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 ¹712 Pages. 3336
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. Longitudinal slot radiators cut in circular waveguide E.Y. Belogurov, V.A. Katrich, V.A. Lyaschenko circular waveguide, axial slot, electromagnetic waves, radiation, slot antennas Vestnik KhNU ¹712 Pages. 3741
Using method of magnetomotive forces investigations of behaviors of longitudinal slots that were cut in wall of the circular waveguide were carried out. Expressions of internal selfadmittance and transfer conductance were de rived. The possibility of creation of a tapered illumination that forms radiation pattern with low side lobes on long slot cut in circular waveguide was shown
3. The finite difference scheme in time domain (FDTD) and analytical solution to KleinGordon equation Yu Zheng, B. A. Kochetov, A.Yu Butrym KleinGordon equation, FDTD, finite difference equation, Laguerre impulse Vestnik KhNU ¹712 Pages. 9194
A finite difference algorithm for solving inhomogeneous KleineGordon equation in Time Domain with arbitrary waveform pointwise source is considered in the paper. The numerical results were compared with analytical solution that was obtained using Laplace transformation in a convolution operator form. The results confirm validity of both the obtained numerical algorithm and the analytical solution
4. 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 ¹712 Pages. 127131
Based on the model considerations it was shown that irradiation of liquids containing gas inclusions with electromagnetic fields of "slowlyconvective" intensity is conducive to the changes in the inclusion size
5. On the field fluctuations in the diffraction pattern of focusing systems Ya.S. Shifrin fluctuations, amplitude, phase, focal plane Vestnik KhNU ¹756 Pages. 510
There are considered the amplitude and phase fluctuations of the field in the focal plane of the focusing system, when a was with the field fluctuations falls on it. Plots illustrating the distribution of dispersions of amplitude and phase of the field along coordinate axes in the focal plane are given. There are analyzed a general case when both the amplitude and phase fluctuation of the field are present in the incident wave, as well as cases when it is possible to be restricted by regard of only either the phase or the amplitude fluctuations of the field in the antenna aperture. It is shown that in the latter cases, for determination of dispersions of the phase and amplitude fluctuation of die field in the focal plane, it is possible to use the same pictures with tk corresponding replacement of curves and conclusions accompanying them.
6. On the directive gain of the selffocusing antenna Ya.S. Shifrin directive gain, selffocusing antenna, inhomogeneities, structure function Vestnik KhNU ¹756 Pages. 1117
The influence of the atmospheric inhomogeneities on the directive gain of the selffocusing antenna array (SFAA) at description of the atmosphere by the theory of the localisotropic turbulence is considered. There are analyzed two cases when a size of the SFAA subaperture is respectively more or less than the turbulence scale of the medium. It is shown mat the results of the meat directive gain estimation for the two cases are well conformed qualitatively with the analogous estimates obtained at the atmosphere description wife the help of the Gaussian correlation function of its refractivity index
7. Radioacoustic wind sounding of the atmosphere bo un dat y layer: history of the development and perspectives Y. N. Ulyanov, V. I. Vetrov, N. G. Maksimova radioacoustic, wind, sounding, atmosphere, boundary layer, profile, adaptation Vestnik KhNU ¹756 Pages. 2732
The article is devoted to the potentialities of the method of radioacoustic sounding when monitoring the vertical structure of the wind in the atmosphere boundary layer (ABL). A review of methods for radioacoustic measurements of the horizontal wind velocity and direction is based on the developments of the authors and their experience in this field as well as on the world experience. It is emphasized that the radioacoustic method for sounding the wind in ABL is perspective, since for the RAS equipment, there are not characteristic neither high levels of the electromagnetic pollution of the environment like for radiolocation wind profilers  radars nor loss of the serviceability at ligh levels of the ambient acoustic noise like for acoustic wind profilers  sodars.
8. Onedipole inverse problem of magnetostatics for reconstruction of hearttorso electric activity from magnetocardiography measurements Bagatskaya O., Butrym A., Durneva Yu., Shulga S. Do not determinated Vestnik KhNU ¹756 Pages. 4750
Do not determinated
9. SCATTERING AMLITUDE ERROR ESTIMATION FOR MOMENT'S METHOD IN L_{2} FOR 2D SCREENS A.G. Tyzhnenko, Y.V. Ryeznik testing, reference solution, moment's method, 2D screens Vestnik KhNU ¹756 Pages. 6570
The scattering amplitude error estimation problem for practically used MoM solutions in L_{2} function space for scattering from 2D screens is addressed. To this end, a rigorous Galerkin solution in L_{2} 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 illconditioning connected with high mesh density for any MoM solution to the EFIE in L_{2}. Using the approach, the asymptotic decay rate of scattering amplitude error is investigated for some MoM algorithms widely used in practice
10. 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 ¹756 Pages. 8386
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.
11. On the primary mechanism for microwave therapeutic effects arising during gamma ray pathology B. G. Yemets electromagnetic microwaves, gamma rays, air bubbles, biologically active points Vestnik KhNU ¹756 Pages. 139143
The biologically active points (BAP) show an increase in size due to an increase in size of air bubbles at nearmembrane water layer in the biologically active point cells. The increase in the air bubble size is produced by sweeping the microwave frequency.
12. THE H_{10} 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 ¹806 Pages. 1417
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
Download >>
13. 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 ¹806 Pages. 3339
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.
Download >>
14. Identification and localization of radar impulses buried in noise A. G. Tyzhnenko, Y. V. Ryeznik radar, pulse, identification, localization, low SNR Vestnik KhNU ¹806 Pages. 7074
Statistical method identification and localization of radar impulses buried in noise is addressed. To this end, the correlation coefficient between carrier samples measured in the extremal points and analogous set of points of received signal is proposed to implement. Such measurements for receiving signal need to be done at least by one tenth of the half period of the carrier. Because of very simple algorithm proposed, such measurements do not lead to heavy computational burden. To decrease identification and localization errors for given signal to noise ratio (SNR) one needs to increase the number of measurements points, and hence, the pulse width. To prevent this issue, one can increase the carrier frequency. In general, the method accuracy increases with the carrier frequency. The method proposed permits theoretically to identify with fidelity impulses buried in noise for SNR lower than 30 dB.
Download >>
15. 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, threedimensional images, vacuumarc method, thin AlN films Vestnik KhNU ¹806 Pages. 99102
For the first time the digital holographic interference microscope (DHIM) was used for investigation of thin films on transparent substrates. Threedimensional images of AlN of thin films, deposited on acryl substrates by the vacuumarc 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.
Download >>
16. Increase of free volume 0f the aip abundant in the water by the millimeter waves of low intensity B. G. Yemets electromagnetic waves, air bubbles, field of temperature, convection Vestnik KhNU ¹806 Pages. 103106
Using an NMR technique the volume growth of the free ("bubble") air contained in water caused by lowintense electromagnetic waves is obtained. This change is caused by rectified diffusion of the dissolved air mass into bubbles. The increase in the free air may occure only under those conditions when there is no convection in the liquid, i. e. in the case of irradiating by means of lowintense waves.
Download >>
17. Subterahertz diffraction radiation on the BWO frequency harmonics in the parametrical tworegimes electron device E.N.Odarenko, A.A.Shmat’ko, P.V. Yudintcev diffraction radiation, SmithPurcell effect, subterahertz waves, beamwave interaction, nonlinear processes Vestnik KhNU ¹834 Pages. 1317
Diffraction radiation nonlinear theory that takes into account tworegimes interaction – selfconsistent regimes of the BWO and GDI on the BWO frequency harmonics is developed. The existence of the BWO generation regime on the first harmonic and parametric type diffraction radiation amplification regime on the BWO frequency harmonics is shown on the base of the selfconsistent equations set numerical solution. Ranges of the task parameters values that correspond to tworegimes interaction are defined
Download >>
18. 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 ¹834 Pages. 6367
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 crosssection by field with the previously calculated time dependence are considered . Numerical simulation of short impulse irradiation of layered medium with losses is carried out
Download >>
19. Pulse water insonification for laboratory research of electromagnetic wave propagation and dispersion in randomly inhomogeneous media in order to meet the conditions close to working ones V.B. Yuferov, A.N. Ponomarev, E.V. Mufel, A.N. Ozerov, I.V. Buravilov, V.N. Ishenko electromagnetic wave propagation, inhomogeneous medium, air bubbles in liquid, acoustic pulse pneumatic radiator Vestnik KhNU ¹834 Pages. 114119
The efficiency of pulse water insonification by pneumatic radiator is shown. Such radiator enables the formation above the water surface of hydrometcors and aerosols with a desired concentration. It is necessary for laboratory research of fluctuation phenomena of the electromagnetic wave propagation in randomly inhomogeneous media. The use of pneumatic radiator makes possible lo remove salt from the solution. This enables a certain degree of control over liquid permittivity
Download >>
20. Single cone with longitudinal slots excitation by an impulse point source A.V. Artyukh, y.A. Doroshenko, Y.D. Shimuk impulse source, cone, longitudinal slots, analytical solution, numerical solution Vestnik KhNU ¹853 Pages. 5156
In this work the excitation of a semiinfinite perfectly conducting cone with periodic longitudinal slots by an impulse radial source problem is investigated. The solution of the wellposed initialboundary problem is found using an analytically numerical method based upon Green function and MelerFock integral transforms applying. It is shown that the original electrodynamic problem is equivalent to the one of the Fredholm linear algebraic equations system of the second kind solving. Analytical view of the solution is derived and the graphs illustrating the field dependence on the aperture angle and angle slot width are presented
Download >>
21. 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 ¹853 Pages. 8894
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
Download >>
22. Random inhomogeneous liquid medium as a continuous laser of lowintensity 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 ¹853 Pages. 95100
When a medium is irradiated by laser pulses, sound waves are excited in this medium, i.e., the wellknown 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 (thermooptical 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
Download >>
23. Polarization and energy characteristics Xslots in the waveguide with the complex load and the dielectric inserts Blinova N.K., Yatsuk N.N., Selyutin A.V. Õslots , ellipse coefficient, VSWR level , circular polarization. Vestnik KhNU ¹966 Pages. 7781
The Õslots in a rectangular waveguide with the end complex loading and dielectric inhomogeneity at the waveguide input are considered. Calculation and experimental results of power and polarization descriptions are carried out for such systems. The possibilities of polarization and power characteristics of Õslot control are investigated. The variation of dielectric inhomogeneity and complex end loading parametors allows to obtain the circular polarization, high radiation coefficient and low VSWR level
Download >>
24. 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 ¹966 Pages. 3749
Mathematical models, computational algorithms, and also prospects of development and application of three new methods of recognition and classification (RÀC), 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.
Download >>
founded: 24 result (s)
