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scientific edition of Bauman MSTU

SCIENCE & EDUCATION

Bauman Moscow State Technical University.   El № FS 77 - 48211.   ISSN 1994-0408

# 01, January 2013

Machine Building and Engineering Science

Analytical solution of the Hertzian contact problem of elastic deformations of a thin plate positioned in a cylindrical cavity
# 01, January 2013
DOI: 10.7463/0113.0517977
S.N. Dmitriev
The author proposes an analytical solution of the contact problem of elastic deformations of a thin plate rolled up into a cylinder and placed into a cylindrical cage of the same radius. In this case, the plate is only partially adjacent to the surface of the cylinder, on the other part there is delamination. For linearization of basic correlations it is assumed that the plate deviates from the surface of the cylindrical cavity to a very little degree; therefore, it is possible to use the equilibrium equation, as well as physical and geometric equations of cylindrical shell. It is considered that the shell bending is cylindrical. The rolling of the plate is taken into account as a pre-stressed state. It is supposed that it is a state of pure bending in plane. As a result of solution, the angle of delamination, displacement and internal power factors are determined.

Constructional Material Processing in Machine Building

Determining the deformity of cutting waste during cutting a material with heterogenious properties
# 01, January 2013
DOI: 10.7463/0113.0541311
N.A. Yaroslavceva
In this article the author presents analytical dependences for determination of geometrical parameters and orientation in the root of cutting waste of a rectangular dividing grid after two consecutive great inelastic deformations (surface plastic deformation and cutting). Images of deformed condition of a material, obtained during real processing by means of the micro-coordinate dividing grid method (square side of a grid cell is equal to 60 µ m), are also presented in the article. The author also compares estimated eformities and corresponding experimental data recorded in the area of chip formation for materials of different machinability groups. It was established that during cutting of materials with surface deformation, deformation values were redistributed across the thickness of cutting waste; relative smoothing of deformation degree across the section of a layer being cut also occurs.

Power Machine Building, Metallurgical Machine Building and Chemical Engineering

Automatic pressure regulation at the input of the main line pump during emergency cutout of an electric motor
# 01, January 2013
DOI: 10.7463/0113.0518041
D.N. Popov, N.G. Sosnovskii
This article describes a method of mathematical modeling of systems with centrifugal pumps. A structure chart directed at interactive solution of an optimal control problem of controlling pumping units was created with the use of this mathematical model. In this article, along with the results of calculations, the authors provide an example of an emergency cutout of a pumping module subject to the inertia of the pumping unit rotor, rotating frequency of its spindle, the pump’s head-capacity curve and parameters which determine hydraulic wave processes in the pipelines connected with the pump. Controlled parameters in this case are the pump module’s shaft speed and pressure generated by irregular fluid motion on intake side of the pump. Transition processes were determined for these parameters in case of an emergency cutout of the main line pump’s electric drive. Schematic diagram of the proposed mathematical model for investigation of centrifugal pump’s emergency modes was published for the first time
Dynamic processes in an electrohydraulic pressure controller with electric pressure feedback
# 01, January 2013
DOI: 10.7463/0113.0517493
M.A. Andreev, S.E. Semenov
The article gives a description of dynamic processes in the electrohydraulic pressure controller with electric pressure feedback. Linear equations of the lumped-parameter mathematical model, allowing for inertia of fluid in the connecting pipeline in lumped parameters, were composed. The authors analyzed the effect of different factors on stability of the system. The conducted research showed that the electrohydraulic pressure regulator might experience sustained oscillations; their existence depends on parameters of hydraulic resistance of the connecting pipeline regulator. Special attention should be paid to the difference of natural frequencies of amplifier and electro hydraulic accumulators.

Mathematics and Mathematical Modeling

Modeling of dielectric properties of composite materials on the basis of asymptotic averaging
# 01, January 2013
DOI: 10.7463/0113.0531682
Yu.I. Dimitrienko, A.P. Sokolov, M.N. Markevich
In this paper, the authors consider calculation of effective dielectric parameters of composite materials with complex three-dimensional armoring. The method of asymptotic averaging of periodic structures is used for averaging of long-term quasi-static electric fields in composites with dielectric components. Series of local electrostatic tasks were formulated with the use of periodicity cells; electrostatic variational problems were also formulated. To solve spatial local problems for composite materials with three-dimensional complex armoring, the finite element numerical method was used. In this article, the authors proposed an algorithm for computation of effective tensor of dielectric permeability of three-dimensional armored composite materials. Test computations were carried out in order to obtain distribution of the local electric field, effective dielectric characteristics of three-dimensional orthogonal armored composite materials with different inclusion volume fractions.
Paleoclimate simulation with the use of a global climate model
# 01, January 2013
DOI: 10.7463/0113.0517953
V.P. Parhomenko
Influence of important climate parameters (atmosphere CO2 concentration, solar constant), configuration of continents, as well as distribution of ocean depths corresponding to the considered time periods, on climate was investigated. The author used a global climate model that includes a 3D model of the thermohaline circulation of the ocean, an energy and moisture balance model of the atmosphere and a sea ice evolution model. Numerical experiments corresponding to periods of 124 million years ago and 200 million years ago with drastically different parameters were carried out. It was established that a stationary climate system state is achieved after 1500-2000 years of development. General global and spatial climatic characteristics for the atmosphere, oceans and sea ice were obtained. Estimated global mean atmospheric temperature is agreed with the reconstructed observed data. Features of the ocean circulation were studied for the corresponding periods.

Aeronautical and Rocket Space Engineering

Influence of interaction of gas masses on efficiency of intermittent-cycle engines
# 01, January 2013
DOI: 10.7463/0113.0522954
D.S. Khantalin
 The article presents results of numerical investigation of mass interaction influence on propulsion performance characteristics of a spherical resonator of an intermittent-cycle engine. Analysis of the resonator’s flow features compared to the theory of unsteady outflow was conducted. Main attention was paid to research of influence of joining cyclic and external masses on traction performance. A problem of improving the numerical method for fast processes was formulated while comparing calculation data with experimental results. Impact on propulsion performance characteristics of mechanical and geometrical relations, intensification of the process of joining masses and elasticity of high-temperature gas was also investigated. On the basis of the obtained results the need for more integrated studies of non-stationary effects of the oscillatory pulsing process was indicated.
Experimental research of influence of acoustic noises of different types on results of automatic speech recognition
# 01, January 2013
DOI: 10.7463/0113.0508614
O.N. Korsun, A.A. Yacko, I.M. Finaev, V.Ya. Chuchupal
The article presents estimation results of automatic speech recognition by the system based on the method of hidden Markov models. The research was carried out in the following conditions: in a laboratory in the absence of acoustic noises, under the influence of acoustic noises of different types. The presented results give objective quantitative estimation of such characteristics as speaker-independence and noise-immunity of speech recognition systems with little vocabulary, based on Markov models; recommendations on improving speech recognition characteristics are formulated. The authors propose further development of the techniques developed for estimation of influence of flight overloads on speech characteristics and its automatic recognition.

Instrument Engineering, Metrology and Information-Measuring Devices and Systems

Metrological support of phase-chronometric systems (part 2)
# 01, January 2013
DOI: 10.7463/0113.0514350
V.I. Pronyakin
This article presents a description of a measuring plan for estimating metrological characteristics of a measuring channel for operation of a complex technical object where there is a restriction on access to its primary transducers due to repair intervals. In these conditions it is necessary to evaluate metrological characteristics of measuring channels while machines and mechanisms operate. In this case, controlled parameters of the measuring channel must be independent of the features of the device operation and external actions. The proposed method is implemented with the use of multi measurement and measurement planning processes. The quality of the measuring process relative to the systematic error and dispersion using a test signal is also evaluated.
Simulation of communication in the "heart-vessels" system
# 01, January 2013
DOI: 10.7463/0113.0513571
N.S. Buldakov, N.S. Samochetova, A.V. Sitnikov, S.I. Suyatinov
 Problems of constructing a model of sphygmic mechanism of cardiovascular system are considered in this article. The model is based on information received from an electrocardiogram, phonogram and pulsogram. Signals are processed in interrelation and with the use of the Volterra neural network.
Complex control of onboard measurements of critical parameters of an aircraft flight
# 01, January 2013
DOI: 10.7463/0113.0508634
O.N. Korsun, P.A. Motlich
In this article errors of modern means of onboard measurements and registration are analyzed. Equations of spatial movement of the plane, which are expedient to use for identification of errors of onboard measurements, are distinguished. The proposed algorithm is implemented in the form of a computer program with a developed graphic interface that defines its practical importance. Results of approbation of the algorithm presented in the article and based on flight test data display possibilities of the proposed approach and the main methodical receptions of identification with its help of errors of onboard measurements.

Informatics, Computer Science and Management

Evaluation of efficiency of optimizing transformation for algorithms of ultra-graph operations
# 01, January 2013
DOI: 10.7463/0113.0547731
V.A. Ovchinnikov, G.S. Ivanova, A.E. Pavlov
 In this article the authors consider experimental evaluation of reducing computational complexity of algorithms of ultra-graph operations. According to the results of theoretical analysis of the algorithms of ultra-graph operations, procedures, which introduce the greatest contribution to their computational complexity, were defined; ways of its reducing were selected. With the help of special software contribution of optimizing transformations to reducing computational complexity of vertex addition was estimated. Experimental results showed high efficiency of the conversion process - total reduction of computational complexity of the algorithm was up to 87%.
Cryptographic hash functions based on generalized cellular automata
# 01, January 2013
DOI: 10.7463/0113.0534640
P.G. Klyucharev
In this paper the author introduces a family of cryptographic hash functions based on using generalized cellular automata. The structure of the proposed functions is a dendrogram which includes a one-way pseudorandom function built with the use of a generalized cellular automaton whose graph is a Ramanujan graph. The local link function of the cellular automata is a balanced function with large nonlinearity and some additional properties. The family of proposed hash functions may find practical application in a number of information security tasks, including authentication, integrity, digital signature, etc.
Synthesis of orientation mechanisms for the space observatory «Millimetron». 1. Capabilities of parallel mechanisms for orientation of the space observatory «Millimetron»
# 01, January 2013
DOI: 10.7463/0113.0534292
Yu.N. Artemenko
This paper is an introductory start of a series of four papers dedicated to design of parallel mechanisms for orientation of the space observatory «Millimetron». General description of the «Millimetron» project is provided in this paper. Variations of the space observatory design concepts are considered. The whole series of papers is briefly described. The «Millimetron» project is aimed at creation of a space observatory with a 10-meter cryogenic radar telescope which is capable of working within the waveband from 20 mm to 20 um. The «Millimetron» observatory is designed for conducting investigations of various types of highly sensitive objects (single telescope mode) and record high angular resolution (ground-space interferometer mode) within the infrared and millimeter ranges of wave length. Very high sensitivity of a space telescope is achieved by means of cryogenic cooling of an antenna reflector, thermal shields and receiving equipment with liquid helium.
Solving systems of linear algebraic equations by preconditioning on graphics processing units
# 01, January 2013
DOI: 10.7463/0113.0525190
A.P. Karpenko, S.K. Chernov
The authors consider an algorithm for solving systems of linear algebraic equations (SLAE) with preconditions. The authors introduce parallel algorithms and software for image processing devices that implement the basic operations of the algorithm - multiplication of the matrix by a set of vectors and solutions of a block triangular SLAE. The results of extensive studies of effectiveness of the proposed algorithmic and software solutions are provided in this paper. These results show a fairly high efficiency of the developed algorithms and software for multiplication of the matrix by a set of vectors. Acceleration of computations in this case is four to sixteen times. Algorithms and programs for solving the block triangular SLAE showed satisfactory results which allow to expect an acceptable acceleration for practically significant SLAE of high dimension and when using professional GPU.
Design and analysis of low power consumption software using software power efficiency metrics
# 01, January 2013
DOI: 10.7463/0113.0511596
A.V. Yurchenko
There is permanent growth of requirements for power efficient operation of the majority of portable computing devices. In this paper the author considers power efficient software design and proposes metrics for energy consumption analysis in software systems. Sources of power consumption in digital circuits are considered. It was proved that power consumption depends on executing software. The author gives a description of energy measures which form a basis for definition of software energy metrics. The defined metrics can be used for calculating the level of energy consumption of any software system.
Flight control of highly maneuverable aircraft during aerial refueling
# 01, January 2013
DOI: 10.7463/0113.0500331
D.I. Cheglakov
The author considers aircraft flight control during aerial refueling. Results of hardware-in-loop simulation and flight tests are presented in this paper. A corrected model of aerodynamic coupling of a tanker with a receiver is the first main outcome of this study. The control law for the fly-by-wire system’s aerial refueling special mode is another one. This control law ensures desired handling qualities for the aerial refueling task and could be used in fly-by-wire systems. That fact was validated by hardware-in-loop simulation and flight tests. The author’s further study will include development of a control law for the automatic docking procedure during aerial refueling.

Mechanics

Interaction of rigid bodies in oscillatory systems with elastic linkages and couplings under external vibrations
# 01, January 2013
DOI: 10.7463/0113.0486817
S.V. Eliseev, V.A. Piskunova, A.A. Savchenko
 The authors propose a technique of creating various mathematical models of mechanical oscillatory systems with two degrees of freedom with elastic supports and a rigid body for protection against vibrations. The problem is solved by selection of corresponding motion coordinates. It is supposed that after realization of a system of joints between the rigid body and the base of the system, choice of corresponding coordinates is made. Those coordinates describe relative movement between two selected points. After transformation of a mathematical model and the setting coordinate of relative movement equal to zero, the system loses one degree of freedom. The mathematical model of the system is simplified; it allows one to estimate dynamical properties of the system from the required point of view. The proposed method also allows one to search for and estimate new constructional and technical solutions in the field of protection against vibration and vibration isolation of technical systems.

Power Engineering

Experimental study of parameters of surfaces coated with regular relief
# 01, January 2013
DOI: 10.7463/0113.0532996
S.A. Burtsev, V.K. Vasil'ev, Yu.A. Vinogradov, N.A. Kiselev, A.A. Titov
This article presents an analysis of published data on numerical and physical (experimental) study of thermal-hydraulic characteristics of different methods of heat exchange vortical enhancement. It is shown that the most effective is the use of heat exchange surfaces coatedwith regular relief (holes) which have a simple production technology combined with high thermal-hydraulic characteristics. The authors present a modernized test bench that allows, in a single experiment, to determine resistance and heat exchange parameters for two plates which are parallel to each other (smooth plates and plates coated with regular relief). In this case, resistance is determined by "weighing" on tensometric scales, and parameters are determined by a time-dependent heat exchange method using thermal imaging equipment. The authors present data of an experimental study of two types of heating surfaces. It is shown that surfaces with oval holes have a large (20-35%) resistance than surfaces with hemispherical holes.

Metallurgical Engineering

Discussion of results of thermodynamic instability of materials structure
# 01, January 2013
DOI: 10.7463/0113.0530839
T.V. Kurihina, V.N. Simonov, E.A. Sergievskii
The authors propose an energy method for calculating degradation rate of a non-equilibrium structure while in opeartion. With the use of differential scanning calorimetry it is possible to determine the presence of phase transformations in case of alloy aging, decay of supersaturated solid solutions, secondary crystallization and also assess heat content of the system during the transient process from the non-equilibrium state into the thermodynamic equilibrium state with extra energy release. Differentiating the current value of extra energy with respect to time, it’s also possible to determine the value of the chemical activity coefficient during phase transformations in alloys at working temperatures. Estimated dependence of the rate of energy dissipation χ on the initial value of a superfluous chemical potential was derived for the first time.
Christon elastic fields in formation of bainitic ferrite lath structure
# 01, January 2013
DOI: 10.7463/0113.0529309
M.P. Kaschenko, K.N. Djemilev, V.G. Chaschina
The authors analyze elastic fields of a separate prismatic loop and a set of loops (special cases of christon) modeling shear deformation media in shear bands with orientations of the borders close to {558} γ. It is shown that christons can act as dislocation nucleation centers for lath crystals forming the composition of bainite macroplate. The obtained results support the dynamic picture according to which individual laths of ferrite crystals are formed like martensite laths. However, between stages of forming ferrite rods there occurs carbon diffusion redistribution. As a result, there arise new areas of austenite which are beneficial for rapid growth of the next generation of lath crystals.
Simulation of ion nitriding
# 01, January 2013
DOI: 10.7463/0113.0501016
S.A. Gerasimov, M.G. Krukovich, E.A. Baderko, N.P. Klochkov
The authors analyzed processes occurring in the saturating medium and work material; the analysis allowed to account for reasons of high rate of phase growth during ion nitriding. It was shown that the kinetic coefficient is a link between technological parameters and process output results. An algorithm for calculating process output characteristics is proposed.

Economic Sciences

77-48211/516648 Informational and statistical methods of random process analysis
# 01, January 2013
S.V. Yudin
A new approach to analysis of random processes, based on applying information theory methods and new “distribution entropy” statistics, is proposed in this paper. Use of information-theoretical methods was justified when solving several statistical problems such as tests of statistical hypothesis, analysis of process state, and so forth. It was shown that entropy is a universal statistical estimate which allows to solve almost every simulation problems and analyze complex process, including identification of the distribution law and solving discrimination problems. The main advantage of this method is a possibility of considering non-linear models with non-Gaussian factors. An example of creation and analysis of informational model of labor productivity dependence on the salary is considered.
Appendix

Foreign Education

GERMANY: German University Builds Bridge to Eastern Europe
# 01, January 2013
The Viadrina, as it is known, was founded in 1991, just a year after German reunification and long before Poland became part of the European Union.“It was founded with a clear mission to build a bridge between East and West,” said Annette Bauer, a university spokeswoman. The stated goal is to attract a third of the student body from abroad.Although Germany has a reputation for sending many students overseas, it also hosts the third-largest number of foreign students in Europe, after Britain and France.German universities, which have good reputations and low or no tuition fees, have been attracting more students from Eastern Europe, especially since the region opened up politically.The drawback of often having to learn a complicated language like German is outweighed by easier access and greater opportunities once in the system.Viadrina has one of Germany’s highest rates of students spending part of their studies abroad: 54 percent go overseas for at least a semester. It has partnerships with many overseas universities, from the University of California, Berkeley, to St. Petersburg. Some of the student exchanges are financed by the Erasmus Program, while others rely on joint agreements.
GMAT Retains its Popularity Among MBA Applicants
# 01, January 2013
More and more North American business schools are offering the GRE as an alternative to the GMAT entry test, but prospective students are not interested, it seems. According to a survey from Kaplan Test Prep, which trains students to sit the two tests, 69 per cent of business schools now give applicants the option of submitting scores from the GRE (Graduate Record Exam) rather than the GMAT (Graduate Management Admissions Test), compared to just 24 per cent in 2009. But almost half the business schools surveyed (46 per cent) said that fewer than 10 per cent of applicants submitted a GRE test score.Students may be right to be wary of the GRE, says Kaplan. Although more than two-thirds of business schools (69 per cent) say they view scores from both tests equally, 29 per cent say that applicants who submit a score from the business-focused GMAT rather than the more general GRE are at an advantage.
UK Universities in Online Launch to Challenge US
# 01, January 2013
A partnership of UK universities is launching an online project, challenging US universities that have dominated this emerging market.They will aim to give the public access to higher education courses via computers, tablets or smartphones.The partnership will include the Open University, King's College London, Bristol, Exeter, Warwick, East Anglia, Leeds, Lancaster, Southampton, Cardiff, Birmingham and St Andrews.Courses will be offered from next year.This could "revolutionise conventional models of formal education", says Universities Minister David Willetts.

History of Progress

77-48211/533355 In Memory of Nikola Tesla (1856 – 1943)
# 01, January 2013
V.P. Samokhin
A brief review of ma in works and achievements ofNikola Tesla is presented. He is a prominent American inventor, a Serb by nationality, author of more than 7 00 patents, developer industrial power systems, AC motors and high-frequency applications, the pioneer of wireless communication, have been widely used all over the world. Are pedigree information for parents and relatives of Tesla, the interesting facts of his life and work, including details of the work in Paris and Strasbourg before resettlement in the United States and the subsequent construction of power plant at Niagara Falls and his experiments with high-voltage and high-frequency. Tesla described contacts with Edison, Westinghouse and other U.S. and European inventors and scientists, and entries from his diary, kept in the Museum of Belgrade, and other evidence about the Tunguska catastrophe in 1908 could be the result of his experiments with atmospheric electricity.
 
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