Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "transforms" wg kryterium: Temat

  Lista filtrów

Dostawca treści

Wyrównaj
Wyświetlanie 1-50 z 54
Tytuł:
The Abel summation of the Kontorovich-Lebedev integral representation
Autorzy:
Cojuhari, P.A.
Gomilko, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/255109.pdf
Data publikacji:
2005
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
integral transforms
transforms of special functions
special functions
operational calculus
Kontorovich-Lebedev
Opis:
A new result on the summation of the Kontorovich-Lebedev integral representation in the sense of Abel mean is given.
Źródło:
Opuscula Mathematica; 2005, 25, 1; 101-107
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A two cones support theorem
Autorzy:
Estrada, R.
Powiązania:
https://bibliotekanauki.pl/articles/255211.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Radon transforms
support theorems
distributions
Opis:
We show that if the Radon transform of a distribution ƒ vanishes outside of an acute cone Co, the support of the distribution is contained in the union of Co and another acute cone C1, the cones are in a suitable position, and ƒ vanishes distributionally in the direction of the axis of C1, then actually supp ƒ C ⊂ Co. We show by examples that this result is sharp.
Źródło:
Opuscula Mathematica; 2016, 36, 2; 207-213
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convolution equations in the space of Laplace distributions
Autorzy:
Pliś, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1294292.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Laplace distributions
Laplace transforms
convolution equations
Opis:
A formal solution of a nonlinear equation P(D)u = g(u) in 2 variables is constructed using the Laplace transformation and a convolution equation. We assume some conditions on the characteristic set Char P.
Źródło:
Annales Polonici Mathematici; 1998, 69, 3; 271-281
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Poincaré theorem and nonlinear PDEs
Autorzy:
Pliś, Maria
Powiązania:
https://bibliotekanauki.pl/articles/1294309.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Laplace distributions
Laplace transforms
formal solutions
Opis:
A family of formal solutions of some type of nonlinear partial differential equations is found. Terms of such solutions are Laplace transforms of some Laplace distributions. The series of these distributions are locally finite.
Źródło:
Annales Polonici Mathematici; 1998, 69, 2; 99-105
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power system frequency estimation algorithm for electric energy metering of nonlinear loads
Autorzy:
Peng, Z.
Hong-Bin, L.
Powiązania:
https://bibliotekanauki.pl/articles/220639.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
frequency estimation
power systems
wavelet transforms
Opis:
In this paper, a discrete wavelet transform (DWT) based approach is proposed for power system frequency estimation. Unlike the existing frequency estimators mainly used for power system monitoring and control, the proposed approach is developed for fundamental frequency estimation in the field of energy metering of nonlinear loads. The characteristics of a nonlinear load is that the power signal is heavily distorted, composed of harmonics, inter-harmonics and corrupted by noise. The main idea is to predetermine a series of frequency points, and the mean value of two frequency points nearest to the power system frequency is accepted as the approximate solution. Firstly the input signal is modulated with a series of modulating signals, whose frequencies are those frequency points. Then the modulated signals are decomposed into individual frequency bands using DWT, and differences between the maximum and minimum wavelet coefficients in the lowest frequency band are calculated. Similarities among power system frequency and those frequency points are judged by the differences. Simulation results have proven high immunity to noise, harmonic and inter-harmonic interferences. The proposed method is applicable for real-time power system frequency estimation for electric energy measurement of nonlinear loads.
Źródło:
Metrology and Measurement Systems; 2012, 19, 2; 307-320
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The New Insight into the Theory of 2-D Complex and Quaternion Analytic Signals
Autorzy:
Snopek, K. M.
Powiązania:
https://bibliotekanauki.pl/articles/226235.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
2-D Fourier transform
quaternion Fourier transforms
2-D Hilbert transforms
2-D analytic signals
Opis:
The paper presents the overview of the theory of 2-D complex and quaternion analytic signals with the 1st-quadrant spectrum support. Both signals are expressed as complex/hypercomplex sums of partial and total 2-D Hilbert transforms. Moreover, starting with the definition of 2-D complex and quaternion Fourier transforms, the 2-D Hilbert transforms are derived in the form of sums of parts of different parity with respect to signal-domain variables. Some new relations for Hilbert quaternion spectra have been derived. The paper is illustrated with the example of the 2-D separable Cauchy signal.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 3; 285-291
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of information on sleep apnoea contained in two symmetric EEG recordings
Autorzy:
Prucnal, Monika A.
Polak, Adam G.
Powiązania:
https://bibliotekanauki.pl/articles/220736.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sleep apnoea detection
EEG signal
discrete wavelet transforms
Hilbert transforms
analysis of variance
multivariate regression analysis
Opis:
Electroencephalogram (EEG) is one of biomedical signals measured during all-night polysomnography to diagnose sleep disorders, including sleep apnoea. Usually two central EEG channels (C3-A2 and C4-A1) are recorded, but typically only one of them are used. The purpose of this work was to compare discriminative features characterizing normal breathing, as well as obstructive and central sleep apneas derived from these central EEG channels. The same methodology of feature extraction and selection was applied separately for the both synchronous signals. The features were extracted by combined discrete wavelet and Hilbert transforms. Afterwards, the statistical indexes were calculated and the features were selected using the analysis of variance and multivariate regression. According to the obtained results, there is a partial difference in information contained in the EEG signals carried by C3-A2 and C4-A1 EEG channels, so data from the both channels should be preferably used together for automatic sleep apnoea detection and differentiation.
Źródło:
Metrology and Measurement Systems; 2019, 26, 2; 229-239
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abel means of operator-valued processes
Autorzy:
Blower, G.
Powiązania:
https://bibliotekanauki.pl/articles/1288981.pdf
Data publikacji:
1995
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Abel means
martingale transforms
subadditive ergodic theory
Opis:
Let $(X_j)$ be a sequence of independent identically distributed random operators on a Banach space. We obtain necessary and sufficient conditions for the Abel means of $X_n...X_2 X_1$ to belong to Hardy and Lipschitz spaces a.s. We also obtain necessary and sufficient conditions on the Fourier coefficients of random Taylor series with bounded martingale coefficients to belong to Lipschitz and Bergman spaces.
Źródło:
Studia Mathematica; 1995, 115, 3; 261-276
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Detecting epileptogenesis in power variant domains
Autorzy:
Lewis, R. A.
Parks, B.
Shmueli, D.
Capinst, S.
Powiązania:
https://bibliotekanauki.pl/articles/206373.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
intracortical electroencephalograms automata
epilepsy
Fourier transforms
rough sets
Opis:
This paper presents the merging of two sets of experiments in the continuing endeavor to mine epileptiform activity from Electroencephalograms (EEG). The goal is to develop robust classification rules for identifying epileptiform activity in the human brain. We present advancements using the author's proprietary developed spectral analysis software to link power spectra of rat EEGs experiencing epilepsy seizures with the authors DFA algorithm and their MATLAB spectral analysis. Our system links 1) power spectra of seizures, in sleep, spike and seizure states, with 2) Deterministic Finite Automata (DFA). Combining power spectra with DFA to correctly predict and identify epileptiform activity (spikes) and epileptic seizures opens the door to creating classifiers for seizures. We also present a DFA that separates the states between seizure and nonseizure using robust testing and additional algorithms to increase the rigor when the methodology analyses noisy signals. Our results show optimal identification of seizures even when significant artifact and noise is present in the polyphonic domain. Herein we present a dual methodology that increases epileptoid identification in a noisy domain that links time and frequency domain components from MATLAB and proprietary software to clinical epileptiform activity.
Źródło:
Control and Cybernetics; 2011, 40, 2; 293-314
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response due to mechanical source in second axisymmetric problem of micropolar elastic medium
Autorzy:
Singh, R.
Powiązania:
https://bibliotekanauki.pl/articles/955263.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
transformata Laplace'a
siła skupiona
sprężystość
eigenvalue
micropolar elastic medium
Laplace transforms
Hankel transforms
concentrated force
microrotation
Rhomberg’s integration
Opis:
The second axisymmetric problem in a micropolar elastic medium has been investigated by employing an eigen value approach after applying the Laplace and the Hankel transforms. An example of infinite space with concentrated force at the origin has been presented to illustrate the application of the approach. The integral transforms have been inversed by using a numerical technique to obtain the components of microrotation, displacement, force stress and couple stress in the physical domain. The results for these quantities are given and illustratred graphically.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 4; 1249-1261
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Natural frequency and critical velocities of heated inclined pinned PP-R pipe conveying fluid
Autorzy:
Mohmmed, J. H.
Tawfik, M. A.
Atiyah, Q. A.
Powiązania:
https://bibliotekanauki.pl/articles/1818780.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
finite Fourier sine transforms
Laplace transforms
natural frequency
inclined pipe conveying fluid
transformacja Fouriera
transformacja Laplace'a
częstotliwości drgań własnych
Opis:
Purpose: The flow velocity and pressure of fluid flowing through a pipeline can cause the vibration of pipes, and consequently result in the modification in natural frequency via fluid-structure interaction. The value of the natural frequency of a component when approaches the excitation force to a certain degree, a severe resonance failure may occur. Hence, avoiding the resonance failure of a pipe subjected to complex conditions is an essential issue that requires to be solved urgently in the engineering field. This work treats the transverse vibration for flexible inclined heated pipe, made of polypropylene randomcopolymer (PP-R), conveying fluid assuming pinned connections at the ends. The pipe was placed at different support angles and subjected to variant temperatures. Design/methodology/approach: The inclined pipe is modelled as Euler-Bernoulli beam taking into account its self-weight, temperature variation, inclination angle, aspect ratio, and internal fluid velocity. The integral transforms method, which includes the finite Fourier sine and the Laplace transforms, was used to develop an analytic solution to the modified equation of motion and the analytical expressions for dual natural frequencies of the pipefluid interaction system were computed. Findings: The proposed solution technique via finite Fourier sine and Laplace transforms offers a more convenient alternative to calculate the dynamic characteristic of pipes conveying fluid. The obtained results showed that the dynamical behaviour of pipe–fluid system is strongly affected by fluid flow velocity, degree of inclination, temperature variation, and aspect ratio of the pipe in transverse modes. Research limitations/implications: This work focuses on fundamental (first) mode in the most discussions. Practical implications: It was revealed that the thermal effects in the pipe are a very important factor and more significant in comparison with the internal fluid velocity and the inclination angle has a larger impact on vibration characteristics at a higher aspect ratio. The findings can be useful for the design of engineering components. Originality/value: Determining the combining effect of inclination angle, aspect ratio, and thermal loading on vibration characteristic of the pipes conveying fluid by using an improved analytic solution to the modified equation of motion via mixed of finite Fourier sine and Laplace transforms.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2021, 107, 1; 15--27
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Induction motor fault classification via entropy and column correlation features of 2D represented vibration data
Autorzy:
Basaran, Murat
Fidan, Mehmet
Powiązania:
https://bibliotekanauki.pl/articles/1841827.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
entropy
fault diagnosis
support vector machines
wavelet transforms
Opis:
Due to long-term use under challenging conditions, the sub-elements of induction motors may suffer certain defects over time. Such defects impair the vibration characteristics of the motors in different ways, depending on the type of defect. Therefore, the change in vibration characteristic provides indicators about the fault type and can be used in preventive maintenance strategies to ensure safe operation of the system. In this work, discrete-time vibration data were transformed into 2-dimensional grey-level images and decomposed into individual components by the Wavelet decomposition method. Features based on entropy and column correlation were extracted from these components and used to classify motor faults by using the Support Vector Machine method implemented by using the Sequential Minimal Optimisation algorithm. When the selected classifier is compared with other popular Machine Learning algorithms, it is observed that motor faults are more successfully classified, and these observations are presented in detail with comparative classification performance results.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 132-142
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of fundamental solutions to fractional diffusion-wave equation in polar coordinates
Autorzy:
Povstenko, Y.
Powiązania:
https://bibliotekanauki.pl/articles/121886.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Humanistyczno-Przyrodniczy im. Jana Długosza w Częstochowie. Wydawnictwo Uczelniane
Tematy:
równanie ułamkowe
problem Cauchy'ego
transformaty Laplace'a
transformata Hankela
fractional equations
Cauchy problem
Laplace transforms
Hankel and Laplace transforms
Opis:
The diffusion-wave equation is a mathematical model of a wide range of important physical phenomena. The first and second Cauchy problems and the source problem for the diffusion-wave equation are considered in cylindrical coordinates. The Caputo fractional derivative is used. The Laplace and Hankel transforms are employed. The results are illustrated graphically.
Źródło:
Scientific Issues of Jan Długosz University in Częstochowa. Mathematics; 2009, 14; 97-104
2450-9302
Pojawia się w:
Scientific Issues of Jan Długosz University in Częstochowa. Mathematics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The elasticity problem for a stratified semi-infinite medium containing a penny-shaped crack filled with a gas
Zagadnienie półnieskończonego uwarstwionego ośrodka sprężystego zawierającego szczelinę kołową wypełnioną gazem
Autorzy:
Monastyrskyy, B.
Kaczyński, A.
Powiązania:
https://bibliotekanauki.pl/articles/386663.pdf
Data publikacji:
2007
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
sprężystość
naprężenie
transformacja Hankela
stress intensity
elasticity
Hankel transforms
Opis:
This paper deals with a periodic two-layered elastic half-space weakened by an interface penny-shaped crack tilled with a gas. The study is based on the approximate treatment by using the linear elasticity with microlocal parameters in the axisymmetric case. Applying the Hankel integral transforms, we obtain a system of dual integral equations. It is reduced to a set of two integral equations which are solved numerically. Some results concerning the variation of the internal gas pressure and the stress intensity factors of mode I and mode II are illustrated graphically.
Niniejsza praca poświęcona jest zagadnieniu periodycznej dwuwarstwowej półprzestrzeni sprężystej osłabionej międzywarstwową szczeliną kołową wypełnioną gazem. Zastosowano przybliżone podejście oparte na liniowej teorii sprężystości z parametrami mikrolokalnymi w osiowo-symetrycznym przypadku. Używając transformacji Hankela, otrzymano układ dualnych równań całkowych, który sprowadzono do numerycznego rozwiązania równań całkowych. Zależności dotyczące wewnętrznego ciśnienia gazu i współczynników intensywności naprężeń zilustrowano graficznie.
Źródło:
Acta Mechanica et Automatica; 2007, 1, 1; 63-66
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On Derivation of Discrete Time Fourier Transform from Its Continuous Counterpart
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/227150.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sampling of signals
discrete time
continuous time
Fourier transforms
Opis:
This paper is devoted to some problems that appear in derivations of the discrete time Fourier transform from a formula for its continuous time counterpart for transformation from the time into the frequency domain as well as to those regarding transformation in the inverse direction. In particular, the latter ones remained so far an unresolved problem. It is solved for the first time here. Many detailed explanations accompanying the solution found are presented. Finally, it is also worth noting that our derivations do not exploit any of such sophisticated mathematical tools as the so-called Dirac delta and Dirac comb.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 2; 355-360
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seminormal systems of operators in Clifford environments
Autorzy:
Mircea, M.
Powiązania:
https://bibliotekanauki.pl/articles/255159.pdf
Data publikacji:
2017
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
multidimensional operator theory
joint seminormality
Riesz transforms
Putnam inequality
Opis:
The primary goal of our article is to implement some standard spin geometry techniques related to the study of Dirac and Laplace operators on Dirac vector bundles into the multidimensional theory of Hilbert space operators. The transition from spin geometry to operator theory relies on the use of Clifford environments, which essentially are Clifford algebra augmentations of unital complex C*-algebras that enable one to set up counterparts of the geometric Bochner-Weitzenbock and Bochner-Kodaira-Nakano curvature identities for systems of elements of a C*-algebra. The so derived self-commutator identities in conjunction with Bochner’s method provide a natural motivation for the definitions of several types of seminormal systems of operators. As part of their study, we single out certain spectral properties, introduce and analyze a singular integral model that involves Riesz transforms, and prove some self-commutator inequalities.
Źródło:
Opuscula Mathematica; 2017, 37, 1; 81-107
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Układ sortujący obiekty na podstawie rozpoznawania kształtów
System sorting objects on the base of shape recognition
Autorzy:
Sokołowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/316897.pdf
Data publikacji:
2013
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
transformacja Fouriera
układ sortujący obiekty
Fourier transforms
object sorting system
Opis:
W pracy przedstawiony został projekt urządzenia sortującego obiekty na podstawie ich kształtu. Proces sortowania odbywa się z wykorzystaniem wybranych transformacji całkowych, tutaj z wykorzystaniem transformacji Fouriera. Urządzenie sterowane jest z wykorzystaniem systemu ekspertowego.
There is presented object sorting system in the paper. System is working on the base of shapes recognition. Sorting process is taking place with use of integral transformations, here with help of Fourier transforms. The device is controlled with help of expert system.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2013, 14, 3; 1269-1273
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A radial version of the Kontorovich-Lebedev transform in the unit ball
Autorzy:
Yakubovich, S. B.
Vieira, N.
Powiązania:
https://bibliotekanauki.pl/articles/255671.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Kontorovich-Lebedev transform
modified Bessel function
index transforms
Fourier integrals
Opis:
In this paper we introduce a radial version of the Kontorovich-Lebedev transform in the unit ball. Mapping properties and an inversion formula are proved in Lp.
Źródło:
Opuscula Mathematica; 2011, 31, 1; 137-146
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Eigen value approach to two dimensional problem in generalized magneto micropolar thermoelastic medium with rotation effect
Autorzy:
Singh, R.
Kumar, V.
Powiązania:
https://bibliotekanauki.pl/articles/265881.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
termosprężystość
elastyczność
transformacje całkowe
magneto micropolar
thermoelasticity
eigenvalue
elasticity
integral transforms
Opis:
In this study an eigen value approach has been employed to examine the mechanical force applied along with a transverse magnetic field in a two dimensional generalized magneto micropolar thermoelastic infinite space. Results have been obtained by treating rotational velocity to be invariant. Integral transforms have been applied to solve the system of partial differential equations. Components of displacement, normal stress, tangential couple stress, temperature distribution, electric field and magnetic field have been obtained in the transformed domain. Finally numerical inversion technique has been used to invert the result in the physical domain. Graphical analysis has been done to described the study.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 1; 205-219
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Riesz means of Fourier transforms and Fourier series on Hardy spaces
Autorzy:
Weisz, Ferenc
Powiązania:
https://bibliotekanauki.pl/articles/1217804.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Hardy spaces
p-atom
atomic decomposition
interpolation
Fourier transforms
Riesz means
Opis:
Elementary estimates for the Riesz kernel and for its derivative are given. Using these we show that the maximal operator of the Riesz means of a tempered distribution is bounded from $H_p(ℝ)$ to $L_p(ℝ)$ (1/(α+1) < p < ∞) and is of weak type (1,1), where $H_p(ℝ)$ is the classical Hardy space. As a consequence we deduce that the Riesz means of a function $⨍ ∈ L_1(ℝ)$ converge a.e. to ⨍. Moreover, we prove that the Riesz means are uniformly bounded on $H_p(ℝ)$ whenever 1/(α+1) < p < ∞. Thus, in case $⨍ ∈ H_p(ℝ)$, the Riesz means converge to ⨍ in $H_p(ℝ)$ norm (1/(α+1) < p < ∞). The same results are proved for the conjugate Riesz means and for Fourier series of distributions.
Źródło:
Studia Mathematica; 1998, 131, 3; 253-270
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel tool for Non Destructive Testing using frequency analysis of IR image sequences
Autorzy:
Więcek, P.
Strąkowska, M.
Powiązania:
https://bibliotekanauki.pl/articles/114539.pdf
Data publikacji:
2015
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
IR thermography
wavelet
Fourier
short-time Fourier transforms
functional thermal imaging
Opis:
In this paper, a novel methodology and a software tool for advanced image processing of thermal image sequences are presented. The software implements 1-D Fourier, short-time Fourier and wavelet transforms. The tool uses temperature variation in time for each pixel in the sequence of IR images. It is dedicated to Non Destructive Testing (NDT) testing and the functional time-dependent thermal imaging, e.g. for screening in medical diagnosis. The overall methodology is based on 2-stage analysis. The first, preliminary one is to estimate the right scale/frequency and the moment in time for the final frequency analysis. It can simplify characterization of materials and detection of cracks and defects.
Źródło:
Measurement Automation Monitoring; 2015, 61, 6; 219-222
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
R peak determination using a WDFR algorithm and Adaptive threshold
Autorzy:
Nguyen, Thanh-Nghia
Nguyen, Thanh-Hai
Ngo, Ba-Viet
Powiązania:
https://bibliotekanauki.pl/articles/38437166.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Promocji Wiedzy
Tematy:
ECG signal
wavelet transforms
WDFR algorithm
R peak determination
adaptive threshold
Opis:
The determination of the R peak position in the ECG signal helps physicians not only to know the heart rate per minute, but also to monitor the patient’s health related to heart disease. This paper proposes a system to accurately determine the R peak position in the ECG signal. The system consists of a pre-processing block for filtering out noise using a WDFR algorithm and highlighting the amplitude of the R peak and a threshold value is calculated for determining the R peak. In this research, the MIT-BIH ECG dataset with 48 records are used for evaluation of the system. The results of the SEN, +P, DER and ACC parameters related to the system quality are 99.70%, 99.59%, 0.70% and 99.31%, respectively. The obtained performance of the proposed R peak position determination system is very high and can be applied to determine the R peak of the ECG signal measuring devices in practice.
Źródło:
Applied Computer Science; 2022, 18, 3; 19-30
1895-3735
2353-6977
Pojawia się w:
Applied Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Riesz-Laplace Wavelet Transform and PCNN Based Image Fusion
Autorzy:
Sun, Shuifa
Tang, Yongheng
Mei, Zhoujunshen
Yang, Min
Tang, Tinglong
Wu, Yirong
Powiązania:
https://bibliotekanauki.pl/articles/2204258.pdf
Data publikacji:
2023
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Instytut Informatyki Technicznej
Tematy:
image fusion
Riesz transforms
polyharmonic spline
Laplacian wavelet
pulse-coupled neural networks
PCNN
Opis:
Important information perceived by human vision comes from the low-level features of the image, which can be extracted by the Riesz transform. In this study, we propose a Riesz transform based approach to image fusion. The image to be fused is first decomposed using the Riesz transform. Then the image sequence obtained in the Riesz transform domain is subjected to the Laplacian wavelet transform based on the fractional Laplacian operators and the multi-harmonic splines. After Laplacian wavelet transform, the image representations have directional and multi-resolution characteristics. Finally, image fusion is performed, leveraging Riesz-Laplace wavelet analysis and the global coupling characteristics of pulse coupled neural network (PCNN). The proposed approach has been tested in several application scenarios, such as multi-focus imaging, medical imaging, remote sensing full-color imaging, and multi-spectral imaging. Compared with conventional methods, the proposed approach demonstrates superior performance on visual effects, contrast, clarity, and the overall efficiency.
Źródło:
Machine Graphics & Vision; 2023, 32, 1; 73--84
1230-0535
2720-250X
Pojawia się w:
Machine Graphics & Vision
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Fast Classification Method of Faults in Power Electronic Circuits Based on Support Vector Machines
Autorzy:
Cui, J.
Shi, G.
Gong, C.
Powiązania:
https://bibliotekanauki.pl/articles/220922.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
power electronics
fault diagnosis
wavelet transforms
support vector machines
directed acyclic graph
nearest neighbours
Opis:
Fault detection and location are important and front-end tasks in assuring the reliability of power electronic circuits. In essence, both tasks can be considered as the classification problem. This paper presents a fast fault classification method for power electronic circuits by using the support vector machine (SVM) as a classifier and the wavelet transform as a feature extraction technique. Using one-against-rest SVM and one-against-one SVM are two general approaches to fault classification in power electronic circuits. However, these methods have a high computational complexity, therefore in this design we employ a directed acyclic graph (DAG) SVM to implement the fault classification. The DAG SVM is close to the one-against-one SVM regarding its classification performance, but it is much faster. Moreover, in the presented approach, the DAG SVM is improved by introducing the method of Knearest neighbours to reduce some computations, so that the classification time can be further reduced. A rectifier and an inverter are demonstrated to prove effectiveness of the presented design.
Źródło:
Metrology and Measurement Systems; 2017, 24, 4; 701-720
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Option pricing by Esscher transforms in the cases of normal inverse Gaussian and variance gamma processes
Autorzy:
Troush, N. N.
Kuzmina, A. V.
Powiązania:
https://bibliotekanauki.pl/articles/92926.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Przyrodniczo-Humanistyczny w Siedlcach
Tematy:
Esscher transforms
option pricing
generalized hyperbolic process
normal inverse Gaussian process
variance gamma process
Opis:
The class of Esscher transforms is an important tool for option pricing Gerber and Shiu (1994) showed that the Esscher transform is an efficient technique for valuing derivative securities if the log returns of the underlying securities are governed by certain stochastic processes with stationary and independent increments. Levy processes are the processes of such type. Special cases of the Levy processes such as the normal inverse Gaussian process and the variance gamma process are considered at this paper. Values of these processes parameters for the existence of Esscher transform are deduced. A new algorithm of a normal inverse Gaussian process and variance gamma process simulation is also presented in this paper. These algorithm is universal and simpler one compared with analogous algorithms.
Źródło:
Studia Informatica : systems and information technology; 2012, 1-2(16); 35-43
1731-2264
Pojawia się w:
Studia Informatica : systems and information technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A double index transform with a product of Macdonalds functions revisited
Autorzy:
Yakubovich, S. B.
Powiązania:
https://bibliotekanauki.pl/articles/255241.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Macdonald function
index transforms
Kontorovich-Lebedev transform
double Mellin transform
Plancherel theorem
Parseval equality
Opis:
We prove an inversion theorem for a double index transform, which is associated with the product of Macdonald's functions Kiτ (√x(2)+y(2)-y) Kiτ (√ x(2)+y(2)+y), where (x, y) ∈ R(+) x R(+) and iτ, τ ∈ R(+) is a pure imaginary index. The results obtained in the sequel are applied to find particular solutions of integral equations involving the square and the cube of the Macdonald function K(iτ) (t) as a kernel.
Źródło:
Opuscula Mathematica; 2009, 29, 3; 313-329
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Digital image watermarking using fast parametric transforms
Autorzy:
Lipinski, P.
Puchala, D.
Powiązania:
https://bibliotekanauki.pl/articles/201352.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
watermarking of digital images
fast parametric transforms
znak wodny obrazów cyfrowych
szybkie transformacje parametryczne
Opis:
This paper proposes a novel method for digital image watermarking, in which watermarks are embedded in the domain of fast para-metric transforms based on known spread spectrum approaches. Fast parametric transforms have the ability to adapt the forms of base vectors, which enables automatic selection of the domain of watermarking in relation to the pair: a marked image – a watermarking attack. The process of adapting the forms of fast parametric transforms is carried out with aid of the classical genetic algorithm with the fitting function based on the known measure of separability of watermarks. The effectiveness of the proposed method has been verified experimentally on the basis of the images of two classes, i.e. natural images and technical diagrams. The results taking into account both the efficiency of watermark embedding and the generated distortions in the marked images are summarized in tables and accompanied by an appropriate commentary.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2019, 67, 3; 463-477
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of a z-transforms method for investigation of Markov G-networks
Autorzy:
Matalytski, M.
Naumenko, V.
Powiązania:
https://bibliotekanauki.pl/articles/122773.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
open G-network
positive and negative messages
expected incomes
z-transforms method
dochody oczekiwane
Opis:
The purpose of this research paper is to find the expected incomes in open Markov queueing networks with incomes, positive and negative messages at any time by the multidimensional transformations. Investigations were carried out in cases when incomes from the network transitions between the states are deterministic functions not dependent on network states and time. It is assumed that all network systems are one-line. It was proved the theorem on the expression for the multidimensional z-transform. An algorithm was proposed for calculation of expected incomes. It is calculated an example on the PC.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2014, 13, 1; 61-73
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-analytic approach to calculating the Strehl ratio for a circularly symmetric system. Part 1: static wavefront
Autorzy:
Castaño-Fernandez, A. B.
Martínez-Finkelshtein, A.
Iskander, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/174316.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image quality assessment
optical transfer function
mathematical methods in physics
finite analogs of Fourier transforms
Opis:
Close-form expression for the Strehl ratio calculated in the spatial frequency domain of the optical transfer function (SOTF) is considered for the case of an optical system that has circular symmetry. First, it is proved that the SOTF for the aberration-free diffraction limited optical system is equal to one. Further, a semi-analytic solution for the SOTF for a system described by the second (defocus) and the fourth (spherical) order aberrations is provided. It is shown that the proposed semi-analytical solution is of an order of a magnitude computationally more efficient than the commonly used approach based on the discrete Fourier transformation.
Źródło:
Optica Applicata; 2018, 48, 2; 201-210
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signal reconstruction from given phase of the Fourier transform using Fejér monotone methods
Autorzy:
Schott, Dieter
Powiązania:
https://bibliotekanauki.pl/articles/729265.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
signal reconstruction
convex feasibility problem
projection onto convex sets
Fejér monotone iterative methods
Fourier transforms
Opis:
The aim is to reconstruct a signal function x ∈ L₂ if the phase of the Fourier transform [x̂] and some additional a-priori information of convex type are known. The problem can be described as a convex feasibility problem. We solve this problem by different Fejér monotone iterative methods comparing the results and discussing the choice of relaxation parameters. Since the a-priori information is partly related to the spectral space the Fourier transform and its inverse have to be applied in each iterative step numerically realized by FFT techniques. The computation uses MATLAB routines.
Źródło:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization; 2000, 20, 1; 27-40
1509-9407
Pojawia się w:
Discussiones Mathematicae, Differential Inclusions, Control and Optimization
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Joint compression and encryption of visual data using orthogonal parametric transforms
Autorzy:
Puchala, D.
Yatsymirskyy, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/201442.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
data encryption
parametric linear transforms
lossy data compression
szyfrowanie danych
parametryczne transformacje liniowe
kompresja danych
Opis:
In this paper, we introduce a novel method of joint compression and encryption of visual data. In the proposed approach the compression stage is based on block quantization while the encryption uses fast parametric orthogonal transforms of arbitrary forms in combination with a novel scheme of intra-block mixing of data vectors. Theoretical analysis of the method indicates no impact of encryption stage on the effectiveness of block quantization with an additional step of first order entropy coding. Moreover, a series of experimental studies involving natural images and JPEG lossy compression standard were performed. Here, the obtained results indicate a high level of visual content concealment with only a small reduction of compression performance. An additional analysis of security allows to state that the proposed method is resistant to cryptanalytic attacks known for visual data encryption schemes including the most efficient NZCA attack. The proposed method can be also characterized by high computational efficiency and feasibility of hardware realizations.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 2; 373-382
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal disturbances in twinned orthotropic thermoelastic material
Autorzy:
Rani, L.
Singh, V.
Powiązania:
https://bibliotekanauki.pl/articles/265550.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
termoelastyczność
transformaty Fouriera
czas relaksacji
generalized thermoelasticity
orthotropic material
relaxation time
Fourier transforms
instantaneous loading
Opis:
This paper deals with deformation in homogeneous, thermally conducting, single-crystal orthotropic twins, bounded symmetrically along a plane containing only one common crystallographic axis. The Fourier transforms technique is applied to basic equations to form a vector matrix differential equation, which is then solved by the eigen value approach. The solution obtained is applied to specific problems of an orthotropic twin crystal subjected to triangular loading. The components of displacement, stresses and temperature distribution so obtained in the physical domain are computed numerically. A numerical inversion technique has been used to obtain the components in the physical domain. Particular cases as quasi-static thermo-elastic and static thermoelastic as well as special cases are also discussed in the context of the problem.
Źródło:
International Journal of Applied Mechanics and Engineering; 2018, 23, 4; 897-910
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Essential norm estimates for multilinear singular and fractional integrals
Autorzy:
Meskhi, Alexander
Powiązania:
https://bibliotekanauki.pl/articles/1912838.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Matematyczne
Tematy:
Multilinear Hilbert and Riesz transforms
multilinear fractional integrals
measure of noncompactness
weighted inequalities
Banach function lattices
Opis:
We derive lower two-weight estimates for the essential norm (measure of noncompactness) for multilinear Hilbert and Riesz transforms, and Riesz potential operators in Banach function lattices. As a corollary we have appropriate results in weighted Lebesgue spaces. From these statements we conclude that there is no \((m+1)\)-tuple of weights \((v,w_1, \dots, w_m)\) for which these operators are compact from \(L^{p_1}_{w_1} \times \dots \times L^{p_m}_{w_m}\) to \(L^q_v\).
Źródło:
Commentationes Mathematicae; 2019, 59, 1-2
0373-8299
Pojawia się w:
Commentationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of the automatic control system of pumping station for urban water supply
Rozwój automatycznych systemów sterowania stacją pomp zasilającą miasto w wodę
Autorzy:
Pistun, E.
Yakymchuk, N.
Powiązania:
https://bibliotekanauki.pl/articles/408422.pdf
Data publikacji:
2014
Wydawca:
Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej
Tematy:
water resources
wavelet transforms
fuzzy control
adaptive systems
zasoby wodne
transformata falkowa
sterowanie rozmyte
systemy adaptacyjne
Opis:
The analysis of the automatic control of water intake area of the pumping station, which is based on a controller with fuzzy logic and systematization using seasonally and hourly water consumption by using wavelet transforms.
Analiza automatycznej kontroli poboru wody pompowni, opartej jest na regulatorze rozmytym i systematyzacji na podstawie sezonowego i godzinowego zużycia wody z wykorzystaniem transformaty falkowej.
Źródło:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2014, 2; 68-71
2083-0157
2391-6761
Pojawia się w:
Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finitely additive functions in measure theory and applications
Autorzy:
Alpay, Daniel
Jorgensen, Palle
Powiązania:
https://bibliotekanauki.pl/articles/29519748.pdf
Data publikacji:
2024
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Hilbert space
reproducing kernel
probability space
Gaussian field
transforms
covariance
Itô integration
Itô calculus
generalized Brownian motion
Opis:
In this paper, we consider, and make precise, a certain extension of the Radon–Nikodym derivative operator, to functions which are additive, but not necessarily sigma-additive, on a subset of a given sigma-algebra. We give applications to probability theory; in particular, to the study of μ-Brownian motion, to stochastic calculus via generalized Itô-integrals, and their adjoints (in the form of generalized stochastic derivatives), to systems of transition probability operators indexed by families of measures μ, and to adjoints of composition operators.
Źródło:
Opuscula Mathematica; 2024, 44, 3; 323-339
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A semi-analytic approach to calculating the Strehl ratio for a circularly symmetric system.Part 2: dynamic wavefront
Autorzy:
Castaño-Fernandez, A. B.
Martínez-Finkelshtein, A.
Iskander, D. R.
Powiązania:
https://bibliotekanauki.pl/articles/173593.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
image quality assessment
optical transfer function
longitudinal vibrations
mathematical methods in physics
finite analogs of Fourier transforms
Opis:
Close-form expression for the Strehl ratio calculated in the spatial frequency domain of the optical transfer function (SOTF) is considered for the case of time-varying dynamic optical system that has circular symmetry. Specifically, closed-form expressions for the temporally averaged SOTF are considered, which can be easily evaluated numerically (what we call a semi-analytic solution). As for the case of a static wavefront, described in Part 1 of this work, it is shown that the proposed methods are computationally more efficient than the commonly used approach based on the discrete Fourier transform.
Źródło:
Optica Applicata; 2018, 48, 2; 211-223
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some practical applications of generating functions and LSTS
Autorzy:
Ziółkowski, M.
Powiązania:
https://bibliotekanauki.pl/articles/122043.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Humanistyczno-Przyrodniczy im. Jana Długosza w Częstochowie. Wydawnictwo Uczelniane
Tematy:
matematyka stosowana
teoria kolejkowania
transformata Laplace'a-Stieltjesa
transformaty Laplace'a
applied mathematics
queuing theory
Laplace transforms
Opis:
In many various practical problems we often deal with computing distribution functions of sums of independent non-negative random variables. In applied mathematics (ex. queueing theory) we can find many formulas with Stieltjes convolutions of distribution functions of random variables of the same type. Finding convolutions on the base of definition is not easy and convenient, because there are some technical problems connected with computations. There are some interesting ways to obtain such distribution functions applying other methods. In this paper we present methods connected with applications of generating functions and Laplace-Stieltjes transforms.
Źródło:
Scientific Issues of Jan Długosz University in Częstochowa. Mathematics; 2012, 17; 97-110
2450-9302
Pojawia się w:
Scientific Issues of Jan Długosz University in Częstochowa. Mathematics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tablica interaktywna w pracy współczesnego nauczyciela szkoły podstawowej
Interactive Board at Work of Modern Teacher of Primary School
Autorzy:
MAMROŁ, ANDRZEJ
Powiązania:
https://bibliotekanauki.pl/articles/457326.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Rzeszowski
Tematy:
przemiany procesu kształcenia
tablica interaktywna
kompetencje medialne nauczycieli
transforms/changes in educational process
interactive board
teachers’ psychic competence
Opis:
W obliczu dynamicznych przeobrażeń społecznych oraz wyzwań, przed którymi stoi ludz-kość, a także przeobrażeń w mentalności i podejściu do życia współczesnych dzieci i młodzieży zmianie powinny ulec sposoby oddziaływania szkoły. Wychodząc tym zjawiskom naprzeciw, powinna ona w większym aniżeli dotąd stopniu wykorzystywać nowoczesne technologie eduka-cyjne. Duże możliwości w tym względzie daje np. tablica interaktywna. Odpowiednie jej zastoso-wanie podnosi efektywność pracy nauczyciela, a także zwiększa atrakcyjność zajęć, odpowiadając zapotrzebowaniu uczniów na konkretny rodzaj bodźców i aktywności. Tablica interaktywna staje się powoli codziennością szkoły, jednak istnieje ciągle wiele czynników, które ograniczają jej wykorzystanie.
In the face of dynamic social transforms and challenges, which stands before humanity and also transforms in mentality and attitude towards life of modern children and youth the ways of influence of school should be changed. To meet the expectations of these phenomenon school should use much better than so far modern educational technologies. High potential in these re-spect gives for example interactive board. Its appropriate use enhances effectiveness of teacher’s work but also makes the classes more attractive, what is relevant to students demands for special kind of stimulus and activity. The interactive board slowly becomes reality of school, however there are still many factors that restrict its use.
Źródło:
Edukacja-Technika-Informatyka; 2018, 9, 1; 144-153
2080-9069
Pojawia się w:
Edukacja-Technika-Informatyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Axisymmetric vibration for micropolar porous thermoelastic circular plate
Autorzy:
Kumar, R.
Kaushal, P.
Sharma, R.
Powiązania:
https://bibliotekanauki.pl/articles/266270.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
micropolar porous thermoelasticity
eigen value
Laplace and Hankel transforms
thermomechanical sources
porowatość termoelastyczna
transformata Laplace'a
transformata Hankela
Opis:
The present investigation is concerned with a two dimensional axisymmetric problem in a homogeneous isotropic micropolar porous thermoelastic circular plate by using the eigen value approach. The Laplace and Hankel transform are used to solve the problem. The expression of displacements, microrotation, volume fraction field, temperature distribution and stresses are obtained in the transformed domain subjected to thermomechanical sources. A computer algorithm is developed for numerical computations. To obtain the resulting quantities in a physical domain, a numerical inversion technique is used. The resulting quantities are depicted graphically for a specific model. Some special cases are also deduced.
Źródło:
International Journal of Applied Mechanics and Engineering; 2017, 22, 3; 583-600
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Are infinite dimensional models applicable in modelling and analysis of cancer chemotherapy?
Autorzy:
Świerniak, A.
Kimmel, M.
Śmieja, J.
Rzeszowska-Wolny, J.
Powiązania:
https://bibliotekanauki.pl/articles/333061.pdf
Data publikacji:
2004
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
odporność na leki
nieskończenie wymiarowy system
przekształcenia Laplace'a
drug resistance
branching random walk
infinite-dimensional systems
Laplace transforms
Opis:
Drug resistance and phase dependence have been regarded by many authors as the main obstacles against successful cancer chemotherapy. We propose a model which takes into account both these phenomena and give a tool to use phase specificity as an advantage rather than a fault and make it resistant of drug resistance. It combines models that so far have been studied separately, taking into account both the phenomenon of gene amplification and drug specificity in chemotherapy, in their different aspects. The mathematical description is given by an infinite dimensional state equation with a system matrix, the form of which enables decomposition of the model into two interacting subsystems. While the first one, of finite dimension, can have any form, the second one is infinite dimensional and tridiagonal.
Źródło:
Journal of Medical Informatics & Technologies; 2004, 8; MM3-10
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise robust illumination invariant face recognition via bivariate wavelet shrinkage in logarithm domain
Autorzy:
Chen, Guang Yi
Krzyżak, Adam
Duda, Piotr
Cader, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/2147140.pdf
Data publikacji:
2022
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
face recognition
dual-tree complex wavelet transforms
DTCWT
collaborative representation-based classifier
CRC
invariant features
pattern recognition
computer vision
Opis:
Recognizing faces under various lighting conditions is a challenging problem in artificial intelligence and applications. In this paper we describe a new face recognition algorithm which is invariant to illumination. We first convert image files to the logarithm domain and then we implement them using the dual-tree complex wavelet transform (DTCWT) which yields images approximately invariant to changes in illumination change. We classify the images by the collaborative representation-based classifier (CRC). We also perform the following sub-band transformations: (i) we set the approximation sub-band to zero if the noise standard deviation is greater than 5; (ii) we then threshold the two highest frequency wavelet sub-bands using bivariate wavelet shrinkage. (iii) otherwise, we set these two highest frequency wavelet sub-bands to zero. On obtained images we perform the inverse DTCWT which results in illumination invariant face images. The proposed method is strongly robust to Gaussian white noise. Experimental results show that our proposed algorithm outperforms several existing methods on the Extended Yale Face Database B and the CMU-PIE face database.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2022, 12, 3; 169--180
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Recognition of unknown scale objects
Rozpoznawanie obiektów o nieznanej skali
Autorzy:
Żorski, W.
Powiązania:
https://bibliotekanauki.pl/articles/209558.pdf
Data publikacji:
2008
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
transformata Hough'a
systemy widzenia robotów
widzenie maszynowe
dobieranie wzorców
Hough transforms
robot vision systems
machine vision
pattern matching
Opis:
This paper presents an application of the Hough Transform to the task of identifying objects of unknown scale, e.g. within a scene in a robot vision system. The presented method is based on the Hough Transform for irregular objects, with a parameter space defined by translation, rotation and scaling operations. The high efficiency of the technique allows for poorquality or highly complex images to be analysed. The technique may be used in robot vision systems, identification systems or for image analysis, directly on grey-level images.
Artykuł prezentuje zastosowanie transformaty Hougha do zadań identyfikacji obiektów o nieznanej skali, np. na scenie w systemie widzenia robota. Metoda wykorzystuje transformatę Hougha dla wzorców nieregularnych, z przestrzenią parametrów określoną przez operacje: translacji, obrotu i skalowania. Wysoka sprawność techniki pozwala na analizę obrazów o słabej jakości lub dużej złożoności. Technika może być przykładowo zastosowana w systemach widzenia robotów, do bezpośredniej analizy obrazów pozyskanych w poziomach szarości.
Źródło:
Biuletyn Wojskowej Akademii Technicznej; 2008, 57, 4; 197-207
1234-5865
Pojawia się w:
Biuletyn Wojskowej Akademii Technicznej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Beurlings theorems and inversion formulas for certain index transforms
Autorzy:
Yakubovich, S. B.
Powiązania:
https://bibliotekanauki.pl/articles/255306.pdf
Data publikacji:
2009
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Beurling theorem
Kontorovich-Lebedev transform
Lebedev-Skalskaya transforms
Fourier transform
Laplace transform
modified Bessel functions
uncertainty principle
Nicholson function
Opis:
The familiar Beurling theorem (an uncertainty principle), which is known for the Fourier transform pairs, has recently been proved by the author for the Kontorovich-Lebedev transform. In this paper analogs of the Beurling theorem are established for certain index transforms with respect to a parameter of the modified Bessel functions. In particular, we treat the generalized Lebedev-Skalskaya transforms, the Lebedev type transforms involving products of the Alacdoriald functions of different arguments and an index transform with the Nicholson kernel function. We also find inversion formulas for the Lebedev-Skalskaya operators of an arbitrary index and the Nicholson kernel transform.
Źródło:
Opuscula Mathematica; 2009, 29, 1; 93-110
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification in the Gabor time-frequency domain of non-stationary signals embedded in heavy noise with unknown statistical distribution
Autorzy:
Świercz, E.
Powiązania:
https://bibliotekanauki.pl/articles/907771.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
sygnał niestacjonarny
klasyfikacja sygnału
rozpoznawanie obrazów
transformator czas-częstotliwość
non-stationary signals
signal classification
pattern recognition
time-frequency transforms
Opis:
A new supervised classification algorithm of a heavily distorted pattern (shape) obtained from noisy observations of nonstationary signals is proposed in the paper. Based on the Gabor transform of 1-D non-stationary signals, 2-D shapes of signals are formulated and the classification formula is developed using the pattern matching idea, which is the simplest case of a pattern recognition task. In the pattern matching problem, where a set of known patterns creates predefined classes, classification relies on assigning the examined pattern to one of the classes. Classical formulation of a Bayes decision rule requires a priori knowledge about statistical features characterising each class, which are rarely known in practice. In the proposed algorithm, the necessity of the statistical approach is avoided, especially since the probability distribution of noise is unknown. In the algorithm, the concept of discriminant functions, represented by Frobenius inner products, is used. The classification rule relies on the choice of the class corresponding to the max discriminant function. Computer simulation results are given to demonstrate the effectiveness of the new classification algorithm. It is shown that the proposed approach is able to correctly classify signals which are embedded in noise with a very low SNR ratio. One of the goals here is to develop a pattern recognition algorithm as the best possible way to automatically make decisions. All simulations have been performed in Matlab. The proposed algorithm can be applied to non-stationary frequency modulated signal classification and non-stationary signal recognition.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 1; 135-147
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kompresja stratna dźwięku
Autorzy:
Grad, L.
Powiązania:
https://bibliotekanauki.pl/articles/91439.pdf
Data publikacji:
2007
Wydawca:
Warszawska Wyższa Szkoła Informatyki
Tematy:
kompresja stratna dźwięku
liniowy model predykcji
transformacje ortogonalne
model psychoakustyczny
sound loose compression
linear predictive coding
orthogonal transforms
psychoacoustic model
Opis:
W artykule przedstawione zostały elementarne wiadomości z zakresu kompresji stratnej dźwięku. Przedstawiony został liniowy model predykcji, wykorzystywany w kompresji dźwięku w paśmie telefonicznym oraz opisane zostały transformacje ortogonalne i model psychoakustyczny człowieka mające podstawowe znaczenia w kompresji dźwięku wysokiej jakości.
This paper presents an overview of the basic information on sound loose compression. Linear predictive coding, which is used in voice compression in the phone band, as well as orthogonal transforms and psychoacoustic model, which are very important in high level sound compression (voice, speech), are revised.This paper presents an overview of the basic information on sound loose compression. Linear predictive coding, which is used in voice compression in the phone band, as well as orthogonal transforms and psychoacoustic model, which are very important in high level sound compression (voice, speech), are revised.
Źródło:
Zeszyty Naukowe Warszawskiej Wyższej Szkoły Informatyki; 2007, 2, 2; 39-58
1896-396X
2082-8349
Pojawia się w:
Zeszyty Naukowe Warszawskiej Wyższej Szkoły Informatyki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analiza rzędów w diagnostyce niestacjonarnych procesów wibroakustycznych
Order analysis in the diagnostic nonstacjonary vibroacustic process
Autorzy:
Korbiel, T.
Powiązania:
https://bibliotekanauki.pl/articles/329138.pdf
Data publikacji:
2007
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
analiza sygnałów
diagnostyka procesów niestacjonarnych
transformata czasowo-częstotliwościowa
krzywe sklejane
order analysis
nonstacjonary process diagnostics
time-frequency transforms
spline curve
Opis:
Analiza określonej klasy sygnałów drganiowych w diagnostyce technicznej odbywa się poprzez transformatę z dziedziny czasu do dziedziny częstotliwości. Najczęściej wykorzystywany jest algorytm transformaty Fouriera. Jednym z ograniczeń tych algorytmów jest wymóg stacjonarności badanych sygnałów. W diagnostyce maszyn rotacyjnych istotna informacja dotycząca stanów dynamicznych zawarta jest w strukturze częstotliwościowej sygnału drganiowego. W przypadku stałej prędkości obrotowej transformata Fouriera poprawnie pokazuje tą strukturę. Dla zmiennych obrotów analiza taka jest utrudniona. Do analizy sygnałów niestacjonarnych wykorzystywane są inne narzędzia, takie jak STFT, TVW czy transformata falkowa. Są to narzędzia analizy czasowo- częstotliwościowej. W analizie sygnałów drganiowych maszyn rotacyjnych składowe częstotliwościowe są powiązane funkcyjnie nie z czasem, lecz z prędkością obrotową. Wskazane jest, zatem zastosowanie takiej analizy, która przeprowadzi sygnał z dziedziny czasu w dziedzinę prędkości obrotowej. Takie możliwości daje między innymi analiza rzędów. W referacie przedstawiono algorytm analizy rzędów oparty o interpolacje krzywymi sklejanymi. Przedstawiono wyniki badania tego algorytmu pod kątem wykorzystania w diagnostyce technicznej maszyn rotacyjnych. Zaprezentowano przykładową analizę diagnostycznych sygnałów drganiowych.
The analysis of particular class of vibration signals is performed by transformation from the time domain to frequency domain. The algorithm of Fourier transformation is the most used one. One of the limitations of the mentioned fourier is the demand of stationarity of the signals. In rotary machines diagnostics information on dynamic states is important, which is contained in the frequency structure of the vibration signal. With the constant rotation speed Fourier transform describes frequency structure correctly. With variable speed such analysis is not possible. In that case other tools are used, such as STFT, TVW or wavelet transform. Those are time-frequency analysis tools. In rotary machine vibration signal analysis frequency components are functionally tied to rotations, not time. It is recommended then to use analysis that transforms the signal from the time domain into rotation speed domain. Such transformation is possible with rank analysis. The paper presents the rank analysis algorithm based on spline curve interpolation. The algorithm was tested in use for rotary machines technical diagnostics. Sample vibration signal analysis is presented.
Źródło:
Diagnostyka; 2007, 3(43); 99-104
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MHD flow past a parabolic flow past an infinite isothermal vertical plate in the presence of thermal radiation and chemical reaction
Autorzy:
Muthucumaraswamy, R.
Sivakumar, P.
Powiązania:
https://bibliotekanauki.pl/articles/265859.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
MHD
płyta pionowa
promieniowanie cieplne
metoda transformacji Laplace'a
isothermal
radiation
vertical plate
thermal radiation
chemical reaction
Laplace transforms technique
Opis:
The problem of MHD free convection flow with a parabolic starting motion of an infinite isothermal vertical plate in the presence of thermal radiation and chemical reaction has been examined in detail in this paper. The fluid considered here is a gray, absorbing emitting radiation but a non-scattering medium. The dimensionless governing coupled linear partial differential equations are solved using the Laplace transform technique. A parametric study is performed to illustrate the influence of the radiation parameter, magnetic parameter, chemical reaction parameter, thermal Grashof number, mass Grashof number, Schmidt number and time on the velocity, temperature, concentration. The results are discussed graphically and qualitatively. The numerical results reveal that the radiation induces a rise in both the velocity and temperature, and a decrease in the concentration. The model finds applications in solar energy collection systems, geophysics and astrophysics, aerospace and also in the design of high temperature chemical process systems.
Źródło:
International Journal of Applied Mechanics and Engineering; 2016, 21, 1; 95-105
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet method of edge detection in images with high-noise level
Metoda falkowa detekcji krawędzi w obrazach o wysokim poziomie szumów
Autorzy:
Niedziela, Tadeusz
Powiązania:
https://bibliotekanauki.pl/articles/1818413.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Technologiczno-Humanistyczny im. Kazimierza Pułaskiego w Radomiu
Tematy:
characteristic features
detection of non-sharp edges
Haar-Gauss wavelet
wavelet transforms
transformata falkowa
detekcja krawędzi
cecha charakterystyczna
falka Haara-Gaussa
Opis:
In the paper a mathematical model addressed to non-sharp edges in the images is proposed. This model is based on and integral transform with Haar-Gauss wavelet and matching algorithm of bandwidth, such model is used to detection of the edges in images with high-level noises, both in the x plane and the frequency domains. There is shown that applying the integral Haar-Gaussian transformation the detection of single and double edges is possible. Demonstrated in the paper results confirm that wavelet transform supported by the matching wavelet algorithm of wavelength bandwidth make an important exploration tool of the images with the edges possessing a large depth of sharpness.
W artykule zaproponowano model matematyczny nieostrej krawędzi oraz całkową transformatę z falka Haara-Gaussa wraz z algorytmem dopasowania pasma zarówno w przestrzeni x jak i w dziedzinie częstotliwości. Zilustrowano detekcję pojedynczej i podwójnej krawędzi wykorzystując całkową transformatę Haara-Gaussa. Proponowany model krawędzi wraz z transformatą falkową i algorytmem dopasowania szerokości pasma częstotliwości falki może być ważnym narzędziem w rozpoznawaniu obiektów przez nowoczesne wizyjne systemy transportowe.
Źródło:
Journal of Civil Engineering and Transport; 2020, 2, 3; 119-130
2658-1698
2658-2120
Pojawia się w:
Journal of Civil Engineering and Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostyka uszkodzeń uzwojeń stojana silnika indukcyjnego z wykorzystaniem dyskretnej transformaty falkowej obwiedni prądu stojana
Diagnosis of induction motor stator winding fault using discrete wavelet analysis of the stator current envelope
Autorzy:
Wolkiewicz, M.
Kowalski, C.
Powiązania:
https://bibliotekanauki.pl/articles/1367714.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Napędów i Maszyn Elektrycznych Komel
Tematy:
silnik indukcyjny
zwarcia zwojowe
obwiednia prądu stojana
dyskretna transformata falkowa
induction motor
inter-turn fault
envelope of stator current
discrete wavelet transforms
Opis:
This paper deals with the application of stator current envelope analysis in the incipient diagnosis of the stator winding short circuits. To separate of the characteristic symptoms of stator damage Discrete Wavelet Transform were used. Based on this analysis the energy coefficients of the stator current envelope for the chosen decomposition levels were calculated. The proposed method was implemented for a small power induction motor (with special physical modeling of shorted turns in the stator phases) supplied by voltage source inverter in open control loop. The virtual measurement-diagnostic device, developed in the LabVIEW environment includes algorithms: data acquisition, Hilbert transform for the determination of stator current envelope and wavelet transform to extract the failure symptoms. Experimental results presented In this paper show that changes of the proposed energy factor constitutes a very efficient index for the evaluation of the stator winding state.
W artykule przedstawiono analizę możliwości wykorzystania sygnału obwiedni prądu fazowego stojana do wykrywania zwarć zwojowych, w możliwie wczesnej fazie powstania uszkodzenia. Do wyodrębnienie charakterystycznych dla uszkodzenia stojana symptomów wykorzystano dyskretną transformatę falkową oraz obliczony na jej podstawie współczynnik zmian energii sygnału dla wybranych poziomów dekompozycji. Badania eksperymentalne zrealizowano dla silnika indukcyjnego małej mocy zasilanego z przemiennika częstotliwości w otwartej pętli sterowania (sterowanie skalarne U/f=const). Środowisko LabVIEW posłużyło do zaprojektowania oraz przetestowania aplikacji przyrządu pomiarowo-diagnostycznego. Aplikacja zawierała algorytmy: akwizycji danych, transformaty Hilberta do wyznaczenia obwiedni sygnału oraz transformaty falkowej sygnału do wyodrębnienia symptomów uszkodzenia. Zmiany wartości współczynnika zmian energii dla obwiedni prądu stojana dla poszczególnych poziomów dekompozycji okazały się bardzo dobrym kryterium oceny stanu uzwojenia stojana.
Źródło:
Maszyny Elektryczne: zeszyty problemowe; 2015, 3, 107; 13-18
0239-3646
2084-5618
Pojawia się w:
Maszyny Elektryczne: zeszyty problemowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On axisymmetrical boundary problem of unsteady motion of micropolar fluid in the half-space
Autorzy:
El-Sirafy, I. H.
Aboutahoun, A. W.
Powiązania:
https://bibliotekanauki.pl/articles/200251.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
micropolar fluid
axisymmetrical motion
Laplace-Hankel transforms
problem brzegowy
płyn mikropolarny
transformacja Laplace'a
transformacja Hankela i Laplace'a
warunek brzegowy Hankela
Opis:
The aim of this paper is developing an exact solution for the problem of axisymmetrical flow of unsteady motion of micropolar fluid in the half-space when the shear stresses are given on the boundary. The Laplace-Hankel transform technique is used to solve this problem. Some physical quantities such as velocities, pressure and microrotations are obtained and illustrated numerically.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 1; 51-62
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-50 z 54

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies