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scientific edition of Bauman MSTU

SCIENCE & EDUCATION

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

Science and Education

Subsections:

Multidimensional matrix algebra for adapted data model processing
# 07, July 2011
D.V. Eliseev, A.V. Baldin
The article is devoted development of the mathematical tool for processing of the adapted data model. The generalized structure of the multidimensional space which describes the relational model is offered for the adapted data model. The offered structure of multidimensional space is considered as a multidimensional matrix. The multidimensional matrix set based on the multidimensional matrix of the whole multidimensional space defines various parts of this space. Different operations for the multidimensional matrix set are entered and the multidimensional matrix algebra is defined.
Hardware implementation of Berlekamp-Massey key equation solver for Reed-Solomon codes in FPGA
# 07, July 2011
S.V. Fedorov
A review of different aproaches for decoding Reed-Solomon codes in terms of hardware cost and performance is given. We have developed a modified version of the key equation solver for Reed-Solomon decoder based on the Berlekamp-Massey algorithm. A distinctive feature of the proposed implementation is the combination of size and speed, which places it between existing implementations based on Berlekamp-Massey and Euclid algorithms.
About indefiniteness of own frequency of a drosselling hydraulic actuator.
# 07, July 2011
D.N. Popov, A.A. Knyajanskii
The wave model a current of liquid in a hydraulic actuator is considered. It is shown that own frequency of a drosselling hydraulic actuator can decrease in 1,41 times at the identical weight led to a target link. As a result of numerical experiments influence of nonlinearity of a dynamic characteristic on self-oscillatory processes arising in a hydraulic actuator is defined. Results of numerical experiments have been compared with results of tests of the hydro-mechanical monitor drive applied in laboratory installation of chair E-10 "The hydromechanics, the hydrocars and Hydro-pneumatic Systems" MSTU named after N. E. Bauman. Values of frequencies of self-oscillations received at tests of the laboratory sample of a hydromechanical actuator and registered at numerical experiments are almost equal and differ from calculated on linear mathematical model in 1,41 times. Thus, it is possible to conclude that the decrease in own frequency of self-oscillations of a hydromechanical drive found out at mathematical modeling represents the facts.
Efficiency of thin films deposition in vacuum as object of quality management
# 07, July 2011
M.A. Kolesnik, L.L. Kolesnik
Questions of effective quality management system for production with required properties are considered. Methodology of finding key setting of technology process and building quality area which can guarantee getting production with required features is shown by example of multilayers thin films depositions on large area substrates.
Collapsibility conditions. Sufficiency theorems and enumeration
# 07, July 2011
A.N. Bojko
This article is a continuation of works devoted to the modeling of mechanical linkages machinery and mechanical appliances. To describe the positional relationships of mechanical products author is offering to use the language of hypergraphs. It is shown that this medium is an adequate model-based environment and can provide product assembly process as a sequence of normal contractibility of the hyperedges. The necessary conditions for the contractibility of the general form of hypergraphs. We prove sufficient conditions for a number of important cases. The technique of enumeration contracted hypergraph. We obtain recurrence relations that allow to find the number of such objects with n vertices.
Mechanics of cutting processes of plastically deformed metals with non-uniform properties of cutting layer
# 08, August 2011
DOI: 10.7463/0811.0195350
V.M. Yaroslavtsev
Mechanism of influence of metals surface strain hardening to chip disposal process has been studied. It has been clarified that the form changing process evolution while two continuous stages of deformation in cutting of mechanical hardened materials satisfy the condition of linear addition of deformation specific works in accordance with unite flow curve σi - εi, which can be appreciated as a theoretical base of mechanics of cutting process for deformed metals with non-uniform in depth mechanical properties. Theoretical relationships have been derived for estimation of main component of chip disposal force. Figs. 5.
Modeling of viscoelastic properties and mechanical behavior of polymeric composite leaf springs
# 07, July 2011
N.N. Staroverov, G.O. Kotiev, I.Z. Dashtiev
The method of hysteretic damping systems modeling using fractional calculus is analysed in this article. Mathematical model of mechanical viscoelastic behavior of composite leaf spring with polymer interleaves is described. The properties of the model is analysed in the article, the calculation of ride comfort parameters of the vehicle with such leaf springs is made.
New in cutting process
# 07, July 2011
DOI: 10.7463/0711.0195080
V.M. Yaroslavtsev
It is shown that cutting is an explosion modification, and the data confirming this statement are given. New concepts of deforming and destruction at cutting are presented; a combined physical-technological model of the process of chip formation and formation of surface layer quality is elaborated. A new version of classical "σi–εi" diagram, namely, diagram of large deformations for dynamic destruction is proposed. A common mechanism of formation at metal cutting of chip of any type is theoretically substantiated. It is shown that physics of high dynamic pressures can serve as a research basis for machining by cutting. Figs. 2. Tabs. 3.
Engineering Methods of Calculations of the Connection of Details on Cylindrical Surfaces with Small Gap (if Details with Hole Are Considered Boundless). Examples.
# 06, June 2011
D.S. Blinov, V.F. Alyoshin
Engineering methods of calculation of the connection of details were defined with the usage of the theory of elasticity. Several graphs were acquired. The methods described in the article are easy to employ and have much in common due to the usage of dimensionless forms. The main parameter is radial gap. The methods are probabilistic, for size of the details can vary.
An application of polymeric composite materials in the suspension systems of wheeled vehicles
# 06, June 2011
N.N. Staroverov, G.O. Kotiev, A.A. Smirnov
The suspension system dynamics of special all-road vehicles with low pressure tires is analysed in this article and concluded an opportunity of decrising of the required damping measure. The optimal parameter of linear-viscous damping in the suspension system of the special all-road vehicle is calculated while it drives along different roads throughout the range of possible speeds. Russian and foreign developer’s experience of polymeric composite material’s and other polymeric material’s application in the suspension systems of the vehicles is analysed in this article.
Modelling support of the learning systems. The review
# 07, July 2011
DOI: 10.7463/0715.0193116
A.P. Karpenko, A.A. Dobryakov
The paper presents the review of the basic mathematical models used in modern learning systems. We discuss the models of knowledge, the learner, the learning process, the control of educational achievements, and also some other models. As models of knowledge we present the frame-model, formal-logic models and models based on semantic networks. Such classes of the pupil models, as overlay models, imitating models, difference models, perturbation and stereotypical models are considered. From all variety of the training process models the review includes the models based on the Petry networks, probability models and the models based on the finite-state automations. As models of the control of educational achievements of the learner the paper presents the models based on the classical test theory (CTT) and models based on the item response theory (IRT).
Estimation of insurance efficiency of the risk industrial and economic activity
# 06, June 2011
D.S. Reznichenko
The article examines the main approaches to assessing the effectiveness of risk management and assessment of the effectiveness of the insurance of industrial and economic activities of industrial enterprises by the example of the relationship model of insurance risk and insurance transactions. Also give definition of the efficiency the insurance process, the mathematical model of risk management and examine specific character and objectives of each subject of the insurance process. And make suggestions to facilitate the procedures of insurance risks and improve risk management.
Structural strain in metalwork of rotary parking lift under different combinations of loads.
# 06, June 2011
S.G. Gnezdilov
Presented here is the procedure for determining cases of most unfavorable combination of loads upon load-carrying metalwork of a new design of rotary /car/ parking system - rotary /car/ parking lift. This procedure was set out within the framework of thesis suggesting optimization methods of the said metalwork design. In accordance with this procedure using Pro/Engineer program, cases of most unfavorable combination of loads for a particular design of load-carrying metalwork of rotary /car/ parking lift were determined and relevant information concerning loading of its components under different combinations of loads was made available.
Quickly proceeding transitive modes of functioning turbine dtive shaft of the powerful turbine unit
# 05, May 2011
M.I. Kiselev, V.I. Pronyakin
The article contains research results of transients into turbine shafts of power turbine units of thermal power station and a state district power station made with a help of new phase-chronometric method using precision measurements with the relative error no more than 5∙10-4 on industrial frequency. The acceptability  of  a method is also regarded in respect of turbine units diagnostics. The researches have been executed on two types turbine units Т-250 and Т-200. There are shown in details the results of transients registration at generator switching  in an external network and switching off it, influencing weariness accumulation in turbine shaft metal. There is also presented an influence of impulses from an internal network on a turbine shaft rotation mode, not  be registering by regular equipment of thermal power station. The turbine shaft twisting fluctuations spectra of turbine units  are presented
Motion control biped walking robot on the program trajectory
# 05, May 2011
A.K. Kovalchuk, D.B. Kulakov, S.E. Semenov
The article deals with motion control actuator bipedal walking robot on the program of path. A mathematical model of the tree-actuator robot, recorded by the apparatus of the block matrices and graph theory, presented in a way traditional for actuators with a simple kinematic chain. Presented, developed by the authors, the algorithms forming the trajectory of the robot on a horizontal plane and the results of their implementation on the operating experimental two-legged walking robot with electrohydraulic actuators .An algorithm for stabilizing the movement of the actuator robot controlled by changes of the moments on the feet and the block diagram of the stabilization system, which implements this algorithm. The results of experimental studies robot walking on a horizontal surface.
A hypergraps operations application for partitioning networks
# 07, July 2011
V.A. Ovchinnikov, A.A. Plamadyalov
In this paper, we present the two realizations networks partitioning: in set operations and with using hypergraph operations. The second variant partitioning description is more compact and clear. The asymptotic computation complexity of both realizations is equal. The formal description of multilevel hypergraph partitioning is received. This description make possible easily to estimate the transformations that demand very large quantity actions.
Theoretical prerequisites and the practical realization of the electric-contact welding of wire with the braking of the contact roller
# 07, July 2011
V.V. Bulychev
The theoretical prerequisites of an increase in strength of the electric-contact welding of wire due to its slippage on the base layer are examined. The method of welding with the braking of contact roller and the results of its use with the forming of multilayer coatings is examined.
Ordered set operations
# 06, June 2011
V.A. Ovchinnikov
The decisive rules of algorithms execution ordered set operations are substantiated. Conditions for achieving maximum of multitude elements comparisons are formulated. The asymptotic computation complexities of operations are received. The efficiency of using ordered set operations is estimated.
Conceptual bases of simulation of interactive informational space
# 06, June 2011
M.F. Menyaev
Intensive production assumes the organization management system, formed on the basis of the knowledge about the production situation. For the establishment of a knowledge needed to manage information space. In this sense one can speak about the system of management of interactive communications, enabling to form the new knowledge for the management of complex manufacturing processes. For its analysis of proposed conceptual approach, based on a system of axioms, determining interaction of objects in the process of interactive communication. Based on the developed system of axioms in the form of the geometry of the information space it is possible to model the basic interactive processes, show conditions of domination in the process of interactive communication, to determine the requirements to ensure the sustainability of the interactive process in the information space of industrial organization
Forecasting quality of the welded pipes
# 06, June 2011
O.V. Sokolova, A.E. Lepestov
The Article is dedicated to production of the oil-gas welding pipes and discovery parameter technological process, under which occurs arising the marriage. Present-day day possible to minimize the amount unimproved tubes, as well as shorten time an testing work when mastering new type welding tubes from different marks of steel, by analysis result modeling behaviour bands under forming. Hereunder avoiding disadvantage conditions of the process.
 
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