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scientific edition of Bauman MSTU

SCIENCE & EDUCATION

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

# 02, February 2013

Machine Building and Engineering Science

New concept of metal cutting waste
# 02, February 2013
DOI: 10.7463/0213.0541318
V.M. Yaroslavtsev
It was shown that cutting waste is a product of unique complex mixed-mode energy deposition combined in the place (the area of chip formation) and time; this deposition can be considered as special unstudied up until today transformation method of condensed medium properties. Dynamic destruction with explosion parameters combined with other physical and chemical features of the cutting process allows to assert that this processing technology of ingoing material of a work-piece may lead to creating brand new materials with a non-traditional complex of mechanical and physical properties which have their own application domains. Studying formation conditions of properties of cutting waste material would allow to find new approaches to regulation of product quality parameters during the cutting process.

Constructional Material Processing in Machine Building

Investigation of mechanical properties of multilayer carbon nanotubes
# 02, February 2013
DOI: 10.7463/0213.0533309
Yu.S. Belov, E.V. Vershinin, D.S. Govorov, B.M. Loginov, A.V. Ponomarev
Basing on the previously developed mathematical model with the use of combinational potential, the stress-strain state of single layer and multilayer carbon nanotubes was analyzed. Introduction of a dimensionless parameter defining the nanotube length to radius ratio allowed to unify the results obtained for single layer nanotubes. For single layer and multilayer nanotubes of different types dependences of strain on extra energy per one nanotube atom were calculated. Specific regularities of bifurcation processes development, depending on the number of nanotubes layers, their geometry characteristics and chirality are discussed.

Power Machine Building, Metallurgical Machine Building and Chemical Engineering

Development of a low-pressure helium compression control system strategy
# 02, February 2013
DOI: 10.7463/0213.0539096
R.R. Nagimov
Cryogenics is now widely used in large accelerator projects using applied superconductivity. Economic considerations require an increase in performance of superconducting devices. One way to achieve this is by lowering their operating temperature and cooling with superfluid helium. For this reason, large cryogenic systems operating at 1.8 K and capable of producing refrigeration capacity in the kW range, have to be developed and implemented. These cryogenic systems require large pumping capacity at very low pressure using integral cold compression or mixed cold-warm compression. The author compares and describes different cooling methods using cold and hybrid cycles along with cycle operational capabilities, and reviews a developed low-pressure helium compression control strategy for these cycles.

Transportation, Mining and Construction Machine Building

Influence of step length on energy efficiency of walking type of motion
# 02, February 2013
DOI: 10.7463/0213.0541387
V.V. Chernyshev
In this article the author analyzes influence of step length on energy efficiency of movement of walking machines and heavy robots. Marching modes of walking machines with periodic leg movement are considered. The analysis is based on theoretical research results and field tests of prototypes of walking machine with cyclic propulsion plants. The nature of changes in the structure of energy consumption by increasing step length is determined. The most significant components of energy consumption at different speeds are identified. It is shown that an increase in step length, at a constant speed, significantly reduces inertial load of walking machines and reduces the power required for movement. It was also shown that walking machines with simple and reliable cyclic walking propellers can be claimed for introduction of new soil conservation and resource-saving technologies in agriculture.

Aeronautical and Rocket Space Engineering

Influence of liquefied natural gas composition and functional specifications of storages of launching equipment on rollover phenomenon time
# 02, February 2013
DOI: 10.7463/0213.0552136
N.S. Korolev
The urgency of liquefied natural gas applications as long-range rocket fuel is connected with better characteristics in comparison with rocket kerosene. However, if liquefied natural gas is stored in ground facilities it can be affected by the negative phenomenon called rollover. Studying causes of occurrence of this phenomenon is the primary design task for creating safe storage systems. In this article major factors influencing the start time of the rollover phenomenon are described. The results of the research can be used at designing fueling systems of spaceport ground facilities.
Simulation of variables in time and rolling load, caused by gas-dynamic influence of a space rocket propulsion pack
# 02, February 2013
DOI: 10.7463/0213.0539497
V.A. Boshnyak, V.A. Zverev, A.V. Ul'yanenkov
The authors consider the problem of parameter representation of gas-dynamic influence of the rocket power-plant jet on structural elements of the launching system for space rockets. Vectors of nodal loads and time dependences are used for modeling this type of influence; these vectors correspond to the rocket position when moving along the calculated trajectory, while time dependences establish a connection between those vectors. The obtained results reflect time and type varying load, which is a distinct feature of this publication. This approach may be applicable for modeling other variables in time and for load point modeling.
Simulation technique of fuel consumption from aircraft fuel tanks in the presence of alternating g-loads
# 02, February 2013
DOI: 10.7463/0213.0533503
A.E. Novikov, G.F. Resh, M.Yu. Ivanov
The aim of this work is to simulate operating process in the aircraft fuel systems, with consideration of external influencing factors. The authors propose a new technique of simulating fuel consumption from fuel tanks during the flight along the trajectory and maneuvering; this technique is based on application of CAD systems and a specially developed finite element FuelTanks solver. The efficiency of this method was demonstrated on a specific example; calculation results were confirmed experimentally. Application domain for the developed method and mathematical software is a wide class of aircraft pneumatic-hydraulic systems along with ground systems which use pressure feed systems. Further development of the work presupposes software product development that follows the whole cycle of creating pneumatic-hydraulic systems from front-end engineering to diagnostic engineering during the operation.
Possible ways to reduce the mass of an aircraft’s rudder control system
# 02, February 2013
DOI: 10.7463/0213.0531715
I.S. Shumilov
Nowadays reduction of the mass of an aircraft’s rudder control system (RCS) still is an important problem for designers, which can be solved by structured design methods or selection of optimal parameters of control system’s different elements. It’s also essential not to degrade the required flight safety and reliability level and meet the demands of airworthiness (AP25), including the influence of the so-called “human factor” on the flight safety. That’s why, to reduce the mass of MCS, one can try to reduce the mass of each element; one has to deal with working levers and control-loading devices, remote signal transmission, rudder gears, energy supply systems and mass and geometry optimization system for several elements of RCS. This article provides analyses and necessary recommendations for designers on every of listed directions.

Instrument Engineering, Metrology and Information-Measuring Devices and Systems

Laser gas analysis for multicomponent gas mixtures with essentially different gas concentration
# 02, February 2013
DOI: 10.7463/0213.0539070
V.A. Gorodnichev, M.L. Belov, A.Yu. Busargin, L.N. Eremenko
The paper describes the problem of gas reconstruction in laser analysis of multicomponent gas mixtures with essentially different gas concentration. Signal processing procedures based on the projective method are described. Usage of the projective method allowed to solve the problem of gas reconstruction efficiently for multicomponent gas mixtures in cases of distinctions in gas concentrations by one or two orders of magnitude and even more.
Assessment of technical condition of a machine tool UT16P by a phase-chronometric method
# 02, February 2013
DOI: 10.7463/0213.0532755
A.S. Komshin, K.G. Potapov, A.B. Syritskiy
In this article the authors propose a new approach to information and metrological support and assessment of technical condition of metal-cutting machines, based on a phase-chronometric method. A phase-chronometric information measuring system for the UT16P machine was created. The authors carried out studies of operation of the UT16P machine by measuring kinematic parameters of rotation of a spindle with application of the phase-chronometric method. Results of measurements during processing of a cylindrical work piece made of steel ShH15 with a firm alloy T15K6 are presented. The authors obtained steady diagnostic signs in the form of ranges of spindle’s natural oscillation frequency.
Research of duplicating afocal optical system’s characteristics in devices designed for measuring objects’ movement.
# 02, February 2013
DOI: 10.7463/0213.0531036
V.Ya. Kolyuchkin, T.H. Chan
This paper describes the results of investigations which can be used for developing devices for high-accuracy measurement of transverse objects’ movement distance to which can vary significantly. In order to tackle this problem one can use the method based on measuring the location of a test optical signal projected onto the surface of the object by an afocal optical system. With the use of a mathematical model of the afocal optical system under the conditions of coherent illumination the influence of its parameters on distribution of intensity in the image with defocusing was analyzed. It was shown that a combination of parameters of the afocal optical system could be selected in such a manner that distribution of intensity in the image doesn’t depend on defocusing.
Automated method for image analysis of breast immunocytochemical preparations
# 02, February 2013
DOI: 10.7463/0213.0529424
N.S. Klimenko, O.A. Artyukhova, E.Yu. Amel'kina, A.V. Samorodov
This paper presents results of developing a segmentation method and algorithm for microscopic images of breast immunocytochemical smears; this method is the key stage in creating a system of smears’ automated analysis. The developed segmentation method was adapted to the currently used method of preparing immunocytochemical smears and provided an opportunity to work with microscopic images of smears with different color-luminance characteristics. The obtained results will allow to objectify quantitative assessment of immunocytochemical reactions and contribute to widespread usage of this type of analysis in clinical practice.

Informatics, Computer Science and Management

Implementation and testing of hash functions based on the two-dimensional Ising model
# 02, February 2013
DOI: 10.7463/0213.0541576
S.V. Belim, A.Yu. Shereshik
The authors propose an algorithm for hashing data, basing on the increase in entropy during simulation of physical processes. The two-dimensional Ising model was selected as a system. The Ising model was studied with the use of the Metropolis algorithm. A computer experiment was carried out in order to detect collisions and determine the avalanche effect. The model’s preferred parameters such as temperature and size were identified experimentally. It was shown that the avalanche effect becomes large enough when the temperature is higher than the critical one by 28%. The dimension of the system must be chosen depending on the size of the output digest. It was also shown that the two-dimensional Ising model has sufficient mixing properties for cryptographic hash functions. The authors conducted a comparison with common algorithms MD5 and SHA-1. The developed hash algorithm is scalable, unlike traditional hash algorithms.
Multiobjective optimization of water slotted filter geometry
# 02, February 2013
DOI: 10.7463/0213.0539055
A.P. Karpenko, D.T. Mukhlisullina, A.A. Cvetkov
 The article deals with a three-objective optimization of slotted filter geometry produced by an innovative method of deforming cutting. This method was developed by Professor N.N. Zoubkov from BMSTU. The multiobjective problem is solved by using the interactive PREF method proposed by the authors. This method is based on the assumption that a decision maker (DM) is able to provide, in some form, preference information related to various solutions proposed by multiobjective optimization software. The DM’s utility function is approximated by a neural network. This work presents a three-objective optimization problem statement of filter design, a short description of an interactive method and its software implementation along with results of computational experiments. 
Kinematics of a single-section parallel «dodekapod» manipulator
# 02, February 2013
DOI: 10.7463/0213.0539000
S.H. Dang
The aim of the work is to investigate kinematics of a single-section parallel “dodekapod” manipulator. The “dodekapod” is an extension of a hexapod and has 12 degrees of freedom. In the article, direct and inverse kinematic problems of the “dodekapod” were solved with the use of the Yaw, Pitch and Roll transformation method. Using matrix of transformation, one can express position and orientation of any plane in two ways: by a directed vector or by transformation parameters. The particle swarm optimization method (PSO) was applied to solving a direct kinematic problem. Results of this work subsequently are used to find the workspace of the “dodekapod”, and also to solve the problem of its dynamics.
Approach to selection of a way to upgrade a LAN server
# 02, February 2013
DOI: 10.7463/0213.0535392
V.M. Postnikov, S.B. Spiridonov
This article describes methods of decision-making theory which allow the decision maker to analyze various promising ways of upgrading a LAN server in detail and chose the best one; these ways are selected by a working group of experts. Recommendations are proposed on use of given methods in practice. A wide range of server’s operating parameters is taken into account along with nameplate engineering data. Practical guidelines on numerical composition of initial promising variants of upgrading a LAN server are also given. An example that demonstrates potentials of the proposed method is provided in the article.
Synthesis of minimal-order robust controllers
# 02, February 2013
DOI: 10.7463/0213.0533324
O.S. Kozlov, L.M. Skvorcov
Many modern methods of synthesis of controllers haven’t become widely applied. It is explained by a variety of reasons, among which one can list lack of simple and clear communication between the minimized functional and quality indicators put into practice, and also unreasonable complexity of the synthesized controller. At the same time in industry simple controllers of low order are in demand. In this article the problem of synthesis of minimal order controllers is considered. These controllers provide the given quality of a linear continuous system at uncertainty of object parameters. Synthesis is carried out with the use of quality indicators which are very simply expressed through coefficients of a characteristic polynomial.
Method of the automated composition of monitoring materials on the basis of numerical assessment of mutual importance rate of educational elements
# 02, February 2013
DOI: 10.7463/0213.0533251
A.V. Makarov, A.V. Samohin, K.V. Makarov
In the present article authors analyze a topical problem of automated formation of control and monitoring materials the contents of which would most completely meet the requirements of the theory of pedagogical monitoring. Key shortcomings of existent widely applied methods of automated test formation are given. The authors introduce a hypothesis of necessity for recording results of semantic-logical analysis of training materials during formation of control and monitoring materials. They present a model of functional dependences of mutual importance of educational elements and scales of groups of control tasks according to their difficulties. On the basis of pilot studies of the developed method, they draw a conclusion on its consistency.
Method of improving efficiency of digital simulation systems for modeling a real time hydro-acoustic situation
# 02, February 2013
DOI: 10.7463/0213.0531784
A.A. Sotnikov
A method of improving computer systems for simulating a real time hydro-acoustic situation was developed. This method reduces the cost of hardware and laboriousness of software development of the modeling system while maintaining adequacy requirements for the mathematical model. The article gives a brief analysis of the acoustic systems structure. Relevance of the problem, scope, limitations and efficiency evaluation of the method were defined. Practical application of the method is possible in design of monitoring and diagnosing computer sonar systems, software development and tests of sonar guidance algorithms.
Rational ordering of alternatives in a dialogue with DM
# 02, February 2013
DOI: 10.7463/0213.0531045
A.N. Bojko
In this paper a method of selecting a rational linear order of a set of admissible alternatives is discussed. The author offers a way of representing a set of permutations of high power in a compact set of partial orders called στ-decomposition. Disparate elements of the expansion are a source of combinatorial diversity of acceptable alternatives. Additional ordinal information from the DM can reduce search space of the best linear order, and in a few iterations, get a better alternative. The proposed technique can be used to generate rational design decisions at the stage of technological preparation of production.
Adaptive cluster model of minimal speech units in analysis and speech recognition problems
# 02, February 2013
DOI: 10.7463/0213.0527867
V.V. Savchenko, D.Yu. Akat'ev
This article deals with the problem of variability of word pronunciation in analysis and speech recognition tasks. An adaptive acoustic model defined as a multitude of minimal sound units (MSU) united into a cluster-phoneme under the principle of minimum informational mismatch in Kullback-Leibler metric, is proposed. An adaptive algorithm of filling the MSU cluster from a continuous stream of speech was developed on the basis of the whitening filter method. An example of its practical implementation is also provided in the article. As a result of this experiment, from the total list of phonemes of the national language the authors selected the phonemes which, in their implementation, are the most sensitive to conditions of their pronunciation by the speaker. Adjusting an information system to such a phoneme, the authors guarantee maximum sensitivity of perception in relation to the speaker’s emotional and physical state.

Power Engineering

Application of above-critical carbon-dioxide cycles in industrial heat recycling facilities
# 02, February 2013
DOI: 10.7463/0213.0533901
I.G. Surovcev, A.N. Arbekov
The authors consider schemes of gas turbine power units with above-critical carbon dioxide parameters designed for industrial heat recycling at manufacturing enterprises or gas turbine electric power stations. An approach to selection of such schemes was formulated and justified. The authors propose multi-threaded variants of heat schemes for recycling facilities which allow to increase the coefficient of heat usage. Thermo dynamic cycles of carbon-dioxide above-critical gas turbine devices were investigated for the proposed schemes. Possibility of significant increase in the degree of utilized heat, up to 2/3 of the total amount of disposed heat, was demonstrated.
Appendix

General Problems of Engineer Education

77-48211/536105 On the design of the physics course at technical university: competency building approach
# 02, February 2013
A.F. An
In this article the most significant topics for learning disciplines of a professional cycle and bases of physical outlook of the technical university graduate by a specific training area are highlighted on the basis of expert estimates of an approximate physics course’s content, which rely on the structural and logical and frequency analysis of the learning content. Proposed approaches and obtained results can be used as an approximate basis for improving the content of specified physics course as a part of competence focused educational programs and for developing educational and methodical complexes, procedures and funds for estimative diagnostic tools in order to check the level of training according to the requirements of the federal and institutional components of educational standard.

Foreign Education

SWITZERLAND: Swiss Universities Try to Catch the MOOC Wave
# 02, February 2013
Free interactive online university courses known as MOOCs - massive open online courses - are quickly spreading far beyond the United States, writes Simon Bradley for the Swiss Broadcasting Corporation. Lausanne’s Federal Institute of Technology and other Swiss universities are keen to experiment.The Lausanne Federal Institute of Technology (EPFL) is an early MOOC adopter. It became one of Coursera’s 33 university partners last June, offering a course in Scala computer programming to which 53,000 students signed up, five times the number on campus.
UNITED KINGDOM: Over-60s are Told: Go Back to University and Retrain
# 02, February 2013
People in their sixties should go to university to retrain because they will be expected to work for longer before retirement, the Government has suggested.Older workers who take courses to keep their skills up to date will be more likely to keep their jobs, claims David Willetts, the higher education minister. Mr Willetts said the age limit on student loans to cover tuition fees had been lifted, making a degree course “great value” for older people. This would help them cope with the pressure they would face to keep up to date as they worked well into their sixties, he suggested.
INDONESIA: Foreign Uuniversities are Inevitable - Vice President
# 02, February 2013
Indonesia’s Vice President Boediono said last Tuesday that it was impossible to prevent foreign universities from operating in Indonesia, particularly in the current era of globalisation, reports The Jakarta Post.“Do you think we should isolate ourselves like people in North Korea? It’s impossible. Therefore, all sectors have to deal with the potential impact of globalisation,” said Boediono, as quoted by Antara news agency.
KENYA: Why E-learning is the Way to Go in Kenya
# 02, February 2013
Kenyan universities are opening satellite campuses across the country as they seek to meet the growing demand for education. Currently, there are over 29 constituent universities across the country and the number is rising. However, some experts feel there is a better and cheaper way to improve access to education. This is by investing in e-learning.Njambi Muchane, the Director of Kenya School of Government e-learning and Development Institute (eLDi) says that instead of replicating the face-to-face learning in the main campus, universities should set up small offices but train via e-learning.
 
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