in the room tk. The criteria for the study of the efficiency of the load modes of the autonomous heating system in intermittent mode have been determined. The task of optimizing the load modes of the heating system is formulated. Based on the results of solving the optimization problem on the mathematical model, the corresponding daily load schedules of the heating system optimal in terms of energy efficiency were obtained. The effect of limitations on the thermal power of the heating system on the effectiveness of the morning heating of the room in the intermittent heating mode was investigated. The study was performed based on the maximum average daily load of the heating system at a calculated outside air temperature of -15 ºС. Options for using thermal insulation to improve the efficiency of the morning heating of the room are considered. The use of combined thermal insulation of the building (external and internal) is proposed as a way to increase the efficiency of the intermittent heating mode while limiting the thermal power of the heating system. Energy savings and efficiency of the intermittent heating mode compared to round-the-clock heating were evaluated. [ABSTRACT FROM AUTHOR]

The paper proposes a methodology for mathematical modeling of the step-by-step development of nodes and transport routes in a hierarchical network with multicommodity discrete flows of correspondence based on solving the problems of optimizing its structure and distribution of flows. As a rule, such networks consist of a decentralized trunk network and networks in the internal service areas of trunk nodes. In a multicommodity network, each node can exchange correspondence (products, goods, cargo, messages) with other nodes. Correspondence is characterized by a source node, a sink node, and a quantity, which for data transmission networks is given by the number of bytes, kilobytes, etc., and for transport networks by the number of cargo units in a package of uniform size. In the trunk network, all correspondence is transmitted via communication channels or transported in vehicles in transport blocks of a given size (capacity, volume). The authors considered the main postulates of generating a mathematical model of the perspective development of the trunk network and gave a method of mathematical modeling of the step-by-step development of nodes and transport routes, which includes, for each stage of development, the forecasting of data and network parameters, solving the problem of packing correspondence and choosing the structure of the network, solving the problem of distribution and routing of flows of transport blocks. [ABSTRACT FROM AUTHOR]

Investments, primarily in manufacturing, are a guarantee that enterprises will be able to update their production assets in a timely manner and maintain or even strengthen their position in markets of goods and services. However, the issue of defining factors that affect the volume and dynamics of investments is quite problematic, which makes it difficult to create appropriate economic and mathematical models. Foreign and Ukrainian scientists have long been engaged in determining such factors. Usually, they include: GDP per capita of the country; the rate of economic growth; national savings; currency exchange rate; inflation; discount rate; the level of tax burden (primarily -- corporate income tax); the price index for industrial products; the level of income on invested capital (return on investment coefficient); wages; labor productivity, etc. But in each country, the strength of influence of different factors may vary. The process of modeling investments is also complicated by the fact that some factors (for example, GDP per capita) are complex in themselves and depend on other factors. Therefore, the objective of this paper is to define the factors influencing investment in Ukraine and to develop appropriate economic and mathematical models, which are supposed to be used in the future to build a comprehensive system-dynamic model of the impact of digitalization on ensuring sustainable development of Ukraine. Such a comprehensive model can become not only a convenient tool for determining the consequences for industry of changes in investment volumes under the influence of various factors, but also the level of Labor morbidity and environmental pollution. According to results of the study, it was found that the volume of investment in the Ukrainian industry is most affected by the NBU discount rate. The paper suggests an appropriate investment model and justifies its adequacy. Investments in industrial digital capital are influenced by the factors of the US dollar index and tax burden, and investments in environmental digital capital are affected by factor of tax burden. However, due to the very approximate statistics on which the calculations were performed, the corresponding models are not reliable. Taking into account the results of the study, recommendations for the development of a methodology for collecting and presenting statistical information related to investments in digital equipment and technologies by enterprises of the country and digital capital for environmental and industrial purposes (by structure) are made. Their implementation will make it possible to make more accurate calculations in the future and create more reliable economic and mathematical models that can become a convenient tool for defining the directions of development of the country's economy. [ABSTRACT FROM AUTHOR]

This paper explores the problem of formalizing the development of autonomous artificial intelligence systems (AAIS), whose mathematical models may be complex or non-identifiable. Using the value-iterations method for Q-functions of rewards, a methodology for constructing of ε-optimal strategies with a given accuracy has been developed. The results allow us to outline classes (including dual-use), for which it is possible to rigorously justify the construction of optimal and ε-optimal strategies even in cases where the models are identifiable but the computational complexity of standard dynamic programming algorithms may not be strictly polynomial. [ABSTRACT FROM AUTHOR]

This paper considers the planning of logistics missions for hybrid transport systems, which include a car or other vehicle that can move from a base to other locations along a designated route, carrying one unmanned aerial vehicle (UAV). A meaningful formulation and mathematical models of optimization problems of distributing objects to bases, selecting bases, and generating UAV routes during the inspection or maintenance of a given set of objects in the presence of flight resource constraints are proposed. We have developed an algorithm based on ant colony optimization to solve the resulting combinatorial optimization problems. We present the results of a computational experiment. [ABSTRACT FROM AUTHOR]

The paper presents the advantages of protected insulated wires for medium-voltage (up to 35 kV) overhead power lines compared to the lines with traditional non-insulated wires. The mathematical model is developed and the computer calculations are realized for a 20 kV protected insulated wire with a steel-aluminum core. For such design, the distributions of the magnetic field and current density in three wires of overhead power line are analyzed, their resistance is determined taking into account the nonlinear properties of the steel core within the frequency range of 50–10000 Hz. This makes it possible to compute the electrical losses in the conductors of the power lines under the transient conditions and at high harmonics in the power network. References 8, figures 4. [ABSTRACT FROM AUTHOR]

Fractured rock aquifers are regarded as of particular scientific and practical interest because of their importance for underground water supply, energy storage and safety radioactive waste disposal. The study of fissure waters of crystalline rocks in the context of global warming to address issues of drinking water supply is highly relevant today. It has potential practical importance for the future.The sustainable use of groundwater in fractured rock aquifers requires a detailed knowledge of their hydraulic properties. The complexity of hydrogeological conditions in massive fractured rocks results from uncertainties about the configuration of the fractures, while the potential for groundwater movement in such rocks is primarily determined by their permeability and, consequently, hydraulic conductivity. Fractures (fracture networks) have different permeability properties, which is one of the key parameters required for understanding and predicting fluid and water flow. This paper reviews and analyses the results of global studies of fracturing and permeability of crystalline rock massifs and the fault zones occurring in them. Since the study of permeability of crystalline rocks concerns many disciplines -- including structural geology, tectonophysics, petrophysics, hydrogeology, and hydrology -- this review highlights information about the distribution of groundwater in fractured crystalline rocks in the context of their potential exploitation. This study consists of two parts: generalization of research results concerning fracturing and permeability of crystalline rocks, and particularities of structure of fracture zones in crystalline rocks and of the presence of groundwater in them. Based on this review of the structure and development of fracture zones (including their evolution under the influence of weathering and other secondary processes), recommendations are given for using tectonophysical reconstructions to improve hydro geo logical field works and mathematical modeling. [ABSTRACT FROM AUTHOR]

This article is devoted to the development of an affordable household cost-effective photogrammetry technology for creating three-dimensional virtual models of real physical objects for subsequent printing on a 3D-printer. A 3D-prototype created using this technology (saved in the form of hidden mathematical dependencies as a file with the STL or OBJ extension) can also be used to improve the parameters of the initial object, improve its various characteristics without actually creating a model. The paper shows that 3D-printing has now become an integral part of industrial production, provides an overview of existing 3D-printing technologies, considers the most common FDM technology, shows the areas of application of this technology, and concludes that research in this direction is promising. The results of the analysis are also presented, which showed the advantages of scanning physical objects over other methods of creating virtual mathematical and computer models, the types and areas of application of scanning technologies are analyzed. In this work, a detailed analysis of the possibility of using photogrammetry in everyday life to obtain virtual three-dimensional models is carried out, a step-by-step technology of household photogrammetry for obtaining 3D-models is formulated. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental studies of the volumetric wear rate and friction coefficient when using fullerene compositions in the lubricant and changing the loadspeed range of operation. The rational content of fullerene composition consisting of fullerene fine powder, pre-dissolved in vegetable high-oleic rapeseed oil, is substantiated and experimentally confirmed. It is proved that a rational concentration can be a theoretically substantiated and experimentally confirmed average value: 0,75 g/kg of fullerenes + 99,25 g/kg vegetable high oleic oil, as a solvent, followed by addition to the base oil. The direction of reducing the volumetric wear rate by increasing the concentration of the fullerene composition is more than 100 g/kg can be considered ineffective and experimentally confirmed. Experimental results have been obtained that confirm the hypothesis of the formation of a lubricating film on the friction surface of tribosystems in the presence of fullerene compositions in lubricants. The degree of influence of fullerene compositions on the volumetric wear rate is established, which allows to draw a conclusion about the adequacy of the developed mathematical model to the experimental data. The decrease in wear rate is 20...25%, the simulation error is 5,2...14,0%. Experimental studies have shown that the use of fullerene compositions most effectively reduces the coefficient of friction (by 32,4 ... 86%), compared with the wear rate (by 20 ... 25%). Based on these results, it is concluded that the fullerene composition in liquid lubricants is antifriction and to a lesser extent antiwear. It is experimentally established that the use of fullerene compositions in lubricants has a rational load-speed range of operation. In this range there is a maximum reduction of the coefficient of friction. [ABSTRACT FROM AUTHOR]

Purpose. Definition of the direction for further research to improve accuracy of the calculation of rated parameters of ground grids based on the analysis of statistical databases of electrophysical characteristics of the soil. Methodology. To solve this problem we compiled the statistical base of soil of Ukraine in the location of electrical substation, we performed the statistical analysis for the number of layers of geoelectric structure, and electrical characteristics. In the experiments implemented the comparing of accuracy calculation of the most typical three-layer soil in the Ukraine, by the new three-layer model of ground grids and the equivalent two-layer model, which used previously. Results. On the results of analysis the ranges of the electrical resistivity and statistical distribution for electro-physical characteristics of the soil are determined. The resulting distributions allow to develop criteria for instruments, installations and means of interpretation during the sounding of soil, as well as the requirements for mathematical models of ground grids. It was found that the most typical for places of locations the electrical substations in Ukraine are three-layer geoelectric structures. In the paper the statistical distribution for three-layer soil by type (Q, K, H, A) are described. The results of numerical experiments show that the use of methods to simplify of the multilayers soil does not allow the calculation of grounding grids with high accuracy. In the work recommendations for applicability the method equivalenting depending on the type of geoelectric structure are developed. Originality. For the first time, we obtained the statistical distribution of stratification of the soil in the location of power plant in Ukraine, determined the accuracy of the method to simplify a multi-layer soil in determining the rated parameters of grounding grids. In the paper the necessity to develop a mathematical model of the grounding device located in the three-layer soil is shown, as well as a new installation of soil sounding, which allows to increase the depth of sounding and new means of interpreting the results of sounding Wenner installing a four-layers geoelectric structure. Practical value The resulting recommendations for the applicability of equivalenting of multilayer soil, as well as research in specific work areas would help to reduce costs on materials and labours during the modernization and upgrade of grounding devices, moreover it will increase the electrical safety and reliable operation of electrical substation. [ABSTRACT FROM AUTHOR]

The paper presents the results of experimental research aimed at confirming the adequacy of the developed mathematical models method of forming a wear-resistant lubricating film on friction surfaces in the presence of fullerene compositions for different base oils. From the analysis of the presented experimental values and their comparison with theoretical dependences it follows that the mathematical model of formation of a lubricating film on a friction surface of triboelements, which is developed in previous works of the authors, adequately reflects the process of friction and wear and is in a functional relationship with the wear rate and coefficient of friction. Experimental studies have confirmed the theoretically obtained in previous works, the use of fullerene composition, consisting of a solvent-vegetable oil and a fine powder of fullerenes, reduces the rate of wear when changing the tribological properties of base oils by 20,1 ... 22,6%. The simulation error is 6,5 ... 9,2%. Based on experimental studies, it is concluded that the introduction of fullerene composition in base oils with low values of tribological properties reduces the coefficient of friction by 18%. The maximum effect of reducing the coefficient of friction is equal to 71 - 86%, characteristic of base oils with average values of tribological properties. Experimental studies have confirmed that the increase in the concentration of fullerene composition in the base oil from 50 g/kg up to 150 g/kg allows to reduce the volumetric wear rate and the coefficient of friction between these concentrations by 7,8% (theoretical result 6,4%). Therefore, the direction of reducing the volumetric wear rate and friction coefficient by increasing the concentration of the fullerene composition more 100 g/kg can be considered ineffective and experimentally confirmed. [ABSTRACT FROM AUTHOR]

The paper deals with the possibility of constructing mathematical models of the dependence of mechanical properties of silicon- manganese steels designed for ESW, which have high brittle fracture resistance in the HAZ, as well as of the overheated zone, on chemical composition. Data on mechanical properties of these steels were obtained as a result of studying the influence of additional alloying (microalloying) of silicon-manganese steel by manganese, chromium, vanadium, boron, cerium and zirconium on overheating resistance at electroslag welding. The method of multiple linear regression was used for construction of mathematical models. Mathematical models were constructed for the following set of base metal mechanical properties: impact toughness for temperatures of (+20, –40, –60, –70 °С), yield limit, ultimate strength, relative elongation and reduction in area. For overheated zone at electroslag welding mathematical models were constructed for impact toughness (KCU and KCV) for temperatures of +20, –60, –70 °С. Initial validation of the constructed models was performed. 9 Ref., 12 Tabl., 2 Fig. [ABSTRACT FROM AUTHOR]

Copyright of Science-Based Technologies is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Technical Electrodynamics / Tekhnichna Elektrodynamika is the property of National Academy of Sciences of Ukraine, Institute of Electrodynamics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper, general infinitesimal deformations of higher orders of simply connected surfaces are considered in three-dimensional Euclidean space E3, which are important in the study of their continuous deformations. The problem of finding the displacement vectors of these strains is reduced to the study and solution of a system of n equations (or basic equations) of general infinitesimal deformations of finite order n, which are obtained with respect to an arbitrarily chosen coordinate system on the surface. It is shown that for closed surfaces of positive Gaussian curvature, the mathematical model of this problem in the conjugate-isothermal coordinate system is a system of n heterogeneous equations of a complex form, which in the case of an ovaloid is reduced to an system of n integral equations. Using tensor methods, the apparatus of the theory of generalized analytic functions, and methods of functional analysis, it is proved that a regular ovaloid in E3 “as a whole” admits a general infinitesimal deformation of finite order n, which is uniquely determined by predefined 3n functions. Their geometric meaning is found: setting them is equivalent to setting the values of the variations of the normal unit vector and the area element up to the order n inclusively. The strain vector fields are determined up to constant vectors. It was established that the ovaloid will be tough with respect to the general infinitesimal deformations of finite order n if and only if all values of the variations of the normal unit vector and the area element up to order n inclusive are identically equal to zero. A sphere of radius R is considered as a confirming example of the surface. The displacement vectors are found in explicit form. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of KNUTD is the property of Kyiv National University of Technology & Design (KNUTD) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper presents a methodological approach to modeling volumetric velocity wear in reverse tribosystem designs based on known values for direct construction. Based on experimental data obtained mathematical expressions for modeling volumetric wear rate. It is shown that the total volumetric wear rate of the reverse tribosystem over materials is 2.43 times the total volumetric wear rate of a straight line tribosystems. It was found that an increase in the total space velocity wear occurs due to an equal increase in wear rate mobile and motionless triboelements. A similar result was obtained for inverse tribosystem in geometry. The friction coefficient of such structures tribosystems, in comparison with a direct, does not change. It is established that wear resistance the inverse tribosystem for materials and geometry at the same time has the lowest result from all presented designs. Total space velocity wear increases by 2.9 times compared with the direct tribosystem. Got further development of the definition of weights in mathematical expressions for determining the volumetric wear rate of moving and motionless triboelements in reverse tribosystem designs. Shown, that coefficient values are a function of the difference in hardness of materials in tribosystem. The maximum value of the weight coefficients is typical for inverse tribosystem for materials and geometry at the same time. This allows to conclude that such a tribosystem will be a "weak link" in the overall design machines and limit the resource during operation. [ABSTRACT FROM AUTHOR]

Copyright of Radio Electronics, Computer Science, Control is the property of Zaporizhzhia National Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Machinery & Energetics is the property of National University of Life & Environmental Sciences of Ukraine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Problems of Economy is the property of Research Centre for Industrial Developmen Problems of Nas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the paper, we show the necessity of normalization of the static geomagnetic field (GMF) inside high-rise frame-monolithic houses to safe values (90% of the natural rate at least). Massive ferromagnetic construction of these buildings significantly (up to 50 %) weakens the natural GMF. The normalization methods are based on mathematical modeling of GMF in a residential area. Simplified physical models of reinforced concrete building structures are developed and used. The results of experimental studies are also used in the framework of the development of the methods. The following methods of normalization of GMF are presented and justified: 1) the use of special steel with a relative permeability less than 70 in housing construction; 2) restrictions on the use of long steel elements with the elongation coefficient in the critical range of 4

Purpose. Development of circuitry and control system with capacitive storage device in the exciting circuit of the synchronous motor for forcing and blacking out the field. Methodology. Mathematical modeling of transient process in dynamic modes in exciting coil of the synchronous motor with taking into consideration the flux linkage in the exciting circuit and analysis of the received results, possible future researches in this field. Results. This paper analyzes the existing loading patterns of regulating exciting current of the synchronous motors. The authors study the issues of applying the storage device in the circuit coil and suggest the structure of the system of controlling dynamic modes of exciting synchronous motor which allows maintaining the specified synchronous motor exciting circuit during a certain period of time due to the capacitor energy introduced into the exciting circuit by a transistor converter. A mathematical model of the suggested device has been developed. There have been received diagrams of the transient process by modeling dynamic modes. Originality. The authors suggest the system of exciting with the storage condenser to apply effectively the compensative ability and enhance stability of the synchronous engine by regulating the exciting circuit in the dynamic modes. Practical value. On the basis of the conducted investigations the device ensures two-way transmission of energy between the exciting coil and capacitor with high characteristics of the circuit change speed which can provide sufficient characteristics for enhancing the automatic control system performance of exciting the synchronous motor is developed. [ABSTRACT FROM AUTHOR]

Copyright of Science-Based Technologies is the property of National Aviation University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The paper outlines the concepts of using mathematical models of crowd behavior, developed by the authors for explanation, forecasting and managing drastic social-economic processes, for management of ecological-economic processes which are fundamentally more general – socio-ecological-economic or even sociogeosystem processes. Such processes are mainly large-scale ones, they correspond to the mechanisms of mutual influence, depend on socio-psychological characteristics of communication persons - the levels of perception and influence. The behavior of ecological and economic processes persons is largely determined by the imitation of the leaders behavior,individuals of enveloping societys. The developed mathematical (in the form of difference and differential equations) and simulation (in the form of cellular automata) models of crowd behaviour dynamics can be used to predict pollution or environment regeneration, taking into account economic losses, to determine managerial impacts through the state and local government system, mass media, educational and cultural institutions. Particularly, it should be emphasized the use of dynamics models for persons susceptibility of socioeconomic communication to the inductors effects. The susceptibility level is one of the main characteristics of person mentality as a system of feelings, stereotypes, imaginations about the environment and its ecological component. The mentality dynamics determines changes in this system structure, its main characteristics – levels of perception, as well as infuence (induction) of various points of view, points of view on social phenomena, including environmental and economic ones. Management of this dynamics is the key factor in the formation of positive behavior stereotypes of a person concerning environmen protectiont. The proposed mathematical models of this dynamics in the form of iterative schemes, finite probabilistic automata adequately reflect the changes of stereotypes and behavior patterns. Estimates of behavior parameters and mentality dynamics can be determined by survey methods, regular observations of the environment state and its dependence on methods influencing behavioral stereotypes of socio-economic communities. [ABSTRACT FROM AUTHOR]

Copyright of Problems of Economy is the property of Research Centre for Industrial Developmen Problems of Nas and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The main goal of this article is to design a multifactorial model for rapid evaluation of the effective operation of reactors for biological wastewater treatment, which is based on: changes in the concentration of organic pollutants in the bioreactor over time; changes in the concentration of activated sludge in the bioreactor over time; changes in the concentration of activated sludge in the reactor over time, taking into account the unevenness of the flow of wastewater to treatment facilities; the process of transporting the substrate to the bioreactor (it is possible to obtain different amounts at different times). The software implementation of the proposed algorithm for finding the appropriate model problem in the Python environment has been developed. The results of computer experiments on the study of the effectiveness of wastewater treatment in biological treatment reactors for different operating modes of the installations are given. The obtained results will be useful during calculations in the case of designing biological treatment facilities or during the reconstruction of existing bioreactors for their promising operation in new operating conditions. [ABSTRACT FROM AUTHOR]

Introduction. The complexity of the theoretical description of the magnetic pulse treatment of the material is in the mutual coupled processes of electromagnetic and thermal fields with plastic deformation of the material and processes in an electrical circuit. The paper deals with the combined transient mathematical model of the system of equations of the electromagnetic field, theory of elasticity, thermal conductivity and electrical circuit. Purpose. Research and testing of the developed mathematical model and assess the impact of various parameters on the process of deformation of the work piece. Methodology. Investigation of nonlinear mathematical model is carried out by the finite element method using a special software package. Results. The resulting solution of the transient mathematical model allows studying the influence of parameters of the circuit, the speed and the characteristics of the material to plastic deformation and heating of the work piece, which allows to select the optimum process parameters. Originality. This is an integrated approach to the development of a mathematical model, which includes the electromagnetic field equations, the theory of elasticity, thermal conductivity and electrical circuit equations with a storage capacitor. Conclusions. A comprehensive mathematical model and its solution are obtained. It is established a small effect of heating temperature on the amount of strain. Currents caused by movement of the work piece must be taken into account in the calculations. Inertial forces significantly affect the nature of the deformation. During the deformation it is necessary to consider the nonlinearity of elasticity modulus. Thermal deformation of the work piece is much less mechanical strain and opposite in sign to them, but the surface temperature stresses due to the high temperature gradient equal to 20 % of the yield strength of the work piece. [ABSTRACT FROM AUTHOR]

The development of the market of international road freight transport directly depends on the use of innovative technologies in the processes of transportation, logistics, physical distribution, due to the implementation of the concept of Industry 4.0. This leads to the need to restructure the stereotypes of transport operation and the rapid introduction of modern technologies in the activities of motor transport enterprises in order to increase the economic efficiency of their operation. The article is devoted to the research of ways to increase the economic efficiency of the functioning of motor transport enterprises of Ternopil region in the segment of international road transport. A comprehensive analysis of the activities of international freight carriers registered in the Ternopil region, which revealed the key factors influencing the efficiency of their operation in the modern economy. According to the results of the survey of international carriers of Ternopil region, the factors influencing the efficiency of transportation were selected and structured, divided into external and internal, and they, in turn, were divided into positive and negative. The algorithm of economically justified choice of strategy of the motor transport enterprise, considering its current economic condition is made. It is recommended during the substantiation to use an enlarged set of mathematical models for determining the criterion of efficiency, in accordance with the current economic condition of the trucking company. The expediency of forming a database of methodological approaches and models for determining the economic efficiency of transportation, in particular in international traffic, is determined. The examples illustrate the selection of methods for determining the criterion of economic efficiency of transportation in accordance with the current state of the trucking company, during the reasonable choice of strategy. [ABSTRACT FROM AUTHOR]

A method of estimating the effective data rate in channels of the Standard 802.11 was proposed. It provides for the measurement of the main energy parameter using the software and hardware of the subscriber device. This method is based on the empirical models of statistical relationships between the main parameters of the channel which are obtained on the basis of experimental studies using monitoring algorithms. The solutions obtained during the implementation of this method make it possible to take into account the maximum possible number of destabilizing factors and significantly reduce the time of assessment of the effective data rate. It should be noted that this method can be used for technical diagnostics of wireless networks of Standards 802.11x at the stages of network design and operation. It was established that when using the coefficient of energy efficiency, a significant error in the displacement of the points of intersection of the linear and logarithmic mathematical model occurs. This can lead to a discrepancy between the mathematical estimates of the effective data rate and real values. The statistical relationship gives a smaller error; however, it increases requirements for empirical studies to obtain the maximum possible reliability. One of the features of the proposed method is the reliability of assessment of the effective data rate. This reliability depends on three main factors: accuracy of assessing the results based on which the mathematical model was obtained; estimation of fluctuation intervals and characteristics of the Standard 802.11 equipment of different manufacturers. The last factor can be considered as a disadvantage that involves the creation of a database of parameters of the model of statistical relationship for different devices with correction coefficients. [ABSTRACT FROM AUTHOR]

Purpose. The research paper involves solving of the following tasks: 1) refinement of the mathematical model for determining the traction and dynamic, fuel and economic, environmental indicators of mobile energy facilities; 2) methodology development of theoretical studies of automatic control systems, static and dynamic characteristics automotive-tractor diesel with a gas turbine supercharger and a mobile power facility. Methodology. The work studies the working processes of vehicles and machine-tractor aggregates by mathematical simulation and the development of algorithms and programs for the calculation of these processes in actual operational conditions. The system of equations has been developed for theoretical research. It describes a nonlinear mathematical model of the automatic control system of an automotive-tractor diesel rotating frequency. In addition to the differential equations of the first and second order, equations are used in mathematical simulation of working processes of traction vehicles. These equations describe experimental characteristics of an automatic regulator, a high-pressure fuel pump, a turbocharger and an engine, as well as moments of engine mechanical losses and an external load. Findings. The developed mathematical model allows determining the effectiveness of new design, operational and technological developments, as well as various measures in order to improve the fuel-economic and environmental performances of vehicles and machine-tractor aggregates in operating conditions. Originality. For the first time, the mathematical model "Tractor driver – machine-tractor aggregate – road (field)" was developed. It allows conducting research of transport tractor aggregates by driving cycles, taking into account the processes of starting and speeding up the mobile-power sources with gear shift. Practical value. In conditions of a protracted economic crisis, in the absence of the necessary equipment, instruments, combustible and lubrication materials, comparative research of mobile power sources can be carried out thanks to the developed mathematical models with corresponding algorithms and programs that are brought to practical use. For these computer programs State Intellectual Property Service of Ukraine issued Certificates on registration of copyright No. 49285, No. 49286, No. 49287 of May 22, 2013.

Copyright of Radio Electronics, Computer Science, Control is the property of Zaporizhzhia National Technical University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose. Development of methodology and experimental studies of the layout of the active screening of technogenic power frequency magnetic fields with different control algorithms with a single coil magnetic executive body. Methodology. In the course of mathematical modeling to determine geometrical size of the magnetic coil executive body based on the size of the protected area, and the configuration of the coil magnetic executive body is determined based on the required uniformity of the magnetic field distribution in the protected area. Results. Experimental studies of open, closed and combined systems of active screening of technogenic power frequency magnetic fields with a single coil magnetic executive body. Originality. For the first time experimentally confirmed the possibility of reducing the level of induction of man-made power frequency magnetic fields in a given area 3-5 times with a single coil magnetic executive body.. The possibility of reducing the level of the magnetic field in a limited area of the space by 15-20 times Practical value. On the basis of the calculations the layout of active screening of technogenic power frequency magnetic fields with different control algorithms with a single coil magnetic executive body has been made. [ABSTRACT FROM AUTHOR]