Implementation of the discrete wavelet transform and multiresolution analysis in the encrypted domain

2011 ◽  
Author(s):  
Peijia Zheng ◽  
Jiwu Huang
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Discrete Wavelet

scholarly journals Wavelet Transform Based Fault Identification and Reconfiguration for a Reduced Switch Multilevel Inverter Fed Induction Motor Drive

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1023
Author(s):  
Arigela Satya Veerendra ◽  
Akeel A. Shah ◽  
Mohd Rusllim Mohamed ◽  
Chavali Punya Sekhar ◽  
Puiki Leung
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Short Circuit ◽  
Open Circuit ◽  
Multilevel Inverter ◽  
Fault Identification ◽  
Discrete Wavelet ◽  
The Novel ◽  
Inverter Topology

The multilevel inverter-based drive system is greatly affected by several faults occurring on switching elements. A faulty switch in the inverter can potentially lead to more losses, extensive downtime and reduced reliability. In this paper, a novel fault identification and reconfiguration process is proposed by using discrete wavelet transform and auxiliary switching cells. Here, the discrete wavelet transform exploits a multiresolution analysis with a feature extraction methodology for fault identification and subsequently for reconfiguration. For increasing the reliability, auxiliary switching cells are integrated to replace faulty cells in a proposed reduced-switch 5-level multilevel inverter topology. The novel reconfiguration scheme compensates open circuit and short circuit faults. The complexity of the proposed system is lower relative to existing methods. This proposed technique effectively identifies and classifies faults using the multiresolution analysis. Furthermore, the measured current and voltage values during fault reconfiguration are close to those under healthy conditions. The performance is verified using the MATLAB/Simulink platform and a hardware model.

scholarly journals Eliminated aliasing effect on wavelet transform based multiresolution analysis

2016 ◽  
Vol 55 (3) ◽  
Author(s):  
Ernesto González-Flores ◽  
José Oscar Campos-Enríquez ◽  
Erick Camacho-Ramírez ◽  
David Ernesto Rivera-Recillas
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Synthetic Data ◽  
Seismic Signal ◽  
Discrete Wavelet ◽  
Frequency Bands ◽  
Analysis Technique ◽  
The Time Domain ◽  
Seismic Signal Processing

Multiresolution analysis, based on the discrete wavelet transform, is here incorporated in seismic signal processing. This analysis technique enables decomposing a seismic signal, in different frequency bands, and thus to analyze the information contained in these frequency bands. Multiresolution analysis allows visualizing in the time domain the information contained in the frequency bands. Wavelets commonly used in the discrete wavelet transform present an overlay between scales, this constitutes an aliasing effect that gives rise to spurious effects. Vaidyanathan wavelet minimizes the overlay between scales. We applied this wavelet to synthetic data and to a 3D seismic cube. Accordingly, spurious effects from aliasing generated by overlay between scales are minimized with the Vaidyanathan wavelet.

Multiresolution analysis signal in a three beam path Mach-Zehnder interferometer based on a discrete wavelet transform

2018 ◽  
Author(s):  
Daniel Jauregui Vasquez ◽  
Eduardo Cabal Yepez ◽  
Julian Moises Estudillo Ayala ◽  
Juan Carlos Hernandez Garcia ◽  
Roberto Rojas Laguna ◽  
...  
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Zehnder Interferometer ◽  
Discrete Wavelet ◽  
Beam Path ◽  
Mach Zehnder Interferometer

Discrete wavelet transform-based multiresolution analysis and spectral enhancement to characterize heavy oil reservoirs in the southern Gulf of Mexico region

2016 ◽  
Vol 4 (4) ◽  
pp. T497-T505 ◽  
Author(s):  
Erik Camacho-Ramírez ◽  
Ernesto Gonzalez-Flores ◽  
José Oscar Campos-Enriquez
Keyword(s):  
Wavelet Transform ◽  
Gulf Of Mexico ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Heavy Oil ◽  
Resolution Enhancement ◽  
Discrete Wavelet ◽  
Seismic Resolution ◽  
Spectral Enhancement ◽  
Southern Gulf Of Mexico

In Neogene geologic settings, seismic resolution plays an important role in the static characterization of large stratigraphically complex reservoirs. Attenuation of high frequencies due to absorption and scattering of waves propagating through the subsurface contributes to the loss of seismic resolution, resulting, in particular, to a poor delineation of thin beds. This case history comprised the resolution enhancement of seismic data from one petroleum field located in the southern Gulf of Mexico. We applied discrete wavelet transform-based multiresolution analysis to identify frequency components in the data that required spectral enhancement. The resulting enhanced power spectrum contains a higher frequency content, which made it possible to identify new heavy oil (11°–23° API) reservoirs located in thin sandstones of deltaic sedimentary environments. The methodology used here helped us to cope with the attenuation problem.

Multidimensional periodic discrete wavelets

2021 ◽  
Author(s):  
P. A. Andrianov
Keyword(s):  
Wavelet Transform ◽  
Discrete Wavelet Transform ◽  
Multiresolution Analysis ◽  
Discrete Wavelet ◽  
Discrete Wavelets ◽  
Definition Of

In this paper, the definition of a periodic discrete multiresolution analysis is provided. The characterization of such systems is obtained in terms of properties of scaling sequences. Wavelet systems generated by such multiresolution analyses are defined and described. Decomposition and reconstruction formulas for the associated discrete wavelet transform are provided.

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