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Tytuł:
Three-dimensional octonion wavelet transform
Autorzy:
Katunin, A.
Powiązania:
https://bibliotekanauki.pl/articles/122330.pdf
Data publikacji:
2014
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
octonion wavelet transform
spatial data processing
octonionic wavelets
Opis:
The necessities of processing of spatial data require developing new feature-sensitive tools such as extensions of the wavelet transform. Considering the advantages of the application of complex wavelets and their extension to quaternionic wavelets for twodimensional data structures, the new octonion discrete wavelet transform for the analysis of three-dimensional data structures was introduced in this paper. The construction of the wavelet pyramid as well as octonionic wavelets were presented.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2014, 13, 1; 33-38
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time series denoising with wavelet transform
Autorzy:
Kozłowski, B.
Powiązania:
https://bibliotekanauki.pl/articles/309048.pdf
Data publikacji:
2005
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
wavelet transform
WaveShrink
filtration
noise reduction
Haar basic wavelet function
Opis:
This paper concerns the possibilities of applying wavelet analysis to discovering and reducing distortions occurring in time series. Wavelet analysis basics are briefly reviewed. WaveShrink method including three most common shrinking variants (hard, soft, and non-negative garrote shrinkage functions) is described. Another wavelet-based filtering method, with parameters depending on the length of wavelets, is introduced. Sample results of filtering follow the descriptions of both methods. Additionally the results of the use of both filtering methods are compared. Examples in this paper deal only with the simplest "mother" wavelet function - Haar basic wavelet function.
Źródło:
Journal of Telecommunications and Information Technology; 2005, 3; 91-95
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet transform and binary coalescence detection
Autorzy:
Innocent, Jean-Michel
Torrésani, Bruno
Powiązania:
https://bibliotekanauki.pl/articles/1342594.pdf
Data publikacji:
1997
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Opis:
We give a short account of some time-frequency methods which are relevant in the context of gravity waves detection. We focus on the case of wavelet analysis which we believe is particularly appropriate. We show how wavelet transforms can lead to efficient algorithms for detection and parameter estimation of binary coalescence signals. In addition, we give in an appendix some of the ingredients needed for the construction of discrete wavelet decompositions and corresponding fast algorithms.
Źródło:
Banach Center Publications; 1997, 41, 2; 179-208
0137-6934
Pojawia się w:
Banach Center Publications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet transform in vibroacoustic diagnostic of machines
Autorzy:
Haller, Piotr
Jankowski, Antoni
Kaźmierczak, Andrzej
Wróbel, Radosław
Powiązania:
https://bibliotekanauki.pl/articles/244246.pdf
Data publikacji:
2019
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
DSP
wavelet
LDV
combustion engine
Opis:
This article discusses the use of wavelet decomposition in the diagnostics of vibrometric signals of an engine. Apart from presenting the possibility of using wavelets in diagnostics, the authors take up the subject of the applicability range of processing for stationary signals, which until now has been reserved for non-stationary signals. A unified definition of signal stationarity has been proposed, which is not based on statistics. The authors presented methods of wavelet decomposition of a vibrometric signal of combustion engine vibrations, measured with the use of LDV (Laser Doppler Vibrometry). Laser measurements allows for studying an object without 'touching' its housing. Basing on the relative velocity of engine vibrations, the authors indicate how reliable vibrations are in diagnostics. Despite higher costs, this measurement method gives better results (for specific cases) than acoustic studies. Transform – wavelet decomposition is a solution hardly ever used in machine diagnostics; it is more often applied in medicine and image recognition. The authors presented the differences that can be obtained for different levels of decomposition, and also presented the impact on the engine condition assessment through the use of filtering (windowing) the signal before decomposition.
Źródło:
Journal of KONES; 2019, 26, 1; 47-55
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuous wavelet transform in hydroacoustics signals analysis
Autorzy:
Zak, A.
Powiązania:
https://bibliotekanauki.pl/articles/332508.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Paper presents method of Continuous Wavelet Transform (CWT) used in process of hydroacoustics signals analysis. The continuous wavelet transform can be used to produce spectrograms which show the frequency content of signals as a function of time. Such representation is very useful during analysis of non-stationary signals which can be acquired during passive measurements of hydroacoustics field of moving ships. In paper there is described the continuous wavelet transform analysis method by presenting the mathematical background of CWT and its properties. At the end some examples of hydroacoustics signals analysis and its brief descriptions was shown.
Źródło:
Hydroacoustics; 2011, 14; 267-274
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Implementation of the Wavelet Transform with SSE Extensions
Autorzy:
Łyszkowski, T.
Wiechno, T.
Yatsymirskyy, M.
Powiązania:
https://bibliotekanauki.pl/articles/108711.pdf
Data publikacji:
2013
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
Orthogonal Filters
discrete wavelet transform
SSE extensions
Opis:
It has been shown that application of assembly implementation of Streaming SIMD Extensions (SSE) shortens the time needed to apply filtration in twochannel filter bank by tenfold, comparing to non-optimized version, written in Microsoft Visual C++ 2010 Express, without assembler extensions. The implementation described in this paper can be applied to computation of Discrete Wavelet Transform on general-purpose processors.
Źródło:
Journal of Applied Computer Science Methods; 2013, 5 No. 2; 123-135
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Heart Rate Variability Fluctuations by Wavelet Transform
Autorzy:
Popov, A.
Karplyuk, Y.
Fesechko, V.
Powiązania:
https://bibliotekanauki.pl/articles/226306.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heart rate variability
HRV fluctuations
HRV wavelet analysis
time-dependent HRV estimation
wavelet transform
Opis:
Technique for separate estimation of fast and slow fluctuations in the heart rate signal is developed. The orthogonal dyadic wavelet transform is used to separate the slow heart rate changes in approximation part of decomposition and fast changes in detail parts. Experimental results using the recordings from persons practicing Chi meditation demonstrated the applicability of estimation heart rate fluctuations with the proposed approach.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 3; 395-400
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-frequency analysis of seabed echoes using wavelet transform
Autorzy:
Moszyński, M.
Stepnowski, A.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332256.pdf
Data publikacji:
1999
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The methods based on analysis of boftom backscatter data from a single-beam echosounder have achieved special attention in the seabed identification problem. due to their simplicity over ofher more sophisticated acoustic techniques like side scan sonar or multibeam surveys. The majority of these methods analyses the scattering phenomena mostly in time domain (echo envelope). However, the frequency echo components carry concurrent information, which can be also used in boftom characterisation. The paper proposes the time-frequency approach to the boftom characterisation and presents the application of Wigner- Ville Distribution and wavelet transform of boftom backscatter data. The examples of continuous and discrete wavelet transforms of actual echo envelopes received at three boftom types for three different operating frequencies (38, 120 and 420 kHz) are shown. Their characteristic features are compared and parameters for classification schemes are proposed. The results of classification procedure are good with comparison with those of ofher simple acoustic methods.
Źródło:
Hydroacoustics; 1999, 2; 85-90
1642-1817
Pojawia się w:
Hydroacoustics
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:
Type of modulation identification using Wavelet Transform and Neural Network
Autorzy:
Walenczykowska, M.
Kawalec, A.
Powiązania:
https://bibliotekanauki.pl/articles/201661.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
modulation identification
artificial neural networks
continuous wavelet transform (CWT)
identyfikacja modulacji
sztuczne sieci neuronowe (SSN)
transformacja falkowa (CWT)
Opis:
Automatic recognition of the signal modulation type turned out to be useful in many areas, including electronic warfare or surveillance. The wavelet transform is an effective way to extract signal features for identification purposes. In this paper there are M-ary ASK, M-ary PSK, M-ary FSK, M-ary QAM, OOK and MSK signals analysed. The mean value, variance and central moments up to five of continuous wavelet transform (CWT) are used as signal features. The principal component analysis (PCA) is applied to reduce a number of features. A multi-layer neural network trained with backpropagation learning algorithm is considered as a classifier. There are two research variants: interclass and intraclass recognition with a wide range of signal-to-noise ratio (SNR).
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2016, 64, 1; 257-261
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crack identification in plates using 1-D Discrete Wavelet Transform
Autorzy:
Knitter-Piątkowska, A.
Guminiak, M.
Hloupis, G.
Powiązania:
https://bibliotekanauki.pl/articles/281595.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage detection
crack
plates
wavelet transform
Boundary Element Method
Opis:
In the present work, the defect detection while using Discrete Wavelet Transform in rectangular plate structures is investigated. The plate bending is described by using the Boundary Element Method with boundary integral equations formulated in a modified simplified approach. The boundary elements of a constant type in a non-singular approach are implemented. Defects are introduced by additional edges forming slots or holes in relation to the basic plate domain. Estimation of the defect position is performed while using wavelet coefficients of curvature and deformation signals as well as a newly proposed moving variance estimator.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 2; 481-496
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adaptive synthesis of a wavelet transform using fast neural network
Autorzy:
Stolarek, J.
Powiązania:
https://bibliotekanauki.pl/articles/202390.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelets
neural networks
filter parametrization
fast algorithms
Opis:
This paper introduces a new method for an adaptive synthesis of a wavelet transform using a fast neural network with a topology based on the lattice structure. The lattice structure and the orthogonal lattice structure are presented and their properties are discussed. A novel method for unsupervised training of the neural network is introduced. The proposed approach is tested by synthesizing new wavelets with an expected energy distribution between low- and high-pass filters. Energy compaction of the proposed method and Daubechies wavelets is compared. Tests are performed using sound and image signals.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2011, 59, 1; 9-13
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wavelet transform for time-frequency representation and filtration of discrete signals
Autorzy:
Popiński, Waldemar
Powiązania:
https://bibliotekanauki.pl/articles/1340246.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
spectro-temporal filtration
orthonormal wavelet base
Discrete Fourier Transform
finite duration signals
Opis:
A method to analyse and filter real-valued discrete signals of finite duration s(n), n=0,1,...,N-1, where $N=2^p$, p>0, by means of time-frequency representation is presented. This is achieved by defining an invertible discrete transform representing a signal either in the time or in the time-frequency domain, which is based on decomposition of a signal with respect to a system of basic orthonormal discrete wavelet functions. Such discrete wavelet functions are defined using the Meyer generating wavelet spectrum and the classical discrete Fourier transform between the time and the frequency domains.
Źródło:
Applicationes Mathematicae; 1995-1996, 23, 4; 433-448
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phase Autocorrelation Bark Wavelet Transform (PACWT) Features for Robust Speech Recognition
Autorzy:
Majeed, S. A.
Husain, H.
Samad, S. A.
Powiązania:
https://bibliotekanauki.pl/articles/177326.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech recognition
feature extraction
phase autocorrelation
wavelet transform
Opis:
In this paper, a new feature-extraction method is proposed to achieve robustness of speech recognition systems. This method combines the benefits of phase autocorrelation (PAC) with bark wavelet transform. PAC uses the angle to measure correlation instead of the traditional autocorrelation measure, whereas the bark wavelet transform is a special type of wavelet transform that is particularly designed for speech signals. The extracted features from this combined method are called phase autocorrelation bark wavelet transform (PACWT) features. The speech recognition performance of the PACWT features is evaluated and compared to the conventional feature extraction method mel frequency cepstrum coefficients (MFCC) using TI-Digits database under different types of noise and noise levels. This database has been divided into male and female data. The result shows that the word recognition rate using the PACWT features for noisy male data (white noise at 0 dB SNR) is 60%, whereas it is 41.35% for the MFCC features under identical conditions.
Źródło:
Archives of Acoustics; 2015, 40, 1; 25-31
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykrywanie dróg z wykorzystaniem transformaty falkowej
Road detection using wavelet transform
Autorzy:
Marmol, U.
Powiązania:
https://bibliotekanauki.pl/articles/158401.pdf
Data publikacji:
2014
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
LIDAR
ortofotomapa
teoria falek
intensywność odbicia
lidar
orthophotomap
wavelet theory
intensity
Opis:
W niniejszym artykule na wybranym polu testowym przeprowadzono próbę wyodrębnienia dróg z wykorzystaniem informacji o intensywności pochodzącej z danych laserowych oraz informacji geometrycznej i radiometrycznej zawartej w zdjęciach lotniczych. W procesie badawczym wykorzystano możliwości jakie niesie transformata falkowa w zakresie ekstrakcji krawędzi na obrazie. Końcowym etapem prac było scalenie informacji. Uzyskany obraz przebiegu dróg jest zgodny z istniejącą ortofotomapą.
Road detection based on remote sensing data is an important research theme allowing performing many spatial analysis. Recently the possibility of road network extraction using the elevation data from airborne laser scanning has aroused great interest. The carried out studies revealed the potential of LIDAR data, but also their limitations and shortcomings. Based on the performed investigations it can be concluded that the most reliable results are obtained by integrating the laser and image data. In this paper the road extraction test is carried out on the selected test field, using the information of the intensity derived from the laser data and the geometric and radiometric information contained in aerial photographs. Based on the laser data, the exact parameter of intensity, the initial image of the roads was generated with use of simple morphological operators. The next step was to detect the edges based on orthophotos using the wavelet transform. Wavelet transformation proved to be a useful tool to detect sudden changes in brightness. The final stage of the work was to merge the information from these two sources. The resulting image corresponds to the roads in the orthophotomap. In conclusion, it can be stated that the integration of photogrammetry and laser data is the optimal approach to solving problems of spatial object detection.
Źródło:
Pomiary Automatyka Kontrola; 2014, R. 60, nr 3, 3; 144-147
0032-4140
Pojawia się w:
Pomiary Automatyka Kontrola
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Wavelet Transform in Regression
Zastosowanie transformacji falkowej do budowy modeli regresyjnych
Autorzy:
Trzęsiok, Joanna
Powiązania:
https://bibliotekanauki.pl/articles/905049.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Łódzki. Wydawnictwo Uniwersytetu Łódzkiego
Tematy:
wavelets
wavelet transform
wavelet thresholding
nonparametric regression
Opis:
The wavelet transform was introduced in the 19S0's and it was developed as an alternative in tin short time Fourier transform. The wavelets theory is very popular in signal processing and pattern recognition and its applications are still growing. This paper presents the wavelet transform in nonparametric regression. The use of wavelets, in statistical applications was pioneered by D. Donoho and I. Johnstone. Here we discuss their methodology - wavelet shrinkage. The wavelet transform is compared with another nonparametric regression method - splines.
Transformacja falkowa została zaproponowana na początku lat osiemdziesiątych, jako alternatywa do transformacji Fouriera. Metoda ta szybko znalazła swoje zastosowanie w teorii sygnałów oraz w rozpoznawaniu obrazów, a zakres jej aplikacji nadal dynamicznie się rozwija. Autorami pionierskich prac z zakresu zastosowań teorii lalek w statystyce są David Donoho and Iain Johnstone. Zaproponowali oni w roku 1994 procedurę WaveShrink wykorzystywaną do estymacji funkcji gęstości oraz budowy nieparametrycznych modeli regresji oparła na transformacji falkowej. W artykule przedstawione zostało zastosowanie transformacji falkowej oraz procedury WaveShrink do budowy modelu regresyjnego. Omawianą metodę porównano z inną nieparametryczny metodą regresji - krzywymi sklejanymi.
Źródło:
Acta Universitatis Lodziensis. Folia Oeconomica; 2009, 225
0208-6018
2353-7663
Pojawia się w:
Acta Universitatis Lodziensis. Folia Oeconomica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental damage assessment of support condition for plate structures using wavelet transform
Autorzy:
Abdulkareem, Muyideen
Bakhary, Norhisham
Vafaei, Mohammadreza
Md Noor, Norhazilan
Abd Samat, Roslida
Powiązania:
https://bibliotekanauki.pl/articles/280431.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
damage
plate
continuous wavelet transform
discrete wavelet transform
Opis:
Wavelet transforms (WTs) have gained popularity due to their ability to identify singularities by decomposing mode shapes of structures. In VBDD, the support condition of a structure influences structural responses and modal properties. In fact, the structural responses and modal properties are a lot more sensitive to changing boundary conditions than to crack and fatigue damage, resulting in inaccurate damage detection results. Therefore, in this study, sensitivity tests to estimate a suitable distance range which allows damage detection by imposing single support damage are carried out. The estimated appropriate distance is then applied to detect damage at multiple supports. This involved the applicability of response acceleration of plate structures to support assessment by applying continuous wavelet transform (CWT) and discrete wavelet transform (DWT). The damage cases have been introduced by releasing bolts at specified fixed supports of the plate to simulate the damage. The response accelerations of the rectangular plate at points close to the supports were measured and decomposed using CWT and DWT to assess the structural integrity of each support. The results showed that an appropriate distance range was necessary for accurate damage detection, and both, CWT and DWT could provide reliable outputs. However, the first- and fourth-level detail coefficients of DWT failed to indicate damage in some cases. A more detailed investigation of the effect of different wavelet scale ranges on damage detection using CWT demonstrated that the accuracy of damage detection increased as the scale decreased.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 2; 501-518
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fault diagnosis of analog circuit based on wavelet transform and neural network
Autorzy:
Wang, Hui
Powiązania:
https://bibliotekanauki.pl/articles/141368.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog circuit
fault diagnosis
neural network
wavelet transform
Opis:
Analog circuits need more effective fault diagnosis methods. In this study, the fault diagnosis method of analog circuits was studied. The fault feature vectors were extracted by a wavelet transform and then classified by a generalized regression neural network (GRNN). In order to improve the classification performance, a wolf pack algorithm (WPA) was used to optimize the GRNN, and a WPA-GRNN diagnosis algorithm was obtained. Then a simulation experiment was carried out taking a Sallen–Key bandpass filter as an example. It was found from the experimental results that the WPA could achieve the preset accuracy in the eighth iteration and had a good optimization effect. In the comparison between the GRNN, genetic algorithm (GA)-GRNN and WPA-GRNN, the WPA-GRNN had the highest diagnostic accuracy, and moreover it had high accuracy in diagnosing a single fault than multiple faults, short training time, smaller error, and an average accuracy rate of 91%. The experimental results prove the effectiveness of the WPA-GRNN in fault diagnosis of analog circuits, which can make some contributions to the further development of the fault diagnosis of analog circuits.
Źródło:
Archives of Electrical Engineering; 2020, 69, 1; 175-185
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformata falkowa wybranych sygnałów diagnostycznych
Discrete wavelet transform of select diagnostic signals
Autorzy:
Józefczyk, I.
Powiązania:
https://bibliotekanauki.pl/articles/257656.pdf
Data publikacji:
2007
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
sygnał
dyskretna transformacja falkowa
falka
falka macierzysta
signal
discrete wavelet transform
wavelet
mother wavelet
Opis:
W artykule przedstawiono dyskretną transformcję falkową (DWT) kilku sygnałów symulacyjnych z zastosowaniem falek, których użyteczność potwierdziły wcześniejsze badania. Przedmiotem badań były sygnały o znanej strukturze częstotliwościowej - wzorce oraz sygnały powstałe z wzorca poprzez dodanie tła losowego - zakłóceń. Te drugie poddawano transformacji falkowej, chcąc w ten sposób wyeliminować czynnik losowy. Przedstawiono głównie wyniki tych falek, które najlepiej odzwierciedlają zaprogramowane informacje. Uzyskane rezultaty wskazują na konieczność dobrego doboru falki (najlepsze wyniki uzyskano dla falki dmey) oraz kryterium stopu.
The paper presents the discrete wavelet transform (DWT) of a few simulated signals using wavelets whose usefulness was confirmed by earlier studies. The subjects of the examination were pure signals of known frequency and signals distorted with random noise. The latter were put under discrete wavelet transformation in order to eliminate the influence of random noise. Only those results which show programmed information in the best way were presented. The obtained results point at the necessity of good selection of wavelet and stop criterion. The best results were achieved using dmey wavelet.
Źródło:
Problemy Eksploatacji; 2007, 1; 167-177
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformata falkowa w diagnostyce urządzeń technicznych
Wavelet transform in mechanical devices diagnostics
Autorzy:
Józefczyk, I.
Powiązania:
https://bibliotekanauki.pl/articles/258117.pdf
Data publikacji:
2008
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
sygnał
dyskretna transformacja falkowa
falka
falka macierzysta
diagnostic information
digital signal processing
wavelet transform
Opis:
Artykuł jest poszukiwaniem odpowiedzi na pytanie: jakie warunki musi spełniać falka, aby sygnał poddany transformacji falkowej nadawał się do zdekodowania informacji diagnostycznej. Obróbce poddano dwa sygnały symulacyjne (stacjonarny i niestacjonarny) oraz sygnał pobrany z urządzenia mechanicznego. W oparciu o uzyskane rezultaty potwierdzona została hipoteza mówiąca, iż bardzo istotny jest dobór falki. Podkreślono także przydatność transformacji falkowej jako narzędzia do obróbki wstępnej, dla celów diagnostyki urządzeń technicznych.
The article attempts to define the conditions that must be fulfilled by the wavelet. These conditions ensure that after the wavelet transformation, the signal will be able to decode diagnostics information. The transformation embraced two simulation signals (stationary and non-stationary) and a signal from a mechanical appliance. Based on the results, the thesis attaching a great importance to wavelet selection has been corroborated. Also, emphasis was put on wavelet transformation as a useful tool for initial transformation.
Źródło:
Problemy Eksploatacji; 2008, 4; 81-90
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Two Dimensional Wavelet Transform for Classification of Power Quality Disturbances
Autorzy:
Mollayi, N.
Mokhtari, H.
Powiązania:
https://bibliotekanauki.pl/articles/262752.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
power quality
event detection and classification
two dimensional wavelet transform
pattern classification
image processing
feature
classifier system
Opis:
Identification of voltage and current disturbances is an important task in power system monitoring and protection. In this paper, the application of two-dimensional wavelet transform for characterization of a wide variety range of power quality disturbances is discussed, and a new algorithm, based on image processing techniques is proposed for this purpose. A matrix is formed based on a specified number of cycles in such a way that the samples of voltage signal in each cycle form one row of that matrix. This matrix can be regarded as a two dimensional image. A two-dimensional wavelet transform is used to decompose the image into approximation and details, which contain low frequency and high frequency components along the rows and columns, respectively. Different disturbances result into different special patterns in detail images. By processing the detail images, specific features are defined which can suitably discriminate various types of disturbances. Combination of the feature generation algorithm and a classifier system leads to a smart system for classification of wide variety range of disturbances.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2014, 17, 2; 1-7
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An application of continuous wavelet transform and wavelet coherence for residential power consumer load profiles analysis
Autorzy:
Kapler, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2086818.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
residential power consumers
load profiles
power demand
continuous wavelet transform
wavelet coherence
odbiorcy energii lokalni
zapotrzebowanie na energię
profil obciążenia
ciągła transformata falkowa
spójność falkowa
Opis:
Load profiles of residential consumers are very diverse. This paper proposes the usage of a continuous wavelet transform and wavelet coherence to perform analysis of residential power consumer load profiles. The importance of load profiles in power engineering and common shapes of profiles along with the factors that cause them are described. The continuous wavelet transform and wavelet coherence has been presented. In contrast with other studies, this research has been conducted using detailed (not averaged) load profiles. Presented load profiles were measured separately on working day and weekend during winter in two urban households. Results of applying the continuous wavelet transform for load profiles analysis are presented as coloured scalograms. Moreover, the wavelet coherence was used to detect potential relationships between two consumers in power usage patterns. Results of coherence analysis are also presented in a colourful plots. The conducted studies show that the Morlet wavelet is slightly better suitable for load profiles analysis than the Meyer’s wavelet. Research of this type may be valuable for a power system operator and companies selling electricity in order to match their offer to customers better or for people managing electricity consumption in buildings.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 1; art. no. e136216, 1--8
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An application of continuous wavelet transform and wavelet coherence for residential power consumer load profiles analysis
Autorzy:
Kapler, Piotr
Powiązania:
https://bibliotekanauki.pl/articles/2090695.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
residential power consumers
load profiles
power demand
continuous wavelet transform
wavelet coherence
odbiorcy energii lokalni
zapotrzebowanie na energię
profil obciążenia
transformata falkowa ciągła
spójność falkowa
Opis:
Load profiles of residential consumers are very diverse. This paper proposes the usage of a continuous wavelet transform and wavelet coherence to perform analysis of residential power consumer load profiles. The importance of load profiles in power engineering and common shapes of profiles along with the factors that cause them are described. The continuous wavelet transform and wavelet coherence has been presented. In contrast with other studies, this research has been conducted using detailed (not averaged) load profiles. Presented load profiles were measured separately on working day and weekend during winter in two urban households. Results of applying the continuous wavelet transform for load profiles analysis are presented as coloured scalograms. Moreover, the wavelet coherence was used to detect potential relationships between two consumers in power usage patterns. Results of coherence analysis are also presented in a colourful plots. The conducted studies show that the Morlet wavelet is slightly better suitable for load profiles analysis than the Meyer’s wavelet. Research of this type may be valuable for a power system operator and companies selling electricity in order to match their offer to customers better or for people managing electricity consumption in buildings.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 1; e136216, 1--8
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Signal analysis on soil stress from vibrating compaction based on wavelet transform
Autorzy:
Qing-Zhe, Z.
Bing, Y.
Jing-Liang, D.
Bao-Gui, Y.
Powiązania:
https://bibliotekanauki.pl/articles/231144.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
grunt
zagęszczanie wibracyjne
naprężenia ściskające
analiza sygnałów
transformata falkowa
wykrywanie osobliwości
soil
vibrating compaction
compressive stress
signal analysis
wavelet transform
singularity detection
Opis:
The paper presented the wavelet transform method for de-noising and singularity detection to soil compressive stress signal. The study results show that the reconstruction signals by the wavelet de-noising keeps the low frequency component at [0, 31.25Hz] of the original signal and improves the high frequency property at other frequency bands. The impaction time from the start time to resonance time of the stress signals varies with the depth of the soil. With the increase of times of compaction, the impaction time of the stress is decreasing in every layer. But the speed of reaching compacted status in each layer is different.
Źródło:
Archives of Civil Engineering; 2014, 60, 2; 257-268
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of deviations of cylindrical surfaces with the use of wavelet transform
Autorzy:
Stępień, K.
Makieła, W.
Powiązania:
https://bibliotekanauki.pl/articles/220818.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelet transform
cylindricity profile
decomposition
approximation
Opis:
Wavelet transform becomes a more and more common method of processing 3D signals. It is widely used to analyze data in various branches of science and technology (medicine, seismology, engineering, etc.). In the field of mechanical engineering wavelet transform is usually used to investigate surface micro- and nanotopography. Wavelet transform is commonly regarded as a very good tool to analyze non-stationary signals. However, to analyze periodical signals, most researchers prefer to use well-known methods such as Fourier analysis. In this paper authors make an attempt to prove that wavelet transform can be a useful method to analyze 3D signals that are approximately periodical. As an example of such signal, measurement data of cylindrical workpieces are investigated. The calculations were performed in the MATLAB environment using the Wavelet Toolbox.
Źródło:
Metrology and Measurement Systems; 2013, 20, 1; 139-150
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Certain properties of continuous fractional wavelet transform on Hardy space and Morrey space
Autorzy:
Verma, Amit K.
Gupta, Bivek
Powiązania:
https://bibliotekanauki.pl/articles/2049016.pdf
Data publikacji:
2021
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fractional Fourier transform
continuous fractional wavelet transform
Hardy space
Morrey space
Opis:
In this paper we define a new class of continuous fractional wavelet transform (CFrWT) and study its properties in Hardy space and Morrey space. The theory developed generalize and complement some of already existing results.
Źródło:
Opuscula Mathematica; 2021, 41, 5; 701-723
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Falkowy korelator połączonej transformaty Fouriera
Wavelet transform correlator for Fourier joint transform purposes
Autorzy:
Niedziela, T.
Powiązania:
https://bibliotekanauki.pl/articles/314122.pdf
Data publikacji:
2016
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
metody korelacyjne
transformata Fouriera
metody optoelektroniczne
correlation methods
Fourier transform
optoelectronic methods
Opis:
Niniejsza praca stanowi próbę dyskusji występujących często kłopotów technicznych w dziedzinie korelacyjnych metod rozpoznawania ze scen z wieloma zaszumionymi obiektami. Wskazano na nieuniknione problemy jakich należy oczekiwać w wielu praktycznych zastosowaniach metod korelacyjnych. Szybkie metody optoelektroniczne skutecznie eliminują nieostrość pików korelacyjnych. Symulacje komputerowe metod korelacyjnych mogą istotnie obniżyć koszty budowy układów połączonej transformaty Fouriera.
The paper discusses the technical disadvantages of correlation methods as they are referred to recognition scenes with the multi noisy objects. There are shown the problems of correlation methods difficult to be avoided in practice. In course of that the fast optoelectronic methods eliminating non sharpness of correlation picks and advantages of computer simulations are proposed. Such procedures allow to reduce the costs of application of the joint Fourier Transform methods.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2016, 17, 6; 1458-1461
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Damage localization in truss girders by an application of the discrete wavelet transform
Autorzy:
Knitter-Piątkowska, Anna
Kawa, Olga
Guminiak, Michał Jan
Powiązania:
https://bibliotekanauki.pl/articles/2204501.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
truss structures
damage localization
finite element method
discrete wavelet transform
konstrukcja kratownicowa
lokalizacja uszkodzeń
metoda elementów skończonych
dyskretna transformata falkowa
Opis:
The paper demonstrates the potential of wavelet transform in a discrete form for structural damage localization. The efficiency of the method is tested through a series of numerical examples, where the real flat truss girder is simulated by a parameterized finite element model. The welded joints are introduced into the girder and classic code loads are applied. The static vertical deflections and rotation angles of steel truss structure are taken into consideration, structural response signals are computed at discrete points uniformly distributed along the upper or lower chord. Signal decomposition is performed according to the Mallat pyramid algorithm. The performed analyses proved that the application of DWT to decompose structural response signals is very effective in determining the location of the defect. Evident disturbances of the transformed signals, including high peaks, are expected as an indicator of the defect existence in the structure. The authors succeeded for the first time in the detection of breaking the weld in the truss node as well as proved that the defect can be located in the diagonals.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 1; art. no. e144581
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Image compression and encryption algorithm with wavelet-transform-based 2D compressive sensing
Autorzy:
Fan, Jing-Hui
Liu, Xian-Bao
Chen, Yan-Bin
Powiązania:
https://bibliotekanauki.pl/articles/175122.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wavelet transform
compressive sensing
chaos scrambling
image encryption
image compression
Opis:
By combining a wavelet transform with chaos scrambling, an image compression and encryption algorithm based on 2D compressive sensing is designed. The wavelet transform is employed to obtain the sparse representation of a plaintext image. The sparse image is measured in two orthogonal directions by compressive sensing. Then, the result of 2D compressive sensing is confused by the Arnold transform and the random pixel scrambling. The combination of four-dimensional chaos and logistic map is exploited to generate the first row of the key-controlled circulant matrix. The proposed algorithm not only carries out image compression and encryption simultaneously, but also reduces the consumption of the key by controlling the generation of measurement matrix. Experimental results reveal that the proposed image compression and encryption algorithm is resistant to noise attacks with good compression performance and high key sensitivity.
Źródło:
Optica Applicata; 2019, 49, 3; 461-472
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Direct measurement of surface acoustic wave velocities and accuracy enhancement by wavelet transform
Autorzy:
Kosbi, K.
Scheer, U.
Boseck, S.
Powiązania:
https://bibliotekanauki.pl/articles/331852.pdf
Data publikacji:
1997
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The aim of this work is to show that the wavelet transform as an image processing technique has the capability to improve quantitative measurements of surface acoustic wave (SAW) velocities. An outline of the basic properties of the wavelet transform and its advantages is given. We apply the wavelet transform to a recently developed measurement technique for the determination of SAW velocities. This technique is based on a modified scanning acoustic microscope (SAM) and can be thought as directly imaging SAWs that propagate on the surface of a solid. Results for the SAW velocity of silicon single crystals are presented.
Źródło:
Hydroacoustics; 1997, 1; 195-198
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High impedance fault detection in radial distribution network using discrete wavelet transform technique
Autorzy:
Suliman, Mohammed Yahya
Alkhayyat, Mahmood Taha
Powiązania:
https://bibliotekanauki.pl/articles/1955195.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
high impedance fault
HIF
multiresolution analysis
MRA
overcurrent relays
discrete wavelet transform
DWT
uszkodzenie o wysokiej impedancji
analiza wielorozdzielcza
przekaźniki nadprądowe
dyskretna transformata falkowa
Opis:
Detecting high impedance faults (HIFs) is one of the challenging issues for electrical engineers. This type of fault occurs often when one of the overhead conductors is downed and makes contact with the ground, causing a high-voltage conductor to be within the reach of personnel. As the wavelet transform (WT) technique is a powerful tool for transient analysis of fault signals and gives information both on the time domain and frequency domain, this technique has been considered for an unconventional fault like high impedance fault. This paper presents a new technique that utilizes the features of energy contents in detail coefficients (D4 and D5) from the extracted current signal using a discrete wavelet transform in the multiresolution analysis (MRA). The adaptive neurofuzzy inference system (ANFIS) is utilized as a machine learning technique to discriminate HIF from other transient phenomena such as capacitor or load switching, the new protection designed scheme is fully analyzed using MATLAB feeding practical fault data. Simulation studies reveal that the proposed protection is able to detect HIFs in a distribution network with high reliability and can successfully differentiate high impedance faults from other transients.
Źródło:
Archives of Electrical Engineering; 2021, 70, 4; 873-886
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Continuous wavelet transform as effective tools for detecting motion artefacts in electrogastrographical signals
Autorzy:
Mika, B.
Tkacz, E.
Kostka, P. S.
Powiązania:
https://bibliotekanauki.pl/articles/333532.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Śląski. Wydział Informatyki i Nauki o Materiałach. Instytut Informatyki. Zakład Systemów Komputerowych
Tematy:
żołądek
falka
przetwarzanie sygnałów
electrogastrogram
EGG
stomach
wavelet
signal processing
Opis:
The cutaneous recording of gastric myoelectrical activity of the stomach known as electrogastrography (EGG) seems to be the promising tool for the non-invasive assessment of gastric motility. Unfortunately the EGG recording is usually severely contaminated both by motion artefacts and endogenous biological noise source. In order to use EGG signals as reliable diagnostic tool it is necessity to look for the effective artefacts removal methods. In this paper Continuous Wavelet Transform (CWT) was applied for detection motion artefacts from the EGG data. The set of own mother wavelets extracted directly from EGG signal was created and applied for detecting motion artefacts from one channel EGG recording. The results was compared with the effects obtained by using standard mother wavelets. The proposed method based on CWT with own mother wavelet presents very good performance for detecting motion artefacts from the EGG data.
Źródło:
Journal of Medical Informatics & Technologies; 2011, 18; 59-68
1642-6037
Pojawia się w:
Journal of Medical Informatics & Technologies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformata falkowa w diagnozowaniu urządzeń wyciągowych
Wavelet transform in diagnostics of hoisting machines
Autorzy:
Batko, W.
Mikulski, A.
Powiązania:
https://bibliotekanauki.pl/articles/328926.pdf
Data publikacji:
2004
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
przetwarzanie sygnałów
liny stalowe
badania nieniszczące
analiza falkowa
NDT
non-destructive testing
steel ropes
signal processing
wavelet analysis
Opis:
W artykule przedstawiono nowe metody przetwarzania sygnałów niestacjonarnych zastosowane w praktyce do diagnostyki urządzeń wyciągowych. Przedmiotem badań były liny stalowe, węzły łożyskowe kół linowych oraz elementy zbrojenia szybowego. Przetwarzanie sygnałów pomiarowych każdego z urządzeń napotyka inne problemy. W pierwszym przypadku należy rozpoz.nać składnik impulsowy w sygnale, który jest symptomem uszkodzenia, w przypadku łożysk należy rozwiązać problem niestacjonarności związanej ze zmienną prędkością łożyska, natomiast w ostatnim przykładzie kłopot sprawia filtracja silnie tłumionego sygnału pomiarowego. Problemy powyższe udało się rozwiązać wykorzystując własności filtrujące i aproksymujące analizy falkowej.
This paper presents new methods processing of non-stationary signals in diagnostics of hoisting machines. Objects of investigation were: steel wire ropes, rolling bearings and shaft inner structure. Signal processing of them to come across different problems. In the first we have to recognize an impulse component in signal. This component can be a symptom of a failure and its proper identification is necessary while estimation of a rope's wear and tear. In case of bearings there are some problems with non-stationary connected with changeable rotary speed. In the third case the problem is filtration of powerful damped signal. Problems above-mentioned are solved by means of wavelet analysis.
Źródło:
Diagnostyka; 2004, 30, T. 1; 61-68
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformata falkowa wybranych sygnałów symulacyjnych
The discrete wavelet transform of the selected simulation signals
Autorzy:
Józefczyk, I.
Małecki, R.
Powiązania:
https://bibliotekanauki.pl/articles/257140.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
sygnał
dyskretna transformacja falkowa
falka
signal
discrete wavelet transform
wavelet
Opis:
W artykule przedstawiono dyskretną transformcję falkową (DWT) dwóch sygnałów symulacyjnych z zastosowaniem falki dmey (dyskretny Meyer), której użyteczność potwierdziły wcześniejsze badania [5]. Przedmiotem badań były sygnały - wzorce oraz sygnały powstałe z wzorca poprzez dodanie tła losowego - zakłóceń. W celu wyeliminowania czynnika losowego sygnały zakłócone poddawano transformacji falkowej. Celem badań było poszukiwanie narzędzi statystycznych do określenia jakości transformacji falką dmey na różnych poziomach dekompozycji.
In the article, there was a Discrete Wavelet Transform (DWT) of two simulation signals shown with the usage of waves which had been proven to be effective in previous research. The subjects of the article are signals-modules and the signals created from the modules by adding a randomised background-interference. In order to eliminate the random factor, DWT was used against disrupted signals. The aim of the research was the search for statistical tools to assess the quality of dmey wave transformation.
Źródło:
Problemy Eksploatacji; 2013, 1; 27-34
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improving energy compaction of a wavelet transform using genetic algorithm and fast neural network
Autorzy:
Stolarek, J.
Powiązania:
https://bibliotekanauki.pl/articles/964025.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelet transform
neural networks
genetic algorithms
signal processing
lattice structure
Opis:
In this paper a new method for adaptive synthesis of a smooth orthogonal wavelet, using fast neural network and genetic algorithm, is introduced. Orthogonal lattice structure is presented. A new method of supervised training of fast neural network is introduced to synthesize a wavelet with desired energy distribution between output signals from low–pass and high–pass filters on subsequent levels of a Discrete Wavelet Transform. Genetic algorithm is proposed as a global optimization method for defined objective function, while neural network is used as a local optimization method to further improve the result. Proposed approach is tested by synthesizing wavelets with expected energy distribution between low– and high–pass filters. Energy compaction of proposed method and Daubechies wavelets is compared. Tests are performed using image signals.
Źródło:
Archives of Control Sciences; 2010, 20, 4; 417-433
1230-2384
Pojawia się w:
Archives of Control Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on marine fhotovoltaic power forecasting based on Wavelet Transform and Echo State Network
Autorzy:
Du, X.
Wang, S.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/260584.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
marine photovoltaic power system
power forecasting
Wavelet Transform
Echo State Network
Opis:
With the rapid development of photovoltaic power generation technology, photovoltaic power generation system has gradually become an important component of the integrated energy system of marine. High precision short-term photovoltaic power generation forecasting is becoming one of the key technologies in ship energy saving and ship energy efficiency improving. Aiming at the characteristics of marine photovoltaic power generation system, we designed a highprecision power forecasting model (WT+ESN) for marine photovoltaic power generation system with anti-marine environmental interference. In this model, the information mining of the photovoltaic system in marine environment is carried out based on wavelet theory, then the forecasting model basing on echo state network is construct ed. Lastly, three kinds of error metrics are compared with the three traditional models by Matlab, the result shows that the model has high forecasting accuracy and strong robustness to marine environmental factors, which is of great significance to save fuel for ships, improve the energy utilization rate and assist the power dispatching and fuel dispatching of the marine power generation system.
Źródło:
Polish Maritime Research; 2017, S 2; 53-59
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vision-based parking lot occupancy evaluation system using 2D separable discrete wavelet transform
Autorzy:
Kłosowski, M.
Wójcikowski, M.
Czyżewski, A.
Powiązania:
https://bibliotekanauki.pl/articles/201876.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
computer vision
discrete wavelet transform
sensor system
sensor application
wizja komputerowa
czujnik
dyskretna transformata falkowa
Opis:
A simple system for rough estimation of the occupancy of an ad-hoc organized parking lot is presented. A reasonably simple microprocessor hardware with a low resolution monochrome video camera observing the parking lot from the location high above the parking surface is capable of running the proposed 2-D separable discrete wavelet transform (DWT)-based algorithm, reporting the percentage of the observed parking area occupied by cars. A simple calibration is needed – the mask covering all the areas outside the parking lot must be prepared. The proposed system has been tested on the dedicated FPGA-based hardware in real conditions and proven immune to scene and light changes. As it is discussed in the paper, it can be used in low-power wireless sensor networks.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 3; 569--573
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time invariant property of weighted circular convolution and its application to continuous wavelet transform
Autorzy:
Yi, Hua
Ru, Yu-Le
Dai, Yin-Yun
Powiązania:
https://bibliotekanauki.pl/articles/2086853.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
continuous wavelet transform
linear convolution
weighted circular convolution
generalized discrete Fourier transform
ciągła transformata falkowa
splot liniowy
splot kołowy ważony
transformata Fouriera uogólniona dyskretna
Opis:
Time invariant linear operators are the building blocks of signal processing. Weighted circular convolution and signal processing framework in a generalized Fourier domain are introduced by Jorge Martinez. In this paper, we prove that under this new signal processing framework, weighted circular convolution also has a generalized time invariant property. We also give an application of this property to algorithm of continuous wavelet transform (CWT). Specifically, we have previously studied the algorithm of CWT based on generalized Fourier transform with parameter 1. In this paper, we prove that the parameter can take any complex number. Numerical experiments are presented to further demonstrate our analyses.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2021, 69, 4; e137726, 1--9
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Digital watermarking algorithm based on 4-level discrete wavelet transform and discrete fractional angular transform
Autorzy:
Li, Jing-You
Zhao, Chun-Hui
Zhang, Guang-Da
Powiązania:
https://bibliotekanauki.pl/articles/2033921.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
digital watermarking algorithm
mix optical bistability
Harris feature point detection
discrete wavelet transform
discrete fractional angular transform
singular value decomposition
Opis:
Nowadays, there are many watermarking algorithms based on wavelet transform. The simple one is to insert directly the watermark into the wavelet transform coefficients. However, most of the existing watermarking schemes can only resist traditional signal processing attacks, such as image compression, noise and filtering. When the watermarked image is subject to geometric transformations, especially rotation attack, it is hard to detect the watermark successfully. In this paper, a digital watermarking algorithm is proposed based on 4-level discrete wavelet transform and discrete fractional angular transform. To enhance the security of the algorithm, the watermark is scrambled with the simplicity of Arnold transform and chaos-based mix optical bistability model, since the chaos is pseudorandom and sensitive to the initial values. And the watermark is embedded into the medium frequency sub-band of the 1-level wavelet decomposition according to the Harris feature point detection. Simulation results show that the proposed digital watermarking algorithm by combining 4-level discrete wavelet transform with discrete fractional angular transform could resist rotation attack and other common attacks.
Źródło:
Optica Applicata; 2021, 51, 4; 605-619
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selection of viscous damping coefficients using the continuous wavelet transform method for a gear system
Autorzy:
Yousfi, Nourhaine
Zghal, Bacem
Akrout, Ali
Walha, Lassaad
Haddar, Mohamed
Powiązania:
https://bibliotekanauki.pl/articles/2055029.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
viscous damping formulation
optimum frequencies
continuous wavelet transform
dominant frequency
Opis:
Viscous damping is frequently used in the equation of motion to present the dissipation mechanism of a mechanical system. The orders of frequencies can be easily selected to determine viscous damping coefficients (VDCs) when the degree of freedom of the structure is low. For complex structures, difficulties in selecting the orders of reference frequencies to obtain reasonable VSCs are encountered. This paper mainly discusses the capability of the CWT method to select optimum frequencies of viscous damping formulation. The proposed procedure considers both the classical Rayleigh, modal and the proposed full model modal damping. The method is validated using a numerical time domain response of a two-stage gear system.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 3; 585--598
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Selected problems of damage detection in internally supported plates using one-dimensional Discrete Wavelet Transform
Autorzy:
Guminiak, M.
Knitter-Piątkowska, A.
Powiązania:
https://bibliotekanauki.pl/articles/281731.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
Kirchhoff plates
Boundary Element Method
Discrete Wavelet Transform
Opis:
The paper is concerned with damage detection in plates while using the Discrete Wavelet Transform (DWT). Rectangular plate structures resting on a Winkler or elastic half-space type foundation, with free boundaries are examined. Plate bending is described and solved by the Boundary Element Method in a direct approach. Defects are introduced by additional edges forming slots in relation to the basic plate domain. Numerical investigation is conducted basing on signal analysis of the structural static response and by taking advantage of multi-resolution analysis (MRA) of the signal function which can be represented in a multi-scale manner. The obtained signal is decomposed with the use of Daubechies or Coiflet wavelet families. The white noise generator is used to model measurement inaccuracy which is an inevitable element of a real experiment. The efficiency of DWT of the contaminated signal in damage detection is studied.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 3; 631-644
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Transformata falkowa w wibroakustycznej diagnostyce technicznej
Discrete wavelet transform of select simualated vibro-acoustic signal
Autorzy:
Józefczyk, I.
Powiązania:
https://bibliotekanauki.pl/articles/257988.pdf
Data publikacji:
2006
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
sygnał
dyskretna transformacja falkowa
falka
falka macierzysta
discrete wavelet transform
signal
vibroacoustic signal
Opis:
W artykule przedstawiono analizę wielorozdzielczą symulowanego sygnału wibroakustycznego. Celem analizy było określenie kryterium wyboru falki oraz głębokości dekompozycji w zależności od rodzaju zakłóceń wprowadzonych do sygnału wibroakustycznego. Artykuł przedstawia dekompozycje z zastosowaniem tylko tych falek, za pomocą których uzyskano najlepsze odzwierciedlenie zaprogramowanych informacji.
The paper presents multi-distributive analysis of simulated vibroacoustic signal. The aim of the analysis was defining the criterion of wavelet selection and intensity of the decomposition according to the type of noise added to the vibroacoustic signal. The article describes only those analyses by wavelets which appeared sufficiently good with respect to ordinary data.
Źródło:
Problemy Eksploatacji; 2006, 1; 7-13
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical properties of wavelet transform coefficients of backscattering signal from soft tissues and their phantoms
Autorzy:
Gambin, B.
Doubrovina, O.
Powiązania:
https://bibliotekanauki.pl/articles/331908.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper contains the wavelet approach to registered backscattered RF signals from two different cases. First, the wavelet analysis has been performed for RF signals registered from soft tissue phantoms. The second case is the wavelet analyses of RF scattered signals from regions of healthy and BCC changed human skin. The three phantoms made from tissuemimicking material with different structures have been measured. We claim that there are visible differences in the statistical parameters of wavelets coefficients of signals between healthy and BCC changed skin regions as well as between phantoms without scatterers and with different number of strong small scatterers.
Źródło:
Hydroacoustics; 2013, 16; 59-66
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The progressive transmission method based on the 2-D wavelet transform for a digital video signal
Autorzy:
Murawski, K.
Powiązania:
https://bibliotekanauki.pl/articles/273329.pdf
Data publikacji:
2001
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
wavelet transform
digital transmission
video stream
multiresolution analysis
Opis:
This paper presents a method of progressive digital transmission of a video stream, based on picture frame multi-resolution analysis.
Źródło:
Biuletyn Instytutu Automatyki i Robotyki; 2001, R. 7, nr 15, 15; 15-25
1427-3578
Pojawia się w:
Biuletyn Instytutu Automatyki i Robotyki
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pre-trained deep neural network using sparse autoencoders and scattering wavelet transform for musical genre recognition
Autorzy:
Kleć, M.
Korzinek, D.
Powiązania:
https://bibliotekanauki.pl/articles/952940.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
Sparse Autoencoders
deep learning
genre recognition
Scattering Wavelet Transform
Opis:
Research described in this paper tries to combine the approach of Deep Neural Networks (DNN) with the novel audio features extracted using the Scatter- Ing Wavelet Transform (SWT) for classifying musical genres. The SWT uses A sequence of Wavelet Transforms to compute the modulation spectrum coef- Ficients of multiple orders, which has already shown to be promising for this Task. The DNN in this work uses pre-trained layers using Sparse Autoencoders (SAE). Data obtained from the Creative Commons website jamendo.com is Used to boost the well-known GTZAN database, which is a standard bench- mark for this task. The final classifier is tested using a 10-fold cross validation To achieve results similar to other state-of-the-art approaches.
Źródło:
Computer Science; 2015, 16 (2); 133-144
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An attempt of an employment of a continuous wavelet transform for evaluation of temporary comfort disturbances
Autorzy:
Grzegożek, W.
Szczygieł, J.
Król, S.
Powiązania:
https://bibliotekanauki.pl/articles/244076.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
ride comfort analysis
continuous wavelet transform (CWT)
vibration discomfort
comfort on discrete events
Opis:
This paper focuses on an attempt of an employment of a continuous wavelet transform as a tool of time-frequency analysis to identify and asses the comfort on discrete events. A short review of practical procedures for predicting vibration discomfort defined by ISO 2631-5 and BS 6041, ENV 12299 is enclosed. The results of research of tram temporary comfort disturbances are also described in the paper. The research enclosed the comfort on curve transitions and comfort on discrete events. Research was carried out in the old city centre as in this area there are a lot of curves and large number of excitations can be expected. An exemplary analysis of tram comfort using a continuous wavelet transform is presented. The signals in time intervals in which PCr and PDE indexes that have high values are analyzed. Moreover, the evaluation of comfort disturbances using wavelet transform based on Morlet mother wavelet is done. The continuous wavelet transform that was employed proves high usefulness of this method for assessment of temporary comfort disturbances. The results of Fourier transform of the signals measured are also presented in this article. Traditional methods based on the vibration dose value and frequency weighting methodsfor assessment of these vibrations are less useful in respect to non-stationary character of temporary disturbances.
Źródło:
Journal of KONES; 2009, 16, 1; 165-172
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Speech Enhancement Based on the Multi-Scales and Multi-Thresholds of the Auditory Perception Wavelet Transform
Autorzy:
Tao, Z.
Zhao, H. M.
Zhang, X-J.
Wu, D.
Powiązania:
https://bibliotekanauki.pl/articles/177021.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
speech enhancement
low SNR
auditory perception wavelet transform
unvoiced enhancement
masking effect
Opis:
This paper proposes a speech enhancement method using the multi-scales and multi-thresholds of the auditory perception wavelet transform, which is suitable for a low SNR (signal to noise ratio) environment. This method achieves the goal of noise reduction according to the threshold processing of the human ear’s auditory masking effect on the auditory perception wavelet transform parameters of a speech signal. At the same time, in order to prevent high frequency loss during the process of noise suppression, we first make a voicing decision based on the speech signals. Afterwards, we process the unvoiced sound segment and the voiced sound segment according to the different thresholds and different judgments. Lastly, we perform objective and subjective tests on the enhanced speech. The results show that, compared to other spectral subtractions, our method keeps the components of unvoiced sound intact, while it suppresses the residual noise and the background noise. Thus, the enhanced speech has better clarity and intelligibility.
Źródło:
Archives of Acoustics; 2011, 36, 3; 519-532
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution of some problems of single-scale wavelet transform processor using a magnetostatic surface wave device
Autorzy:
Lu, W.
Kuang, L.
Lü, X.
Zhu, C.
Zhang, T.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/221174.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
wavelet transform processor
magnetostatic surface wave (MSSW)
interdigital transducer
direct coupling
insertion loss
Opis:
In this paper, we investigate the implementation schemes of a single-scale wavelet transform processor using magnetostatic surface wave (MSSW) devices. There are three implementation schemes: the interdigital transducer, the meander line transducer and the grating transducer. Because the interdigital transducer has excellent properties, namely, good frequency characteristic and low insertion loss, we use the interdigital transducer as the implementation scheme of a single-scale wavelet transform processor using MSSW device. In the paper, we also present the solutions to the three key problems: the direct coupling between the input transducer and the output transducer, the insertion loss, and the loss characteristics of the gyromagnetic film having an influence on the wavelet transform processor. There are two methods of reducing the direct coupling between the input transducer and the output transducer: increasing the distance between the input transducer and the output transducer, and placing a metal "wall" between the input transducer and the output transducer. There also are two methods of reducing the insertion loss of a single-scale wavelet transform processor using a MSSW device for scale: the appropriate thickness of the yttrium iron garnet (YIG) film and the uniform magnetic field. The smaller the ferromagnetic resonance linewidth of the gyromagnetic film, the smaller the magnetostatic wave propagation loss.
Źródło:
Metrology and Measurement Systems; 2012, 19, 4; 685-692
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using the discrete wavelet transform in assessing the effectiveness of rehabilitation in patients after ACL reconstruction
Autorzy:
Czaplicki, A.
Kuniszyk-Jóźkowiak, W.
Jaszczuk, J.
Jarocka, M.
Walawski, J.
Powiązania:
https://bibliotekanauki.pl/articles/306454.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
ACL
rehabilitacja
transformacja falkowa
wavelet
rehabilitation
Opis:
Purpose: The purpose of the current study was to assess the effectiveness of rehabilitation in patients after anterior cruciate ligament reconstruction (ACLR) using a wavelet analysis of the torque-time curve patterns of the extensors of the affected knee. The analysis aimed at the quantitative evaluation of irregularities in these torque-time patterns. Methods: The study involved a group of 22 men who had had ACL reconstruction. The torque-time characteristics were recorded 3, 6 and 12 months after the surgery by an isokinetic dynamometer. They were then examined using the orthogonal Daubechies 4 (Db 4) and biorthogonal Bior 3.1 wavelets. Results: A statistical analysis of the results revealed significant differences in values of the high-frequency energy stored in the details of the signal from the dynamometer between the first and last measurements, both for the Db 4 ( p ≤ 0.023) and Bior 3.1 ( p ≤ 0.01) wavelets. These differences were found in 73% of patients whose curve patterns were analysed using the Db 4 wavelet and in 82% of patients in the case of the Bior 3.1 wavelet. Conclusions: The wavelet transform proved to be an effective research tool in the qualitative evaluation of irregularities occurring in the curve patterns of the torque generated by the extensors of the ACL reconstructed knee. The findings of the study suggest that time-frequency analyses of these characteristics can be of practical importance, as they help assess the state of the patient’s knee joint and his progress in rehabilitation after ACLR.
Źródło:
Acta of Bioengineering and Biomechanics; 2017, 19, 3; 139-146
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
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