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scientific edition of Bauman MSTU

SCIENCE & EDUCATION

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

# 09, September 2010

Science and Education
Influence of the oscillatory mechanism of crystallization on process of crushing of primary structure of metal of a seam and zone of thermal influence
# 09, September 2010
V.P. Morozov
Process of crystallization of metal of a bath after continuous welding is characterized by a number of physical and chemical laws which have the general character without dependence from a mode of influence of a source of heating. Existence of the oscillatory mechanism of hardening of metal of a welded bath in the form of formation of periodically repeating isotherms of crystallization, is characteristic for different metals and alloys. It is established that at influence of heat from an external periodically operating source with frequency to corresponding own frequency of crystallization of metal of a seam conditions of a resonance which promote crushing of cast structure of a seam and a zone of thermal influence are created.  The fine-grained structure of welded connection received for the account of efficient control by the oscillatory mechanism of moving of front of crystallization, allows to raise essentially resistibility to formation of hot cracks and, possibly, cold cracks at the expense of change of conditions of the structural transformations unattainable at usual welding
Influence of distribution of streams of capacity between sections on traction possibilities of the jointed transportno-technological system
# 09, September 2010
E.E. Bajenov
Article is devoted questions of modelling of movement of the active jointed transportno-technological cars. The objective approach to modelling of the jointed transportno-technological cars is considered. The universal model for research of influence of distribution of power streams between leading elements of the transport car is offered, allowing in a wide range to change the factors influencing efficiency of transport operation. Distribution of streams is offered to be regulated by means of change of parametres of elements distributing power streams (distributing boxes, differentials).
Communication definition between periodicity of process of crystallization of metal of a welded seam, changes of instant speed hardening and indicators of technological durability
# 09, September 2010
V.P. Morozov
Existence of the oscillatory mechanism of hardening of metal of a welded bath in the form of formation of periodically repeating isotherms of crystallization, is characteristic for different metals and alloys.  Without dependence from a mode of influence of a source of heating a number of the physical and chemical laws connected with a heredity of properties of metal in a liquid state, are closely connected with transition not only to microlevel, but also to the macroscale sizes of elements of structure of a welded seam at its formation. Periodicity of process of crystallization of metal is connected with fluctuations of speed of crystallization of interphase border at its movement with accelerations both the subsequent delays and a stop.It is established that at influence of heat from an external periodically operating source with frequency to corresponding own frequency of crystallization of metal of a seam conditions of a resonance which promote crushing of cast structure of welded connection are created.  The fine-grained structure of welded connection received for the account of efficient control by the oscillatory mechanism of moving of front of crystallization, allows to raise essentially resistibility to formation of hot cracks at the expense of periodic changes of temperature in a germinal zone, overcooling of liquid metal and the subsequent changes of rate of internal shrinkable deformations in a temperature interval of fragility.
Structural Synthesis as discret optimization task
# 09, September 2010
A.N. Bojko
The article is devoted to structural synthesis of technical objects. It discusses an approach based on the representation of multiple analogs and prototypes in the form of directed hypergraph. The formulation of the problem of structural synthesis in the form of discrete mathematical programming is proposed. The system of constraints, describing the restrictions on the combination and terms of coercion is introduced.
Influence of design data caterpillar движителя on passableness
# 09, September 2010
A.A. Anikin, L.V. Barakhtanov
It is shown that the search for ways to improve off-road capabilities of tracked vehicles in the snow must be based on comprehensive analysis of the influence of design parameters of the caterpillar drive as a quantitative resistance force, diving machines, traction control, and on the nature of the interaction of a caterpillar drive with snow cover. Computational and theoretical research, experimental-design work has shown that off-road capabilities of tracked vehicles in snow can be enhanced by quantitative changes in the geometric parameters of the chassis (track width, base, ground clearance) and a qualitative change in the nature of the interaction of caterpillar drive with snow cover (lining of the pressure diagrams and increasing the active length of the support surface caterpillar drive). There are shown the dependence of the resistance movement, traction and traction supply of track width, clearance and pressure drive in the snow.
Dynamics research of a multi-section trunk robot-manipulator
# 09, September 2010
DOI: 10.7463/0910.0157912
A.P. Karpenko, A.M. Shmonin
This paper presents multi-section trunk robot-manipulator based on parallel kinematics “hexapod” mechanism. The paper purpose is working out of mathematical model and dynamics research of this manipulator. Means of program system MatLab/Simulink develop dynamic models of one-section and three-section manipulators. Research of transients and the maximum loadings in their drives is executed at various weight of tong and parameters of automatic control system.
Estimating document relevance in ontology knowledge base
# 09, September 2010
DOI: 10.7463/0910.0157379
A.P. Karpenko
The paper discusses ontology knowledge bases focused on support of decision making in corporate information systems. We assume that search of decisions in knowledge bases is performed using metadata of the document. Metadata are formed on the basis of the semantic network of the ontology. Relevance of the document is estimated by computing affinity in metrics of the semantic network of the document and the semantic network of the query.
The Development of Pseudorandom Binary Sequences Generators Based on Cellular Automata
# 09, September 2010
B M Sukhinin
In this article we propose new generators of uniformly distributed pseudorandom sequences based on cellular automata. The advantages of such generators are good statistical properties of output sequences and high performance of hardware implementation. We justify the choice of the structure and parameters of generators and describe details of classical and non-uniform cellular automata usage in the structure of generators. We also compare hardware implementations of our generators and eSTREAM candidates.
Neural network control and identification of the parallel kinematics ⌠tripod■ mechanism.
# 09, September 2010
DOI: 10.7463/0910.0157066
S.М. Gomenyuk, A.P. Karpenko
The article considers execution level of trunk-manipulator, considers control system of the tripod as a section of the manipulator. The article describes classical nonparametric identification and neural network identification based on NNARX model. Both method of identification were implemented in Matlab with Neural Network Toolbox and System Identification Toolbox. The paper considers classical  and neural network nonadaptive control system of the tripod. Classical two-circuit control system based on PID controllers. Neural network control system based on inverse model of the tripod. Also the article describes adaptive control system. There are two method describe in article. First method  based on classical control system with the reference model of tripod. Other method based on neural network control system. All neural networks model were implemented in Matlab with Neural Network Toolbox.  Modeling of control systems were implemented in Matlab/Simulink.
Mehaniko-mathematical model of a cross-section-striped muscle
# 09, September 2010
DOI: 10.7463/0910.0155231
E.V. Galiamova, A.M. Guskov, V.V. Syuzev
In article the new approach to modelling of parametres of the human muscle describing a condition of a muscle (weakened or strained) is offered. The universal curve gives possibility to compare various muscles in relative units, as
Experimental researches long-base the jointed transportn-technological system
# 09, September 2010
E.E. Bajenov
Article is devoted research tests of the active lorry convoy, as special case of the active jointed transport system. The object of research, measurement and control system, the experiment plan are described. Tests have shown high efficiency of application of the active jointed transport systems. The results of research tests showing dependence of force of draught on a hook from a kinematic mismatch in a drive of the second section of the car are resulted. Recommendations about introduction in a drive of the second section of system of the kinematic mismatch providing the maximum value of force of draught on a hook of the car on various types of a soil surface are given
Substantiation of working capacity of caterpillars with elastic expanders
# 09, September 2010
A.A. Anikin
The article discusses a series of works on the justification of durability of caterpillar’s flexible wideners, including the following milestones: development of a mathematical model and algorithm for calculating the deflections of wideners; the study of the deformed state in order to select the geometric and force parameters; the development of design wideners; conducting laboratory bench and road tests. There are compiled computational model that simulates the passage of widener single obstacle and widener dive into the snow.  There are shown the solution of the problem of determining the strain state of a rubber track widener in a geometrically and physically nonlinear formulation.  There are presented the results of computational studies on a rational choice of elastic stiffness widener caterpillars.
Appendix

Foreign Education

INDIA: World's largest university to open in Europe
# 09, September 2010
The Indira Gandhi National Open University, the largest in the world, will open study centres in six European nations, including Germany and France, to offer personalised courses, reports Sify Finance.
UK: English degrees may become world's most expensive
# 09, September 2010
An analysis of international data reveals that a small rise in fees would push England to the top of a league table of the most costly places to study - overtaking nations including Iceland and the United States. The University and College Union, which conducted the research, called on the coalition government to scrap a proposed tuition fee hike to avoid the "unenviable" tag.
WALES: Universities expect more foreign students
# 09, September 2010
Despite a freeze on UK undergraduates, up to 20% more international students are set to enrol in universities in Wales this autumn, reports the BBC. The Welsh Assembly Government wants universities to take on more foreign students in order to boost finances.
JAPAN: Universities looking to go global
# 09, September 2010
Fostering global human resources seems all the rage these days and several Japanese universities are jumping in, opening their doors to foreign students who aren't proficient in Japanese in a bid to snatch top-class talent from around the world.Under the Global 30 project initiated by the education ministry last year, by the end of fiscal 2013 more than 130 undergraduate and graduate courses conducted completely in English will be launched at 13 universities acting as Japan's "global education hubs."The schools, selected by the education ministry, include the University of Tokyo and Waseda, Keio, Meiji and Nagoya universities. Global 30 is one of the measures launched to achieve a goal set out in 2008 by then Prime Minister Yasuo Fukuda to attract 300,000 foreign students a year by 2020.
US: Women doctoral graduates outstrip men
# 09, September 2010
For the first time, more women than men in the United States received doctoral degrees last year, the culmination of decades of change in the status of women at colleges nationwide, writes Daniel de Vise for The Washington Post.
MALAYSIA: Asia-Pacific shows steep research growth
# 09, September 2010
While researchers at universities and institutes in many Western countries fret about budget pressures, scientists in many Asian nations are translating huge investments in research and development into impressive gains in research output, writes Liz Gooch for The New York Times.
 
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