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  • Software for stereovisualization of FEM simulating results

    The presented work extends the state-of-art of visualization construction simulations in three dimensions (3D). Classical computer graphics methods can be used to instrument construction models to automatically generate dynamic visualizations of any construction models. The visualization problem of FEM analysis is considered. A description is presented of programs of convertation and visualization of results of finite element method analysis of geodesic domes.

    Keywords: simulation, computer graphics, geodesic domes, finite element method, convertation, visualization

  • Consensus Protocol in Asynchronous Networks with Failures

    Consensus problem involves a system of processes, some of which may be faulty. A fundamental problem of fault-tolerant distributed computing is for the reliable processes to reach a agreement on a same decision. One approach to achieving such agreement is for processes to vote and agree on the majority value. In the absence of faults, this works fine, but the vote even one faulty process can swing the outcome. In this paper we present some result of analysis of a mixed-failure model, where t processes may fail, b out of which is the Byzantine failures and remaining c is crash processes. In a asynchronous model of computation for several distributed problems it turns out that a collection of N processes can tolerate c crash failures if 2c < N, while robustness against b Byzantine failures requires 3b < N. Our algorithm rely on a weak definition of the Byzantine failures which disallows them act as a dead or a crash processes and can tolerate the 2(N – 2c)/3 failures.

    Keywords: fault tolerance, distributed algorithms, asynchronous networks, byzantine failures

  • Microwave band-pass filter on waveguides of complex cross-section, integrated into a multilayered chip with SIW technology

    The possibilities of waveguide elements realization in the structure of multilayered integrated chips of centimeter and millimeter ranges with SIW (Substrate Integrated Waveguide)-technology application are considered. The approaches allowing effectively using in new structures the algorithms and techniques of the electrodynamic analysis and synthesis of passive devices on classical all-metal waveguides are offered. Advantages of use in SIW structure the waveguides of complex cross-section are considered on the example of the microwave band-pass filter.

    Keywords: A.A. Gadzieva, V.V. Zemlyakov, S.V. Krutiev

  • An algorithm for finding the linear functional quality of complex technical systems with varying degrees of competence of experts.

    This article describes an algorithm for finding the linear functional quality that describes the order of preference on a set of technical systems. The basic idea, which implements the algorithm is to break the complex solutions of the preference (for many variables) into a number of simple solutions (in pairs of variables), followed by a formal synthesis of the overall solution.

    Keywords: The algorithm for finding the linear functional quality of the order of preference on a set of technical systems, formal synthesis, the numerical value of the degree of competence of the individual experts

  • Capital structure determinants of construction companies

    This paper presents key capital structure determinants of construction companies and their impact on fund raising and financing mix formation in accordance with the conditions of construction activity. It was found that profitability and tangibility have a positive effect on leverage, risk - the negative and the effect of company size, assets growth rate and taxes is ambiguous.

    Keywords: capital structure determinants, profitability, risk, taxes, tangibility, construction companies

  • The investigation of properties of gas sensitive materials based on SiO2SnOxCuOy thin films used in gas sensors for multisensory air monitoring system

    The establishment of automated air monitoring systems is a promising way of the air monitoring devices development. The comparative analysis of literature has shown that thin films based on semiconductor metal oxides are effective and widely used material for air monitoring systems creation. In order to create effective and more sensitive sensors it is important to research processes that occur on the surface of the gas sensitive material when it contacts with different substances. The processes that proceed on the surface of gas sensitive material based on SiO2SnOxCuOy during the interaction with molecules of nitrogen dioxide. Quantum chemical calculations have shown that there are three possible mechanisms of interaction between the molecules of nitrogen dioxide with a surface of gas sensitive material.

    Keywords: multitouch system of the monitoring, gas-sensitive material, molecules of dioxide of nitrogen

  • Sensitivity analysis of ZnO thin film deposited by rf reactive magnetron sputtering

      Results of researches of gas sensitive properties of zinc oxide films grown by reactive rf magnetron sputtering was shown. Process parameters, affected on the gas-sensitive ratio, response time, recovery time and the type of electrical conductivity of obtained films were identified. Optimal modes of magnetron sputtering of zinc oxide for implementing gas sensors (RF sputtering Zn target in a gas mixture of oxygen and argon at a concentration of 80% oxygen, a chamber pressure of 0.8 Pa and the magnetron power 100 W) were established. Avarage response time on NO2 gas was 5-15 sec.  The obtained values ​​of the gas-sensitivity were in the range 30-67% for NO2 concentrations from 20 to 100 ppm, CO and CO2 from 50 to 100 ppm and 81-97% for higher gas concentrations from 500 to 1000 ppm.  

    Keywords: Nanotechnology, magnetron sputtering, zinc oxide, thin films, gas sensitivity

  • Accounting for the effects of differences between the moduli of elasticity in compression and tension in the calculation of the strength of reinforced beams with filler of foamy fibrous concrete

    The article investigates the impact on the normal stresses of inequality of the young modulus for tension and compression in the bending of reinforced beams. Obtained formulas for determination of the bending moments that arise in the fixture, compressed and stretched zone of the aggregate. Found the formula for the normal stresses arbitrarily supported reinforced beams, arbitrary cross section and arbitrarily loaded bending loads. For example, reinforced beams of rectangular cross-section shows the determination of the neutral line and maximum stresses.

    Keywords: reinforced beam, elastic modulus, stress, normal concrete

  • A method of numerical modeling of spectrometric systems of gas sensors

      A principle of spectrometric systems of gas sensors was described. A model and a method of numerical modeling of spectrometric gas sensor with the combined radiator-receiver of infrared radiation on the basis of the punched semiconductor thermoresistor were proposed.

    Keywords: spectrometric gas sensor, model, method of modeling

  • Multichannel OpAmp and JFET follower IC on radiation hardened array

    The features of circuit engineering and results of chip computer simulation which consists of 4-channel operational amplifier (op amp) and 2-channel electrometric voltage follower, designed for pre-processing of sensors signals in high-energy physics are considered. 
    The characteristic properties of designed op amp are the absence of current source in the input differential stage and the use of parallel high-frequency channel for increasing of the bandwidth and slew rate.
    The results of experimental research that have confirmed the low sensitivity of the parameters of designed integrated circuits created on the field programmable gate array "FGPA-1.3" without the horizontal p-n-p transistors to the influence of gamma-irradiation and electrons with energy of 4 MeV are given.  

    Keywords: operational amplifier, field programmable gate array, voltage follower, sensor, sensing element, radiation resistance.

  • Geostatistics methods for cadastral value of land horticultural non-profit association leningrads region

    The author of the article identified the cadastral value of land horticultural non-profit organizations of Leningrad region, using the method of geostatistics. Determined by the maximum distance between objects evaluation. Point at a distance lag more than the maximum distance, not spatially correlated. The construction of the cadastral value of the surface, using deterministic methods and methods of geostatistics is illustrated.

    Keywords: cadastral value, geostatistics, log, correlation, regression

  • The concept of organization of processing of the information in the systems of diagnostics and detection

     In the article there are considered the problems arising in the building of systems of diagnostics and recognition, provides methods to detect deviations in functioning of the various objects.

    Keywords: Diagnostics, еmpirical mode decomposition, extreme filtering, time-frequency distributions

  • Electronics module for avalanche photodiode signal readout

    Circuit features of the electronics module for avalanche photodiode signal read-out, created on a basis of the specialized analog IC, are considered. Measurement re-sults of characteristics and noise depending on signal source capacity are given.

    Keywords: avalanche photo diode, readout electronic, charge sensitive amplifier, shaper, electronics module

  • Development and design of bimorph thermal actuator and а micromirror based on it

    A design of the actuator, consisting of a thin layers of silicon dioxide and aluminum is proposed. There are calculations made of the response speed and heat dissipation of the actuator. By making the best selection of layer thicknesses and optimization stages of technological process, in particular the deep selective etching of silicon, the best performance on the angle of inclination of the actuator and the speed of the device could be achived. The greater the difference between the initial temperature and the heating temperature, the stronger the beam of the actuator is lowered to the plane of the silicon plate, and, therefore, less angle of elevation above the surface of the silicon plate. It is thus possible to control the angle of the beam by selecting the appropriate heater and voltage, providing the desired temperature. The design of the micromirror device based on the proposed actuator is provided. The developed design is based on the actuator and allows for controling the tilt of the mirror in a wide range.

    Keywords: silicon, termoactuator, micromechanical systems, bimorph structure, micromirrors

  • Research questions of flexural reinforced concrete elements, strengthened with different types of composite materials

    The questions related to the study of various varying factors on the strength of normal sections in beams. Here's a program of research by one methodology designed to study the effect of the type and content of steel reinforcement and externally composite on the strength of normal sections that have not previously been investigated.

    Keywords: Concrete, reinforced concrete, the percentage of reinforcement, carbon frp sheets, fiberglass, laminates