scholarly journals A HIGH ACCURACY CONFORMAL METHOD FOR EVALUATING THE DISCONTINUOUS FOURIER TRANSFORM

2010 ◽  
Vol 109 ◽  
pp. 425-440 ◽  
Author(s):  
Chun-Hui Zhu ◽  
Qing Huo Liu ◽  
Yi Shen ◽  
Lijun Liu
Keyword(s):  
Fourier Transform ◽  
High Accuracy ◽  
Conformal Method

IDENTIFICATION OF INTERHARMONICS BASED ON WAVELET PACKET TRANSFORM

2021 ◽  
Vol 3 (1) ◽  
pp. 031-036
Author(s):  
S. A. GOROVOY ◽  
◽  
V. I. SKOROKHODOV ◽  
D. I. PLOTNIKOV ◽  
◽  
...  
Keyword(s):  
Fourier Transform ◽  
Simulation Model ◽  
Frequency Domain ◽  
Time Domain ◽  
Wavelet Packet ◽  
High Accuracy ◽  
Wavelet Packet Transform ◽  
Mathematical Apparatus ◽  
Nonlinear Load ◽  
The Time Domain

This paper deals with the analysis of interharmonics, which are due to the presence of a nonlinear load. The tool for the analysis was a mathematical apparatus - wavelet packet transform. Which has a number of advantages over the traditional Fourier transform. A simulation model was developed in Simulink to simulate a non-stationary non-sinusoidal mode. The use of the wavelet packet transform will allow to determine the mode parameters with high accuracy from the obtained wavelet coefficients. It also makes it possible to obtain information, both in the frequency domain of the signal and in the time domain.

Identification of Natural Bamboo Fibers and Flax Fibers

2013 ◽  
Vol 821-822 ◽  
pp. 153-157 ◽  
Author(s):  
Wei Dong Li ◽  
Xin Hou Wang ◽  
Li Hua Peng
Keyword(s):  
Cluster Analysis ◽  
Fourier Transform ◽  
Near Infrared ◽  
Hierarchical Cluster ◽  
High Accuracy ◽  
Flax Fibers ◽  
First Derivative ◽  
Near Infrared Spectra ◽  
Bamboo Fibers ◽  
The Fourier Transform

In this paper, the method based on the testing of the Fourier transform near infrared (NIR) spectra is proposed to identify natural bamboo fibers and flax fibers. The discrimination models between natural bamboo fibers and flax fibers are established by means of Ward’s algorithm and Hierarchical Cluster Analysis after the first derivative and vector normalization pretreatment. The verification results indicated that these two kinds of fibers could be classified into two separated groups for the identification and the near infrared spectra model is high accuracy.

Fourier Transform Method for Interferogram Analysis with High Accuracy

2015 ◽  
Vol 44 (11) ◽  
pp. 1112004
Author(s):  
粟银 SU Yin ◽  
范琦 FAN Qi ◽  
王云飞 WANG Yun-fei ◽  
杨鸿儒 YANG Hong-ru ◽  
黎高平 LI Gao-ping ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Accuracy ◽  
Transform Method ◽  
Fourier Transform Method

scholarly journals An Extension of Phase Correlation-Based Image Registration to Estimate Similarity Transform Using Multiple Polar Fourier Transform

2018 ◽  
Vol 10 (11) ◽  
pp. 1719 ◽  
Author(s):  
Yunyun Dong ◽  
Weili Jiao ◽  
Tengfei Long ◽  
Guojin He ◽  
Chengjuan Gong
Keyword(s):  
Fourier Transform ◽  
Image Registration ◽  
Fractional Fourier Transform ◽  
Correlation Method ◽  
High Accuracy ◽  
Phase Correlation ◽  
Estimation Methods ◽  
Registration Method ◽  
Similarity Transform ◽  
Polar Grid

Image registration is a core technology of many different image processing areas and is widely used in the remote sensing community. The accuracy of image registration largely determines the effect of subsequent applications. In recent years, phase correlation-based image registration has drawn much attention because of its high accuracy and efficiency as well as its robustness to gray difference and even slight changes in content. Many researchers have reported that the phase correlation method can acquire a sub-pixel accuracy of 1 / 10 or even 1 / 100 . However, its performance is acquired only in the case of translation, which limits the scope of the application of the method. However, there are few reports on the estimation of scales and angles based on the phase correlation method. To take advantage of the high accuracy property and other merits of phase correlation-based image registration and extend it to estimate the similarity transform, we proposed a novel algorithm, the Multilayer Polar Fourier Transform (MPFT), which uses a fast and accurate polar Fourier transform with different scaling factors to calculate the log-polar Fourier transform. The structure of the polar grids of MPFT is more similar to the one of the log-polar grid. In particular, for rotation estimation only, the polar grid of MPFT is the calculation grid. To validate its effectiveness and high accuracy in estimating angles and scales, both qualitative and quantitative experiments were carried out. The quantitative experiments included a numerical simulation as well as synthetic and real data experiments. The experimental results showed that the proposed method, MPFT, performs better than the existing phase correlation-based similarity transform estimation methods, the Pseudo-polar Fourier Transform (PPFT) and the Multilayer Fractional Fourier Transform method (MLFFT), and the classical feature-based registration method, Scale-Invariant Feature Transform (SIFT), and its variant, ms-SIFT.

scholarly journals Iterative local Fourier transform-based high-accuracy wavelength calibration for Fourier transform imaging spectrometer

2020 ◽  
Vol 28 (4) ◽  
pp. 5768
Author(s):  
Yixuan Xu ◽  
Jianxin Li ◽  
Caixun Bai ◽  
Ming Wei ◽  
Jie Liu ◽  
...  
Keyword(s):  
Fourier Transform ◽  
High Accuracy ◽  
Imaging Spectrometer ◽  
Wavelength Calibration

scholarly journals Load Identification Using Harmonic Based on Probabilistic Neural Network

2019 ◽  
Vol 7 (1) ◽  
pp. 71-82
Author(s):  
Dimas Okky Anggriawan ◽  
Aidin Amsyar ◽  
Eka Prasetyono ◽  
Endro Wahjono ◽  
Indhana Sudiharto ◽  
...  
Keyword(s):  
Neural Network ◽  
Fourier Transform ◽  
Probabilistic Neural Network ◽  
Harmonic Distortion ◽  
Electrical Equipment ◽  
High Accuracy ◽  
Current Sensor ◽  
Harmonic Load ◽  
Load Identification ◽  
Current Waveform

Due to increase power quality which are caused by harmonic distortion it could be affected malfunction electrical equipment. Therefore, identification of harmonic loads become important attention  in the power system. According to those problems, this paper proposes a Load Identification using harmonic based on probabilistic neural network (PNN). Harmonic is obtained by experiment using prototype, which it consists of microcontroller and current sensor. Fast Fourier Transform (FFT) method to analyze of current waveform on loads become harmonic load data. PNN is used to identify the type of load. To load identification, PNN is trained to get the new weight. Testing is conducted To evaluate of the accuracy of the PNN from combination of four loads. The results demonstrate that this method has high accuracy to determine type of loads based on harmonic load

A new approach to high accuracy measurement of the focal lengths of lenses using a digital Fourier transform

1997 ◽  
Vol 136 (5-6) ◽  
pp. 370-374 ◽  
Author(s):  
M. de Angelis ◽  
S. De Nicola ◽  
P. Ferraro ◽  
A. Finizio ◽  
G. Pierattini
Keyword(s):  
Fourier Transform ◽  
High Accuracy ◽  
New Approach ◽  
Accuracy Measurement ◽  
High Accuracy Measurement

Accurate atomic data for Galactic Surveys

2017 ◽  
Vol 12 (S330) ◽  
pp. 203-205
Author(s):  
Maria Teresa Belmonte ◽  
Juliet C. Pickering ◽  
Christian Clear ◽  
Florence Liggings ◽  
Anne P. Thorne
Keyword(s):  
Fourier Transform ◽  
Spectroscopic Data ◽  
High Accuracy ◽  
Fourier Transform Spectroscopy ◽  
Oscillator Strengths ◽  
Atomic Data ◽  
Chemical Abundances ◽  
Atomic Parameters

AbstractFourier Transform spectroscopy is able to provide high accuracy atomic parameters needed by many ongoing galactic surveys. Our laboratory has carried out a study of the neutral iron spectrum over the last years to measure oscillator strengths much needed for the calculation of chemical abundances. The main aim of this contribution is to encourage further dialogue with astronomers regarding their current necessities of spectroscopic data, as this would help spectroscopists to prioritise present-day needs within the field.

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