Fast fourier transforms: A tutorial review and a state of the art

Duhamel, Pierre; Vetterli, Martin

doi:10.1016/0165-1684(90)90158-u

Cited by 811 publications

(393 citation statements)

References 98 publications

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“…Although one row direction appears to dominate the image, the adsorbed layer in fact has hexagonal symmetry (indicated by the blue lines on the image) with a repeat spacing of ~0.5 nm, confirmed by fast Fourier transform (FFT), 45 shown as an inset. This repeat spacing is consistent with the lattice spacing of the underlying mica (0.52 nm) 46 , within experimental error, and with previous studies of the protic IL-mica interface.…”

Section: Resultsmentioning

confidence: 94%

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Elbourne

Cronshaw

Voïtchovsky

et al. 2015

Phys. Chem. Chem. Phys.

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Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-pro t purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. * Corresponding author AbstractIn situ amplitude modulated -atomic force microscopy (AM-AFM) has been used to probe the nanostructure of mixtures of propylammonium nitrate (PAN) with n-alkanols near a mica surface. PAN is a protic ionic liquid (IL) which has a bicontinuous sponge-like nanostructure of polar and apolar domains in the bulk, which becomes flatter near a solid surface. Mixtures of PAN with 1-butanol, 1-octanol, and 1-dodecanol at 10 -70 vol% n-alkanol have been examined, along with each pure n-alkanol, to reveal the effect of composition and n-alkanol chain length. At low concentrations the butanol simply swells the PAN nearsurface nanostructure, but at higher concentrations the nanostructure fragments. Octanol and dodecanol first lower the preferred curvature of the PAN near-surface nanostructure because, unlike n-butanol, their alkyl chains are too long to be accommodated alongside the PAN cations. At higher concentrations, octanol and dodecanol self-assemble into n-alkanol rich aggregates in a PAN rich matrix. The concentration at which aggregation first becomes apparent decreases with n-alkanol chain length.2

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Section: Resultsmentioning

confidence: 94%

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Elbourne

Cronshaw

Voïtchovsky

et al. 2015

Phys. Chem. Chem. Phys.

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“…, L being the FFT length [17]. However, they have different performance depending on the value of L. The most common algorithm is the Cooley-Tukey algorithm, which requires that L be a composite number [18].…”

Section: Fft Lengthmentioning

confidence: 99%

“…There are also algorithms that can perform the FFT when L is a prime number, less efficiently however [19], [20]. A state of the art of FFT algorithms can be found in [17].…”

Section: Fft Lengthmentioning

confidence: 99%

Acquisition of modern GNSS signals using a modified parallel code-phase search architecture

2014

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The acquisition of global navigation satellite system signals can be performed using a fast Fourier transform (FFT). The FFT-based acquisition performs a circular correlation, and is thus sensitive to potential transitions between consecutive periods of the code. Such transitions are not occurring often for the GPS L1 C/A signal because of the low data rate, but very likely for the new GNSS signals having a secondary code. The straightforward solution consists in using two periods of the incoming primary code and using zeropadding for the local code to perform the correlation. However, this solution increases the complexity, and is moreover not efficient since half of the points calculated are discarded. This has led us to research for a more efficient algorithm, which discards less points by calculating several sub-correlations.It is applied to the GPS L5, Galileo E5a, E5b and E1 signals. Considering the radix-2 FFT, the proposed algorithm is more efficient for the L5, E5a and E5b signals, and possibly for the E1 signal. The theoretical number of operations can be reduced by 21 %, the processing time measured on a * Corresponding author Email address: jerome.leclere@epfl.ch (Jérôme Leclère)Preprint submitted to Signal Processing July 2, 2013 software implementation is reduced by 39 %, and the memory resources are almost halved for an FPGA implementation.

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“…The power spectrum density(PSD) represented on a logarithmic scale was obtained after Fast Fourier Transform(FFT) for arc sound signals [30,31], as shown in Fig. 2(c).…”

Section: Arc Sound Signals Pretreatment and Characteristics Analysismentioning

confidence: 99%

Quantitative evaluation method of arc sound spectrum based on sample entropy

Yao

Zhou

Zhu

2017

Mechanical Systems and Signal Processing

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Fast fourier transforms: A tutorial review and a state of the art

Cited by 811 publications

References 98 publications

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Near surface properties of mixtures of propylammonium nitrate with n-alkanols 1. Nanostructure

Acquisition of modern GNSS signals using a modified parallel code-phase search architecture

Quantitative evaluation method of arc sound spectrum based on sample entropy

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