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Tytuł:
Analyzing the variations in roundness profile parameters during the wavelet decomposition process using the MATLAB environment
Autorzy:
Adamczak, S.
Makieła, W.
Powiązania:
https://bibliotekanauki.pl/articles/221022.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
mother wavelet
Fourier transform
wavelet transform
surface texture
surface roundness
roundness profile parameters
Opis:
Signal analysis performed during surface texture measurement frequently involves applying the Fourier transform. The method is particularly useful for assessing roundness and cylindrical profiles. Since the wavelet transform is becoming a common tool for signal analysis in many metrological applications, it is vital to evaluate its suitability for surface texture profiles. The research presented in this paper focused on signal decomposition and reconstruction during roundness profile measurement and the effect of these processes on the changes in selected roundness profile parameters. The calculations were carried out on a sample of 100 roundness profiles for 12 different forms of mother wavelets using MATLAB. The use of Spearman's rank correlation coefficients allowed us to evaluate the relationship between the two chosen criteria for selecting the optimal mother wavelet.
Źródło:
Metrology and Measurement Systems; 2011, 18, 1; 25-33
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of multiband filtering, empirical mode decomposition and short-time fourier transform used to extract physiological components from long-term heart rate variability
Autorzy:
Adamczyk, Krzysztof
Polak, Adam G.
Powiązania:
https://bibliotekanauki.pl/articles/2052173.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
heart rate variability
nonstationary signal analysis
multiband filtering
empirical mode decomposition
short-time Fourier transform
Hilbert transform
Opis:
Heart rate is constantly changing under the influence of many control signals, as manifested by heart rate variability (HRV). HRV is a nonstationary, irregularly sampled signal, the spectrum of which reveals distinct bands of high, low, very low and ultra-low frequencies (HF, LF, VLF, ULF). VLF and ULF components are the least understood, and their analysis requires HRV records lasting many hours. Moreover, there are still no well-established methods for the reliable extraction of these components. The aim of this work was to select, implement and compare methods which can solve this problem. The performance of multiband filtering (MBF), empirical mode decomposition and the short-time Fourier transform was tested, using synthetic HRV as the ground truth for methods evaluation as well as real data of three patients selected from 25 polysomnographic records with a clear HF component in their spectrograms. The study provided new insights into the components of long-term HRV, including the character of its amplitude and frequency modulation obtained with the Hilbert transform. In addition, the reliability of the extracted HF, LF, VLF and ULF waveforms was demonstrated, and MBF turned out to be the most accurate method, though the signal is strongly nonstationary. The possibility of isolating such waveforms is of great importance both in physiology and pathophysiology, as well as in the automation of medical diagnostics based on HRV.
Źródło:
Metrology and Measurement Systems; 2021, 28, 4; 643-660
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation, characterization and optimization of cross-linked fructosyltransferase aggregates for the production of prebiotic fructooligosaccharides
Autorzy:
Ademakinwa, A.N.
Ayinla, Z.A.
Omitogun, O.G.
Agboola, F.K.
Powiązania:
https://bibliotekanauki.pl/articles/81247.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fructosyltransferase
Aureobasidium pullulans
fructooligosaccharide
prebiotic
statistical optimization
scanning electron microscopy
X-ray spectroscopy
Fourier transform infrared spectroscopy
biotransformation
chemometric analysis
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fourier, Laguerre, Laplace Transforms with applications
Autorzy:
Aghili, Arman
Powiązania:
https://bibliotekanauki.pl/articles/2052384.pdf
Data publikacji:
2021
Wydawca:
Politechnika Rzeszowska im. Ignacego Łukasiewicza. Oficyna Wydawnicza
Tematy:
Fourier transform
Laplace transform
Laguerre transform
singular integral equation
Bessel's functions
fractional heat equation
przekształcenie Fouriera
przekształcenie Laplace'a
przekształcenie Laguerre'a
osobliwe równanie całkowe
funkcje Bessela
ułamkowe równanie ciepła
Opis:
In this article, the author considered certain time fractional equations using joint integral transforms. Transform method is a powerful tool for solving singular integral equations, integral equation with retarded argument, evaluation of certain integrals and solution of partial fractional differential equations. The obtained results reveal that the transform method is very convenient and effective. Illustrative examples are also provided.
Źródło:
Journal of Mathematics and Applications; 2021, 44; 5-17
1733-6775
2300-9926
Pojawia się w:
Journal of Mathematics and Applications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Construction of nonuniform periodic wavelet frames on non-Archimedean fields
Autorzy:
Ahmad, Owais
Powiązania:
https://bibliotekanauki.pl/articles/2078967.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Nonuniform frame
wavelet mask
scaling function
Fourier transform
Opis:
In real life applications not all signals are obtained by uniform shifts; so there is a natural question regarding analysis and decompositions of these types of signals by a stable mathematical tool. Gabardo and Nashed, and Gabardo and Yu filled this gap by the concept of nonuniform multiresolution analysis and nonuniform wavelets based on the theory of spectral pairs for which the associated translation set \(\Lambda= \{0,r/N\}+2\mathbb{Z}\) is no longer a discrete subgroup of \(\mathbb{R}\) but a spectrum associated with a certain one-dimensional spectral pair and the associated dilation is an even positive integer related to the given spectral pair. In this paper, we introduce a notion of nonuniform periodic wavelet frame on non-Archimedean field. Using the Fourier transform technique and the unitary extension principle, we propose an approach for the construction of nonuniform periodic wavelet frames on non-Archimedean fields.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2020, 74, 2; 1-17
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparative analysis of variants of Gabor-Wigner Transform for crossterm reduction
Autorzy:
Ajab, M.
Taj, I. A.
Khan, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/221743.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Wigner Distribution
Gabor transform
Gabor Wigner Transform
fractional Fourier transform
Opis:
Gabor Wigner Transform (GWT) is a composition of two time-frequency planes (Gabor Transform (GT) and Wigner Distribution (WD)), and hence GWT takes the advantages of both transforms (high resolution of WD and cross-terms free GT). In multi-component signal analysis where GWT fails to extract auto-components, the marriage of signal processing and image processing techniques proved their potential to extract autocomponents. The proposed algorithm maintained the resolution of auto-components. This work also shows that the Fractional Fourier Transform (FRFT) domain is a powerful tool for signal analysis. Performance analysis of modified fractional GWT reveals that it provides a solution of cross-terms of WD and blurring of GT.
Źródło:
Metrology and Measurement Systems; 2012, 19, 3; 499-508
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mycoremediation of Heavy Metals Contaminated Soil by Using Indigenous Metallotolerant Fungi
Autorzy:
Akram, Muhammad Bilal
Khan, Ibrar
Ur Rehman, Mujaddad
Sarwar, Abid
Ullah, Najeeb
ur Rahman, Shafiq
Aziz, Tariq
Alharbi, Metab
Alshammari, Abdulrahman
Alasmari, Abdullah F.
Powiązania:
https://bibliotekanauki.pl/articles/27315654.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Mycoremediation
Heavy Metals Contaminated Soil
Korangi Industrial Estate
FTIR
Fourier Transform Infrared Spectroscopy
SEM
Scanning Electron Microscope
Opis:
The present study was aimed to identify the indigenous fungal strains which could possibly be applied to the bioremediation of heavy metal-contaminated soil. The contaminated soil samples of Korangi Industrial Estate Karachi were found to have total concentration of Cu 1.044 mgL1 , and Pb 0.631 mgL–1. A total of eight indigenous strains of the fungus were isolated and screened for bioremediation capacity from heavy metals-contaminated soil. For the bioremediation of Lead (Pb) these same indigenous eight fungal strains were used for biological remediation. All the fungal isolated with enhanced bioremediation capability were through phenotypic and genotypical characterization. The topology of the phylograms established that the fungal isolates used in this study were allocated to: K1 (Penicillium notatum), K2 (Aspergillus parasiticus), K3 (Aspergillus fumigatus), K4 (Aspergillus flavus), K5 (Aspergillus terries), K6 (Fusarium solani), K7 (Penicillium chrysogenum), K8 (Aspergillus niger), K9 (Penicillium piceum) and K10 (Penicillium restrictum). Thus, K8 fungal isolate was found to be more efficient with maximum bioremediation capacity, for copper and lead removal efficiency, and selected for FTIR and SEM to find out the uptake of Cu and Pb which of the functional groups are involved, and further to detect the effects of bioleaching of both heavy metals on to the surface of K8 fungus biomass. The current study indicates that indigenous fungal isolates could be used with high potency to remediate or clean up the heavy metals-contaminated soil either by the technique of in situ or ex-situ bioremediation.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 3; 1--13
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Comparative Investigations to Evaluate Cavitation Conditions within a Centrifugal Pump Based on Vibration and Acoustic Analyses Techniques
Autorzy:
Al-Obaidi, Ahmed Ramadhan
Powiązania:
https://bibliotekanauki.pl/articles/177056.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
centrifugal pump
cavitation
Fast Fourier Transform
vibration
acoustic
normalise features
Opis:
Cavitation is an essential problem that occurs in all kinds of pumps. This cavitation contributes highly towards the deterioration in the performance of the pump. In industrial applications, it is very vital to detect and decrease the effect of the cavitation in pumps. Using different techniques to analysis and diagnose cavitation leads to increase in the reliability of cavitation detection. The use of various techniques such as vibration and acoustic analyses can provide a more robust detection of cavitation within the pump. In this work therefore, focus is put on detecting and diagnosing the cavitation phenomenon within a centrifugal pump using vibration and acoustic techniques. The results obtained from vibration and acoustic signals in time and frequency domains were analysed in order to achieve better understanding regarding detection of cavitation within a pump. The effect of different operating conditions related to the cavitation was investigated in this work using different statistical features in time domain analysis (TDA). Moreover, Fast Fourier Transform (FFT) technique for frequency domain analysis (FDA) was also applied. Furthermore, the comparison and evaluation system among different techniques to find an adequate technique incorporating for accuracy and to increase the reliability of detection and diagnosing different levels of cavitation within a centrifugal pump were also investigated.
Źródło:
Archives of Acoustics; 2020, 45, 3; 541-556
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, spectroscopic and thermogravimetric interpretations of UO2(II), ZrO(II), Zr(IV), VO(II) and V(V) ciprofloxacin antibiotic drug complexes
Autorzy:
Albedair, Lamia A.
Powiązania:
https://bibliotekanauki.pl/articles/1849331.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
ciprofloxacin
complexation
FTIR
Fourier transform infrared spectroscopy
diamagnetic
TEM
transmission electron microscopy
nanoscale
Opis:
New five ciprofloxacin (CIP) complexes of dioxouranium(II), oxozirconium(II), zirconium(IV), oxovanadium(II) and vanadium(IV) in the proportion 1:2 have been prepared using CIP as a drug chelate with UO2(NO3)2. 6H2O, ZrOCl2. 8H2O, ZrC4, VOSO4. xH2O and V2O5 respectively. The CIP complexes have been characterized based on the elemental analysis, molar conductance, magnetic, (FTIR & 1HNMR) spectral and thermal studies. The molar conductance studies of the synthesized complexes in DMSO solvent with concentration of 10–3 M indicate their non-electrolytic properties. At room temperature, the magnetic moment measurements revealed a diamagnetic behavior for all CIP prepared complexes. The different formulas of the new complexes can be represented as [UO2(CIP)2(NO3)2] (I), [VO(CIP)2(SO4)(H2O)] (II), [V2(O)(O2)2(CIP)2] (III), [Zr(O)(CIP)2(Cl)2] (IV), and [Zr(CIP)2(Cl)4] (V). The thermal analysis data of the complexes indicates the absence of coordinated water molecules except for vanadyl(II) complex (II). The CIP chelate is a uni-dentate ligand coordinated to the mentioned metal ion through terminal piperazinyl nitrogen. The transmission electron microscopy (TEM) investigation confirms the nano-structured form of the complexes.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 1; 45-52
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radial internal clearance analysis in ball bearings
Autorzy:
Ambrożkiewicz, Bartłomiej
Syta, Arkadiusz
Meier, Nicolas
Litak, Grzegorz
Georgiadis, Anthimos
Powiązania:
https://bibliotekanauki.pl/articles/1841795.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
ball bearings
radial internal clearance
statistical analysis
recurrence
fast fourier transform
continuous wavelet transform
Opis:
Radial internal clearance (RIC) is one of the most important parameters influencing on rolling bearing exploitation in mechanical systems. Lifetime of rotary machines strongly depends on a condition of applied rolling elements, thus a study on applied clearance is very important in terms of maintenance and reliability. This paper proposes, a novel approach of studying RIC, based on a nonlinear dynamics method called recurrences. The results are confronted with standard analyses, i.e. statistical condition indicators, Fast Fourier Transform and Continuous Wavelet Transform. The application of the mentioned methods allowed us to find the optimal radial clearance for operating bearings. To ensure precise measurements of the clearance, an automated setup for RIC measurements is applied and next mounted in a plummer block and tested to finally measure vibration acceleration. The proposed methods are useful for a condition monitoring and lifetime prediction of bearings or bearing-based systems in which a proper value of radial clearance is crucial.
Źródło:
Eksploatacja i Niezawodność; 2021, 23, 1; 42-54
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of sway and roll excitations on sloshing loads in a KC-1 membrane LNG tank
Autorzy:
An, Se-yeol
Jeong, Hyeon-won
Kim, Ohyoung
Shim, W. Jaewoo
Powiązania:
https://bibliotekanauki.pl/articles/34600997.pdf
Data publikacji:
2023
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
KC-1 membrane LNG tank
sloshing
sway
roll
coupled sway-roll
Fast Fourier transform (FFT)
Opis:
This study investigates the effects of sway and roll excitations on sloshing liquid loads in a tank, using Ansys Fluent software. The model considered in the study is a 1:50 scaled membrane-type tank, based on a KC-1 membrane LNG tank designed by Korea Gas Corporation (KOGAS). The volume of fluid (VOF) method is used to track the free surface inside the tank, and the standard k-ε model is applied to express the turbulent flow of the liquid. To explore the motion of the tank under excitation, a user-defined function (UDF) and a dynamic mesh technique are employed to control the external forces exerted on the tank through its motion. The results, in the form of time series data on the sloshing pressures in the tank under pure sway, roll, and coupled sway-roll, are analysed, with specific ranges for the excitation amplitudes and frequencies. We show that variations in excitation frequency and amplitude significantly influence the sloshing loads. Sloshing loads are found to intensify when the excitation frequency matches the tank’s primary natural frequency, 1.0 ω'1. Furthermore, with coupled sway-roll excitations, the sloshing loads are weakened when the sway and roll are in-phase and are intensified when these are out-of-phase. Fast Fourier transform analysis provides insights into the frequency domain, showing that the dominant frequency is 0.88 Hz and it is approximately equal to the tank’s primary natural frequency, 1.0 ω'1.
Źródło:
Polish Maritime Research; 2023, 4; 43-53
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wybrane aspekty cyfrowego przetwarzania sygnałów diagnostycznych
Some aspects of DSP in mechatronics
Autorzy:
Andrych-Zalewska, M.
Włostowski, R.
Wróbel, R.
Powiązania:
https://bibliotekanauki.pl/articles/315645.pdf
Data publikacji:
2017
Wydawca:
Instytut Naukowo-Wydawniczy "SPATIUM"
Tematy:
diagnostyka silnika spalinowego
transformata Fouriera
CPS
combustion engine diagnostic
Fourier transform
DSP
Opis:
W artykule omówiono najważniejsze aspekty cyfrowego przetwarzania sygnałów cyfrowych w diagnostyce silników spalinowych. Omówiono zmianę dziedziny czasu do dziedziny częstotliwości, a także wykorzystanie filtrowania (zarówno w dziedzinie czasu, jak i częstotliwości), wspomagającego właściwą analizę sygnału. Przedstawiono praktyczne zastosowanie wymienionych aspektów CPS na przykładzie analizy sygnałów wibroakustycznych silnika, mierzonych z użyciem laserowej wibrometrii dopplerowskiej, jak i akcelerometrii. Przedstawione przykłady dotyczą zarówno silnika zamontowanego w pojeździe, jak i pomiarów wykonanych na hamowni silnikowej.
The article discusses the most important aspects of digital signal processing in diagnostics of internal combustion engines. It discusses changing the time domain into the frequency domain, as well as the use of filtering (both time and frequency) to support proper signal analysis. The practical application of these aspects of DSP is illustrated by the analysis of vibroacoustic signals of the engine, measured using laser Doppler vibrometry and accelerometry systems.
Źródło:
Autobusy : technika, eksploatacja, systemy transportowe; 2017, 18, 12; 686-689, CD
1509-5878
2450-7725
Pojawia się w:
Autobusy : technika, eksploatacja, systemy transportowe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Decision-making rule efficiency estimation with applying similarity metrics
Autorzy:
Anokhin, M.
Koryttsev, I.
Powiązania:
https://bibliotekanauki.pl/articles/410948.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Oddział w Lublinie PAN
Tematy:
image
classification
probability
recognition of images
Fourier transform
similarity criterion
Opis:
In article the short description of the most often used methods of classification at pattern recognition is given. The main attention is paid to the methods allowing development of a system for image recognition in a real time scale. The features formation method on the base of two-dimensional spatial spectrums of objects images is offered and application of similarity metrics in a decision-making rule for image classification is described. Experimental data of correct and erroneous recognition probabilities as well as image classification time depending on a number of features and on the identification threshold value are presented and analyzed.
Źródło:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes; 2015, 4, 3; 73-78
2084-5715
Pojawia się w:
ECONTECHMOD : An International Quarterly Journal on Economics of Technology and Modelling Processes
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fornasini-Marchesini 2-D State Space Models: Transfer Function Computation Via the Dft
Autorzy:
Antoniou, G.
Emmons, K.
Powiązania:
https://bibliotekanauki.pl/articles/911185.pdf
Data publikacji:
2000
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
teoria systemów
transformata Fouriera
two dimensions system theory
Fourier transform
DFT algorithm
Fornasini-Marchesini's model
Opis:
A new algorithm is presented for the computation of the coefficients of the determinantal polynomial and the coefficients of the adjoint polynomial matrix of a given two-dimensional (2-D) state space model of Fornasini-Marchesini type. The algorithm has been implemented in Matlab and uses the discrete Fourier transform (DFT). The simplicity and efficiency of the technique are illustrated by two examples.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2000, 10, 2; 321-331
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Quantum Factorization of Integers 21 and 91 using Shor’s Algorithm
Autorzy:
Ardhyamath, Poornima
Naghabhushana, N. M.
Ujjinimatad, Rohitha
Powiązania:
https://bibliotekanauki.pl/articles/1070857.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Euclidean Algorithm
Factorization
GCD
Quantum Fourier Transform
Shor’s Algorithm
Opis:
In this paper we focused on the factorization of integer in detail using well known Shor’s algorithm and its quantum part realization. The algorithm finds prime factors any integer more efficiently than any known classical algorithm. It is based on prior knowledge of the answer to the factorization problem. Algorithm includes finding gcd using polynomial time Euclidean algorithm, determination of unknown period from quantum computer and continued fraction expansion approach. Factorization of two integers 21 and 91 are shown in this paper with all steps. Quantum part of the factorization described mathematically.
Źródło:
World Scientific News; 2019, 123; 102-113
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Measurement accuracy verification of phasor measurement unit with dynamic phasor estimation
Autorzy:
Arendarski, B.
Rabe, S.
Heineken, W.
Komarnicki, P.
Powiązania:
https://bibliotekanauki.pl/articles/140719.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
discrete Fourier transform (DFT)
dynamic phasor
measurement accuracy
phasor measurement unit (PMU)
power system
Opis:
Power systems that are highly loaded, especially by a stochastic supply of renew- ables and the presence of storages, require dynamic measurements for their optimal control. Phasor measurement units (PMUs) can be used to capture electrical parameters of a power system. Standards on the PMU dynamic performance have been modified to incorporate their new dynamic mode of operation. This paper examines the PMU dynamic performance and proposes essential algorithms for measurement accuracy verification. Measurements of dynamic input signals, which vary in amplitude or frequency, were taken during au- tomated tests of two PMUs. The test results are presented and expounded with further recommendation for the performance requirements. This paper also presents and examines applied testing procedures with relevance to the specifications of the IEEE Standard for Synchrophasor C37.118.1™-2011 and its amendment C37.118.1a™-2014.
Źródło:
Archives of Electrical Engineering; 2018, 67, 3; 529--543
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A comparison of methods for obtaining nanocellulose using acid and ionic liquid hydrolysis reactions
Autorzy:
Babicka, Marta
Ratajczak, Izabela
Dwiecki, Krzysztof
Powiązania:
https://bibliotekanauki.pl/articles/24072146.pdf
Data publikacji:
2019
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
1-butyl-3-methylimidazolium chloride
sulphuric acid(VI)
acid hydrolysis
ionic liquid hydrolysis
dynamic light scattering
fourier transform infrared spectroscopy
Opis:
A comparison of methods for obtaining nanocellulose using acid and ionic liquid hydrolysis reactions. In this study, two methods were compared, i.e. acid hydrolysis using sulphuric acid (VI) and ionic liquid hydrolysis using 1-methyl-3-butylimidazolium chloride to obtain nanocellulose from Sigmacell Cellulose Type 20. The efficiency of both processes was tested for weight loss of the material during the reaction. The study showed that much more material can be obtained using ionic liquid hydrolysis than using acid hydrolysis. A dynamic light scattering study was performed to determine material particle size before and after these processes. Particles of nanometric size were recorded only for cellulose after the reaction with an ionic liquid. In addition, Fourier transform infrared spectroscopy was performed to determine the chemical structure of the materials tested.
Źródło:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology; 2019, 107; 19--23
1898-5912
Pojawia się w:
Annals of Warsaw University of Life Sciences - SGGW. Forestry and Wood Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inversion of the Riemann-Liouville operator and its dual using wavelets
Autorzy:
Baccar, C.
Hamadi, N. B.
Herch, H.
Meherzi, F.
Powiązania:
https://bibliotekanauki.pl/articles/952838.pdf
Data publikacji:
2015
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
inverse problem
Riemann-Liouville operator
Fourier transform
wavelets
Opis:
We define and study the generalized continuous wavelet transform associated with the Riemann-Liouville operator that we use to express the new inversion formulas of the Riemann-Liouville operator and its dual.
Źródło:
Opuscula Mathematica; 2015, 35, 6; 867-887
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibrations detection in industrial plumps based on spectral analysis to increase their efficiency
Zwiększenie efektywności pomp przemysłowych w wyniku detekcji wibracji bazującej na analizie widma
Autorzy:
Balhadef, R.
Hafajfa, A.
Boumehraz, M.
Powiązania:
https://bibliotekanauki.pl/articles/410075.pdf
Data publikacji:
2016
Wydawca:
STE GROUP
Tematy:
Spectral analysis
vibration signal
vibration analysis
rotating machinery
centrifugal pump
signal estimation
Fourier transform
Prony approach
analiza widma
sygnał wibracji
analiza wibracji
maszyna wirująca
pompa odśrodkowa
estymacja sygnału
transformata Fouriera
model Prony’ego
Opis:
Spectral analysis is the key tool for the study of vibration signals in rotating machinery. In this work, the vibration analysis applied for conditional preventive maintenance of such machines is proposed, as part of resolved problems related to vibration detection on the organs of these machines. The vibration signal of a centrifugal pump was treated to mount the benefits of the approach proposed. The obtained results present the signal estimation of a pump vibration using Fourier transform technique compared by the spectral analysis methods based on Prony approach.
Analiza widma jest kluczowym narzędziem badania sygnałów dotyczących wibracji w maszynach wirujących. W niniejszej pracy proponuje się analizę wibracji dla oceny stanu technicznego tych maszyn w ramach utrzymania prewencyjnego, bazującą na detekcji wibracji ich poszczególnych elementów. Przydatność i korzyści zaproponowanego podejścia zostały ocenione podczas badania pompy odśrodkowej. Uzyskane wyniki przedstawiają estymację sygnałów wibracji pompy z wykorzystaniem transformaty Fouriera w porównaniu z przeprowadzoną analizą widma z zastosowaniem modelu Prony’ego.
Źródło:
Management Systems in Production Engineering; 2016, 1 (21); 55-61
2299-0461
Pojawia się w:
Management Systems in Production Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification of Seizure Types Using Random Forest Classifier
Autorzy:
Basri, Ashjan
Arif, Muhammad
Powiązania:
https://bibliotekanauki.pl/articles/2123290.pdf
Data publikacji:
2021
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
EEG
fast fourier transform
seizure
random forest
Opis:
Epilepsy is one of the most common mental disorders in the world, affecting 65 million people. The prevalence in Arab countries of Epilepsy is estimated at 174 per 100,000 individuals, and in Saudi Arabia is 6.54 per 1,000 individuals. Epilepsy seizures have different types, and each patient needs to have a treatment plan according to the seizure type. Hence, accurate classification of seizure type is an essential part of diagnosing and treating epileptic patients. In this paper, features based on fast Fourier transform from EEG montages are used to classify different types of seizures. Since the distribution of classes is not uniform and the dataset suffers from severe imbalance. Various algorithms are used to under-sample the majority class and over-sample the minority classes. Random forest classifier produced classification accuracy of 96% to differentiate three types of seizures from the healthy EEG reading.
Źródło:
Advances in Science and Technology. Research Journal; 2021, 15, 3; 167--178
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
P-wave interaction with a pair of rigid strips embedded in an orthotropic strip
Autorzy:
Basu, S.
Mandal, S. C.
Powiązania:
https://bibliotekanauki.pl/articles/281710.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
P-wave
Fourier transform
Hilbert transform
Fredholm integral equation
stress intensity factor
Opis:
The present paper is concerned with the problem of scattering of the P-wave by two co- -planer finite rigid strips placed symmetrically in an infinitely long orthotropic strip. Using the Hilbert transform technique, the mixed boundary value problem has been reduced to the solution of dual integral equations which has finally been reduced to the solution of a Fredholm integral equation of the second kind. Solving this integral equation numerically, stress intensity factors have been calculated at the inner and outer edges of the rigid strips, and the vertical displacement outside the strips has been calculated and plotted graphically to show the effect of material orthotropy.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 2; 579-592
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of wavelet-Fourier analysis into drawing-shaft reinforcement diagnostics
Zastosowanie analizy falkowej-Fouriera w diagnostyce zbrojenia szybowego
Autorzy:
Batko, W.
Krzyworzeka, P.
Mikulski, A.
Powiązania:
https://bibliotekanauki.pl/articles/328824.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
diagnostyka
transformata falkowa-Fouriera
analiza niestacjonarna
diagnostic
wavelet-Fourier transform
non-stationary analysis
Opis:
Impulse tests are commonly encountered in the research of dynamic properties of frame constructions in their operation time. One of the most significant problem issue associated with the application of these tests is description problems and unambiguous interpretation of non-stationary measurements results. New approach introduced by the authors involves system response-signal filtration by means of wavelet analysis and taking advantage of the information contained within the signal's energy. The article describes the application of wavelet-Fourier transformation for determining frequency spectrum from recovered impulse response. Practical usage is illustrated by the example shaft reinforcement in an underground mine.
W badaniach własności dynamicznych konstrukcji kratowych w trakcie eksploatacji wykorzystuje się zazwyczaj testy impulsowe. Jednym z istotnych utrudnień ich stosowania są problemy opisu oraz jednoznacznej interpretacji niestacjonarnych wyników pomiaru. Nowością zaproponowaną przez autorów jest filtracja sygnału odpowiedzi układu za pomocą analizy falkowej oraz wykorzystanie informacji zawartej w energii sygnału. Opisano sposób wykorzystania transformacji falkowej-Fouriera dla wyznaczenia widma częstotliwościowego ze zrekonstruowanej odpowiedzi impulsowej. Możliwości praktyczne ilustruje przykład zbrojenia szybowego kopalni podziemnej.
Źródło:
Diagnostyka; 2006, 1(37); 127-133
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the Validity of the Noise Model of Quantization for the Frequency-Domain Amplitude Estimation of Low-Level Sine Waves
Autorzy:
Bellan, D.
Powiązania:
https://bibliotekanauki.pl/articles/221016.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
quantization
amplitude estimation
sine wave
discrete Fourier transform
additive noise
Opis:
This paper deals with the amplitude estimation in the frequency domain of low-level sine waves, i.e. sine waves spanning a small number of quantization steps of an analog-to-digital converter. This is a quite common condition for high-speed low-resolution converters. A digitized sine wave is transformed into the frequency domain through the discrete Fourier transform. The error in the amplitude estimate is treated as a random variable since the offset and the phase of the sine wave are usually unknown. Therefore, the estimate is characterized by its standard deviation. The proposed model evaluates properly such a standard deviation by treating the quantization with a Fourier series approach. On the other hand, it is shown that the conventional noise model of quantization would lead to a large underestimation of the error standard deviation. The effects of measurement parameters, such as the number of samples and a kind of the time window, are also investigated. Finally, a threshold for the additive noise is provided as the boundary for validity of the two quantization models.
Źródło:
Metrology and Measurement Systems; 2015, 22, 1; 89-100
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Oxidative Aging Characterization of Pyro-Oil Modified Binders Using Fourier Transform Infrared Spectroscopy
Autorzy:
Bhagat, Nikita Taran
Hadole, Hemantkumar Prakash
Ranadive, Mahadeo Sambhaji
Powiązania:
https://bibliotekanauki.pl/articles/2201866.pdf
Data publikacji:
2023
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
pyro-oil
aging
asphalt binder
FTIR
Fourier Transform Infrared
carbonyls
sulfoxides
HDPE processing
plastic waste
pyrolysis of plastics
Opis:
The numerous uses for plastics in various industries have led to an increase in its manufacturing on a global scale over time. The accumulation of plastic waste is a direct result of the daily rise in plastic demand. One of the effective and trending ways of reducing the impact of plastic waste on the environment is to pyrolyze it and use the oil obtained from it as fuel for power generation, heating, extraction of chemicals, or as an asphalt binder modifier. In this study, an attempt was made for the modification of asphalt binder with the oil obtained from plastic waste pyrolysis known as pyro-oil, and to analyse aging properties of the modified binder. This paper deals with the modification of VG30 binder with pyro-oil obtained from High Density Polyethylene (HDPE) plastic waste and the analysing the effect of aging on the modified binders. Pyro-oil is yielded from the pyrolysis process of HDPE at about 750°C. The modified binders were prepared by adding 1%, 2%, and 3% pyro-oil by total weight of VG30. The effect of aging for the unmodified and modified binders was analyzed using fourier transform infrared (FTIR) spectroscopy. The binders were short term aged and the changes in their chemical functionalities before and after aging were analyzed. Results of the FTIR test were used to calculate functional group indices for evaluating the aging characteristics of the modified binders. It was observed that binder chemistry is influenced by aging.
Źródło:
Advances in Science and Technology. Research Journal; 2023, 17, 1; 140--149
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automatic Genre Classification Using Fractional Fourier Transform Based Mel Frequency Cepstral Coefficient and Timbral Features
Autorzy:
Bhalke, D. G.
Rajesh, B.
Bormane, D. S.
Powiązania:
https://bibliotekanauki.pl/articles/177599.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
feature extraction
Timbral features
MFCC
Mel Frequency Cepstral Coefficient
FrFT
fractional Fourier transform
Fractional MFCC
Tamil Carnatic music
Opis:
This paper presents the Automatic Genre Classification of Indian Tamil Music and Western Music using Timbral and Fractional Fourier Transform (FrFT) based Mel Frequency Cepstral Coefficient (MFCC) features. The classifier model for the proposed system has been built using K-NN (K-Nearest Neighbours) and Support Vector Machine (SVM). In this work, the performance of various features extracted from music excerpts has been analysed, to identify the appropriate feature descriptors for the two major genres of Indian Tamil music, namely Classical music (Carnatic based devotional hymn compositions) & Folk music and for western genres of Rock and Classical music from the GTZAN dataset. The results for Tamil music have shown that the feature combination of Spectral Roll off, Spectral Flux, Spectral Skewness and Spectral Kurtosis, combined with Fractional MFCC features, outperforms all other feature combinations, to yield a higher classification accuracy of 96.05%, as compared to the accuracy of 84.21% with conventional MFCC. It has also been observed that the FrFT based MFCC effieciently classifies the two western genres of Rock and Classical music from the GTZAN dataset with a higher classification accuracy of 96.25% as compared to the classification accuracy of 80% with MFCC.
Źródło:
Archives of Acoustics; 2017, 42, 2; 213-222
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Boehmians of type S and their Fourier transforms
Autorzy:
Bhuvaneswari, R.
Karunakaran, V.
Powiązania:
https://bibliotekanauki.pl/articles/747250.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Boehmians
spaces of type S
Fourier transform
Opis:
Function spaces of type S are introduced and investigated in the literature. They are also applied to study the Cauchy problem. In this paper we shall extend the concept of these spaces to the context of Boehmian spaces and study the Fourier transform theory on these spaces. These spaces enable us to combine the theory of Fourier transform on these function spaces as well as their dual spaces.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2010, 54, 1
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Zastosowanie algebr hiperzespolonych w przetwarzaniu sygnałów
Application of hypercomplex algebras in signal processing
Autorzy:
Błaszczyk, Ł.
Powiązania:
https://bibliotekanauki.pl/articles/134792.pdf
Data publikacji:
2016
Wydawca:
ADVSEO
Tematy:
hypercomplex algebras
quaternion Fourier transform
octonion Fourier transform
system analysis
partial differential equations
Opis:
The subject of this paper is the application of hypercomplex algebras (in particular quaternions and octonions) in the analysis of time-invariant linear systems. We present the Cayley-Dickson construction of hypercomplex algebras and its important properties. Moreover, we formulate the concept of quaternion and octonion Fourier transform and their properties important from the signal processing point of view. We present an overview of known quaternion Fourier transform applications in the analysis of systems and partial differential equations of two variables. We also point out the direction of further work in the subject of application of the octonion Fourier transform in system analysis and analysis of partial differential equations of three variables. Such considerations are possible thanks to recently proved properties of octonion Fourier transform, which are also stated in this paper.
Źródło:
Technical Issues; 2016, 3; 13-18
2392-3954
Pojawia się w:
Technical Issues
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acoustical Analysis of Enclosure as Initial Approach to Vehicle Induced Noise Analysis Comparatevely Using STFT and Wavelets
Autorzy:
Błażejewski, A.
Kozioł, P.
Łuczak, M.
Powiązania:
https://bibliotekanauki.pl/articles/176551.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
modal analysis
short-time Fourier transform
wavelet transform
acoustic signal processing
Opis:
It is assumed in the paper that the signals in the enclosure in a transient period are similar to a noise induced by vehicles, tracks, cars, etc. passing by. The components of such signals usually points out specific dynamic processes running during the observation or measurements. In order to choose the best method of analysis of these phenomena, an acoustic field in a closed space with a sound source inside is created. Acoustic modes of this space influence the sound field. Analytically, the modal analyses describe the above mentioned phenomena. The experimental measurements were conducted in the room that might comprise the closed space with known boundary conditions and the sound source Br¨uel & Kjær Omni-directional type 4292 inside. To record sound signals before the field’s steady state was reached, the microphone type 4349 and the 4-channel frontend 3590 had been used. The obtained signals have been analysed by using two approaches, i.e. Fourier and the wavelet analysis, with the emphasis on their efficiency and the capability to recognise important details of the signal. The results obtained for the enclosure might lead to the formulation of a methodology for an extended investigation of a rail track or vehicles dynamics.
Źródło:
Archives of Acoustics; 2014, 39, 3; 385-394
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modelling of non-ideal signal sampling via averaging operation and spectrum of sampled signal predicted by this model
Autorzy:
Borys, A.
Powiązania:
https://bibliotekanauki.pl/articles/2172501.pdf
Data publikacji:
2022
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
modelling of non-Ideal signal sampling
non-Ideal signal
spectrum of sampled signal
A/D converters
non-Ideal signal sampling
signal sampling
discrete time fourier transform
Opis:
In this paper, a novel model of a non-ideal signal sampling via a local, periodic averaging operation is present-ed. The spectrum of a sampled signal predicted by this model is also analysed as well as compared with a one following from another model.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2022, 16, 2; 274--278
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtering Property of Signal Sampling in General and Under-Sampling as a Specific Operation of Filtering Connected with Signal Shaping at the Same Time
Autorzy:
Borys, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/226441.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal sampling
filtering
discrete-time Fourier transform
Opis:
In this paper, we show that signal sampling operation can be considered as a kind of all-pass filtering in the time domain, when the Nyquist frequency is larger or equal to the maximal frequency in the spectrum of a signal sampled. We demonstrate that this seemingly obvious observation has wide-ranging implications. They are discussed here in detail. Furthermore, we discuss also signal shaping effects that occur in the case of signal under-sampling. That is, when the Nyquist frequency is smaller than the maximal frequency in the spectrum of a signal sampled. Further, we explain the mechanism of a specific signal distortion that arises under these circumstances. We call it the signal shaping, not the signal aliasing, because of many reasons discussed throughout this paper. Mainly however because of the fact that the operation behind it, called also the signal shaping here, is not a filtering in a usual sense. And, it is shown that this kind of shaping depends upon the sampling phase. Furthermore, formulated in other words, this operation can be viewed as a one which shapes the signal and performs the low-pass filtering of it at the same time. Also, an interesting relation connecting the Fourier transform of a signal filtered with the use of an ideal low-pass filter having the cut frequency lying in the region of under-sampling with the Fourier transforms of its two under-sampled versions is derived. This relation is presented in the time domain, too.
Źródło:
International Journal of Electronics and Telecommunications; 2020, 66, 3; 589-594
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fourier transform, oscillatory multipliers and evolution equations in rearrangement invariant function spaces
Autorzy:
Brandolini, Luca
Colzani, Leonardo
Powiązania:
https://bibliotekanauki.pl/articles/966988.pdf
Data publikacji:
1996
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
rearrangement invariant Banach function spaces
Schrödinger and wave equations
Fourier transform
multipliers
Źródło:
Colloquium Mathematicum; 1996, 71, 2; 273-286
0010-1354
Pojawia się w:
Colloquium Mathematicum
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Power line magnetic field mitigation using a passive loop conductor
Autorzy:
Budnik, K.
Machczyński, W.
Powiązania:
https://bibliotekanauki.pl/articles/376311.pdf
Data publikacji:
2013
Wydawca:
Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej
Tematy:
magnetic field
electric field
electric power lines
Fourier transform
loop conductor
Opis:
The paper presents in a tutorial manner methods of the calculation of magnetic fields in vicinity of overhead electric power lines without and with passive mitigation loops. Exact and simplified methods of the determination of the magnetic field of a straight overhead conductor based on the Fourier transform technique are presented. The mitigation effects due to the passive loop are also investigated, whereas the mitigation loop can be treated as a rectangular loop (two-conductor closed mitigation loop) horizontal located under the power line. The decomposition of the magnetic fields in two components: magnetic field obtained in free space from the Biot-Savart law and the magnetic field produced by earth current shows that in practical cases the effects from earth currents can be neglected as compared with effects from line currents.
Źródło:
Poznan University of Technology Academic Journals. Electrical Engineering; 2013, 73; 137-145
1897-0737
Pojawia się w:
Poznan University of Technology Academic Journals. Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrable Mikusiński operators as ultradistributions
Całkowalne operatory Mikusińskiego jako ultradystrybucje
Autorzy:
Burzyk, J.
Powiązania:
https://bibliotekanauki.pl/articles/87294.pdf
Data publikacji:
2013
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
całkowalny operator Mikusińskiego
ultradystrybucja
transformata Fouriera
integrable Mikusiński operator
ultradistribution
Fourier transform
Opis:
In this paper we introduce a notion of integrable Mikusiński operators. The definition of Fourier transform of such operators is given. We also give a characterization of integrable operators which are ultradistributions.
W artykule wprowadzamy pojęcie całkowalnych operatorów Mikusińskiego, definiujemy ich transformatę Fouriera i podajemy pewien warunek konieczny i wystarczający, aby operator tego typu był ultradystrybucją.
Źródło:
Zeszyty Naukowe. Matematyka Stosowana / Politechnika Śląska; 2013, 3; 5-15
2084-073X
Pojawia się w:
Zeszyty Naukowe. Matematyka Stosowana / Politechnika Śląska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Basic Aspects of Designing a High-performance Processor Structure for Calculating a "true" Discrete Fractional Fourier Transform
Autorzy:
Cariow, A.
Majorkowska-Mech, D.
Powiązania:
https://bibliotekanauki.pl/articles/114579.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
discrete fractional Fourier transform
parallelization of computations
hardware implementation
complexity reduction
Opis:
This paper presents a basic aspects of structural design of the highperformance processor for implementation of discrete fractional Fourier transform (DFrFT). The general idea of the possibility of parallelizing the calculation of the so-called “true” discrete Fourier transform on the basis of our previously developed algorithmic approach is presented. We specifically focused only on the general aspects of the organization of the structure of such a processor, since the details of a particular implementation always depend on the implementation platform used, while the general idea of constructing the structure of the processor remains unchanged.
Źródło:
Measurement Automation Monitoring; 2018, 64, 2; 43-45
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hardware-Efficient Schemes of Quaternion Multiplying Units for 2D Discrete Quaternion Fourier Transform Processors
Autorzy:
Cariow, A.
Cariowa, G.
Chicheva, M.
Powiązania:
https://bibliotekanauki.pl/articles/114724.pdf
Data publikacji:
2017
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
discrete quaternion Fourier transform
fast algorithms
implementation complexity reduction
FPGA implementation
Opis:
In this paper, we offer and discuss three efficient structural solutions for the hardware-oriented implementation of discrete quaternion Fourier transform basic operations with reduced implementation complexities. The first solution – a scheme for calculating sq product, the second solution – a scheme for calculating qt product, and the third solution – a scheme for calculating sqt product, where s is a so-called i -quaternion, t is an j - quaternion, and q – is an usual quaternion. The direct multiplication of two usual quaternions requires 16 real multiplications (or two-operand multipliers in the case of fully parallel hardware implementation) and 12 real additions (or binary adders). At the same time, our solutions allow to design the computation units, which consume only 6 multipliers plus 6 two input adders for implementation of sq or qt basic operations and 9 binary multipliers plus 6 two-input adders and 4 four-input adders for implementation of sqt basic operation.
Źródło:
Measurement Automation Monitoring; 2017, 63, 6; 206-208
2450-2855
Pojawia się w:
Measurement Automation Monitoring
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influences of operating parameters on dry ball mill performance
Autorzy:
Cayirli, S.
Powiązania:
https://bibliotekanauki.pl/articles/110047.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
conventional ball mill
particle size
surface area
grinding aid
fluidity index
Fourier Transform Infrared Spectroscopy
Opis:
The paper is aimed to investigate the influence of operating parameters on dry fine grinding of calcite in a laboratory scale conventional ball mill. Within the context, the influence of operating parameters such as mill speed, ball filling ratio, ball size distribution, powder filling ratio, grinding aid dosage and grinding time were studied. The results of grinding tests were evaluated based on the product particle size (d50, d80) and surface area (m2/kg). As a result of this study, optimum grinding test conditions determined to be 70% of Nc, J=0.35 for ball filling ratio, 40 mm (10%), 32 mm (10%), 20 mm (40%), 12 mm (40%) for ball size distribution, fc=0.125 for powder filling ratio, 2000 g/Mg for grinding aid dosage and 60 min for grinding time. After determining optimum grinding conditions, the influence of grinding aid dosage on powder fluidity was determined. The use of 2000 g/Mg grinding aid dosage had a greater fluidizing effect compared to the other dosages and no aid condition (0 g/Mg). The influence of grinding aid on dry fine grinding of calcite was also examined by Fourier Transform Infrared Spectroscopy (FTIR). FTIR measurements indicated that grinding aid was adsorbed on the ground calcite particles surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 751-762
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solution of a functional equation on compact groups using Fourier analysis
Autorzy:
Chahbi, Abdellatif
Fadli, Brahim
Kabbaj, Samir
Powiązania:
https://bibliotekanauki.pl/articles/747133.pdf
Data publikacji:
2015
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Functional equation
non-abelian Fourier transform
representation of a compact group.
Opis:
Let \(G\) be a compact group, let \(n \in N\setminus \{0,1\}\) be a fixed element and let \(\sigma\) be a continuous automorphism on \(G\) such that \(\sigma^n=I\). Using the non-abelian Fourier transform, we determine the non-zero continuous solutions \(f:G \to C\) of the functional equation \[ f(xy)+\sum_{k=1}^{n-1}f(\sigma^k(y)x)=nf(x)f(y),\ x,y \in G,\] in terms of unitary characters of \(G\).
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2015, 69, 2
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Performance DIF-FFT Using Dissimilar Partitioned LUT Based Distributed Arithmetic
Autorzy:
Cheepurupalli, Kusma Kumari
Charan, Muntha
Rao, Jammu Bhaskara
Noor, Mahammad S.
Powiązania:
https://bibliotekanauki.pl/articles/2055270.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
fast Fourier transform
adders
distributed arithmetic
DSP
Opis:
Real-time data processing systems utilize Digital Signal Processing (DSP) functions as the base modules. Most of the DSP functions involve the implementation of Fast Fourier Transform (FFT) to convert the signals from one domain to another domain. The major bottleneck of Decimation in frequency - Fast Fourier Transform (DIF-FFT) implementation lies in using a number of Multipliers. Distributed arithmetic (DA) is considered as one of the efficient techniques to implement DIF-FFT. In this approach, the multipliers are not used. The proposed technique exploits the very advantage of the look-up table by storing the Twiddle factors, thereby avoiding the multipliers required in the butterfly structure. DIF-FFT using Distributed Arithmetic (DIF-FFT DA) models, with different adders such as Ripple carry adder (RCA), Carry-lookahead adder (CLA), and Sklansky prefix graph adder, are proposed in this paper. The three proposed models are synthesized using Cadence 6.1 EDA tools with a 45nm CMOS technology. Compared to the traditional method, it is observed that the area is improved by 53.11%, 53.35%, and 50.15%, power is improved by 42.31%, 42.52%, and 40.39%, and delay is improved by 45.26%, 45.42%, 41.80%, respectively.
Źródło:
International Journal of Electronics and Telecommunications; 2021, 67, 4; 631--637
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of broadband antenna radiation pulses
Badania anteny szerokopasmowego piramidalnego turbowego promiennika do niszczenia szkodników w glebach
Autorzy:
Cherenkov, A.
Hutsol, T.
Garasymchuk, I.
Pancyr, J.
Terenov, D.
Dubyna, V.
Powiązania:
https://bibliotekanauki.pl/articles/93987.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Inżynierii Rolniczej
Tematy:
antenna
electromagnetic energy emitter
Fourier transform
communicating wave
aperture
biotechnology
broadband pulses
antena
energia elektromagnetyczna
promiennik
transformacja Fouriera
transmisja fali
apertura
biotechnologia
impulsy szerokopasmowe
Opis:
Electromagnetic energy can alter metabolic and biosynthetic processes and under certain parameters of pulsed EMF it can change pulse repetition frequency, operation cycle, power, exposure, as well as it can slow down and inhibit cell growth. MW irradiation range of RNA and DNA - containing virus reduces their infectivity. Inhibition of bacterial cultures growth, changes in phagocytic activity of protein biosynthesis, ultrastructural changes in the cells when exposed to EMF EHF. It was found in experiments with micro-organisms that biological effects of EMF on microorganisms wore a resonant character. One of the basic mechanisms of inhibitory action of EHF radiation on harmful microorganisms is the role of membranes in biological reactions of microorganisms on the EMR.
Energia elektromagnetyczna może zmieniać procesy metaboliczne i biosyntezy oraz w pewnych parametrach pulsacyjnego pola elektromagnetycznego - częstość powtórzeń impulsu, cykl pracy, moc, ekspozycję, spowolnić i hamować wzrost komórkowy. Napromieniowanie w zakresie milimetrów RNA i DNA zawierających wirus prowadzi do zmniejszenia ich zakaźności. Hamowanie wzrostu bakteryjnych kultur, zmian aktywności fagocytowej, biosyntez białka, ultrastrukturalnych zmian w komórkach pod wpływem EMF w zakresie ultra-wysokiej częstotliwości. W eksperymentach z mikroorganizmami ustalono, że biologiczny wpływ działania pól elektromagnetycznych na mikroorganizmy był rezonansowy. Jednym z głównych mechanizmów hamowania promieniowania ultra-wysokiej częstotliwości na szkodliwe mikroorganizmy jest rola błon biologicznych w reakcjach mikroorganizmów na EMF. Istotne znaczenie mają zjawiska elektryczne występujące w biomembranach.
Źródło:
Agricultural Engineering; 2018, 22, 1; 15-28
2083-1587
Pojawia się w:
Agricultural Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Tauberian theorems for vector-valued Fourier and Laplace transforms
Autorzy:
Chill, Ralph
Powiązania:
https://bibliotekanauki.pl/articles/1218589.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Tauberian theorem
Fourier transform
Laplace transform
asymptotically almost periodic
analytic Radon-Nikodym property
Cauchy problem
Opis:
Let X be a Banach space and $f ∈ L^1_loc(ℝ;X)$ be absolutely regular (i.e. integrable when divided by some polynomial). If the distributional Fourier transform of f is locally integrable then f converges to 0 at infinity in some sense to be made precise. From this result we deduce some Tauberian theorems for Fourier and Laplace transforms, which can be improved if the underlying Banach space has the analytic Radon-Nikodym property.
Źródło:
Studia Mathematica; 1998, 128, 1; 55-69
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mobilny system przetwarzania obrazu oparty na platformie Raspberry Pi 4
Mobile image processing system based on the Raspberry Pi 4 platform
Autorzy:
Chlastawa, Łukasz
Powiązania:
https://bibliotekanauki.pl/articles/2014237.pdf
Data publikacji:
2021
Wydawca:
Państwowa Wyższa Szkoła Zawodowa w Tarnowie
Tematy:
cyfrowe przetwarzanie obrazów
dwuwymiarowa szybka transformacja Fouriera
biblioteka OpenCV
aplikacja okienkowa
system wizyjny
digital image processing
two-dimensional fast Fourier transform
OpenCV library
window application
vision system
Opis:
W artykule zaprezentowano system przetwarzania obrazu oparty na platformie Raspberry Pi (RPi). Na początku artykułu omówiono podstawowe założenia oraz cel wykonania systemu. W dalszej części przedstawiono strukturę i sposób działania systemu. Zaprezentowano aplikację okienkową zarządzającą systemem oraz pozwalającą na wykonanie przekształceń kontekstowych oraz widmowych na obrazach, jak również pomiar parametrów, takich jak: czas przetwarzania obrazu oraz błąd średniokwadratowy (ang. Mean Square Error – MSE). Wykonywane przekształcenia oparto zarówno na gotowych formułach zawartych w bibliotece OpenCV, jak również własnych implementacjach, a wśród nich na funkcji realizującej algorytm szybkiej transformacji Fouriera FFT (ang. Fast Fourier Transform) radix-2. Zaprezentowano przykłady przekształceń wraz ze wskazaniem ich użyteczności. Na końcu przedstawiono potencjał rozwojowy utworzonego systemu oraz zaproponowano zastosowanie w konkretnych rozwiązaniach.
The article presents an image processing system based on the Raspberry Pi (RPi) platform. At the beginning of the article, the basic assumptions and purpose of the system are discussed. The following section presents the structure and operation of the system. The window application managing the system and allowing to perform contextual and spectral transformations on images as well as the measurement of parameters such as image processing time and mean square error (MSE) was discussed. The transformations performed were based both on ready formulas contained in the OpenCV library and the author’s implementations, including the function implementing the Fast Fourier Transform algorithm radix-2. Examples of transformations were presented along with their usefulness. In the end, the development potential of the created system is presented and its application in specific solutions is proposed.
Źródło:
Science, Technology and Innovation; 2021, 12, 1; 16-25
2544-9125
Pojawia się w:
Science, Technology and Innovation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Badania oddziaływań drgań pochodzenia komunikacyjnego na budynki mieszkalne i ludzi w aglomeracji warszawskiej
The research concerning the effects of road traffic and its influence on the flat buildings and people in Warsaw agglomeration
Autorzy:
Chyży, T.
Powiązania:
https://bibliotekanauki.pl/articles/182831.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniki Budowlanej
Tematy:
aglomeracja warszawska
drganie komunikacyjne
budynek mieszkalny
ruch drogowy
pomiar
stanowisko pomiarowe
szybka transformacja Fouriera
rozprzestrzenianie drgań
Warsaw agglomeration
traffic vibration
dwelling house
measurement
road traffic
sensors location
fast Fourier transform
vibration propagation
Opis:
Zaprezentowano wyniki badań poziomów drgań w budynkach mieszkalnych, generowanych przez ruch taboru kołowego. Ocenę poziomów drgań odniesiono do pasm 1/3-oktawowych i naniesiono na nomogramy dla analizowanego kierunku drgań zalecone w PN-88/B--02171 oraz instrukcji ITB nr 348/98, względem których dokonano oceny szkodliwości tych drgań. Podano również wyniki badań propagacji drgań źródło-budynek oraz zaprezentowano koncepcję metody odwzorowania dowolnego rodzaju oddziaływań transmitowanych przez podłoże gruntowe.
The development of Warsaw agglomeration and the increase of transported article and persons, causes also the worsening of road surface conditions. It affects the increase of dynamic effects propagated to the environment in the form of noise and vibrations of the ground. These loads are transfered to the buildings situated near communication tracks, enlarging the occupants discomfort and sometimes causing construction damage. In this paper the following problems have presented and discussed: • the results of measurements of the vibrations levels on buildings, generated by road traffic; the measurement points have been localized on the region of the capital town of Warsaw and in neighbouring towns; the results were presented in the 1/3 octave strips (tierce) and were put on the special nomograms • the results of measurements of the vibrations propagation on the way from source (road traffic) to buildings. These results were presented in narrow frequencies strips (5 Hz) • the conception of the new method for reconstruction of possible vibrations, which have affected the buildings in the past - the "reconstruction method".
Źródło:
Prace Instytutu Techniki Budowlanej; 2008, R. 37, nr 1, 1; 19-41
0138-0796
Pojawia się w:
Prace Instytutu Techniki Budowlanej
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Solving dual integral equations on Lebesgue spaces
Autorzy:
Ciaurri, Óscar
Guadalupe, José
Pérez, Mario
Varona, Juan
Powiązania:
https://bibliotekanauki.pl/articles/1205966.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Fourier series
Hankel transform
Bessel functions
dual integral equations
Opis:
We study dual integral equations associated with Hankel transforms, that is, dual integral equations of Titchmarsh's type. We reformulate these equations giving a better description in terms of continuous operators on $L^p$ spaces, and we solve them in these spaces. The solution is given both as an operator described in terms of integrals and as a series $∑_{n=0}^{∞} c_n J_{μ+2n+1}$ which converges in the $L^p$-norm and almost everywhere, where $J_ν$ denotes the Bessel function of order ν. Finally, we study the uniqueness of the solution.
Źródło:
Studia Mathematica; 2000, 142, 3; 253-267
0039-3223
Pojawia się w:
Studia Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The heat equation on time scales
Autorzy:
Cuchta, Tom
Ferreira, Rui A. C.
Powiązania:
https://bibliotekanauki.pl/articles/29519378.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
heat equation
time scales
Fourier transform
Opis:
We present the use of a Fourier transform on time scales to solve a dynamic heat IVP. This is done by inverting a certain exponential function via contour integral. We include some specific examples and directions for further study.
Źródło:
Opuscula Mathematica; 2023, 43, 4; 475-491
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bearing estimation using double frequency reassignment for a linear passive array
Autorzy:
Czarnecki, K.
Leśniak, W.
Powiązania:
https://bibliotekanauki.pl/articles/260131.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
direction of arrival
DOA
instantaneous frequency
short-time Fourier transform
STFT
time-frequency reassignment
intercept and surveillance sonar
crest factor
Opis:
The paper demonstrates the use of frequency reassignment for bearing estimation. For this task, signals derived from a linear equispaced passive array are used. The presented method makes use of Fourier transformation based spatial spectrum estimation. It is further developed through the application of two-dimensional reassignment, which leads to obtaining highly concentrated energy distributions in the joint frequency-angle domain and sharp graphical imaging. The introduced method can be used for analysing, a priori, unknown signals of broadband, nonstationary, and/or multicomponent type. For such signals, the direction of arrival is obtained based upon the marginal energy distribution in the angle domain, through searching for arguments of its maxima. In the paper, bearing estimation of three popular types of sonar pulses, including linear and hyperbolic frequency modulated pulses, as well as no frequency modulation at all, is considered. The results of numerical experiments performed in the presence of additive white Gaussian noise are presented and compared to conventional digital sum-delay beamforming performed in the time domain. The root-mean-square error and the peak-to-average power ratio, also known as the crest factor, are introduced in order to estimate, respectively, the accuracy of the methods and the sharpness of the obtained energy distributions in the angle domain.
Źródło:
Polish Maritime Research; 2017, 3; 26-35
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Classification of fault diagnosis in a gear wheel by used probabilistic neural network, fast Fourier transform and principal component analysis
Klasyfikacja uszkodzeń przekładni zębatych przy wykorzystaniu probabilistycznej sieci neuronowej, szybkiej transformaty Fouriera oraz analizy PCA
Autorzy:
Czech, P.
Powiązania:
https://bibliotekanauki.pl/articles/374597.pdf
Data publikacji:
2007
Wydawca:
Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
Tematy:
przekładnie zębate
diagnostyka uszkodzeń przekładni
probabilistyczne sieci neuronowe
transformata Fouriera
analiza PCA
tooth gear
gear diagnosis
probbilistic neural network
Fourier transform
principial componenet analysis
Opis:
This paper presents the results of an experimental application of artificial neural network as a classifier of the degree of cracking of a tooth root in a gear wheel. The neural classifier was based on the artificial neural network of Probabilistic Neural Network type (PNN). The input data for the classifier was in a form of matrix composed of statistical measures, obtained from fast Fourier transform (FFT) and principal component analysis (PCA). The identified model of toothed gear transmission, operating in a circulating power system, served for generation of the teaching and testing set applied for the experiment.
W artykule przedstawiono wyniki z eksperymentów, których celem było wykorzystanie sztucznej sieci neuronowej jako klasyfikatora stopnia pęknięcia u podstawy zębów kół przekładni. W badaniach użyto probabilistycznych sieci neuronowych (PNN). Dane wejściowe dla klasyfikatorów stanowiły miary statystyczne uzyskane z sygnałów drganiowych, przy wykorzystaniu szybkiej transformaty Fouriera (FFT) oraz analizy PCA. Zidentyfikowany model przekładni zębatej, pracującej w układzie napędowym, posłużył jako źródło danych uczących i testujących dla sztucznych sieci neuronowych.
Źródło:
Transport Problems; 2007, 2, 4; 99-106
1896-0596
2300-861X
Pojawia się w:
Transport Problems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diagnostyka lokalnych uszkodzeń zębów kół przekładni przy użyciu szybkiej transformaty Fouriera i logiki rozmytej
The diagnostic of tooth gears failures by using fast Fourier transform and fuzzy logic
Autorzy:
Czech, P.
Powiązania:
https://bibliotekanauki.pl/articles/328370.pdf
Data publikacji:
2008
Wydawca:
Polska Akademia Nauk. Polskie Towarzystwo Diagnostyki Technicznej PAN
Tematy:
diagnostyka
przekładnia zębata
logika rozmyta
szybka transformata Fouriera
diagnostics
gearboxes
fuzzy logic
fast Fourier transform
Opis:
W artykule przedstawiono wyniki prób mających na celu budowę klasyfikatora lokalnych uszkodzeń zębów kół przekładni, zbudowanego w oparciu o logikę rozmytą. Obiekt badań stanowiła przekładnia zębata o zębach prostych, pracująca na stanowisku mocy krążącej FZG. Badaniami objęto przekładnie z kołami bez uszkodzeń oraz z lokalnymi uszkodzeniami zębów w postaci pęknięcia u podstawy zęba oraz wykruszenia wierzchołka zęba. Zaproponowano również sposób budowy systemów diagnozujących lokalne uszkodzenia zębów kół. Do tego celu wykorzystano sygnały drganiowe poddane odpowiedniej filtracji oraz przetwarzaniu.
This article presents the tests results showing the construction of the local damages classifier of the transmission gear teeth, built on the basis of the fuzzy logic. The tested object was the transmission gear with straight teeth, working on the circulating power FZG stand. The tests included the gears with the undamaged teeth and with the locally damaged teeth in the form of the crack root and the chip tip of the tooth. The construction of the systems diagnosing the local damages of the teeth was also proposed. To achieve this aim, the vibration signals which had undergone proper filtration and processing were used.
Źródło:
Diagnostyka; 2008, 1(45); 43-52
1641-6414
2449-5220
Pojawia się w:
Diagnostyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wykorzystanie algorytmów genetycznych do doboru wejść klasyfikatora uszkodzeń zębów kół przekładni opartego na sieci neuronowej PNN oraz krótkoczasowej transformacie Fouriera
The use of genetic algorithms in the task of choosing inputs for PNN neural network classifier of faults of gear-tooth which used inputs from STFT analysis
Autorzy:
Czech, P.
Powiązania:
https://bibliotekanauki.pl/articles/258316.pdf
Data publikacji:
2007
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Technologii Eksploatacji - Państwowy Instytut Badawczy
Tematy:
diagnostyka
przekładnia zębata
sztuczna inteligencja
sztuczna sieć neuronowa
algorytm genetyczny
krótkoczasowa transformata Fouriera
diagnostic
toothed gear
artificial intelligent method
PNN
genetic algorithm
short-time Fourier transform
Opis:
W artykule przedstawiono wyniki prób mających na celu budowę klasyfikatora lokalnych uszkodzeń zębów kół przekładni, opartego na sztucznych sieciach neuronowych. W badaniach wykorzystywano probabilistyczne sieci neuronowe (PNN). Dodatkowo podjęto próbę wykorzystania algorytmów genetycznych do celów wyboru wejść klasyfikatora neuronowego. Badania oparto na sygnałach drganiowych otrzymanych z modelu dynamicznego przekładni pracującej w układzie napędowym. W artykule zaproponowano sposób budowy deskryptorów lokalnych uszkodzeń zębów kół wykorzystując do tego celu sygnały drganiowe poddane odpowiedniej filtracji oraz przetwarzaniu z użyciem krótkoczasowej transformaty Fouriera (STFT).
The present paper presents the results of an experimental application of probabilistic neural network as a classifier of the degree of cracking root of the tooth in a gear wheel. The input data for the classifier was in a form of matrix composed of statistical measures, obtained from short time Fourier transform. The model of gearbox was used in order to create a base of knowledge. In the experiment genetic algorithms was used to check influence of choosing inputs for neural classifier on diagnostic error.
Źródło:
Problemy Eksploatacji; 2007, 3; 51-70
1232-9312
Pojawia się w:
Problemy Eksploatacji
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Warp-knitted Fabric Defect Segmentation Based on the Shearlet Transform
Analiza defektów dzianin na bazie transformacji Shearleta
Autorzy:
Dong, Z.
Xia, D.
Ma, P.
Jiang, G.
Powiązania:
https://bibliotekanauki.pl/articles/234405.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
warp-knitted fabric defect
Shearlet transform
Fourier transform
segmented threshold de-nosing
defekt dzianiny
transformacja Shearleta
transformacja Fouriera
Opis:
The Shearlet transform has been a burgeoning method applied in the area of image processing recently which, differing from the Wavelet transform, has excellent properties in processing singularities for multidimensional signals. Not only is it similar to the performance of the Curvelet transform, it also overcomes the disadvantage of the Curvelet transform with respect to discretization. In this paper, the Shearlet transform with segmented threshold de-nosing is proposed to segment a warp-knitted fabric defect. Firstly a warp-knitted fabric image of size 512*512 is filtered by the Laplacian Pyramid transform and decomposed into low frequency and high frequency coefficients. Secondly the high frequency coefficients are operated with a pseudo-polar grid and then convoluted by the window function. Thirdly the shearlet coefficients will be obtained through redefining the Cartesian coordinates from the pseudo-polar grid coordinates and de-noised by the segmented threshold method. Then the coefficients which have high energy are selected for reconstruction in an inverse way using the previous steps. Finally the iterative threshold method and object operation based on morphology are applied to segment out the defect profile. The experiment’s result states that the Shearlet transform shows excellent performance in segmenting a common warp-knitted fabric defect, indicating that the segment results can be applied for further defect automatic recognition.
Transformacja Shearleta jest ostatnio dynamicznie rozwijającą się metodą stosowaną w dziedzinie przetwarzania obrazu, która różni się od transformaty Wavelet i ma doskonałe właściwości w przetwarzaniu sygnałów wielowymiarowych. Transformacja Shearleta ma prostszą implementację dyskretną, niż przekształcenie Curveleta w oparciu o rygorystyczne i proste ramy matematyczne. Może także dostarczyć bardziej elastycznego rozkładu na podstawie reprezentacji wieloskalowej i geometrycznej. Ostateczny wynik segmentacji uzyskano poprzez powtarzalną segmentację progową i operację morfologiczną. Wyniki wykazały, że segmentowy profil uszkodzeń jest dość wyraźny i porównywalny w porównaniu z pierwotnymi wadami dzianiny.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 5 (125); 87-94
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved method for phase wraps reduction in profilometry
Autorzy:
Du, G.
Wang, M.
Zhou, C.
Si, S.
Li, H.
Lei, Z.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173793.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phase unwrapping
zero-padding
Fourier transform
carrier-frequency
profilometry
Opis:
In order to completely eliminate, or greatly reduce the number of phase wraps in 2D wrapped phase map, Gdeisat and co-workers proposed an algorithm, which uses shifting the spectrum towards the origin. But the spectrum can be shifted only by an integer number, meaning that the phase wraps reduction is often not optimal. In addition, Gdeisat’s method will take much time to make the Fourier transform, inverse Fourier transform, select and shift the spectral components. In view of the above problems, we proposed an improved method for phase wraps elimination or reduction. First, the wrapped phase map is padded with zeros, the carrier frequency of the projected fringe is determined by high resolution, which can be used as the moving distance of the spectrum. And then realize frequency shift in spatial domain. So it not only can enable the spectrum to be shifted by a rational number when the carrier frequency is not an integer number, but also reduce the execution time. Finally, the experimental results demonstrated that the proposed method is feasible.
Źródło:
Optica Applicata; 2017, 47, 2; 295-306
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
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