The paper deals with a harmonic detection algorithm for hybrid power filters called DQ axis with Fourier (DQF) algorithm. This algorithm is a combination of the advantages of DQ axis method and sliding window Fourier analysis (SWFA). It is flexible and suitable in terms of design for hybrid power filters. This paper also presents the harmonic elimination by using the DQF algorithm for both thre...

An approach reported recently by Alexandrov et al. 1 on optical scatter imaging, termed digital Fourier microscopy (DFM), represents an adaptation of digital Fourier holography to selective imaging of biological matter. Holographic mode of recording of the sample optical scatter enables reconstruction of the sample image. Form-factor of the sample constituents provides a basis for discriminatio...

For spatially dependent functional data, a generalized Karhunen-Lo\`{e}ve expansion is commonly used to decompose data into an additive form of temporal components and correlated coefficients. This structure provides convenient model investigate the space-time interactions, but may not hold for complex spatio-temporal processes. In this work, we introduce concept weak separability, propose form...

We use the simulation model ofCbalfallt and Gallant (IUS5) to investigate the fit of a Fourier flexible form to a cost function when interest is t.o estimate elasticities of substitution. The data is subject to errors in variables and the estimation method is seemingly unrelated regressions. \IVe use two approximating Fourier functional forms * Hesearch supported by C:-IPq ** Banco do Brasil, C...

Non-stationary forced oscillations (FOs) have been observed in power system operations. However, most detection methods assume that the frequency of FOs is stationary. In this paper, we present a methodology for analysis non-stationary FOs. Firstly, Fourier synchrosqueezing transform (FSST) used to provide concentrated time-frequency representation signals allows identification and retrieval si...

The Fourier transform usually has been used in the past for analysis of stationary and periodic signals. Its interest is the knowledge of spectral components existing in a waveform; it doesn't matter the moment where they happen. However, when the time localization of the spectral components is needed, the Wavelet Transform (WT) can be used to obtain the optimal timefrequency representation of ...

Heart and respiration rate measurement using Doppler radar is a non-contact and non-obstructive way for remote thorough-clothing monitoring of vital signs. The modulated back-scattered radar signal in the presence of high noise and interference is non-stationary with hidden periodicities, which cannot be detected by ordinary Fourier analysis. In this paper we propose a cyclostationary approach ...

Fractional Fourier transforms (FrFT) are a natural one-parameter family of unitary transforms that have the ordinary Fourier transform embedded as a special case. In this paper, following the efforts of several authors, we explore the theory and applications of FrFT, from the standpoints of both quantum mechanics and analysis. These include the phase plane interpretation of FrFT, FrFT’s role in...