PL
 |
EN
Nowa wersja platformy, zawierająca wyłącznie zasoby pełnotekstowe, jest już dostępna.
Przejdź na https://bibliotekanauki.pl
Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 8

Liczba wyników na stronie
first rewind previous Strona / 1 next fast forward last
Wyniki wyszukiwania
Wyszukiwano:
w słowach kluczowych:  energy spectrum
help Sortuj według:

help Ogranicz wyniki do:
first rewind previous Strona / 1 next fast forward last
1
Content available remote Spectral characterization of hydrogen-like atoms confined by oscillating systems
100%
Iacob F.
Open Physics
|
2014
|
tom 12
|
nr 9
628-636
EN
The spectral characterization of Coulomb systems confined by a homogeneous pseudo-Gaussian oscillator is investigated. This is done using the efficient computational method of generating functionals. Also, this method is used for the spectral characterization of homogeneous harmonic oscillator confinement, treated as a particular case of pseudo-Gaussian oscillator confinement. Finally, confinement by an impenetrable sphere of finite radius is considered by studying its conjugate effect along with a harmonic oscillator.
2
Content available Standard deviation in the simulation of statistical measurements
100%
Przystupa K. , Kolodiy Z. , Yatsyshyn S. , Majewski J. , Khoma Y. , Petrovska I. , Lasarenko S. , Hut T.
Metrology and Measurement Systems
|
2023
|
tom Vol. 30, nr 1
17--30
EN
Is this article simulation of statistical measurements is performed on the basis of which the analysis of the standard deviation of the obtained results is carried out. It is shown that the standard deviation is minimum and independent from measurement duration while an object is in the state of equilibrium. For objects in a stationary non-equilibrium state the standard deviation depends on the duration measurements and the parameters of the state. The influence of these factors on the standard deviation is assessed with equation which includes the relaxation time. The value of the relaxation time is determined by approximating the energy spectrum of the studied signals. The analysis of energy spectra showed that the spectrum of white noise is inherent in objects in equilibrium; the flicker component of the spectrum occurs when the state of the object deviates from equilibrium.
3
Energy spectrum of turbulence in the gas-solid flow
88%
Poria S. , Mazumdar H. P.
Journal of Technical Physics
|
2007
|
tom Vol. 48, no 1
3-11
EN
In this paper, we have derived several self-preserving turbulence energy spectra for the case of a homogeneous, isotropic, particle-laden turbulent flow, assuming different forms for the energy transfer spectra, as those obtained from the general form for such a transfer spectrum due to TENNEKES [10] and YAGLOM [11]. All these self-preserving turbulence energy spectra are then analyzed from the view-point that the turbulence is affected by the particles in a homogeneous isotropic, particle-laden turbulent flow.
4
Content available remote Exact and approximate solutions to Schrödinger’s equation with decatic potentials
75%
Brandon D. , Saad N.
Open Physics
|
2013
|
tom 11
|
nr 3
279-290
EN
The one-dimensional Schrödinger’s equation is analysed with regard to the existence of exact solutions for decatic polynomial potentials. Under certain conditions on the potential’s parameters, we show that the decatic polynomial potential V (x) = ax 10 + bx 8 + cx 6 + dx 4 + ex 2, a > 0 is exactly solvable. By examining the polynomial solutions of certain linear differential equations with polynomial coefficients, the necessary and sufficient conditions for corresponding energy-dependent polynomial solutions are given in detail. It is also shown that these polynomials satisfy a four-term recurrence relation, whose real roots are the exact energy eigenvalues. Further, it is shown that these polynomials generate the eigenfunction solutions of the corresponding Schrödinger equation. Further analysis for arbitrary values of the potential parameters using the asymptotic iteration method is also presented.
5
Content available remote The application of sample and hold method in the processing of data obtained from a laser doppler anemometer
63%
Stelmach J. , Rzyski E.
International Journal of Applied Mechanics and Engineering
|
2002
|
tom Vol. 7, no 4
1291-1303
EN
Using a laser Doppler anemometer, liquid velocity was measured in the tank in which liquid was mixed by a self-aspirating disk impeller. The energy spectrum was the basis to determine the energy dissipation rate. This rate determines the size of eddies that are formed in the vicinity of the impeller. Results obtained by sample and hold method were compared with those obtained by other methods. An increase in the sampling frequency caused a decrease in the mean liquid velocity at the measuring point.
6
Content available remote Dirac-Kähler particle in Riemann spherical space : analytical and numerical study, visualization
63%
Chichurin A. V. , Ovsiyuk E. M. , Red’kov V. M.
Studia i Materiały / Europejska Uczelnia Informatyczno-Ekonomiczna w Warszawie
|
2015
|
tom Nr 1(9)
41--54
EN
Exact analytical solutions of the Dirac-Kähler equation for the case of the spherical Riemann space of constant positive curvature are constructed. For non-zero values of the total angular momentum, the radial equations are reduced to a pair of complicated fourth-order differential equations. Employing the factorization approach, we have found four independent fundamental solutions written in terms of combinations of the hypergeometric functions. The energy spectrum differs substantially from the energy spectrum of the Dirac particle in spherical Riemann space. The visualization of the constricted solution is performed. The involved 4-th order differential equations are solved numerically. Results of the numerical analysis are in good agreement with analytical study.
PL
Znaleziono rozwiązania analityczne równania Diraca-Kählera w przypadku przestrzeni sferycznej Riemanna o stałej dodatniej krzywiźnie. W przypadku niezerowych wartości kretu równania różniczkowe promieniowe przekształcają się do pary równan różniczkowych czwartego rzędu. Stosując metodę faktoryzacji, znaleziono jego cztery podstawowe niezależne rozwiazania, które zapisano jako kombinacje funkcji hipergeometrycznych. Wyznaczone widmo energii różni się znacznie od widma energii cząstki Diraca w sferycznej przestrzeni Riemanna. Wykonano wizualizację znalezionych rozwiazań. Równania różniczkowe czwartego rzędu są rozwiązywane numerycznie. Wyniki analizy numerycznej są zgodne z badaniami analitycznymi.
7
Content available Local Turbulent Energy Dissipation Rate in a Vessel Agitated by a Rushton Turbine
51%
Šulc R. , Pešava V. , Ditl P.
Chemical and Process Engineering
|
2015
|
tom Vol. 36, nr 2
135--149
EN
The scaling of turbulence characteristics such as turbulent fluctuation velocity, turbulent kinetic energy and turbulent energy dissipation rate was investigated in a mechanically agitated vessel 300 mm in inner diameter stirred by a Rushton turbine at high Reynolds numbers in the range 50 000 < Re < 100 000. The hydrodynamics and flow field was measured using 2-D TR PIV. The convective velocity formulas proposed by Antonia et al. (1980) and Van Doorn (1981) were tested. The turbulent energy dissipation rate estimated independently in both radial and axial directions using the one-dimensional approach was not found to be the same in each direction. Using the proposed correction, the values in both directions were found to be close to each other. The relation /(N3·D2)  const. was not conclusively confirmed.
8
Content available remote Parkinson disease detection using energy direction features based on EMD from voice signal
51%
Zhang T. , Zhang Y. , Sun H. , Shan H.
Biocybernetics and Biomedical Engineering
|
2021
|
tom Vol. 41, no. 1
127--141
EN
Voice disorders are one of the incipient symptoms of Parkinson's disease (PD). Recent studies have shown that approximately 90% of PD patients suffer from vocal disorders. Therefore, it is significant to extract pathological information on the voice signals to detect PD. In this paper, a feature, named energy direction features based on empirical mode decomposition (EDF-EMD), is proposed to show the different characteristics of voice signals between PD patients and healthy subjects. Firstly, the intrinsic mode functions (IMFs) were obtained through the decomposition of voice signals by EMD. Then, the EDF is obtained by calculating the directional derivatives of the energy spectrum of each IMFs. Finally, the performance of the proposed feature is verified on two different datasets: dataset-Sakar and dataset-CPPDD. The proposed approach shows the best average resulting accuracy of 96.54% on dataset-Sakar and 92.59% on dataset-CPPDD. The results demonstrate that the method proposed in this paper is promising in the field of PD detection.
first rewind previous Strona / 1 next fast forward last
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.