A new method to generate synthetic online signatures is presented. The algorithm uses a parametrical model to generate the synthetic Discrete Fourier Transform (DFT) of the trajectory signals, which are then refined in the time domain and completed with a synthetic pressure function. Multiple samples of each signature are created so that synthetic databases may be produced. Quantitative and qua...

This article describes an application the author developed in order to compare analysis and synthesis of musical audio signals through Short Time Fourier transform (STFT), Constant Q and Sliding Discrete Fourier Transform (SDFT). This software is the basis for applications of SDFT and Constant Q to other consolidated synthesis techniques. By itself, it is a stand alone instrument for calculatin...

This paper describes a novel structure for a hardwired fast Fourier transform (FFT) signal processor that promises to permit digital spectrum analysis to achieve throughput rates consistent with extremely wide-band radars. The technique is based on the use of serial storage for data and intermediate results and multiple arithmetic units each of which carries out a sparse Fourier transform. Deta...

the s-transform has widely been used in the analysis of non-stationary time series. a simple method to obtain depth estimates of gravity field sources is introduced in this study. we have developed a new method based on the spectral characteristics of downward continuation to estimate depth of structures. this calculation procedure is based on replacement of the fourier transform with the s-tra...

Periodicity is emerging as a useful method for characterising the structure within biological sequences such as DNA. For sequence data, integer periods are usually of most interest, which poses the problem of fast computation if conventional Fourier-based analyses are applied. This paper adapts an existing complex polynomial re-evaluation algorithm, and proposes a fast approximation rule applic...

The analysis of electrical signals is a pressing requirement for the optimal design of power distribution. In this context, this paper illustrates how to use a variety of numerical tools, such as the Fourier, wavelet, and Hilbert-Huang transforms, to obtain information relating to the active and reactive power absorbed by different types of users. In particular, the Fourier spectrum gives the m...

A Michelson Fourier Transform Spectrometer senses an object/material in the time domain, producing an interferogram. To produce a spectrum, the interferogram is Fourier transformed into the spectral domain. Unless filtering is applied to the interferogram, all the time changing (AC) components of the interferogram contribute to the resulting spectrum. Aperiodic signals are not easily removed fr...

Frequency estimation of complex exponentials using the interpolated Fourier spectrum is analyzed. Data is categorized into two types: phase relationship between components – random/fixed phase difference; and availability of data – single-shot/continuous. When phase difference between exponentials is random the bias component, from interaction of secondary sidelobes, itself becomes random. This...

A novel method for simulating field propagation is presented. The method, based on the angular spectrum of plane waves and coordinate rotation in the Fourier domain, removes geometric limitations posed by conventional propagation calculation and enables us to calculate complex amplitudes of diffracted waves on a plane not parallel to the aperture. This method can be implemented by using the fas...

A new approach to Fourier analysis within the context of circuit simulation is presented that is considerably more accurate and flexible than the traditional SPICE approach. It is based on the direct computation of the Fourier integral rather than on the discrete Fourier transform and so it is not subject to aliasing. It can be used to accurately compute a small number of Fourier coefficients f...