Wavelet analysis and high quality JPEG2000 compression using Daubechies wavelet

2011 ◽  
Author(s):  
Azra Khalid ◽  
Uzma Afsheen ◽  
Saad Umer Baig
Keyword(s):  
Wavelet Analysis ◽  
Daubechies Wavelet ◽  
High Quality ◽  
Jpeg2000 Compression

Transmission of Human Intention by Impulsive Sound

2004 ◽  
Vol 16 (1) ◽  
pp. 39-43
Author(s):  
Kazue Nishihara ◽  
◽  
Noriyuki Kawarazaki ◽  
Tadashi Yoshidame
Keyword(s):  
Wavelet Analysis ◽  
Wavelet Function ◽  
Human Machine Interface ◽  
Daubechies Wavelet ◽  
Scaling Parameter ◽  
Human Intention ◽  
Machine Interface ◽  
Regular Work ◽  
Emergency Stoppage

We discuss a basic human-machine interface for transmitting human intention to a machine via impulsive sound, using wavelet analysis to determine whether impulsive sound is recognized. We found that tapping transmits indicates human intention to a machine, if we choose an appropriate analysis wavelet and its scaling parameter. We found that Daubechies wavelet function parameters were feasible for our purpose at N=3 (order) and j=8 (scaling parameter). This interface should prove useful for orders in regular work and emergency stoppage.

Mixed Noise Image De-Noising Based on EM Algorithm

2014 ◽  
Vol 556-562 ◽  
pp. 4734-4741 ◽  
Author(s):  
Gui Cun Shi ◽  
Fei Xing Wang
Keyword(s):  
Applied Sciences ◽  
Wavelet Analysis ◽  
Em Algorithm ◽  
Gaussian Noise ◽  
Impulse Noise ◽  
Noise Source ◽  
High Quality ◽  
Noise Image ◽  
Mixed Noise ◽  
Non Gaussian

Obtaining high quality images is very important in many areas of applied sciences, but images are usually polluted by noise in the process of generation, transmission and acquisition. In recent years, wavelet analysis achieves significant results in the field of image de-noising. However, most of the studies of noise-induced phenomena assume that the noise source is Gaussian. The use of mixed Gaussian and impulse noise is rare, mainly because of the difficulties in handling them. In the process of image de-noising, the noise model’s parameter estimation is a key issue, because the accuracy of the noise model’s parameters could affect the de-noising quality. In the case of mixed Gaussian noises, EM algorithm is an iterative algorithm, which simplifies the maximum likelihood equation. This thesis takes wavelet analysis and statistics theory as tools, studies on mixed noise image de-noising, provides two classes of algorithms for dealing with a special type of non-Gaussian noise, mixed Gaussian and Pepper & Salt noise.

A Denoise Method of Electrical Discharge Machining Gaps Signal for Non-Conductive Engineering Ceramics Based on Wavelet MMA

2009 ◽  
Vol 407-408 ◽  
pp. 662-666
Author(s):  
Rong Shen ◽  
Yong Hong Liu ◽  
Ji Ming Chen ◽  
Hai Feng Zhang ◽  
Ren Jie Ji
Keyword(s):  
Wavelet Analysis ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Threshold Value ◽  
Wavelet Function ◽  
Daubechies Wavelet ◽  
Current Signal ◽  
Engineering Ceramics ◽  
Meyer Wavelet ◽  
Modulus Maxima

EDM; Gap voltage/current; Wavelet analysis; Modulus maxima algorithm Abstract: According to the characteristics of Electrical Discharge Machining Gaps Signal for Non-conductive Engineering Ceramics, the wavelet modulus maxima algroithm was uesed to denoise the gaps voltage/current signal. Compaered the differernt denoising result of different wavelet function, Maxihat wavelet, Meyer wavelet, Daubechies wavelet and Gaussian wavelet, the fitting wavelet function, Gaussian wavelet which used to denoising the EDM Gaps voltage/current signal was found out, and the fitting scales space [-5,+1] and the normalized threshold value interval [0.1,0.3] was determined.

scholarly journals Nonlinear Alleviation of Edge Effects in the Context of Minimizing Prediction Errors

2018 ◽  
Vol 10 (2) ◽  
pp. 161
Author(s):  
Monika Hadas-Dyduch
Keyword(s):  
Finite Elements ◽  
Wavelet Analysis ◽  
Edge Effects ◽  
Nonlinear Function ◽  
Innovative Approach ◽  
Prediction Errors ◽  
Daubechies Wavelet ◽  
Vanishing Moments ◽  
Filter Length ◽  
Orthogonal Wavelets

The aim of this article is to describe so-called “edge effects” in the context of wavelet analysis. The problem of “edge effects” is displayed in cases where the filter length is greater than 2. This is due to the fact that the calculation of the wavelet coefficients for the development of the last signal of finite elements, the filter - should theoretically move beyond the signal. The article describes different ways to solve this problem using an authored approach. One of the ways presented in the article is an innovative approach in terms of “edge effects”. The author’s proposal is based on the nonlinear function of the trend after the division of the series into smaller units. The results obtained show that in comparison with other methods, the author’s method reduces errors. In this article, the Daubechies wavelet was used for the study. The Daubechies wavelets are a family of orthogonal wavelets, characterized by a maximum number of vanishing moments for a given support.

Early Diagnosis of Spalling in the Gear Teeth

2014 ◽  
Vol 1016 ◽  
pp. 249-255
Author(s):  
Mustapha Merzoug ◽  
Khalid Ait-Sghir ◽  
Abdelhamid Miloudi ◽  
Paul Jean Dron
Keyword(s):  
Signal Processing ◽  
Early Diagnosis ◽  
Wavelet Analysis ◽  
Gear Transmission ◽  
Fault Identification ◽  
Daubechies Wavelet ◽  
Gear Teeth ◽  
Vibratory Analysis ◽  
Stationary Signals ◽  
Spalling Defect

The monitoring and vibratory analysis of gear transmission allow the prediction of a possible malfunction and breakdowns. As the gear transmission product non-stationary signals its treatment is too difficult with the usual tools of signal processing witch can product errors in its interpretation. As the characteristics of gear frequencies are predetermined, it is proposed to monitor (fault identification) using wavelet analysis. To simulate the signal to be analyzed, we intentionally introduced a spalling defect. We chose the Daubechies wavelet type which are the most used in diagnostic. The aim of this work is to try to control the various parameters related to the wavelet analysis for reliable and inexpensive detection, i.e., the order of the wavelet and level decomposition. The approach witch was previously used for bearings, consists on observing the kurtosis for several orders wavelet based on the default severity..

Some problems of objective-prism spectra classification

1966 ◽  
Vol 24 ◽  
pp. 51-52
Author(s):  
E. K. Kharadze ◽  
R. A. Bartaya
Keyword(s):  
Short Wave ◽  
High Quality ◽  
Stellar Spectra ◽  
Objective Prism

The unique 70-cm meniscus-type telescope of the Abastumani Astrophysical Observatory supplied with two objective prisms and the seeing conditions characteristic at Mount Kanobili (Abastumani) permit us to obtain stellar spectra of a high quality. No additional design to improve the “climate” immediately around the telescope itself is being applied. The dispersions and photographic magnitude limits are 160 and 660Å/mm, and 12–13, respectively. The short-wave end of spectra reaches 3500–3400Å.

A non-cyanide method of electropolishing silver

1978 ◽  
Vol 36 (1) ◽  
pp. 146-147
Author(s):  
R. L. Lyles ◽  
S. J. Rothman ◽  
W. Jäger
Keyword(s):  
Electron Microscopy ◽  
Sulphuric Acid ◽  
Methyl Alcohol ◽  
Health Hazards ◽  
Silver Alloy ◽  
High Quality ◽  
Silver Alloys ◽  
Free Sample ◽  
Specimen Quality ◽  
Standard Techniques

Standard techniques of electropolishing silver and silver alloys for electron microscopy in most instances have relied on various CN recipes. These methods have been characteristically unsatisfactory due to difficulties in obtaining large electron transparent areas, reproducible results, adequate solution lifetimes, and contamination free sample surfaces. In addition, there are the inherent health hazards associated with the use of CN solutions. Various attempts to develop noncyanic methods of electropolishing specimens for electron microscopy have not been successful in that the specimen quality problems encountered with the CN solutions have also existed in the previously proposed non-cyanic methods.The technique we describe allows us to jet polish high quality silver and silver alloy microscope specimens with consistant reproducibility and without the use of CN salts.The solution is similar to that suggested by Myschoyaev et al. It consists, in order of mixing, 115ml glacial actic acid (CH3CO2H, specific wt 1.04 g/ml), 43ml sulphuric acid (H2SO4, specific wt. g/ml), 350 ml anhydrous methyl alcohol, and 77 g thiourea (NH2CSNH2).

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