Перегляд Кафедра фізики за Назва
Зараз показано 1 - 20 з 177
Результатів на сторінку
- ДокументA method for determining the parameters of an optical system during the spatial scanning of a biological solution(Технический университет - София - Технологии, 2018) Rybalka, A. V.; Megel, Y. E.; Kalimanova, I. I.; Shlyakhov, V. V.; Kovalenko, S. I.; Kovalenko, S. N.In research, control of biological processes for determining the motility of microorganisms, (estimation of the impact of chemical compounds, electrophoretic mobility, evaluation of severity of pathology, etc.) using a scanning optoelectronic system as the most effective means of solving applied problems, it is necessary to determine the objects number in the optical system field of vision since the measurement accuracy of the solution concentration and the objects motion speed in the solution depend on their number. In the article a probabilistic method for estimation the number of objects and the number of frames during frame-by-frame filming for providing a given accuracy with a given probability is presented.
- ДокументAbsorption Spectra of Thin Films Compounds in the PbCl-CuCl System(Eskisehir Technical University, 2021) Kovalenko, E. N.; Yunakova, O. N.; Yunakov, N. N.
- ДокументAssessment of the effectiveness of laser-acoustic transformation(Technical University of Sofia, 2019) Rybalka, A. I.; Megel, Y. E.; Kalimanova, I.For some biotechnological technologies, there is a problem of separating living cells or destroying their membranes in order to obtain individual elements of the inner structure of the cell. This is usually done using microsurgical operations. In practice, the method of obtaining individual cell fragments without surgery using an acoustic wave is of interest. In this paper, a mathematical model and the results of modeling the process of the formation of an acoustic pressure wave in a liquid biological solution for the destruction of the membrane of a biological object is considered.
- ДокументAtomic Functions in Choi-Williams Analysis of the Ultrawideband Signals(2008) Lazorenko, O. V.Atomic functions (AF) and Kravchenko-Rvachev’s window functions based on them are proposed to be applied for the Choi-Williams analysis of the ultrawideband (UWB) signals. New class of the non-linear Choi-Williams-Rvachev transforms (ChWRT) is considered. The advantages and disadvantages of such transforms are discussed. The abilities of the ChWRT at the sample of the UWB signal model analysis are demonstrated.
- ДокументAutomation of measurement of objects geometrical parameters(Технический университет - София - Технологии, 2017) Rybalka, A.; Megel, Y.; Kalimanova, I.; Kovalenko, S.; Kovalenko, S.The issues of automation of measurement of the basic physical and geometrical parameters of biological object and possibility to obtain quantitative characteristics by optical methods are considered in the article. The prospects of the method of pattern recognition to distinguish the contour of the object in order to increase descriptiveness and precision measurement are shown.
- ДокументCattle breed identification and live weight evaluation the basis of machine learning and computer vision(Національний університет "Запорізька політехніка", 2020) Megel, Y. E.; Rudenko, O. G.; Bezsonov, O. O.; Rybalka, A. I.The problem of the cow’s live weight estimation is considered. A convolutional neural network based method for animal recognition and its breed identification in combination with epipolar geometry approach for object’s size measurement is proposed. Information regarding animal’s size and its breed is further used for LW estimation by multilayer perceptron based predictive model. This approach can be used to replace traditional methods of direct observation and measurement. The proposed system can be widely used in the management of a modern farm. Accuracy and performance of the proposed method has been tested with the participation of the experts.
- ДокументChoi-Williams Analysis of the Non-linear Ultrawideband Signals(2008) Chernogor, L. F.; Lazorenko, O. V.; Vishnivetskiy, O. V.Choi-Williams analysis application for the non-linear ultrawideband signal describing was proposed. The advantages and the peculiarities of Choi-Wiliiams transform were discussed. The non-linear ultrawideband signal models in time domain were given. The Choi-Williams analysis for the analysis of the non-linear ultrawideband signals was performed.
- ДокументDetection of "Wall Thinning" Type Defects in Pipelines by Thermal Method(Eskisehir Technical University, 2019) Orel, R. P.; Meshkov, S. M.; Storozhenko, V. O.; Myagkiy, O. V.A thermophysical model of a pipe with a local defect of the “wall thinning” type is developed. Calculations of thermal anomalies for pipelines with different parameters of hidden defects are performed, illustrating the possibility of using the thermal method of nondestructive testing. The conditions and methods of thermal control of individual sections of pipelines are specified. Thermal imaging examination of steam pipelines of the main condensate of the nuclear power plant was carried out. External factors that make it difficult to detect hidden defects (the influence of external lighting, cylindrical shape of controlled objects, powerful external heat sources) are analyzed. It was found that cavitation phenomena significantly increase the temperature drop in the locations of local defects. The possibility of using the thermal method of nondestructive testing for rapid detection of hidden defects such as “wall thinning” in the pipelines of the main condensate has been confirmed experimentally.
- ДокументDigital analysis of the non-linear ultrawideband processes(2007) Chernogor, L. F.; Lazorenko, O. V.; Lazorenko, S. V.; Vishnivetsky, O. V.The continuous wavelet transform, the analytical wavelet transform, the digital wavelet transform and the Wigner transform are proposed to apply for the digital analysis of the non-linear ultrawideband processes. The advantages and the disadvantages of each transform being significant during that application are discussed. As the convincing example, the results of the analysis of the Earth’s magnetic field disturbances caused by the rocket “Proton” launch taken place 12 February 2000 at cosmodrome Baikonur (Kazakhstan) are considered.
- ДокументDispersion of refractive index of thin films CdI2 and ZnI2(НТК “Інститут монокристалів” Національної академії наук України, 2010) Kovalenko, E. N.; Miloslavsky, V. K.; Yunakova, O. N.A dispersion of refractive index in thin films CdI2 and ZnI2 are measured in the interval of lengths waves 300-1000 nanometers, its processing with the help monooscillator model is in the good agreement with data of experiment. The optical inductivity of two compounds is determined by retrieved parameters of this model, this optical inductivity are utilised for the further analysis of excitons states in CdI2 and ZnI2, and, in particular, for determination of 1s excitons radius. The retrieved values аех are close to parameters of a unit cell of two compounds, that indicates a fitting of excitons in two compounds to excitons of intermediate electron - hole connection
- ДокументEffect of iodine impurity on the absorption spectrum and phase transitions in CsPbCl3 thin films(НТК “Інститут монокристалів” Національної академії наук України, 2018) Kovalenko, E. N.; Yunakova, O. N.; Yunakov, N. N.The absorption spectra of thin films of solid solutions CsPb(Cl1-xIx)3 0
- ДокументElectromagnetic lattice "invisibility" of the resonance cubic crystal made of magnetodielectric spheres(O. S. Popov Odesa National Academy of Telecommunications, 2013) Kozar, A. I.A solution and analysis of a problem on phenomenon of electromagnetic lattice "invisibility" og the limited resonance cubic crystal made of spheres are presented. The obtained results may be used when developing the devices wherein stealth technologies are employed.
- ДокументElectromagnetic lattice "invisibility" of the photon crystal made of magnetodielectric spheres in the form of octahedron(Eskisehir technical university, 2019) Kozar, A. I.Solution and analysis of a problem on electromagnetic lattice “invisibility” of the photon crystal made of magnetodielectric spheres in the form of octahedron with a cubic crystal lattice are presented.
- ДокументElectromagnetic lattice «invisibility» of the resonance cubic crystal made of magnetodielectric spheres(ХНУРЭ, 2017) Kozar, A. I.Solution and analysis of a problem on electromagnetic lattice «invisibility» of the resonance cubic crystal made of magnetodielectric spheres with a cubic crystal lattice are presented
- ДокументElectromagnetic wave scattering by pyramid-shaped photonic crystal from resonant magnetodielectric spheres(Eskisehir Technical University, 2021) Kozar, A. I.The solution of the problem of scattering electromagnetic waves with a discrete convex polyhedron - a pyramid of resonant magnetodielectric spheres based on a complex rhombic crystal lattice is presented.
- ДокументElectromagnetic Wave scattering in a waveguide containing homogeneous magnetodielectric spheres(New York, N.Y. Begell House, 2003) Kozar, A. I.A solution is suggested for the problem of electromagnetic wave scattering by an arbitrary number of small resonant-size spheres in a rectangular waveguide. Expressions have been derived for the scattered fields.
- ДокументElectromagnetic Wave scattering with special spatial lattices of magnetodielectric spheres(New York, N.Y. Begell House, 2004) Kozar, A. I.A problem solution of electromagnetic wave scattering with special compound lattices of resonance spheres has been considered, their spatial distribution has been subjected to a geometric progression. Expressions for the scattered fields have been obtained.
- ДокументElectronic Absorption Spectrum of Thin K2ZnI4 Films(2008) Yunakova, O. N.; Miloslavsky, V. K.; Kovalenko, E. N.The absorption spectrum of thin K2ZnI4 films has been investigated in the range of 3–6 eV at temperatures from 90 to 340 K. It is established that this compound belongs to direct-gap insulators; low-frequency exciton excitations are localized in the ZnI4 lattice layers and have a quasi-two-dimensional character. The spectral analysis revealed the existence of two K2ZnI4 modifications, which presumably belong to the monoclinic (I) and orthorhombic (II) phases. The temperature dependences of the spectral position and halfwidth of the low-frequency exciton band in K2ZnI4 revealed the existence of first-order phase transitions at 215 and 225 K in the monoclinic and orthorhombic phases, respectively.
- ДокументExciton absorption spectra of KPb2Br5 thin films(Institute for Single Crystals, 2016) Kovalenko, E. N.; Kovalenko, V. V.; Yunakova, O. N.; Yunakov, N. N.The absorption spectrum of KPb2Br5 thin film of tetragonal (I) and monoclinic (II) structures were investigated in the spectral region of 2-6 eV and the temperature range 90-440K. It was found that KPb2Br5 (I) of the tetragonal structure irreversibly becomes in KPb2Br5(II) of the monoclinic structure when T = 293 K. It is found that low-frequency exciton excitations of KPb2Br5 (I, II) are localized in the sublattice, which contains ions Pb2+, and its are two-dimensional nature.