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Golub T.,Zaporizhzhya National Technical University
Modern Problems of Radio Engineering, Telecommunications and Computer Science, Proceedings of the 13th International Conference on TCSET 2016 | Year: 2016

This paper discusses some basic methods of text documents classification. Results of its analysis are presented in the table of comparative characteristics in accordance with the list of proposed parameters. © 2016 National University Lviv Polytechnic.

Chumachenko V.P.,Zaporizhzhya National Technical University
Telecommunications and Radio Engineering (English translation of Elektrosvyaz and Radiotekhnika) | Year: 2013

In the paper infinite sets of linear equations are investigated which arise in the course of applying the domain-product technique to analyzing flat-bed waveguide transformers with a convex-polygonal junction plane. Blocks of the system matrix describing the interaction of sides of the polygon are considered in the capacity of operators in the sequence space l1. It is shown that each operator of the kind for adjacent sides can be represented as a sum of a completely continuous operator and the contraction operator. Results of the study are used to justify the solvability by the reduction technique of systems corresponding to the triangular region. It is proved the set of matrix equations arising in the case of an E-plane structure can be considered in the space l1 (3)=l1 ⊕/1⊕/ 1 in the capacity of a functional equation with the Fredholm operator. It is shown that this equation can be solved by the projection technique convergent in the norm of the mentioned space. Similar results are obtained in the case of the H-plane problem. © 2013 by Begell House, Inc.

Shcherbak N.,Zaporizhzhya National Technical University
Modern Problems of Radio Engineering, Telecommunications and Computer Science, Proceedings of the 13th International Conference on TCSET 2016 | Year: 2016

The method for test tasks quality assessment based on expert assessments of test tasks quality indexes has been developed. The single-layer perceptron simulation for test tasks quality assessment problem solving has been conducted. The network structure has been chosen, the training sequence has been prepared and the neural network training has been carried out. The mathematical model has been built and its analysis has been conducted. © 2016 National University Lviv Polytechnic.

Shkarupylo V.,Zaporizhzhya National Technical University
Modern Problems of Radio Engineering, Telecommunications and Computer Science, Proceedings of the 13th International Conference on TCSET 2016 | Year: 2016

A technique of DEVS-driven (Discrete Event System Specification) distributed software systems validation has been proposed. As a case study the Composite Web Service usage scenario has been considered. There are have been considered two approaches to Composite Web Service validity checking - testing-driven one and the approach based on DEVS-driven simulation. Experimental results obtained have shown the reasonability of proposed technique practical usage. © 2016 National University Lviv Polytechnic.

Subbotin S.A.,Zaporizhzhya National Technical University
Automatic Control and Computer Sciences | Year: 2013

The development of mathematical software for training sampling is considered. Exhaustive and evolutionary sampling methods are developed. Criteria for selection, censoring, and pseudoclustering of instances are introduce in these methods. This makes it possible to speed up the sampling process and to ensure the compliance of the samples with the limited size. The proposed methods allow for the automatic allocation of a subset of instances with the minimal size from the original sample. The subset contains the most important instances for the model's construction. The complexity estimates of the developed methods are defined. Experiments to determine the practical applicability of the methods are conducted. The use of the proposed estimates and identified dependences makes it possible to take into account the available computer resources during the sampling. © 2013 Allerton Press, Inc.

Subbotin S.,Zaporizhzhya National Technical University
Optical Memory and Neural Networks (Information Optics) | Year: 2013

The problem of increasing of the quality, of the automation level and the synthesis rate of neuro-fuzzy network (NFN) has been solved in the paper. The method of neuro-fuzzy network synthesis and simplification on precedents has been firstly proposed. It is based on the using of the feature space pseudo-clustering, on the automatic formation of fuzzy terms and rules, on the automatic NFN structure and parameter synthesis by the training set, and on the reducing of NFN structural and parametric complexity by simplifying the rules and reducing the number of redundant terms. This can increase the speed of NFN construction, enhance its properties and generalize interpretability. The proposed method has been implemented in the developed software and was used for the practical problem solving of technical diagnosis. © 2013 Allerton Press, Inc.

Tikhovod S.M.,Zaporizhzhya National Technical University
Russian Electrical Engineering | Year: 2016

Transient electromagnetic processes in electrical systems present a significant risk to machines and influence the reliability of relay protection; therefore, the investigation of these processes is important. Transient modeling in transformers is presently done by construction and solution of state equations for magnetoelectrical equivalent schemes that bring together the electric and magnetic circuits of these devices, taking into account the interaction with each other. Modeling of these processes can be quite long when using modern software. An aim of the given work is development of more fast-acting method of calculation of electromagnetic transients, using a polynomial approximation of the solution, and also development of scheme model of method that creates convenience for engineers in modeling. A method of calculation of transients in electric circuits is developed on the basis of expansion of the solution of state equations in series of orthogonal Chebyshev polynomials. A scheme interpretation of the developed method is offered. It is shown that, in the special equivalent scheme, Kirchhoff’s laws apply to images of currents and magnetic fluxes as vectors containing the values of coefficients of decomposition of these values by Chebyshev polynomials. The given method allows replacement of operations with instantaneous values of currents by operations with direct currents in the presented equivalent scheme. Transient calculation via the suggested method in a single-phase transformer processor is twice as fast as with well-known methods. The presented method is especially appropriate for transient calculation in magnetoelectrical circuits, since it allows the use of voltage sources controlled by the current derivative for easy calculation of the integrals of solutions. © 2016, Allerton Press, Inc.

Korotun A.V.,Zaporizhzhya National Technical University
Physics of the Solid State | Year: 2015

Analytical expressions for the size dependence of the Fermi electronic energy of ultrathin metal films on a dielectric substrate have been derived in the model of free electrons and finite-depth asymmetric potential well. The work functions have been calculated for Al films on SiO2 and Al2O3. It has been shown that the presence of a dielectric leads to a shift in the work function, while retaining the general character of the size dependences. © 2015, Pleiades Publishing, Ltd.

Babich A.V.,Zaporizhzhya National Technical University | Pogosov V.V.,Zaporizhzhya National Technical University
Physics of the Solid State | Year: 2013

A method has been proposed for self-consistent calculations of characteristics of a metal film in dielectrics. The most interesting (asymmetric) case of metal-dielectric sandwiches, where the dielectrics are different on both sides of the film, has been considered in terms of the modified Kohn-Sham method and the stabilized jellium model. The spectrum, electron work function, and surface energy of polycrystalline films placed in passive insulators have been calculated for the first time using Al and Na as an example. It has been found that the dielectric environment generally leads to a negative change in both the electron work function and the surface energy. In addition to the size changes, the shift of the work function is determined by the arithmetic mean of the dielectric constants of the surrounding media. © 2013 Pleiades Publishing, Ltd.

Subbotin S.,Zaporizhzhya National Technical University
IDT 2016 - Proceedings of the International Conference on Information and Digital Technologies 2016 | Year: 2016

The problem of individual blood pressure prediction and control of hypertensive patient is addressed. The method of predictive model synthesis is proposed. It uses the windows method to form training sample from the original data, the feature selection based on information criterion in discretized feature space, the instance selection based on transformation of original multi-dimensional feature space into one-dimensional space of generalized axis, and the multi-layer feedforward neural network trained by the Levenberg-Marquardt method. On the basis of obtained model the proposed method provide selection of optimal individual medications combination. The software implementing the proposed method is developed. The computational experiments on the model synthesis are conducted. The dependencies between the method parameters are experimentally obtained. The recommendations on assignment of method parameters are given. © 2016 IEEE.

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