Kharkov National University
V.N.Karazin
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1.  Telemetering methods, devices and their application in vertebrology
S.N. Kulish, O.Y. Kagan
radiotelemetring research, Transmitter, radio channel, implant devices, spine, impellent segments
Vestnik KhNU 712 Pages. 33-36

In the given job the review and the analysis of existing telemetering methods of research and diagnostics of various diseases in medicine is resulted. It is offered to use means of radiotelemetering research for registration of mechanical parameters arising on contact and lateral surfaces of impellent segments of a backbone. The block diagram of multichannel telemetering system is resulted and the basic requirements shown to this system are described



2.  Radiation of transient fields from the open end of coaxial waveguide with shifted internal conductor
N.N. Gorobets, A.N. Dumin, O.A. Dumina
Transient field, coaxial waveguide with shifted internal conductor, TEM-wave, radiation
Vestnik KhNU 712 Pages. 42-46

The problem of the radiation from the open end of coaxial waveguide with shifted internal conductor excited with transient source is solved in time domain. The incident into the aperture TEM-wave in coaxial waveguide with time dependence in form of gaussian pulse is considered as a source. The influence of a flange on radiated field characteristics is examined. The application of dielectric insertions into the aperture for the increasing of radiation along normal to aperture is studied



3.  Analytical solutions in time domain for electromagnetic fields in a cavity with Debye medium
M.S. Antyufeyeva
dielectric, dispersion, Debye medium, electromagnetic fields in a cavity with a dielectric, evolutionary approach to electromagnetics, Time domain
Vestnik KhNU 712 Pages. 84-90

The theoretical investigation of the properties of electromagnetic oscillations in a cavity with Debye medium is carried out. The problem is considered within the frame of the Analytical Approach to Electromagnetics in the Time Domain (TD), which allows obtaining closed-form solutions in TD for a wide range of electrodynamical problems. For the description of electromagnetic properties of the medium is used representation of the constitutive relation in an integral form. The analytical solutions are obtained for the several excited functions in TD and they validity conditions are defined. Characteristics of electromagnetic oscillations are presented for different relaxation time and dielectric susceptibility



4.  Impedance of connected in series diodes with difference negative conductivity
E.D. Prokhorov
Tunnel diode, negative conductivity, frequency range
Vestnik KhNU 712 Pages. 111-114

The impedance connected in series negative difference conductivity diodes in wide frequency range are analyses. There are frequency region that diodes combination work have been appeared. The operation frequencies for combination of tunnel diodes are 35-40 GHz



5.  Same question of modeling of tunnel contact semiconductor structure
O.V. Botsula, E.D. Prokhorov
Tunnel cathode, negative differential conductivity, contacts, current - voltage characteristics, cathode, anode
Vestnik KhNU 712 Pages. 119-122

Electronic processes are considered at course of a current through semi-conductor structure with the tunnel cathode. The approach to modelling the structures including as a component tunnel geterojunction is offered. Static characteristics of structures to a basis geterojunction GaAs/AIGaAs received with application of the offered technique are resulted



6.  Stimulation of the size evolution of the gas includes in a liquid by electromagnetic waves
B.G. Yemets
electromagnetic waves, air bubbles in liquid, Temperature field, convection
Vestnik KhNU 712 Pages. 127-131

Based on the model considerations it was shown that irradiation of liquids containing gas inclusions with electromagnetic fields of "slowly-convective" intensity is conducive to the changes in the inclusion size



7.  ELECTRODYNAMIC MODELING OF COMPOSITE MEDIA WITH SIMALTENEOUSLY NEGATIVE REAL PARTS OF PERMITTIVITY AND PERMEABILITY
S.N. Shulga, I.E. Khodasevych
composite media, Thin-wire resonance inclusions, permittivity, permeability, scattering of electromagnetic waves
Vestnik KhNU 756 Pages. 38-41

This paper presents physical and mathematical model and investigation of electromagnetic properties of composite material made of straight and curved conducting resonance inclusions placed into isotropic media and forming periodic lattice. The effective constitutive parameters of the composite material are found. It is revealed that on resonance frequency real parts of permittivity and permeability of such media can assume simultaneously negative values. The problem of reflection and transmission of plane electromagnetic wave through a sequence of layers made of such composite material is solved, numerical results are presented



8.  SCATTERING AMLITUDE ERROR ESTIMATION FOR MOMENT'S METHOD IN L2 FOR 2-D SCREENS
A.G. Tyzhnenko, Y.V. Ryeznik
Testing, reference solution, moment's method, 2-D screens
Vestnik KhNU 756 Pages. 65-70

The scattering amplitude error estimation problem for practically used MoM solutions in L2 function space for scattering from 2-D screens is addressed. To this end, a rigorous Galerkin solution in L2 to logarithmically singular and hypersingular EFIE is used as a reference solution for scattering amplitude error estimation by benchmarking. This one requires substantially lower computational efforts than using of the same MoM algorithm but with very high mesh density as a reference solution. To many, the approach helps to avoid unpredictable errors due to the ill-conditioning connected with high mesh density for any MoM solution to the EFIE in L2. Using the approach, the asymptotic decay rate of scattering amplitude error is investigated for some MoM algorithms widely used in practice



9.  DESTRUCTION OF PULSE TRAINS IN WEAKLY NONLINEAR OSCILLATOR
D.D. Vavriv
chaos, dynamical systems, Train pulses, quasi linear oscillator
Vestnik KhNU 756 Pages. 71-78

A study has been carried out on the transition of train of pulses via a weakly nonlinear oscillator. Conditions of destruction of such trains as a result of appearance of chaotic instabilities have been analyzed. Analytically conditions of the appearance of chaotic instabilities have been determined by using the method of secondary averaging.



10.  The analytical method for a periodical sequence of the alternate grates of dielectric bars investigate
V.B. Kazanskiy
Thick grate of dielectric bars, anisotropic layer, periodic structure, propagation constant, scattering coefficients
Vestnik KhNU 756 Pages. 79-82

The electromagnetic properties of a finite periodic sequence of the thick grates of dielectric bars are investigated. The grates are identified with the homogeneous anisotropic layer of an appropriate thickness, in order to generalize, the layers which anisotropic properties of both permittivity and permeability are employed. The sequence scattering .coefficients are determined in analytical form using the circuit theory and the matrix functions techniques. Physical analysis of the frequency, angle and interference dependencies of the scattered field amplitude is carried out.



11.  The Gaussian beam scattering on the bounded sequence of alternate grates of dielectric bars
V.B. Kazanskiy, V.R. Tuz, D.V. Yudintsev
Gaussian beam, Thick grate of dielectric bars, anisotropic layer, periodic structure
Vestnik KhNU 756 Pages. 83-86

The Gaussian beam scattering on bounded periodical sequence of thick grates of dielectric bars are investigated. Identification of discrete structure with appropriate thickness homogeneous anisotropic layer was carried out for define sequence basic element transmission matrix. The sequence scattering coefficients were written down via Mougin polynomials. The effects of form distortion, beam splitting into several beams, side shift of beam axe were shown. Their correlation with scattering coefficients phase and module angle dependence of separate grates was established.



12.  Al0,3Ga0,7As/GaAs cathode transfer electron diode's efficiency
O.V. Botsula Prokhorov E.D, A.V. Dydchenko
doping, cathode contact, Tunnelling, negative differential conductivity, oscillation efficiency
Vestnik KhNU 756 Pages. 97-100

The results of analyse efficiency of GaAs/ Al0,3Ga0,7As/GaAs GaAs/ Al0,3Ga0,7As/GaAs / GaAs cathode transfer electron diode are present. The space charge model are used. There are two region of negative differential conductivity of current - voltage characteristic are shown . The condition lead to oscillation due both region and oscillation efficiency have been determined.



13.  THE H10 WAVE SCATTARING BY THE THIN VARIABLE RADIUS IMPEDANCE VIBRATOR IN A
Nesterenko, E.Y. Belogurov, V.A. Katrich, V.I Kijko
impedance vibrator, biconical vibrator, distributed surface impedance, rectangular waveguide, The method of induced electromotive forces
Vestnik KhNU 806 Pages. 14-17

The problem of the fundamental wave scattering by the thin variable radius impedance vibrator arbitrary situated in a rectangular waveguide was solved. Calculations were carried out and energetic characteristics of such structures were plotted


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14.  Resonance phenomena occurring as a thin refractive cylinder diffracts the hertzian wave
Yu. I. Grebenyuk, N. G. Kokodiy, Khe Shi
diffraction, Thin cylinder, refractive index, scattering, absorption, weakening, resonance
Vestnik KhNU 806 Pages. 33-39

On the basis of solutions to the wave equation, the efficiency of dispersing, absorbing, and weakening the electromagnetic field that a thin cylinder with a large refractive index diffracts has been estimated. The transverse and longitudinal distribution of the electromagnetic field inside and outside of the cylinder has been calculated. The resonance is found to increase the intensity of both the electromagnetic wave field inside the cylinder and the scattered wave outside. Inside the cylinder at resonance, a wave propagating along its surface arises, and under some conditions, a wave propagating through the cylinder is also generated. As the refractive index is increased, the wave tracks the cylinder surface more closely, and its intensity is progressively enhanced.


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15.  The influence of a dispersion and losses to the interaction of impulse signal with the model of the biological tissues
O.N. Zheryobkina, O.V. Kazanskiy
impulse signal, a biological tissue, Time domain, flatlayer dielectric, dispersion
Vestnik KhNU 806 Pages. 40-43

In this paper the interaction of the impulse signal with biological tissues on an example of the flatlayer dielectric that models consecutive layers a skin, fat, muscle tissue is investigated. In this model, it is taken into account dispersion of the dielectric permeability and losses in a medium. The calculation program is received in result. It accounts the space-time characteristics of the reflected and past signals for layers of the flatlayer dielectric with parameters of biological tissues. Influence of values of the dielectric permeability and angle of incidence on the characteristics of past and scattered signals also is considered.


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16.  Spatial and temporal features of the midlatitude total electron content
I. G. Zakharov
Total electron content, dual-frequency Doppler shift measurements, planetary waves
Vestnik KhNU 806 Pages. 82-86

Experimental study of the latitudinal and diurnal variations in the total electron content over Eastern Europe are present. The dual-frequency Doppler shift measurements from navigation satellites and incoherent scatter radar (ISR) data are used The ISR data were collected near Kharkiv city (49.6oN, 36.6oE), and the dual-frequency signals from navigation satellites in circular polar orbits at the altitude of about 1000 km were received at the Kharkiv V. Karazin National University Radiophysical Observatory (49.6oN, 36.3oE). The calculated total electron content maps span the 35o 65oN geographic latitude range and the 24-hour local time range. These maps and other data represent all known features of diurnal and latitudinal total electron content variations at middle and subauroral latitudes, and in particular, they represent the local latitudinal maximum at 50oN geographic latitude in total electron content. The results obtained also indicate that tidal and planetary-scale waves act to noticeably modify the temporal and spatial variability of TEC, including that under quiet conditions.


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17.  Application of the digital holographic interference microscope for investigation of thin films
D.N. Tishko, T.V. Tishko, V.P.Titar, Yu. A. Zadneprovskiy, A.S. Kuprin, I.A.Zgoda
digital holographic interference microscope, Three-dimensional images, vacuum-arc method, Thin AlN films
Vestnik KhNU 806 Pages. 99-102

For the first time the digital holographic interference microscope (DHIM) was used for investigation of thin films on transparent substrates. Three-dimensional images of AlN of thin films, deposited on acryl substrates by the vacuum-arc method have been obtained, their thicknesses have been measured. It has been shown that the DHIM can be successfully used for film surface quality checking, thickness and film damages parameters measurement.


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18.  Fields of the rectangular loop antanna in near-field zone
N.N. Gorobets, .V. Trivaylo
electromagnetic waves, radiation, near-field zone, Hertz vector, Traveling wave antenna, loop antenna
Vestnik KhNU 834 Pages. 18-24

On the basis of potential Hertz technique the expressions for calculating of all components of electromagnetic radiation fields of rectangular loop antenna, stimulated by the running wave of the current in Spherical and Cartesian coordinate systems unrestricted on the size of radiator and distance up to a point of observation have been derived. It has been shown that in a near field zone of radiation electromagnetic vectors in the Cartesian and Spherical coordinate systems have all 6 component. It has been shown that wave processes near by the examined radiators are distinguished by great gradients of amplitudes of the electromagnetic fields


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19.  Radiation of short pulses from the open end of waveguide
O.M. Dumin, O.O. Dumina, V.O. Katrich, Zheng Yu
Transient field, modal basis method, evolutionary equations, impulse field irradiation
Vestnik KhNU 834 Pages. 63-67

The problem of transient electromagnetic field radiation from the open end of waveguide is solved in time domain by the analytical and direct numeral methods. The problem of impulse signal propagation in regular waveguide is converted to the finding of transient wave propagation operator by modal basis method. The application of the operator for the obtaining of time form of signal both for the time change in positive and in the negative direction permits to seek an arbitrary time dependence of field amplitude in any point of waveguide taking into account distortions due to wave dispersion. The correction of diffraction distortions of time form of wave and forming the short probe impulse on the waveguide aperture by the excitation of waveguide in the given cross-section by field with the previously calculated time dependence are considered . Numerical simulation of short impulse irradiation of layered medium with losses is carried out


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20.  Frequency multiplication at impact ionization in GaN-diodes
. V. Botsula, D. V. Pavlenko, E. D. Prokhorov
The GaN diode, coefficient conversion transducing, drift velocity, harmonics
Vestnik KhNU 834 Pages. 100-103

The frequency multiplication at impact ionization in transfer electron GaN diodes nave been considered. The coefficient conversion transducing increase if impact ionization in GaN diodes takes place have been demonstrated. For example, coefficient conversion transducing in second harmonic arrive at 40 %.


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21.  Algorithms of the processing signal from the trellised receiver for measuring of the laser radiation characteristics
Kokodiy N.G., Pak A.O.
The laser, optical radiation, intensity, bolometer, direct task, reverse task
Vestnik KhNU 853 Pages. 37-44

In this paper has been considered the development of the device for the measurement of the intensity distribution in the beam of optical radiation. The algorithm of processing of a signal from the receiver of radiation is studied. The method of measurement of the intensity distribution of optical radiation by the bolometric grid is offered. The developed algorithms for processing a signal from the measuring converter and programs realizing them are checked up experimentally, their serviceability is confirmed. The comparative characteristic of algorithms based on the transformation of Fourier and transformation of Radon has shown an opportunity of their use in practice


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22.  Algorithm of a pulse signals delay definition, based on a Hilbert's transformation
D.O. Batrakov, D.V.Golovin, S.V. Grekov, A.G. Batrakova*
pulse signals, definition of a delay of signals, Hilbert's transformation, plane-layered media, Thickness measurements
Vestnik KhNU 853 Pages. 71-76

In the present paper the algorithm of processing of the pulse signals reflected from plane-layered media is offered. It is supposed, that an effective thickness of layers less than spatial size of an impulse. This feature of a problem complicates use earlier proposed methods of signals time delay evaluating. Therefore in paper the theoretical analysis of possibilities of various approaches for processing of signals is carried out and the algorithm and the corresponding software for definition not only a time delay, but also physical and geometrical characteristics of investigated objects are offered. Results of numerical modelling and experimental researches for the purpose of definition of sensitivity and resolution of a method, and also possibility of its practical use are given


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23.  Theoretical investigation of photonic crystals by means of analysis of photonic density of states maps
I.V. Guryev
photonic crystal, photonic density of states, Transmittance spectrum, plane wave expansion method, finite differences method
Vestnik KhNU 853 Pages. 77-83

In the work, there have been computed the photonic density of states maps of the 2D photonic crystal by means of plane waves expansion method by the analogy with photonic band gap maps. The photonic density of states maps allows precise determination of the parameters of photonic crystals during the design process of the photonic crystal-based device. Moreover, there have been carried out the comparison with analogous characteristics obtained by the finite differences time domain method. Comparison results indicate the similarity of results obtained by two methods, however, the computation of photonic density of states maps requires much less time at the same computation precision. Moreover, in the work there have been carried out the comparison between the efficiencies of the photonic density of sates maps and the photonic band gap maps analysis methods


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24.  HF ionosonde signal focusing by traveling ionospheric disturbances
Yu. B. Milovanov, V. F. Pushin, O. F. Tyrnov
Traveling ionospheric disturbances, signal amplitude variations, Doppler frequency shift, focusing factor, computer simulation
Vestnik KhNU 853 Pages. 88-94

HF signal focusing due to linear and nonlinear wave disturbances occurring during monostatic ionospheric sounding is discussed. A technique is developed for estimating signal amplitude variation due to focusing based on beating amplitude measurements during significant Doppler frequency shift events. The intercomparison of measured and modeled variations in beating amplitudes, the focusing index, and Doppler frequency shift show a qualitative agreement. The simultaneous analysis of variations in the beating amplitude and the Doppler frequency shift makes the interpretation of measurements more definite, e.g., it permits the isolation of large scale disturbances traveling at approximately 1 km/s


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25.  Random inhomogeneous liquid medium as a continuous laser of low-intensity modulator for excitating sound in the medium
B. G. Yemets
laser, random inhomogeneous liquid medium, interference, Temperature field, optical acoustical phenomenon, sound, excitation, modulation
Vestnik KhNU 853 Pages. 95-100

When a medium is irradiated by laser pulses, sound waves are excited in this medium, i.e., the well-known optical acoustical phenomenon occurs. To excite sound oscillations, the specific laser beam modulator is shown to be unnecessary. The role of the modulator can play the liquid itself, which is a random inhomogeneous medium. The real liquid contains suspended solids and gas bubbles of small dimensions (dust particles and the like) that move irregularly in space (fluctuations). As a result, the electromagnetic wave interference taking place in the liquid undergoes random changes. Consequently, the temperature field changes, and hence variations in the local pressure occurs (thermo-optical mechanism for exciting sound). The excitation of sound due to the laser irradiation of low intensity is observed in an increase in the gas bubbles dimensions in the liquid


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26.  Analysis of impulse fields reflected from layered medium with losses using artificial neural network
Shyrokorad D. V., Dumin O.M., Dumina O.O., Katrich V.O.
Time domain, artificial neural network, impulse fields, layered medium
Vestnik KhNU 883 Pages. 35-40

The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificia


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27.  Experimental study of diffraction of electromagnetic waves on the lattice of elements of the complex profile
Ivanchenko D.D., Maleev M. N.
The difraction electromagnetic waves, chiral grates, frequency-poiarization property
Vestnik KhNU 883 Pages. 54-58

In given paper the diffraction of electromagnetic waves on volume grid is investigated experimentally. The grid consists of rectangular elements. Two planes of two-dimensional periodic rectangular metallic string elements located on both dielectric surfac


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28.  About convergence of the mode expansions onto spherical harmonic in time domain
Kochetov B.A., Butrym A.Yu.
mode basis method, Transient field, spherical modes, ring current
Vestnik KhNU 883 Pages. 41-44

The convergence of spherical mode expansions in the time domain to the exact solution is shown on an example of a test problem that has a closed-form solution. Radiation of a ring with transient current in free space is considered. It was shown that there


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29.  Investigation of different temperature modes of auxilliary cathode work in magnetrons with cold secondary-emission cathode
Avtomonov N.I., Vavriv D.M., Sosnytsky S.V.
Magnetron, cathode, Thermionic cathode, Thermo emission, Temperature
Vestnik KhNU 883 Pages. 73-82

A theoretical investigation of the emission current temperature dependence of the auxiliary cathode in magnetrons with cold secondary-emission cathodes is performed. Different methods of providing a spatial-charge limited emission from the auxiliary catho


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30.  Quantum efficiency spectral chracteristics of resonant cavity photodector taking into account thermal gradient
S.V. Gryshchenko,
Resonant cavity photodetector, refractive index, Temperature shift
Vestnik KhNU 883 Pages. 8-11

In paper a theoretical analysis of quantum efficiency of resonance InGaAs/GaAs P-i-n photodetector (RCE PD) is presented. A mathematical model plugs in itself the transfer matrix method, heat conductivity calculation and dependence of index of refraction


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31.  The accumulation of gas in galactic objects
Sorokin A.A., Sorokin A.F., Zaharova M., Sokolova O.V., Gorobets N.N.
astrophysics, galactic objects, The accumulation of gas
Vestnik KhNU 883 Pages. 3-7

The mechanism of the accumulation of gas in the galactic objects submerged in the large-scale magnetic field is examined. As a consequence of the diamagnetism of the plasma subsystem of object, the stopper geometry of magnetic field with the radial electr


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32.  Compromising emanations: overview and system analysis
N.N. Gorobets, .V. Trivaylo
compromising emanations, near-field-zone, electromagnetic, radiation, Time domain
Vestnik KhNU 883 Pages. 83-88

The problem of compromising radiation of spurious signals in the near, intermediate and far zones of observation in time domain are considered. The Compromising emanation system analysis for finding spurious radiation is proposed. The goal of the given approach is to speed the development of technical protection of information. In approximation of the given current distribution it has been suggested a solution considering the influence of the near-field effects upon directional characteristics of spurious signals radiation. The application of the new method allows us to investigate compromising of technical means in time and frequency domain.


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33.  On non-unique definitions the lorentz transformation
Volchenko A.P.
rate of neutrinos, The speed of light, The phenomenon of the aberration of light, The Lorentz transformations
Vestnik KhNU 966 Pages. 82-89

IThe article shows that the Lorentz transformations (LT) if they define as an object of mathematics, allow for different geometric and as a consequence, various kinematic interpretation. In this regard, introduced by the geometric and kinematic interpretation of the corresponding SPs that do not use the postulate of special relativity, whereby the speed of light is the limit for the velocities of the bodies that have mass. The specificity of this definition is illustrated by their use of in the description of the phenomenon of aberration of light.


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34.  Analysis of polarization characteristics of electromagnetic waves in non-orthogonal linearly polarized basis
Gorobets N.N., Chekalin , Chekalina G.N.
lectromagnetic wave, electric field strength,time-distance curve, harmonic basis, The expansion of the harmonic, The polarization model
Vestnik KhNU 966 Pages. 50-55

We solve the problem of determining the polarization characteristics coefficient of ellipticity and orientation angle of the polarization ellipse and the direction of rotation of the polarization vectors of linearly polarized basis with arbitrary angle between the components of the electromagnetic wave. In the special case of orthogonal linearly polarized basis obtaind solutions coincide with the known one. An algorithm for constructing a model of elliptically polarized waves had been elaborated in this article as the totality of hyperbolic and elliptic circles.


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35.  Own magnon polariton surface modes in the open passage resonator with gyromagnetic medium
Mizernik V.N., Shmat'ko A.A.
magnon polatiton oscillations, The ferrite resonator, a junction of waveguides, The through passage open resonator, wavegaide inhomogeneity, area of connection, system of the linear algebraic equations.
Vestnik KhNU 966 Pages. 31-36

The problem about owen modes of the open reentrant resonator partially filled is theoretically solved by gyrotropic ferrite medium and existence magnon polatiton surface (PS) mods with tall concentration of a field on boundary line of the ferrite resonator is established. The every possible combined regimes of existence of superficial and volumetric fashions are analysed, dependences of their resonant frequencies on material parameters of medium and geometrical sizes of the resonator and a ferrite layer are certain.


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36.  Impedance characteristics of planar diodes with tunnel boundaries based on GaAs
Prokhorov E.D., Botsula O.V., Klimenko O.A.
: negative differential conductivity, Tunnel boundary, a diode, The tunneling.
Vestnik KhNU 966 Pages. 13-18

The impedance characteristics of the diodes are consider, which negative differential conductivity (NDC) is arise under cer-tain voltage, due to tunneling of electrons through the side faces of the diode, which can be used for generation, amplification and multiplication. Depending on the active and reactive components of impedance are determined of the diode with the tun-nel boundaries for the real parameters of the diodes. It is shown that the limiting frequency of the diode NDC is in the tera-hertz range and depends on its parameters.


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37.  Determena Frequency properties of intervalley electron transfer in AlN
V. T. Plaksiy, .V.Arhipov, . S. Tischenko, . . Kamishanova, E.D. Prokhorov, .V.Dyadchenko, D. P.Chueshkov
perfect crystal, zone overcrystallization, Temperature gradient
Vestnik KhNU 966 Pages. 19-22

The problem of growing of perfect bismuth-antimony monocrystals having of a uniform distribution of Sb atoms through the crystal by help floating-zone refining method is considered. The expression for temperature gradient in melt and temperature distribution for any melt point have been obtained. The monocrystals growing maximal velocity have been estimated. The growing velocity must be lower then 1 mm per hour was showed. It is velocity not lead to concentration overcooling and arising inhomogeneous dendrite structure. For solution with certain composition ( at = const) overcooling may be eliminated by either increasing of temperature gradient in liquid faze or decreasing growing velocity are showed.


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38.  New statistical methods of recognition and classification for automatic interpretation of remote observations
Koltunov Y.A., Dumin O.M., Katrich V.A., Naumov R.R.
methods of recognition and classification, blenderized models of the probabilistic distributing, Teaching selection
Vestnik KhNU 966 Pages. 37-49

Mathematical models, computational algorithms, and also prospects of development and application of three new methods of recognition and classification (RC), namely, construction of distinctive characteristics of objects; classification on the basis of probabilistic teaching selection with optimization of method RAC; account of dynamics of features of recognized objects are presented in the article. Recognition and classification is an area of modern science that have a boundless list of applications in all spheres of human activity. From the list of applications the only one is selected in the present work, but the most actual one, that is the remote sensing of ground surface in radiofrequency band with the purpose of study and maintainance of natural resources of Earth.


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39.  The geometrical approaches to the calculation of propagation of Gaussian beams in hollow metal waveguides in the terahertz range
Gurin O.V., Degtyarev A.V., Maslov V.A., Svich V.A., Senyuta V.S., Topkov A.N.
metal waveguide, Gaussian beam, Terahertz range, geometrooptical approach, Transmission coefficient
Vestnik KhNU 966 Pages. 3-8

A comparison of the results of calculations of the transmision for Gaussian beams in hollow circular metal waveguide using geometrooptical procedures by Frost and Crenn with the results of experiments in the terahertz range is performed. The conditions of applicability of these methods to study the transmission characteristics of metallic waveguides of different lengths were found. It is shown that in this range the geometrooptical approach, proposed by Frost, provides satisfactory results only for short waveguides, the length of which corresponds to the condition of the near zone. The geometrooptical approach by Crenn is applicable to both short and for long waveguides.


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40.  

earthquakes, VLF emissions, Total electron content, equatorial anomaly
Vestnik KhNU 966 Pages. 103-110

Observational data about variations in VLF emissions and ionospheric total electron content near and at large distances from earthquake areas have been analyzed. The diurnal and day-to-day VLF variations have been shown to have features that correlate with variations in global seismic activity. The effects in the VLF variations occur both prior to enhancements in seismic activity (with the time lag proportional to the earthquake magnitude) and during first 24 h after the earthquake. The effect of violent earthquakes on latitudinal dependence of the total electron content may differ; specifically, the equatorial anomaly can disappear at distances of more than 6,000 km from the epicenter.


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41.  

radioholographic image, radiohologram, Three-dimensional image of object, spatial resolution
Vestnik KhNU 966 Pages. 68-71

The known method of the in-phase adding up of harmonic vibrations with different temporal and spatial frequencies is examined. In ordinary aerial of accordion with different spatial frequencies in sending to the object folded in a phase and the diagram of orientation is formed thus (main and lateral petals). In other directions spatial accordions folded with different phases and fomiruyut lateral petals of diagram of orientation. If to create the multifrequency and multiposition coherent system such, that on separate aerial positions signals are accepted with different bearings frequencies, on the output of general aerial they can be laid down in a phase in certain moment of time like that as it takes a place with spatial frequencies in ordinary aerial. In this case spatial resolution of order of wave-length is provided thus.


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42.  

magnetron, cathode, Thermionic cathode, Thermo emission, Temperature.
Vestnik KhNU 883 Pages. 73-82

A theoretical investigation of the emission current temperature dependence of the auxiliary cathode in magnetrons with cold secondary-emission cathodes is performed. Different methods of providing a spatial-charge limited emission from the auxiliary cathode are studied in order to eliminate the temperature dependence of auxiliary cathode thermionic current. A new design of the auxiliary cathode is proposed, which is supposed to provide a greater stability with respect to the cathode temperature variations as compared to the currently manufactured magnetrons.


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43.  

astrophysics, galactic objects, The accumulation of gas
Vestnik KhNU 883 Pages. 3-7

The mechanism of the accumulation of gas in the galactic objects submerged in the large-scale magnetic field is examined. As a consequence of the diamagnetism of the plasma subsystem of object, the stopper geometry of magnetic field with the radial electric field is formed. In this configuration, effective retention and the accumulation of the plasma, which revolves in the lattice-type fields, occurs. Atoms are tightly connected on the effects of recharge with the ions, which provides their accumulation. The calculated distributions of molecular and atomic hydrogen in our Galaxy, whose the stopper geometry of its magnetic field is well-known, are given. It is shown that this mechanism describes well the basic special features of gas subsystems


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44.  

Time domain, artificial neural network, impulse fields, layered medium
Vestnik KhNU 883 Pages. 35-40

The problem of determination of thickness a layer of layered medium by impulse irradiation is solved. The impulse fields reflected from the layered medium with electrical characteristics close to the characteristics of human skin are analyzed by artificial neural network in time domain directly. The normal incidence of plane wave with Gaussian time form is considered. The reflected electromagnetic field is calculated by FDTD method. Initial data for the neural network analysis are the values of amplitude of electrical component of reflected field. As an example, the network is trained to determine the thickness of one of the layers of the medium. The stability of the determination in presence of interferences, experimental errors and instabilities of medium parameters is investigated.


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45.  

mode basis method, Transient field, spherical modes, ring current.
Vestnik KhNU 883 Pages. 41-44

The convergence of spherical mode expansions in the time domain to the exact solution is shown on an example of a test problem that has a closed-form solution. Radiation of a ring with transient current in free space is considered. It was shown that there exist only a finite number of propagating modes for any frequency at any given radius of a circumventing spherical surface. Thus within the framework of mode basis method in spherical coordinate system a finite number of main modes is sufficient to describe radiation of a transient sources located within a sphere of some given radius.


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46.  Compromising emanations: overview and system analysis
N.N. Gorobets, A.V. Trivaylo
compromising emanations, near-field-zone, electromagnetic, radiation, Time domain
Vestnik KhNU 883 Pages. 83-88

The problem of compromising radiation of spurious signals in the near, intermediate and far zones of observation in time domain are considered. The Compromising emanation system analysis for finding spurious radiation is proposed. The goal of the given approach is to speed the development of technical protection of information. In approximation of the given current distribution it has been suggested a solution considering the influence of the near-field effects upon directional characteristics of spurious signals radiation. The application of the new method allows us to investigate compromising of technical means in time and frequency domain.


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47.  

waveguide resonator, misalignment of the mirrors, Terahertz range, energy losses, mode composition, polarization
Vestnik KhNU 983 Pages. 18-22

The influence of the curvature of the spherical mirror for metallic waveguide resonator of submillimeter laser (lambda = 0.4326 mm) on energy losses and the mode composition of radiation is investigated. It is shown that the presence of quadratic phase aberrations in the mirrors of the waveguide cavity with an increase of its Fresnel number at monotonically decreasing of the energy losses for fundamental asymmetric mode TE11q due to a decrease of waveguide losses also leads to their substantial non-periodic oscillation.


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48.  

Thermal nonlinearity, optical beam, Total reflection, induced inhomogeneity, self-defocusing.
Vestnik KhNU 983 Pages. 33-37

The interaction of optical beams in media characterized by a refractive index depending on temperature is examined. The optical pump beam is partially absorbed by the medium induces a region with an inhomogeneous refractive index. As a result complete reflection, refraction or diffraction of the signal beam on the induced optical inhomogeneity may be observed. Experimental results on the research of this phenomenon are presented. Waveguide propagation of light in the region formed by two narrow pump beams is realized.


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49.  

resonant photodiode, quantum efficiency, modulation characteristic, Transfer matrix method.
Vestnik KhNU 983 Pages. 54-66

In this paper, we have described methods of modeling of resonant cavity photodiods based on semiconductor quantum dimensional structures for ultrashort connections. The problem of misalignment of operating wavelength of emmiter and receiver has been shown and quantum efficiency maxima spectral shift temperature dependence was analysed. Technological control of layer thickness using laser interferometer with 1 atomic layer quality control was shown. Comparative analysis made in this paper of modulation characteristic of regular and resonant cavity detectors shows more than 5 times increasing quantum efficiency and modulation band product in resonant detector case.


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50.  

gravimeter, superconducting suspension, optical registration, Thin films, superconducting ring.
Vestnik KhNU 983 Pages. 107-113

This paper considers the problem of designing and developing optical-cryogenic devices using new physical principles, mathematical methods, and new superconducting materials. The sensor element is based on new ontrolled magnetic levitation phenomenon, high-precision optical registration of mechanical coordinates of levitating body, and the robust signal processing tools. A controlled self-bearing probe dynamics is also analyzed. We have shown how to produce reliable YBCO thin films with controllable surfaces and physical properties and how to integrate them in a ring form into the optical-cryogenic gravimeter so as to reduce its size and render it convenient for future space applications.


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51.  

Thermophysical parameters, The coefficient of heat exchange, The efficiency factor of absorption, The heat constant time.
Vestnik KhNU 927 Pages. 36-42

The paper deals with thin wires that standing on the way of distribution of the laser beam. The measurements were performed for platinum bolometers with diameters 10 and 20 microns and for nickel bolometer with diameter 40 microns. The experimental research of heat properties of these bolometers (platinum and nickel) in the range of temperatures from room up to close to melting temperature is carried out. The dependence of the thermal parameters of bolometer temperature, as well as the error in determining these parameters is considered. The coefficient of heat exchange with external environment, the efficiency factor of radiation absorption in the visible range, the heat constant of bolometer cooling are measured. The polynomial approximation of the received data is made.


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52.  

Gunn diode, dipole domain, accumulation layers, Transit frequency, efficiency generations
Vestnik KhNU 927 Pages. 3-6

Results of research of power and frequency characteristics of Gunn diodes on the basis of Al1-xInxN for various values of concentration of impurity in active area in biharmonic regime are present. It is shown, that using of voltage of the complex form leads to increase of efficiency generation at the basic harmonic in comparison with work in harmonic regime. The increase of impurity concentration in active area leads to increase of efficiency generation both on the first, and on the second harmonic. At the expense of effective work on the second harmonic there is a possibility of reception of generation to frequencies of a submillimetric range.


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founded: 52 result (s)
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