identification of damping parameter is usually more complicated and unreliable comparing to mass or stiffness identification in structural dynamics. there are many factors such as intermolecular friction, coulomb friction and viscous damping affecting the damping mechanisms in a structure. therefore it is difficult, and in some cases impossible, to describe the details of damping mechanisms by ...

A Review on Vibration Analysis for Misalignment of Shaft in Rotary Systems by Using Discrete Wavelet Transform Abhijeet Shirude | S. Y. Gajjal (Mechanical Department, NBNSSoE, Savitribai Phule Pune University, Pune, India, [email protected]) (Mechanical Department, NBNSSoE, Savitribai Phule Pune University, Pune, India, [email protected]) ___________________________________________...

introduction: an efficient method of tomographic imaging in nuclear medicine is positron emission tomography (pet). compared to spect, pet has the advantages of higher levels of sensitivity, spatial resolution and more accurate quantification. however, high noise levels in the image limit its diagnostic utility. noise removal in nuclear medicine is traditionally based on fourier decomposition o...

In this paper, transform domain adaptive filters are studied and reviewed based on previous researches. In transform domain adaptive filters orthogonality properties of transformation such as discrete cosine transform (DCT), discrete sine transform (DST), wavelet transform and discrete fourier transform (DFT) are used to achieve an improved convergence rate as compared to the time domain analys...

The advantages of the wavelet transform over conventional transforms, such as the Fourier transform, are now well recognized. Because of its excellent locality in time-frequency domain, wavelet transform is remarkable and extensively used for signal analysis, compressing and denoising. Defining DWT by Mallat [1] provided possibility of its digitally hardware or software implementation. The disc...

Glossary WT1D The one-dimensional Wavelet Transform as defined in [1]. See also [2] in this volume. WT2D The two-dimensional Wavelet Transform. Discrete Ridgelet Trasnform (DRT) The discrete implementation of the continuous Ridgelet transform. Fast Slant Stack (FSS) An algebraically exact Radon transform of data on a Cartesian grid. First Generation Discrete Curvelet Transform (DCTG1) The discr...

Discrete Wavelet Transform (DWT) and Discrete Cosine Transform (DCT) are the common methods used in signal and image compression. Wavelet transform are very powerful compared to Fourier transform because its ability to describe any type of signals both in time and frequency domain simultaneously. In this paper, we will discuss the use of Discrete Cosine Transform (DCT) and Wavelet Based Image c...

Frequency is a key physical parameter in potential field theory. Accordingly, Fourier transforms play an important role in aeromagnetic processing and many common enhancements are efficiently implemented in the Fourier domain. However, the trade-off for accurately measuring the frequency content of a signal is a complete absence of spatial localisation in the Fourier domain. Fourier-based enhan...

Images require substantial storage and transmission resources, thus image compression is advantageous to reduce these requirements. The objective of this paper is to evaluate a set of wavelets for image compression. Image compression using wavelet transforms results in an improved compression ratio. Wavelet transformation is the technique that provides both spatial and frequency domain informat...