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  • Mathematical modeling of heat transfer processes in energy-saving solar plants

    A mathematical model of heat transfer processes, the discrete model is based on the finite difference method, and the results of calculations of the temperature distribution also will be developed. In addition the program was created which allows to calculate the distribution of temperature over its entire length for given values ​​of insolation, ambient air temperature and air velocity inside the collector  

    Keywords: mathematical modeling, finite difference method, heat transfer processes, solar collector

  • The estimated strength and deformability characteristics and strain diagrams of fiber concrete with aggregate distribution of the fibers

    The article considers the regulatory and estimated characteristics, as well as proposals for the estimate of the strength and deformability characteristics for possible practical inculcation of fiber concrete with aggregate distribution of fibers produced by the shuttle and conveyor technology, and reinforced concrete structures of them.

    Keywords: regulatory, estimated characteristics, stress-strain diagram, compression, tension.

  • Hybrid algorithm of classification of text documents on the basis of the analysis of internal connectivity of the text

    Results of research in the field of methods of classification of badly structured collections of heterogeneous documents are provided. The method is offered and the hybrid algorithm of classification of text documents is developed. The theoretical assessment of complexity of the offered method is executed and the pilot study is made. In article it is considered: mathematical model of the offered hybrid method, its algorithm, theoretical assessment of computing complexity and the experimental comparing with other methods of classification of documents.

    Keywords: fuzzy logic, bayesian classification, classification of text documents.

  • Being self-compacting concrete of the lowered density with application of a volcanic tufa

    Advantages of being self-сщьзсештп concrete of the lowered density (LSUB) before heavy and light concrete are shined, characteristics of components ЛСУБа and influence of their quantitative contents are provided in a mix on properties of the fresh and hardened concrete. The optimum mode of warmly moist processing is offered.

    Keywords: Self-compacting concrete, the supersoftener, knitting, filler, a volcanic tufa.

  • Structure analysis of carbon nanotubes by electron microscopy and electron diffraction

    In this work we have investigated the structure of individual single-walled and multi-walled carbon nanotubes by high-resolution electron microscopy and electron diffraction. To grow carbon nanotubes we used a catalytic chemical vapor deposition method. It was shown, that this synthesis protocol gave in general single-walled and double-walled carbon nanotubes with a high level of crystallinity. The diameters of the nanotubes were in the range 1.5 - 7 nm. We also observed that there was a certain level of amorphous carbon deposited on the nanotube surface during the growth. In this work we also present the structure analysis of the double-walled carbon nanotube by means of electron diffraction. We show that the structural date derived from electron microscopy and electron diffraction agree within the experimental error.

    Keywords: Carbon nanotubes, electron diffraction, electron microscopy

  • Model analysis of electrodynamic parameters of a double-gap klystron cavity

    In the article a double-gap cavity with anti-phase excitation that has wide application in designs of floating-drift klystrons is considered. One of the ways of reduction of time during machine design of klystron’s cavity is using of the simple analytical expression, allowing to determine the main klystron electrodynamic parameters with a sufficient accuracy for practice. In the article we presented the results of physical and mathematical modeling of the double-gap cavity, the corrected mathematical models were introduced that can be utilized in programs of a prompt optimization of klystron's type devices. The technique of creation of approximate mathematical model in this case was reduced to definition of basic analytical function, and the subsequent approximation between experimental and calculated data by means of a method of planned experiment. In presented work the analysis of adequacy was carry out. Analysis revealed inaccuracy of a resonance frequency of an anti-phase type in chosen ranges of change of influencing factors doesn’t exceed 1%, characteristic impedance- 5%. The received analytical ratios allow carrying out quickly calculation of parameters of the cavity, without labor-consuming and expensive experiments and calculations.

    Keywords: double-gap cavity, electrodynamic parameters, mathematical simulation, resonance frequency, characteristic impedance, method of planned experiment

  • Integral robust features based technique for optical identification of railway vehicles

    Identification of railway vehicles is relevant for the conversion from automatic control systems with manual data input to automatic modeling environment of train and vehicle. The most effective and economic inventory number recognition is optical recognition. But there is question about veracity in such technology. This paper represent the qualitatively new approach for optical recognition based on building integral robust constructive features of vehicles and allowed to significantly increase level of recognition veracity. Proposed technique investigated in introduction subject of automatic vehicle number recognition system (ARNV).  Computational experiments demonstrated relevance of proposed technique for using in optical recognition of vehicle numbers.

    Keywords: Automatic systems, number identification, vehicle, optical recognition, ARNV, robust features

  • Model of technical systems management

    We consider the technical systems at the operational stage of the process and study their possible development. The generalized law of the development of technical systems as a function of its components can form the main factors influencing the evolution of the technical system and the process of their modernization.

    Keywords: the evolution of the network, structure, system, process, modification, chains, model development, dependence

  • Simulation of the design activity diversification of innovative enterprise

    The processes happening in system of power supply of the AVO electric drive of gas are considered. The analysis is carried out and the assessment of consumption of electric energy of AVO of gas is executed.

    Keywords: compressor station, device of air cooling of gas, mathematical statistics

  • Broadband differential attenuator with variable transfer factor

    A method of expanding the bandwidth and improve the performance of the differential voltage divider – attenuator (AT), which have parasitic capacitance on the outputs C01, C02. Wide range of transmission of the AT provided by introducing a compensation circuit C01, C02, which is achieving data quality indicators. Simulation results of desired are shown.

    Keywords: a resistive voltage divider, differential attenuator, the parasitic сapacitance load, speed, upper frequency limit, analog-to-digital converters.

  • Observability and controllability of system of stabilization of levels of the melted metal on continuous moulding of preparations machine

    The monitoring system of process of stabilization of levels of metal on continuous moulding of preparations machine, constructed useing the observer of a condition is considered. The developed nonlinear observer allows to increase the accuracy of an assessment of levels of the melted metal in the ladle with steel ,industrial ladle and crystallizers, and also makes continuous diagnostics of a condition of glasses of latches. The analysis made on the basis of linearized model, showed the observability and controllability of system on all interval of pouring.

    Keywords: Machine of continuous moulding preparations,the controllability, the observability, the observer of a condition, the level of metal

  • Indicators of the quality of information and computing systems of railway transport

    There is considered the problem of structuring indicators of the quality of information-computing systems, including transport. For each quality indicator is determined by the number of corresponding criteria. An algorithm for analysis of subscriber delays.

    Keywords: quality, indicator of quality, quality criterion, computer information system of railway transport,subscriber delay

  • Translation of geometric models of two-contour geodesic shells

    In this paper consideration is given to problem of developing a converter which will enable convert models of geodesic domes from external 3D format to preprocessor Patran format and structural analysis of this geodesic domes. A library of Framework and Visual Basic was used for building the converter.  

    Keywords: geodesic dome, structural analysis, geometrical models, grammar, the converter, preprocessor/postprocessor

  • Kinematic investigation of the mechanism of the ladle turning of the rope excavator

    The research devoted to the kinematic mechanism for turning rope of ladle excavator, in the article considered the part of the trajectory of the work process: this process make the turning of the grip relatively to the arrow with the same time turning ladle relatively to the grip. The ladle turning is made because of additional kinematic connection between the ladle and grip and / jr the arrow and implementing internal forces due to the mutual position of the corresponding arrow and grip.

    Keywords: the rope excavator, the ladle turning, kinematics, the analitical investigation

  • The development of toolkit of cognitive modelling for research of difficult systems

    In the article the approach to modelling and the analysis of functioning of difficult systems based on indistinct cognitive maps is described. The theoretical part of the article is devoted description of modern family cognitive maps, the short characteristic and the analysis of following groups is given: Cognitive Maps, Fuzzy Cognitive Maps, Fuzzy Cognitive Maps by Silov, Rules Based Fuzzy Cognitive Maps, Generalized Rules Based Fuzzy Cognitive Maps, Relational Fuzzy Cognitive Maps, Neutrosophic Relational Maps, Dynamic cognitive networks. The concept of fuzzy way is entered for the development of mathematical toolkit and the model of fuzzy pulse process is offered. The practical component of the article is directed on the description of examples of the decision of separate problems of cognitive modelling with application of the device fuzzy directed graph of the 1st kind. The offered approach will allow to develop forecast scenarios of development of difficult system taking into account its reaction on external influences.

    Keywords: difficult system, fuzzy model, fuzzy cognitive map, fuzzy way