Diagnostic of machine using the timefrequency representation of vibration is becoming widely used by many companies and experts. In recent years, the preventive maintenance is no more desirable and in fact it has evolved into the prediction maintenance. The current methods of machine diagnosis can not provide detailed diagnostics and condition prediction. This paper proposes the application of ...

The fractional Fourier transform (FrFT) is used for the solution of the diffraction integral in optics. A scanning approach is proposed for finding the optimal FrFT order. In this way, the process of diffraction computing is speeded up. The basic algorithm and the intermediate results at each stage are demonstrated.

_.a conventional prime factor discrete Fourier transform (DFT) algorithm is used to realize a discrete Fourier-like transform on the finite fieM, GF(qg ). A pipeline structure is used to implement this prime factor DFT over GF(qn). This algorithm is developed to compute cyclic convolutions of complex numbers and to decode ReedSolomon codes. Such a pipeline fast prime factor DFT algorithm over G...

Abslrnrf This paper aim to consider using the Wavelel Transform ( WT), WignerVille Distribution ( W O ) and ChoiWilliams Distribution (CWD) applied for spectrum estimution of non-stationary signals in power sysfems. The main goal is lo emphasize advantage and disadvantage of mentioned methods in comparison with Shun-Tinu Fourier Transform (STFT). Especial& the aspect offrequency resolution are ...

The linear canonical transform (LCT) describes the effect of any quadratic phase system (QPS) on an input optical wave field. Special cases of the LCT include the fractional Fourier transform (FRT), the Fourier transform (FT), and the Fresnel transform (FST) describing free-space propagation. Currently there are numerous efficient algorithms used (for purposes of numerical simulation in the are...

Due to the fast evolution of digital data exchange, security of information becomes important. For industrial process images are used widely, therefore it is necessary to protect the confidential information. In the proposed work for encryption of image by the use of Fractional Fourier Transform(FRFT).This method enhances the security of data in comparison to DFT. In the proposed work we will b...

Because of mass assignment onto grid points in the measurement of the power spectrum using the Fast Fourier Transform (FFT), the raw power spectrum |δ f (k)| 2 estimated with FFT is not the same as the true power spectrum P (k). In this paper, we derive the formula which relates |δ

FRACTIONAL FOURIER INTEGRAL THEOREM AND FRACTIONAL FOURIER SINE AND COSINE TRANSFORM Saleem Iqbal, S.M. Raza, * LalaRukh Kamal and Farhana Sarwar Department of Mathematics/Physics, University of Balochistan, Quetta, Pakistan e-mail: fs1005,saleemiqbal81,[email protected]. ABSTRACT: The fractional Fourier transform (FRFT) is a generalization of the ordinary Fourier transform (FT). Recently...

This paper looks at an approach that uses symmetric properties of the basis function to remove redundancies in the calculation of the discrete Fourier transform (DFT). We develop an algorithm, called the quick Fourier transform (QFT), that reduces the number of oating point operations necessary to compute the DFT by a factor of two or four over direct methods or Goertzel's method for prime leng...

The nonuniform discrete Fourier transform (NDFT), used in many processing schemes, can be computed using a fast algorithm known as the non uniform fast Fourier transform (NFFT). The NFFT is not a new algorithm, but it is an approximation scheme that can be use to calculate an approximate spectrum. In one dimension, computational complexity of the NFFT is O(NlogN) which is a dramatic improvement...