Oles Honchar Dnepropetrovsk National University

Dnipropetrovsk, Ukraine

Oles Honchar Dnepropetrovsk National University

Dnipropetrovsk, Ukraine
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Prokhoda A.S.,Oles Honchar Dnepropetrovsk National University
Crystallography Reports | Year: 2017

Definitions are given, based on which algorithms have been developed for constructing computer models of two-dimensional quasilattices and the corresponding quasiperiodic tilings in plane, the point symmetry groups of which are dihedral groups Dm (m = 5, 7, 8, 9, 10, 12, 14, 18), and the translation subgroups are free Abelian groups of the fourth or sixth rank. The angles at the tile vertices in the constructed tilings are calculated. © 2017, Pleiades Publishing, Inc.

Son M.O.,Ukrainian Academy of Sciences | Novitsky R.A.,Oles Honchar Dnepropetrovsk National University | Dyadichko V.G.,Ukrainian Academy of Sciences
Vestnik Zoologii | Year: 2013

Lower reaches of largest Ukrainian rivers are zones of migrations for exotic euryhaline decapods. During 2000s new records of invasions of three euryhaline exotic decapods, Rhithropanopeus harrisii (Gould, 1841), Eriocheir sinensis Milne-Edwards, 1853 and Macrobrachium nipponense (De Haan, 1849), were made in the channels of Ukrainian rivers. Chinese mitten crab, E. sinensis, spread in the Danube Delta and reservoirs of the Dnieper River; Rh. harrisii - in the channels of the Danube, Dnieper, Southern Bug and small river Gruzskij Yelanchik in the Azov Sea Basin; M. nipponense that was introduced in the Kuchurgan Liman (cooler reservoir of the Moldavian Hydro-power Station) - in the Dniester Delta. The migration zone of the established population can cover significant part of river watershed; it is necessary to take this fact into account at an estimation of biological invasion risk. Main problem in the investigation of exotic decapods in Ukrainian waters is absence of specialized methods used in the standard ecological monitoring. Among euryhaline exotic decapods, only Rh. harrisii is sometimes sampled with the equipment used in the monitoring of macrozoobenthos. A few records of these species at the large extent of their supposed ways of migration are the result of gaps in the study of their distribution in Ukrainian inland waters. Realistic attitude toward this fact is very important for the estimation of invasions in the inland waters of this region.

Drobakhin O.O.,Oles Honchar Dnepropetrovsk National University
2015 International Conference on Antenna Theory and Techniques: Dedicated to 95 Year Jubilee of Prof. Yakov S. Shifrin, ICATT 2015 - Proceedings | Year: 2015

For six-port vector analyzer based on the E-plane waveguide cross-connection of rectangular waveguides, the benefits of determining the values of the complex reflection coefficient with the application of the principles of holography with three reference signals were approved. The value of the condition number of the matrix system of linear algebraic equations formed according to the methods processing considered was used as a criterion for the selection of the waveguides connection angle. It is shown that the allowable angle is 60 degrees. © 2015 IEEE.

Gromov V.A.,Oles Honchar Dnepropetrovsk National University | Shulga A.N.,Oles Honchar Dnepropetrovsk National University
Expert Systems with Applications | Year: 2012

In this study, the novel method to predict chaotic time series is proposed. The method employs the ant colony optimization paradigm to analyze topological structure of the attractor behind the given time series and to single out the typical sequences corresponding to the different part of the attractor. The typical sequences are used to predict the time series values. The method was applied to time series generated by the Lorenz system, the Mackey-Glass equation, and weather time series as well. The method is able to provide robust prognosis to the periods comparable with the horizon of prediction. © 2012 Elsevier Ltd. All rights reserved.

Gromov V.A.,Oles Honchar Dnepropetrovsk National University | Konev A.S.,Oles Honchar Dnepropetrovsk National University
Neural Computing and Applications | Year: 2016

The present paper outlines a novel approach to predict popularity of topics for social network Twitter; the method is designed to identify precociously the topics able to demonstrate “explosive” growth in popularity. First of all, the predictive clustering method ascertains real (not written in hash-tags!) topics of tweets and then predicts popularity rates for the topics. The same clustering algorithm is employed both to ascertain the real topic of a message and to cluster segments of time series (in order to predict topics popularity), namely, maximum likelihood adaptive neural system based upon modelling field theory. In the course of wide-ranging simulation, typical variants of “pre-explosive” dynamics were revealed; some of them were turned out to be equal to heuristic techniques to predict topics popularity well known for PR community collaborating with the network (“crab,” “Pesavento’s butterfly,” etc.). © 2016 The Natural Computing Applications Forum

Gorbonos S.A.,Oles Honchar Dnepropetrovsk National University
Journal of Automation and Information Sciences | Year: 2014

The optimal control problem for a parabolic system with unbounded coefficients is considered. An approach that allows one to get solution of the posed control problem through a series of solutions of optimal control problems, which are defined on perforated subsets with fictitious boundary controls, is proposed. © 2014 by Begell House Inc.

Obodan N.I.,Oles Honchar Dnepropetrovsk National University | Gromov V.A.,Oles Honchar Dnepropetrovsk National University
Thin-Walled Structures | Year: 2016

The present paper presents the complete bifurcation structure of nonlinear boundary problem of thin-walled systems for cylindrical panel subjected to uniform external pressure. We examine various boundary conditions on straight edges (free, simply supported, rigidly clamped edges, edges with prescribed fixed joint conditions); curvilinear edges are simply supported. To construct solutions of the boundary problem in question and to trace equilibrium paths, we employ the non-linear extended Kantorovich method in conjunction with a conventional path-tracing technique. The structure has bifurcation paths associated with symmetric, skew-symmetric, asymmetric, and snap-through deformed shapes that provides a basis for analysis of the worst shape imperfections. © 2016 Elsevier Ltd

Pal'Chikov V.A.,Oles Honchar Dnepropetrovsk National University
Russian Journal of Organic Chemistry | Year: 2015

Reactions of 2-amino-1-(4-nitrophenyl)ethanol with various electrophilic reagents led to the formation of oxazaheterocycles (1,3-oxazolidin-2-one, 1,3-oxazolidine, morpholin-2-, -3-one, and -2,3-dione). In reactions of 2-{(bicyclo[2.2.1]hept-5-en-2-ylmethyl)amino}-1-(4-nitrophenyl)ethan-1-ol with carbonyldiimidazole, oxalyl chloride, benzaldehyde, and formaldehyde the corresponding derivatives of 1,3-oxazolidin-2- one, morpholin-2,3-dione, and 1,3-oxazolidine were obtained. © 2015 Pleiades Publishing, Ltd.

Vytovtov K.A.,Oles Honchar Dnepropetrovsk National University
Proceedings - 2013 International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter and Submillimeter Waves, MSMW 2013 | Year: 2013

an ordinary isotropic stratified structure is offered for frequency detector of terahertz range. It is considered two cases: in-phase and opposite phase frequency detector. © 2013 IEEE.

Prykhodko O.A.,Oles Honchar Dnepropetrovsk National University | Alekseyenko S.V.,Oles Honchar Dnepropetrovsk National University
Technical Physics Letters | Year: 2014

We have developed a software package and related methodology that can be used to simulate the process of airfoil icing during flight in the presence of large supercooled liquid water drops in the oncoming airflow. The motion of a carrier medium is described using the Navier-Stokes equations for a compressible gas. The motion of water drops is described using an inertial model. The process of water deposition and its subsequent freezing on an airfoil surface are described by the method of control volumes based on the equations of conservation of mass, momentum, and energy for each element of the surface. The main results of simulations are presented for the icing of an NACA 0012 airfoil profile with “barrier” ice formation in the absence and presence of heating of the leading edge. The influence of the ice-growth thickness and position on the airfoil chord on the pattern of airflow and aerodynamic characteristics of airfoil is analyzed. © 2014, Pleiades Publishing, Ltd.

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