Другие журналы

scientific edition of Bauman MSTUSCIENCE & EDUCATIONBauman Moscow State Technical University. El № FS 77  48211. ISSN 19940408
# 01, January 2014
Physics of condensed state
Calculation of entropy increment during the heat exchange between two solid bodies
# 01, January 2014 DOI: 10.7463/0114.0681975 УДК: 536.75 This article presents a description of entropy increment during the thermal contact between two solid bodies. It was demonstrated that the entropy function depends on the system’s nonequilibrium coefficient. For a highly nonequilibrium system that function rises logarithmically but when a thermodynamic system is close to equilibrium the type of dependence becomes exponential. Solution to the equation which describes convergence of thermodynamic system’s entropy to the equilibrium state was obtained.
Constructional Material Processing in Machine Building
A heat mathematical model of polymer composite cylinder during microwave treatment
# 01, January 2014 DOI: 10.7463/0114.0658448 УДК: 629.782: 621.763 Traditional technologies of producing epoxy based polymer composite materials (PCM) require a longterm and energy consuming thermal processing. Microwave heating could be used as an alternative technology for heating work pieces made of PCM; this would allow one to reduce treatment time and energy consumption significantly. A mathematical model of temperature distribution inside the cylindrical composite system during microwave treatment was investigated in this paper. The model includes hollow PCM cylinder made of epoxy binder and carbon fibers and solid cylindrical mandrel. Theoretical and experimental results on the temperature state of the system were analyzed and discussed.
Instrument Engineering, Metrology and InformationMeasuring Devices and Systems
Remote control of plant stress at fluorescence excitation within the blue spectral range
# 01, January 2014 DOI: 10.7463/0114.0636811 УДК: 504.064.36 The authors analyzed laserinduced fluorescence spectra of healthy vegetation and vegetation under stress at fluorescence excitation within the blue spectral range. It was shown that a use of fluorescence excitation within the blue spectral range and the registration of fluorescent radiation in three narrow spectral ranges with central wavelengths of 680, 690 and 740 nm allowed one to detect reliably whether the vegetation is under stress. Ratios of the intensity of fluorescence radiation at the wavelengths of 680, 740 nm and at the wavelengths of 690, 740 nm were used as the identifying factors of plant stress.
Calibration method accelerometers unit of inertial navigation system on test stand
# 01, January 2014 DOI: 10.7463/0114.0691573 УДК: 629.7.05 The article described a technique for calibrating accelerometers unit on special test stands. The developed method allows to the determining the bias accelerometers unit, errors of scale factors accelerometers unit and angles of nonorthogonal accelerometers unit without presenting stringent requirements for highprecision testing equipment. Obtained by measuring the provisions of a test bed to which you want to set a block of accelerometers to obtain estimates of the instrumental errors of the block accelerometers. However, that requires precise measurement outputs of the accelerometers.
Laser fluorescent method for monitoring leaks from petrol pipes based on the neural network algorithm
# 01, January 2014 DOI: 10.7463/0114.0676410 УДК: 535.338.41 Current systems for monitoring leaks from petrol pipes can detect large leaks only, and their sensitivity limit is about 1% of the whole petrol pipe’s capacity. In this paper, a problem of remote detection of small leaks (less than 1%) from petrol pipes was considered. One of possible variations of such a system is a monitoring system of oil pollution at the earth surface along the petrol pipe. In this paper experimentally obtained data such as fluorescence spectra of oil products (crude oil, lightend oil products, heavy oil products), various earth surfaces (soil, vegetation, water, asphalt) and oil products spilled over various earth's surface were used for the excitation wavelength of 266 nm. It was shown that use of the laser method based on detection of fluorescence radiation within three narrow spectral bands and a neural network algorithm of measured data processing allowed one to detect oil pollution on the earth surface with a probability of correct classification close to 1 and low probability of false alarm.
Verification of an interaction model of ultrasonic oscillatory system with periodontal tissues
# 01, January 2014 DOI: 10.7463/0114.0640462 Verification of an interaction model of ultrasonic oscillatory system with biological tissues developed in COMSOL Multiphysics was carried out. It was shown that calculation results in COMSOL Multiphysics obtained with a use of “Finer” grid (the ratio of the grid step to a minimum transversal section area of a model ≤ 0.3 mm^{1}) best of all qualitatively and quantitatively corresponded to practical results. The average relative error of obtained results in comparison with the experimental ones didn't exceed 4.0%. Influence of geometrical parameters (the thickness of load) on electrical admittance of ultrasonic oscillatory system interacting with biological tissues was investigated. It was shown that increase in the thickness of load within the range from 0 to 95 mm led to decrease in calculated values of natural resonance frequency of longitudinal fluctuations and electrical admittance from 26,58 to 26,35 kHz and from 0,86 to 0,44 mS.
Informatics, Computer Science and Management
Reliability assessment for redundant multiagent systems
# 01, January 2014 DOI: 10.7463/0114.0696290 УДК: 004.052.3 The application of logicalandprobabilistic methods to evaluation of reliability indexes of distributed hardwaresoftware multiagent systems is examined in the article. The developed model of multiagent system defines faulttolerance technique, which is based on replication of tasks and actuators of the existing system as well as on introduction of redundant sets of executive containers. The developed model is also applicable for multiagent systems with actuators being aggregated into a set of production lines. Criteria of serviceability and the methodology for assessment of reliability, which defines the procedure of construction of an analytic operability function, were developed on a basis of the introduced model. The developed methodology was validated by the computing experiment described in the article. The model of redundant multiagent system and the introduced reliability assessment methodology could be applied to various problems of synthesis of optimal multiagent system with required reliability indexes.
Timed estimates and homomorphisms of asynchronous systems
# 01, January 2014 DOI: 10.7463/0114.0695993 УДК: 519.7 We study asynchronous systems used for mathematical modeling of the parallel computer system. It is considered as a set with partially trace monoid action. This allowed us to introduce homomorphisms of asynchronous systems as corresponding polygonal morphisms. Asynchronous systems with time function are studied using these homomorphisms. An algorithm for computing the minimal execution time of parallel processes in asynchronous systems is constructed. The conditions of homomorphisms of asynchronous systems minimal execution time keeping are found. The algorithm is used for compute of execution time of parallel processes, which consists of Petri net transitions. There are examples of computing minimal execution time for pseudopipeline and wave system. An experiment realized with multithreaded application that is built on a given Petri net is described. The experiment confirms the method of estimating the minimum execution time of the parallel process.
Research and analyze of physical health using multiple regression analysis
# 01, January 2014 DOI: 10.7463/0114.0696028 УДК: 519.2 This paper represents the research which is trying to create a mathematical model of the "healthy people" using the method of regression analysis. The factors are the physical parameters of the person (such as heart rate, lung capacity, blood pressure, breath holding, weight height coefficient, flexibility of the spine, muscles of the shoulder belt, abdominal muscles, squatting, etc..), and the response variable is an indicator of physical working capacity. After performing multiple regression analysis, obtained useful multiple regression models that can predict the physical performance of boys the aged of fourteen to seventeen years. This paper represents the development of regression model for the sixteen year old boys and analyzed results.
A model of algorithmic representation of a business process
# 01, January 2014 DOI: 10.7463/0114.0687808 УДК: 61; 338.2; 338.3 This article presents and justifies the possibility of developing a method for estimation and optimization of an enterprise business processes; the proposed method is based on identity of two notions – an algorithm and a business process. The described method relies on extraction of a recursive model from the business process, based on the example of one process automated by the BPM system and further estimation and optimization of that process in accordance with estimation and optimization techniques applied to algorithms. The results of this investigation could be used by experts working in the field of reengineering of enterprise business processes, automation of business processes along with development of enterprise informational systems.
Synthesis methods of the fast VilenkinChrestenson transforms
# 01, January 2014 DOI: 10.7463/0114.0687462 УДК: 519.216.1/2 This paper deals with the synthesis methods of the high efficiency fast VilenkinChrestensontransforms, using their scalar representation form and distinctive decomposition methods of multipoint transforms. Analytical expressions for the fast VilenkinChrestenson algorithms were obtained at various levels of decimation of signals’ original samples along with analytical estimations of their computational complexity. Tools for graphical representation of this computational process were presented in the form of signal graphs. Presented theoretical results were illustrated by specific examples which confirmed their applied practicability and efficiency.
Statistical modeling of programs' performance
# 01, January 2014 DOI: 10.7463/0114.0679688 A task of evaluation of program's performance occurs often in the process of design of computer systems or during the iterative compilation. A traditional way to solve this problem is an emulation of program's execution on the target system. A modern alternative approach to evaluation of program's performance is based on the statistical modeling of program's performance on a computer under investigation. This statistical method of modeling programs' performance called Velocitas was introduced in this work. The method and its implementation in the Adaptor framework were presented. Investigation of the method's effectiveness showed high adequacy of program's performance prediction.
FPGA implementation of general cellular automata based cryptographic hash functions: performance and effectiveness
# 01, January 2014 DOI: 10.7463/0114.0675812 In the paper the author considers hardware implementation of the GRACEH family general cellular automata based cryptographic hash functions. VHDL is used as a language and Altera FPGA as a platform for hardware implementation. Performance and effectiveness of the FPGA implementations of GRACEH hash functions were compared with Keccak (SHA3), SHA256, BLAKE, Groestl, JH, Skein hash functions. According to the performed tests, performance of the hardware implementation of GRACE–H family hash functions significantly (up to 12 times) exceeded performance of the hardware implementation of previously known hash functions, and effectiveness of that hardware implementation was also better (up to 4 times).
AORTA software system for automation of investigation in the field of estimating patient’s predisposition for atherosclerosis on the basis of genetic and phenotypic markers
# 01, January 2014 DOI: 10.7463/0114.0649691 The authors propose a method for automated investigation of aorta areas affected by atherosclerosis, in order to find a relation between somatic mutations of the mitochondrial genome in the cells of aortic walls and a degree of manifestation of arterial sclerotic disease in these areas. This method consists of several basic steps; they are aorta image segmentation, marking of connected components of the image, plotting an adjacency graph of image areas and decomposition of this adjacency graph. A structure of software system was proposed; AORTA software system which implements the proposed method was designed and developed. Tests and approbation of the system in the SRI of general pathology and pathophysiology of RAMS demonstrated its working capacity and usability.
Mechanics
Damage accumulation and strain of fiber reinforced composites
# 01, January 2014 DOI: 10.7463/0114.0687557 УДК: 539.4 620.22 In design of thinwalled structures made of fiber reinforced composites it is necessary to provide a reliable determination of resistance to loadbearing exposures. Model representations of damage accumulation were described in this paper; it was show that an adequate description is possible with a use of hereditarytype relations. Approaches allowing us to perform nonlinear strain estimation were proposed. Elastic properties of a unidirectional layer and stressstrain curves were used as initial data. Matrix algorithms for constructing constitutive equations for unidirectional and layered composites were developed. Proposed approaches could be used in strength optimization of fiber reinforced materials and in numerical methods of calculating and forecasting mechanical behavior of composite materials and their elements.
Calculation of plastic deformation of a conical shell with the transformation of inner surface into outer one
# 01, January 2014 DOI: 10.7463/0114.0673360 An analytical model of plastic deformation of a conical shell with the transformation of internal surface into outer one was developed with a use of the kinematic method. The shell material was assumed to be perfectly plastic. The theory of thin shells and the kinematic theorem of limit equilibrium were utilized in this work. Both geometric and physical nonlinearities were taken into account. Dependences for calculating radius of curvature of the intensive deformation zones, value of chain ring deformation and values of the deforming force as a function of axial displacement were determined. Analysis showed the possibility of using a conical shell to absorb energy with high efficiency. Obtained results could be used for calculation and selection of optimal parameters of the energyabsorbing elements in shock absorbers.
Mathematical simulation of heat transfer in unidirectional fiber composite
# 01, January 2014 DOI: 10.7463/0114.0657262 In order to justify a reliable application domain for the calculation dependence which allows one to determine the effective heat conductivity coefficient of transversely isotropic unidirectional fiber composite in the plane perpendicular to the fibers; a mathematical model of heat transfer in representative elements of this composite’s structure was created. An ordered arrangement of parallel fibers was considered for the case when their centers coincide with the nodes of cross sectional plane grid with square cells or cells in the form of equilateral triangles. Quantitative analysis of developed mathematical model was performed using the finite element method with controlled integrated computational error. Presented results are important for assessing the temperature condition and efficiency of heatstressed structures made of unidirectional fiber composite.
Modeling of the dynamics of GBB1005 Ball & Beam Educational Control System as a controlled mechanical system with a redundant coordinate
# 01, January 2014 DOI: 10.7463/0114.0646446 A method of stability investigation and stabilization of equilibrium of systems with geometrical constraints was elaborated and applied to real mechatronic device that is GBB1005 Ball & Beam. For constructing mathematical model Shulgin's equations with redundant coordinates were utilized. In order to perform stability investigation it’s necessary to combine Shulgin’s equations with kinematic constraint equations, derived by differentiating geometrical constraint equations with respect to time. First approximation equations in the neighborhood of equilibrium position have zero roots; the number of these roots is equal to the number of constraints. Asymptotic stability equilibrium in mechanical system with redundant coordinates is possible, despite formal reduction to Lyapunov's special case. This work presents a more complete nonlinear model of the mechanical part of GBB1005 Ball & Beam bench. One more equilibrium position of the system was found during the investigation of complete nonlinear cons. At the presence of one geometrical constraint between two coordinates there are two options for selecting a redundant coordinate. It was shown that the choice of linear control subsystem depends on the choice of redundant coordinate
Radiophysics
Inverse magnetostatic problem for ferromagnets
# 01, January 2014 DOI: 10.7463/0114.0695966 УДК: 537.62, 620.1 We consider the problem of multiparameter analysis of the magnetic microtopology to determine the structure of the material and finding defects. We propose a method for the analysis of raw data by dividing the obtained information on a priori criteria, determined by the physical model of a ferromagnet. We show the integral connection between the slowly varying magnetization and the stray field with tensor system functions. We calculate limits of heterogeneity of the magnetization and the external field. The analysis of experimental data for magnetic microtopology steel flat specimens with artificially created defect. The above approach to magnetostatic problem can be used in the microarray analysis and inspection.
Power Engineering
Numerical investigation of heat transfer in flat vortex channels
# 01, January 2014 DOI: 10.7463/0114.0696278 УДК: 536.24 The vortex channels is the method of heat transfer intensification which combines increase of surface area (finned wall) and enhanced convective cooling. The vortex channels is a duct formed by combination of two plates with milled fins intersected at different angles. The investigation of heat transfer and hydraulic characteristics in vortex channels was carried out by means of CFD. Flow was simulated in wide range of Reynolds numbers, heat and hydraulic characteristics were obtained for this duct. It was shown that the sum intensification effect is comprised of convective component and the effect of surface area increase. It was shown that flat vortex channels provide to transfer the higher heat flux, than finned wall at the same conditions.
On percutaneous injection of toxic substances into the human organism from the workplace atmosphere
# 01, January 2014 DOI: 10.7463/0114.0671133 This article describes theoretical research methods of percutaneous injection of uranium hexafluoride and its hydrolysis products into the human organism. Integral and differential models were considered. Capabilities of each model were described. Results on the settling of uranium and fluorine onto the skin surface, on the deposition of those substances in the organism in emergency situation and under regular industry conditions were obtained using both specified models and presented in this paper. The distribution of uranium over separate organs was also presented. It was shown that under certain operating conditions at the place of production, accumulation of uranium in the kidneys exceeds critical value that leads to their disease. The importance of obtained results for solving the matters of protection of employees from occupational diseases and medical assistance to those in emergency situation was demonstrated.
Transportation
Automated control system for the contact wire’s wear
# 01, January 2014 DOI: 10.7463/0114.0676398 During the exploitation of railway roads it’s necessary to automate condition monitoring of the overhead system. Beside other parameters, it’s important to check the contact wire’s wear. Precision, sensitivity and performance efficiency of existent technical solutions are limited. The purpose of this work was a development of automated control system for the contact wire’s wear. Operational circumstances require noncontact measurements. Proposed system is based on a use of electromagnetic (eddy current) method of nondestructive control. The width of contact area between a wire and a pantograph collector was selected as an informationbearing parameter. This system includes a matrix eddy current sensor which consists of 30 eddy current transducers, placed at the pantograph collector, highfrequency generators and signal processing system. Obtained measurement data are transferred to the mobile laboratory’s computer through a fiberoptic carrier line. Further processing and database creation allows one to monitor the condition of a contact wire constantly.
Education Sciences
On the harmonization of logical structure of educational standards
# 01, January 2014 DOI: 10.7463/0114.0676435 For solving a task of socialization of higher technical education at higher methodological and functional levels, the harmonization of educational standards by introducing interdisciplinary courses into the training process was proposed; such courses are associated with providing creative forms of professional activity. Logical structure of such courses includes studying the culture of professional way of thinking or the basis of intellectual competence by examples from scientifictechnical knowledge domains. These features make it possible to use proposed courses not only for taskoriented trainings and forming the required set of professionally significant personal skills but for developing a wide spectrum of key transferable competences.
Appendix History of Progress
In Memory of Edwin Howard Armstrong (1890 – 1954)
# 01, January 2014 A brief review of main works and achievements of Edwin Howard Armstrong is presented, an outstanding American scientist and inventor, author of 42 patents, the creator of the regenerative and superheterodyne receivers, the founder of radio frequency modulation. The information about the Armstrong's parents, the interesting facts of his life and work, including details of his amateur radio hobby, study and work at Columbia University, serving in the U.S. Army expeditionary corps in Paris in the final stages of World War I, work on the development of broadcasting in the United States are presented. Armstrong described contacts with eminent English radio engineer Henry Round discussions with leaders of the emerging science of radio John R. Carson and Murray G. Crosby, the device and the test results of the first in the U.S. FM radio stations, as well as the specifics of Armstrong relations with Lee de Forest and David Sarnoff.



