Vol 25, No 4 (2017)

Articles
TWO-STAGE NORMALIZATION OF OUTPUT SIGNALS OF ARTIFICIAL NEURAL NETWORKS
Girin R.V., Orlov S.P.
Abstract
In the article the problem of interpretation output signals of artificial neural networks was considered in cases when softmax regression is used in them which calculated with heuristics often applied in practice. To use alternative multi-fold activation function in artificial neural network for objects categorizing is proposed. It is shown that output signals, that can be get in case of using the function, possible to be interpreted as probability of full group of events. Additionally, the form of distribution allows to estimate how precise the proposition is. With aim of developed artificial neural net that recognizes hand-written characters from 0 through 9 experiments were made that checks proposed approach.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):7-16
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DETERMINATION OF THE PARAMETERS OF MATHEMATICAL MODELS WITH THE USE OF NEURAL NETWORK TECHNOLOGIES
Gubanov N.G., Kuzichkin A.A.
Abstract
The article proposes a combined intellectual method intended to identify mathematical models of CTP that provide an opportunity to minimize the length of the finding of tuning coefficients by using a neural network to reduce the number of stages of search iterative algorithms at different stages of identification. The purpose of this work is to develop a combined intellectual method that is able to identify mathematical models of CTP. This method combines the NN and the traditional iterative algorithm to reduce the time of finding the tuning coefficients. And the NN, which is considered fairly simple to learn and has a simplified structure, is used to determine the approximate value of the tuning coefficient of the mathematical model. For the purpose of analysis, experimental data were used, which were obtained from an installation carried out by catalytic reforming at JSC "SR". Data was sent to the input of 2 mathematical models. To identify the first model, a traditional iterative method without NN was used. In order to identify the second model, a developed method of iterative-neural network determination was used, which is used by the NN to compensate for the stages of the search algorithm.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):17-22
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OWNERS AND MANUFACTURERS AS OBJECTS OF A CONCEPTUAL MODEL FOR CORPORATIVE DEVELOPMENT
Ivanova L.B.
Abstract
The article is dedicated to a problem of corporations development. It describes two subjects - owners and manufacturers- the elements of a conceptual model for corporations development. The article gives us determinations of the subjects and main connections between them. The possibility of corporative development is shown as well and is based on partnership between the owners and manufacturers of material-energy resources. Transformation of corporations to partnership between owners of capital goods and working collective is suggested as the main model of further corporative development. The article also examines the principles of the gain distribution that prove the possibility and expediency of making partnership between owners and manufacturers.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):23-29
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The distributed control system synthesis of elastic structure
Koval’ V.A., Torgashova O.Y., Stepanov M.F.
Abstract

For an elastic distributed plant with parameters depending on the spatial variable, based on the spectral method of distributed systems analysis and synthesis and considering the internal resistance according to Voigt the transition is made from PDE to an infinite system of ODE in state space form. The boundary conditions are additively included to the obtained spectral representation, which enables to control from the boundaries. The control law for suppression of oscillations is synthesized and the closed system is analyzed. The obtained results can be used in the control systems synthesis for aircraft with active dynamic compensation of elastic vibrations.

Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):30-40
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DYNAMIC MODEL FORM OF A WELDED SEAM FOR ARGON-ARC WELDING WITH NON-MATCHED ELECTRODE
Omelyanenko K.N., Myuller V.V.
Abstract
In this article, a study is made of the existing dynamic models of the shape of the weld during arc welding used in the construction of automatic control algorithms.On the basis of the studies carried out, models of the shape of the weld during argon-arc welding were synthesized, taking into account the dynamic nature of the process of welding in real time. Under experimental verification, the transient processes of deterministic-statistical models and dynamic models with an aperiodic link of the first order were compared. An analysis of the error of the models over time allows us to conclude that they can be used in real welding production.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):41-49
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Optimization of maintenance period for the elements of resource-supplying networks with branching structure
Peschansky A.I., Rogachev G.N., Kovalenko A.I.
Abstract

A restorable system with linear branching structure and finite reliability is considered. Preventive maintenance of its elements is carried out. Operation and restoration periods are assumed to be random values of general kind. Iteration processes of calculation of stationary reliability and economical characteristics of the network are constructed. Optimal intervals between elements’ maintenance are obtained as the functions of their times-to-failure. The examples of electricity supply network and industrial circuit-switched net are given. It is shown that the optimal choice of elements’ preventive maintenance results in economical network indexes improvement.

Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):50-57
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Issues of automated management optimization of fuel consumption for charge mixture sintering to boost productivity and quality of sinter
Ryabchikov M.Y., Ryabchikova E.S., Mukhina E.Y., Simusev Y.A.
Abstract

We examine issues of sinter quality management by means of changing the level of carbon in charge mixture. We show the main problems: low frequency of control of quality indicators and influence of carbon level in mixture on productivity which has to remain high. To solve the problem of sinter quality management we propose using a double-loop system of automated optimization on the basis of an optimum control system and a loop for cold mechanical strength stabilization. We consider issues of loops coordination and explore influence of their setting parameters on management efficiency. We assessed the effeciency by attainable productivity and cold strength levels. We show the need for a compromise between the mentioned indicators for the efficiency assessment when current disturbing frequency increases. We determined a correspondence between the frequency of control of cold mechanical strength index and the share of conforming sinter.

Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):58-68
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STRATEGY OF SYNTHESIS AND OPTIMIZATION OF DIGITAL CONTROL SYSTEMS OF TECHNOLOGICAL PROCESSES OF COMMUNICATION CABLES PRODUCTION
Chostkovskiy B.K., Mitroshin V.N.
Abstract
Method of synthesis of structure of multi-loop automatic control systems of technological processes of communication cables production was considered. Results of a mathematical description of the stochastic process of formation of the probabilistic characteristics of the input reflectivity of a cable chosen as its generalized operational characteristic are presented. The selection of the most universal digital controller and the procedure for its empirical optimization are substantiated. A least squares regulator is proposed to ensure the implementation of an arbitrary desired form of the disturbed process of the controlled system. The optimization criterion connecting the regulator parameters with the operational characteristic of the cable is substantiated.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):69-75
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INFLUENCE OF AXIAL DISPLACEMENTS OF TURBOMACHINE IMPELLER ON THE RESULTS OF MEASUREMENT OF RADIAL CLEARANCES WITH THE SELF-COMPENSATION OF TEMPERATURE IMPACT ON THE SENSOR
Kuteynikova M.M., Podlipnov P.E.
Abstract
The method for measuring of radial clearance is considered. This method involves self-compensation of temperature impact on a single coil eddy-current sensor with sensitive element made as a conductor strip. The results of computational experiments based on the model of the electromagnetic interaction between an idealized sensing element of single-coil eddy current sensor with turbine and compressor blade tips are obtained. These results are given as quantitative evaluation of the influence of radial and axial displacements blades wheels in turbine and compressor. It's shown that the impact is doubled in turbines with a smaller range of variation in axial displacements. This is associated with an increase of the blade airfoil camber.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):76-83
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CORRECTION OF THE DYNAMIC ERROR OF INERTIAL SENSORS
Lange P.K.
Abstract
The method of dynamic error correction for inertia sensor having a transfer function type aperiodic operator of the first order is considered. The method is based on the realization of the inverse sensors operator in a dynamic mode. Correction method uses a parabolic spline-approximation of discrete values of sensors signal, as well as its first derivative. An example of correction of the signal formed by the inertia sensor of a particular type is described. It is shown that the use of a mathematical correction method based on digital filter in-line processing of discrete signal values allows to reduce in several times the dynamic error of inertia sensor. It is proposed to use the method described above also for the correction of the sensors signal, the operator of which having the second order. The considered method can be easily implemented using modern microprocessor measuring systems.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):84-88
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ELECTRICAL LOSSES IN THE STATOR THREE-PHASE ASYNCHRONOUS MOTORS SERIES AIR
Osipov V.S., Timinska E.I.
Abstract
Samara state technical University, Department "power Supply of industrial enterprises". Samara, ul Pervomayskaya 18, KAB. 344. We consider the problem of determination of active resistance of asynchronous electric motors stator with squirrel-cage rotor according to the catalog data for the subsequent calculation of the other parameters of the equivalent circuit and construction of their mechanical characteristics. In the equivalent circuit of the induction motor contains six unknown parameters-resistance, known only nominal and catalogue data of the motor so the definition of one parameter with sufficient accuracy is an important initial step in the determination of other parameters. Catalogue data usually from different sources are specified with the rounding and low accuracy. Calculation of parameters of equivalent circuits of the motor power to five kilowatts is not difficult however, for high power engines the catalogue data errors have a significant impact on the accuracy of the calculations. In work the analysis of the catalogue data sources: power factor, efficiency, slip factor, ratio of maximum moment to nominal, and also the calculation of their average values, approximation and determination of their mutual conformity. As the result analytical expression for the determination of electrical losses in the stator and resistance of the equivalent circuit of asynchronous motors was get.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):89-97
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MODELING AND TESTING OF MICROWAVE ELECTROTECHNOLOGICAL INSTALLATION FOR A HIGH-TEMPERATURE HEAT TREATMENT OF CERAMICS
Trigorly S.V., Kozhevnikov V.Y., Zakharov V.V.
Abstract
The results of modeling and testing of a microwave installation with a traveling-wave camera on an irregular rectangular waveguide for high-temperature thermal treatment of ceramics are presented. A mathematical model is proposed for the microwave heat treatment of ceramics, based on the coupled equations of electrodynamics and heat conductivity. Mathematical modeling was carried out in a three-dimensional setting using the COMSOL Multiphysics software. To determine the best matching of the microwave generator with the working chamber, cold tests were performed, as a result of which the optimal arrangement of the ceramic preform in the working chamber was determined. The tests of heating the ceramic in the microwave installation showed the qualitative convergence of the results of the simulation with the results of the field experiment.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):98-105
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INSTALLATION OF MICROWAVE DIELECTRIC HEATING WITH TUNABLE FREQUENCY
Fedorov N.V.
Abstract
Discusses the use of the generators, tunable in frequency in installations of dielectric heating. The results of calculations of the parameters of the working chambers with a traveling wave and the radiation camera of the type in a single frequency and wide broadband modes. The principle of controlling the frequency of the radiation to compensate for changes in dielectric properties during heating of the dielectric. It is shown that changing the frequency of the microwave generator during the heating of the dielectric in the chamber with a traveling wave is achieved better than in the single frequency mode matching of the microwave generator with the operation of the camera for the duration of the heating and in the chamber of the radial type, it is possible to fix the depth of penetration of electromagnetic wave in the dielectric constant.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):106-113
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BRAKING WITHOUT DEFORMATION OF A BULLET OF FIRE-ARMS WITH HIGH ENERGY
Aleksentseva S.E., Zacharov I.V.
Abstract
Problems of identification of rifled fire-arms are set up. Characteristic traces on the bullet and barrel surfaces left units of the weapon at a shot are shown. Conditions of braking without deformation of a bullet of fire-arms in brake mediums environments are investigated. The technique of working out of the device for braking of bullets with the brake environment is set up. Selection of the brake environment is made for catching of a bullet with high energy in conditions braking without deformation. Conditions of Fulfilment of the experimental researches providing accuracy and a correctness of monitor shooting are set up. The system of catching bullets with high energy with the lead core is created.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):114-120
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ANALYTICAL SOLUTION OF THE NON-STATIONARY HEAT TRANSFER PROBLEM FOR A LAMINAR FLUID FLOW IN A CYLINDRICAL CHANNEL
Kudinov V.A., Eremin A.V., Stefaniuk E.V., Zhukov V.V., Tarabardina T.B.
Abstract
On the basis of the use of the twofold Laplace-Carson integral transformation, the problem of non-stationary heat transfer for a fluid moving in a cylindrical channel is divided into two independent problems - non-stationary and stationary, each of which is defined only in certain ranges of time and space coordinates. The non-stationary problem coincides with the problem of thermal conductivity for an infinite cylinder (heat transfer proceeds as if in a fixed liquid), the exact analytical solutions of which are known. To solve the stationary problem (the Gretz-Nusseltt problem), an integral heat balance method is used when using additional unknown functions and additional boundary conditions. Owing to the use of additional unknown functions, the Gretz-Nusselt problem is divided into two problems, in each of which the solution of the partial differential equation is reduced to the integration of an ordinary differential equation. The use of additional boundary conditions makes it possible, by carrying out the desired solution, the equation only at the boundaries, and obtaining its fulfilment within the region with an accuracy that depends on the number of approximations.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):121-137
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OBTAIN APPROXIMATE ANALYTICAL SOLUTIONS OF HYPERBOLIC EQUATIONS THERMAL CONDUCTIVITY
Kudinov I.V., Kurganova O.Y., Maksimenko G.N., Abisheva L.S.
Abstract
Based on the use of orthogonal method L.V. Kantorovich obtained an approximate analytical solution of the hyperbolic heat equation for an infinite plate with symmetric boundary conditions of the first kind. Found solution describes the thermal state of a plate on the first stage of the process, i.e. before the time when the temperature at the front of the shock of a thermal wave is equal to the initial temperature. The solution is very simple works algebraic coordinate functions to an exponential function of time, which allows the study of the thermal state of the body in the fields of isotherms with the determination of the velocity of their motion on spatial coordinate in time. The official decision on the experimental values of the temperature in any point of the plate by solving the inverse task allows you to find the coefficient of relaxation, experimental determination of which is difficult.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):138-148
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THE PREPARATION OF POWDER NITRIDE COMPOSITION IS AlN-TiN SYSTEMS «HALIDES OF ALUMINUM AND TITANIUM - SODIUM AZIDE» ASIDNEY TECHNOLOGY OF SELF-PROPAGATIHG HIGH-TEMPERATURE SYNTHESIS
Kondratieva L.A.
Abstract
The paper presents the results of studies on the preparation of powder nitride composition is AlN-TiN systems «хAlF3+yNa2TiF6+zNaN3», «хAlF3+y(NH4)2TiF6+zNaN3», «хNa3AlF6+yNa2TiF6+zNaN3», «xNa3AlF6+y(NH4)2TiF6+zNaN3» (with different ratios x, y and z) in the mode of self-propagating high-temperature synthesis with the use of sodium azide precursors, halide salts of nitride elements. The final product is synthesized from all investigated systems, was a homogeneous mixture of three phases: aluminum nitride, titanium nitride and Na3AlF6. Na3AlF6 was a byproduct of the synthesis, which was unable to get rid of water washing of the final product. During the research it was found that the best output (and quantitative phase composition, the morphology of the product) is synthesized from the system «AlF3+3Na2TiF6+15NaN3» microfine (submicrocrystalline) nitride powder composition AlN (6%)-TiN (82 %)-Na3AlF6 (12 %).
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):149-159
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SHS-EXTRUSION OF LONG-DIMENSIONAL RODS BASED ON TiB / Ti
Konstantinov A.S., Bolotskaya A.V., Bazhin P.M., Stolin A.M.
Abstract
The results of studying the technological parameters of the SHS-extrusion process for obtaining long-length rods from a TiB / Ti-based material are presented. X-ray and microstructural analyzes of the rods were carried out, their microhardness and heat resistance at 900 °C were measured for 10 hours. It is shown that, due to high stresses during SHS-extrusion directed along the flow of material, and friction against the walls of the mold, the titanium boride grains predominantly have a longitudinal orientation.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):160-165
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THE OBTAINING NANOPOWDER PSEUDO-LIGATURES CU-ALN FOR MODIFICATION OF ALUMINUM ALLOYS
Kuzina A.A., Titova Y.V.
Abstract
The article presents results of study of the mechanical mixing and subsequent compaction of powder mixture, consisting of powder - carrier electrolytic copper (Cu) with particle size of 20...100 microns with nanopowder composition, modifier, of powders aluminum nitride (AlN) - 65 % and sodium hexafluoroaluminate (Na3AlF6) - 35 % with particle size of 100 nm, obtained by azide technology of self-propagating high-temperature synthesis (SHS). The mixtures, containing 2.5...5 % (mass) of the modifier, were investigated. The preparation of investigated powder mixtures Cu-AlN was performed by mechanical mixing in planetary centrifugal mill «Pulverisette-5» and in mill «Drunken barrel» within 60 minutes with speed 150 rpm/min and 45 rpm/min respectively. The chemical composition of the obtained powder compositions was investigated. Analysis of initial mixing of powder components was conducted. Some physical and technological properties of the obtained powder mixtures: particle size distribution, density, flowability and bulk density, were determined. The formation of ligature briquettes - nanopowder pseudo-ligatures of composition Cu-AlN with different contents of dispersed modifier carried out by uniaxial cold pressing in cylindrical mold on hydraulic press PSU-50 with pressing pressure 19...23 MPa. The dependence of the porosity of the briquettes from the pressure of pressing is determined. Microstructures pseudo-ligatures pressed at minimum pressure of pressing are presented. Nanopowder pseudo-ligatures (compacts) 25 mm diameter, height to 2 mm, weighing 2.5 and 5 g, with relative density 58…87 %, intended for subsequent input in aluminum melt with the aim of modification are received.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):166-173
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DEVELOPMENT OF SENSOR BASED ON Cd-CONTAINING PAN FILMS FOR H2S CONTROL IN ATMOSPHERE
Semenistaya T.V., Ivanenko A.V.
Abstract
The pyrolysis method under the influence of incoherent IK-radiation at low vacuum has been applied to fabricate the Cd-containing polyacrylonitrile films. Analysis of the scientific and technical literature devoted to the creation and study of materials sensitive to hydrogen sulphide was carried out. The data of existing sensors with a sensitive layer in the form of Cd-containing materials are presented in order to reveal originality of studies in the chosen direction. As a result of the research, it has been established that materials based on Cd-containing PAN films with a sufficiently high degree of resistance (107-1010 Ohm) have a sensitivity to H2S (S = 0.2-0.9 r.u.) at low operating temperatures (18 ÷ 46 ºС) and low concentrations of the detected gas. The main operating conditions of the proposed H2S sensor and its main technical characteristics are determined.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):174-181
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COMPETITIVENESS OF ELECTROTHERMAL HEATING METHODS
Zimin L.S., Yeghiazaryan A.S.
Abstract
Comparison of next alternative methods of heating is given: resistance and induction. Indicates the effectiveness of co-design processes of deformation, heating and design construction of heaters. The problems arising at design and operation of high power inductions for preheating of big dimensions slabs are mentioned. At the same time results of the theoretical and pilot studies received when heating slabs of the industrial sizes are given. The reason of emergence of cross section effect is uncovered. The electrodynamics problem at induction heating of rectangular slabs is considered, especially from aluminum alloys. At induction heating at an industrial frequency of current attention is paid to electromagnetic compatibility of single-phase inductors with the system of power supply.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):182-186
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MODERN METHODS OF IMPROVING THE QUALITY OF ELECTRICITY
Milishkina O.V., Zlobin V.A.
Abstract
For the analysis of the quality of electricity, it is most convenient to identify the most frequent abnormal situations. The most common are: voltage dips and rises, temporary voltage drop, long distortion of the voltage waveform, transients. The problem of the quality of electricity is closely related to the reliability and durability of a different kind of load, moreover, particularly demanding loads can function only at high voltage quality. A lot of work has been devoted to the analysis and development of devices for improving the quality of electricity.
Vestnik of Samara State Technical University. Technical Sciences Series. 2017;25(4):187-190
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