Vol 14, No 1 (2013)

The authors present results of analysis of frequency dependence of the main energy indicators of series circuit key amplifier, operating without rearrangement of oscillating system.

The article considers questions of energy efficiency management of communication channels operating in a single communication system. The authors propose data transfer method in wireless networks that can be used for distribution of energy efficiency between communication channels of one communication system. The structures of transmitter and receiver are described. The authors describe a communication system of unmanned aerial vehicle where there is necessity to transmit low-speed telemetry data and to transmit high-speed payload data to ground control unit. The information of low-speed data source is modulated by QAM4 and information of high-speed data source is modulated by QAM16. Synthesized constellation is obtained by summation of QAM4 and QAM16. By adjusting the amplitude of QAM4 we can distribute energy efficiency between communication channels. The proposed method can be generalized for multichannel communication systems. Adaptive distribution of energy efficiency between communication channels allows to improve communication systems energy and spectral efficiency.

Methods of zero-current-switch boost converter control are analyzed in this article. Mathematical model of such converter is proposed. The authors show that the proposed converter under closed loop control has higher damping factor as compared with conventional step-up boost converter under the same conditions.

A novel self-configuring multi-objective algorithm of optimization, based on coevolutional genetic algorithm, is proposed. Results of algorithm efficiency investigation are presented.

This article describes different ways of application of multi-version methodology in the development of multi-version fail-safe software, and presents models of multi-version software architectures in the form of basic GERT-networks. With respect to the necessary and sufficient condition for the operation of multi-version module, the node with IOR input and output is selected to provide deterministic network section that describes the module. Formulas for calculation of probabilistic-time characteristics of multi-version modules, that provide fitness of GERT-network models to describe multi-version software, are presented. This allows to use the equivalent conversion and existing methods of calculation of GERT-networks.

He literary analysis of devices for testing lubricants for anti-wear properties is presented, and device for testing rubbing materials and oils is offered.

The authors show a program for calculation of normal and resonant modes with a procedure of calculation of a network with nonlinear load on the example of traction substation, which allows, on the basis of the analysis of frequency characteristics of the input resistance Z вх = f(v), to appreciate the range of currents and voltages in the network elements, and to assess the levels of active losses and overloads of compensating devices with currents of higher harmonics.

The author considers a problem of free oscillations of a beam with low value of transverse shear stiffness. On the base of Reissner-Midlin plate theory, the finite element of a shear flexible beam is developed. There are transverse shear strains among the basic kinematic nodal variables. The urgency of the model is shown by test modal analysis of beams. Vibrations of sandwich beams and thick layered composite beams under non-classical boundary conditions are investigated.

The authors consider plasticity equations in a stationary two-dimensional case. For Prandtl solution, which describes the compression of plastic layer by rigid plates, the authors consider two velocity fields. The first one is Nadai solution, the second one is the new solution. The authors prove that the current lines in these solutions coincide. Based on the principle of maximum dissipation, the spheres of usage of these velocity fields are defined.

The paper presents a model of reliability analysis of distributed computing systems with client-server architecture. The proposed model allows to obtain correlation between reliability parameters of distributed computing system without any assumptions about the random variables distribution laws and the number of system elements

The author presents the obtained structure of infinite local-finite groups saturated with complete linear groups of 2 dimensionality of the finite fields.

This article offers a methodology of estimation of a spacecraft large-sized transformable reflector surface form, which allows to define the basic geometrical characteristics of the reflector, such as the focal point deflection and the focal axis deflection, zoom effect of paraboloid of the best fit for a deformable reflector surface, as well as the mean-squared deviation of the points which circumscribe the reflector surface.

The paper presents methodology aspects which are the basis for development and design of “intelligent” shape- and dimension- stable structures of space vehicles, made from dielectric polymer materials. Problems of mathematical simulation of such systems are considered, along with approaches connected to experimental investigations of such materials and systems. Methodology of design of “intelligent” structures made from dielectric polymer materials is developed.

Problem questions of application of foreign electric radio products, problems of certified test operations, foreign levels of quality of integrated chips of foreign production, as well as questions of development of a standard program of certified tests of foreign electric radio products are considered.

The authors consider an adaptive phased antenna array with original equal amplitude distribution and appreciate the efficiency of the algorithm of its adaptation with the use of the basis in the form of partial basis of exponential Fourier series in comparison with the optimal algorithm.

In the work the authors present the results of stress-state simulations analysis of the machine for removal of oxide film from surfaces of aluminium ingots. The presented technique of analysis can be used for analysis of stress-strain states of working bodies of machines, operating at high temperatures, by the method of finite elements.

Fe 86Mn 13C alloy has unique mechanical, electrical and magnetic properties due to the special modulated structure. Due to the combination of these properties in thin films, we study Fe 86Mn 13C as a possible material for spintronics problems. The results of electron diffraction patterns transcripts obtained from the alloy films Fe 86Mn 13C are presented in the article. The films were cryomechanicaly processed. The authors show that deformation martensites observed in the films has structure characteristics similar to the characteristics of alloy Fe 86Mn 13C. The authors offer a model of structure formation of deformation martensites in the form of self-organization of clusters in the transition of FCC-BCC structures under the influence of criomechanical processing. The inhomogeneous structure of the cluster causes the effects of magnetic aftereffect in the investigated materials.

In the work the authors present theoretical research of various carbon nanostructures (fullerenes, defects of the carbon planes) as potential material for production of anodes in lithium - ion batteries. Processes of sorption of atoms and lithium clusters in the volume and on the surfaces of these materials are considered as well.

The phase composition of multi-component systems is analyzed. In the process of the study the effect of phase antagonism was observed, the effect revealed itself in the form of correlation between the percentage composition of individual phases in a multi-component mixture, with the percentage composition of the other phases remaining almost unchanged. On the basis of experimental studies, the examples of such phases in multi-phase mixtures are pairs of monoclinic pyrrhotite and somolnokit, goethite and troilite, hexagonal pyrrhotite of different composition and monoclinic pyrrhotite.

The article presents the results of experimental studies of water purification, consisting of passing through it asymmetric alternating current with application of insoluble heterogeneous electrodes, introducing coagulating agent and settling.

The article dwells upon the reasons of loss of cutting ability of metal bound diamond wheels in different conditions of grind of composite materials. The attention is paid to detection of deficiencies of traditional methods of diamond grind, which in most cases do not allow to reach the requited quality of composite materials processing. The researches were performed with the use of methods of raster, optical microscopy and interferometry. The problems under discussion and methods of their solution are directed to technological advancement of machine-building enterprises, for the purpose of rise of profitability and capacity of processing, as well as quality assurance of items made of composite materials.

The article considers actual problems of integration of Russian higher school into the world educational space. The authors give full determination of international market of educational services and analyze the basic problems, which home VUZes (Institutes of Higher Education) face in the process ofjoining the global market.

The article describes an original production cost accounting method developed for enterprises performing innovative activity.

The author considers technique of making out a balance of material resources and control of material and cash flows on the example of mining on the basis of activity networks and materials norm costs control according to uniform arrays of the input data, as far as statistics is accumulated.

The author describes the role and importance of innovative infrastructure in the development of regional economy and principles of its formation: priority development of effective subjects of innovative infrastructure, use of instruments of horizontal and vertical integration, compliance to the environmental conditions and account of typology of implemented innovations, use of not only regional, but branch and technological principle as well, and application of complex approach to formation of set of subjects of the infrastructure.

The authors reveal the basis of formation of compliance policy in investment and construction companies, describe the main problems and mechanisms of the compliance function realization in management of subjects of investment and construction complex. Along with this the authors suggest a formalized structure of commercial policy of subjects of investment and construction complex.