Maximum power pointtracking algorithms are widely used in the solar converters in order to obtain maximum power from the solar array. The article provides a brief description of the work of these algorithms, description of the method of testing based on mathematical modeling using Matlab, Simulink and SimScape packages. The results of modeling and comparative analysis  of the studied algorithms, its  strengths and weaknesses revealed.

Keywords: maximum power point, maximum power point tracker, photovoltaic, buck converter, comparative study of algorithms, perturb and observe method, constant voltage method, constant current method, icremental conductance method

The methods of improving the efficiency of thermal power plants. Improve the efficiency improvement offers reach the combustion process. Outlines the benefits of controlling the combustion of fuel in the ion current signal.

Keywords: power system, power plants, combustion control, the ion current, the detonation

Fe-doped AlN nanorods were studied by means of x-ray absorption spectroscopy above the Fe K- and L2,3- edges. Theoretical simulations of the x-ray absorption spectra show that Fe atoms mainly substitute Al. A minor fraction of Fe interstitials or Fe-Al-N ternary alloy can be identified as well. Bader’s AIM analysis predicts that neutral substitutional FeAl defect is in 2+ charge state, though Al in pure AlN is in 3+ charge state.  Fe L2,3 absorption spectra and photoluminescence data indicate the coexistence of Fe2+/Fe3+ in AlN:Fe nanorods so different charge states of substitutional FeAl should co-exist.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production

This article reviews systems of respiratory activity registration in relation to sports medicine. Attention is devoted to the use of miniature accelerometers that record the movement of the chest, as the optimal method for the diagnosis of the respiratory parameters. Other methods are based on piezo-resistive sensors, pressure and airflow sensors, and airways resistance sensors. The authors' developed device based on three-axis accelerometer is proposed. It recognizes episodes of apnea with sufficient accuracy for long-term monitoring. The algorithm of the accelerometer data processing is described. In order to minimize noise impact on the useful signal it is necessary to transform the three-dimensional cloud of accelerometer data into a flat sector. Then the relation of gravity vector deviation angle and the nominal position in time is determined. This presented device due to its ability to transmit data via Bluetooth technology, after appropriate software development for mobile phone and the receiving terminal of medical professional, will be able to organize a simple ergonomic long-term remote monitoring of respiratory activity.

Keywords: systems of respiratory activity registration, long-term remote monitoring, three-axis accelerometer

In article the structure, functional architecture and mathematical model of the system intended for automated management by information procedures in the automated information system are considered. The offered model is based on monitoring of initial and flowing conditions of the information streams subjected recomposition on the basis of operating markers by the serving router. A system kernel is the Server of configurations supporting discrete disciplines of management by service.

Keywords: information service, priority management, an information stream

The catalytic activity of Pt/C and PtxNi/C electrocatalysts prepared by  borohydride methode was studed. It was established that the specific activity  of fresh prepared Pt3,7Ni/C  catalyst  in oxygen  electroreduction  reaction is higher in compare with Pt/C material. After treatment of Pt3,7Ni/C material in the hot acid  nickel in the surface layers of nanoparticles was dissolved and the composition of nanoparticles was changed to Pt5,6Ni. The electrochemical surface area of the Pt5,6Ni catalyst and specific activity was slightly decreased after corrosion treatment. 

Keywords: platinum electrocatalysts, corrosion stability of the nanoparticles, fuel cells, X-ray diffraction, borohydride synthesis

The problems of building the architecture and design of the database structure for the storage of the structure of the chemical compounds and their analysis using heuristic algorithms
Proposed the structure of the database that allows you to store information about the structure of chemical compounds with varying degrees of detail. This approach simplifies forming of the structural descriptors used to build models of "structure-property" based on the genetic algorithms.

Keywords: database architecture, chemicals, data mining, heuristics

The mixed finite element method has advantages over classical formulations of Lagrange and Castigliano, and ensures high precision and smoothness approximate solutions for strains and stresses.
In practice, using the mixed finite element method is limited by high size of linear equation systems, which leads to significant increasing time costs.
Using the orthogonal finite functions for approximating of unknowns leads to generation of sparse linear systems with a special structure.
That system can be simplified during solution.
This article proposes the algorithm of modificated Gaussian elimination for preliminary transformation an extended matrix of linear system.
This algorithm underlies software complex, which includes LISTSOLVER, the author's solver.
Confirmed the efficiency of created solver in compare with common-type solver.

Keywords: mixed finite element method, sparse linear systems, orthogonal finite functions, Gaussian elimination

In this article, the author has rasmmotreny different approaches to the evaluation of competitiveness in terms of innovation.

Keywords: competitiveness, meso-level and micro-level, macro-level, the ranking of competitiveness advantages, quantitative and qualitative indicators

The research of algebraic cryptanalysis method was carried out in this work. Systems of the equations for tables of various sizes of nonlinear transformations of substitution for simplified model of GOST28147-89 algorithm are received, also we solve a one of this systems by a XL method. During this work we produced a program, which has realised a generation and solving of system of equations describing nonlinear transformations of substitution. We analysed a nonlinear systems of equations and calculated a value of complexity of XL method for eight blocks of substitution.

Keywords: Algebraic cryptanalysis, XL method, nonlinear transformations of substitution, linearization nonlinear systems, Gauss elimination method, a cryptographic key, GOST28147-89 encryption algorithm

ZnO nanorod arrays have been synthesized on silicon wafers by chemical vapor deposition (CVD) technique with different  temperature modes, without metal catalyst.  With this method   vertically aligned ZnO nanostructures  were grown at the quite low temperatures.  Modification of the method allowed to place silicon substrates in areas with different  ratios of concentrations of the molecules in the vapor phase. Photoluminescence spectroscopy and electron microscopy studies have shown that morphologies and optical properties of nanorods depends on different ratios of concentrations of the molecules in the vapor phase.

Keywords: ZnO nanorods,chemical vapor deposition (CVD), photoluminescence

The arrays of ZnO nanorods were obtained on the sapphire substrates by means of pulsed laser deposition under the high pressure of argon. The conditions of synthesis were optimized, and their influence on the morphology of  ZnO nanostructures were revealed. It is shown that the concentration of oxygen vacancies in ZnO nanorods can be changed by regulation of the synthesis temperature from 850 to 915 °. This process can be controlled by the ratio of intensities of the photoluminescence emission in the visible and ultraviolet regions. So, it allows to create nanostructures for UV photodetectors or chemosensors depending on the temperature choice.

Keywords: ZnO nanorods, laser deposition, PLD, photoluminescence

Features of sampling of the piezoceramic transducer for the arrangement of structural monitoring of water supply systems are in-process observed and calculations of basic performances of the sensing transducer (material PZT-5A) are led

Keywords: piezoceramic transducer, ultrasound, monitoring, structure, extending, water supply systems

This paper outlines the implementation of computer model of second-order visual mechanisms that are specific to spatial contrast modulations, and represents the results of testing the model. Computer simulation is based on "Filter-Rectify-Filter" model with some important additions. The inhibitory parts of receptive field of simulated mechanism are non-selective to orientation and spatial frequency of texture elements. Texture modulated by orientation or spatial frequency does not reduce flank inhibition and does not activate the mechanism. Unmodulated texture  also does not cause activation of the filter because the flanking inhibition will be equal to or exceed the excitation. However, increasing the contrast in the center and reduction it on the flanks leads to the activation of the second order mechanism.

Keywords: Second order visual mechanisms, image filtering, texture, spatial modulation, computer simulation

The results of research of raw materials of the logs production for timber construction are considered in the article. Length of logs (for 6 meters assortment), diameter of logs (model logs) and shape of butt (an average shape factor of butt) were studied. The model log is a volume of cylinder which is equal to a calculated volume of logs. The theoretical laws of the random variable for these values are found. The Research was conducted at LLC "Biogran" in Petrozavodsk, Republic of Karelia.

Keywords: Woodworking, cylindering, technological line, wood costraction, factors, length of a log, diameter of a log, butt