An Interpolation Family between Gabor and Wavelet Transformations

2003 ◽  
pp. 363-394 ◽  
Author(s):  
Bruno Nazaret ◽  
Matthias Holschneider
Keyword(s):  
Wavelet Transformations

A Secure Image Encryption Scheme using Chaos and Wavelet Transformations

2018 ◽  
Vol 12 (1) ◽  
pp. 5-14 ◽  
Author(s):  
Bhaskar Mondal ◽  
Tarni Mandal ◽  
Danish Ali Khan ◽  
Tanupriya Choudhury
Keyword(s):  
Image Encryption ◽  
Encryption Scheme ◽  
Wavelet Transformations

Authentication based on wavelet transformations

2006 ◽  
Vol 9 (3) ◽  
pp. 513-521 ◽  
Author(s):  
Koduganti Venkata Rao ◽  
P. S. Avadhani
Keyword(s):  
Wavelet Transformations

DIAGNOSTICS WITH A MULTI-CHANNEL MEASURING SYSTEM WITH A FLEXIBLE STRUCTURE OF BOSCH INJECTORS

2021 ◽  
Vol 1 (142) ◽  
pp. 55-64
Author(s):  
◽  
Viktor E. Tarasenko ◽  
Oleg C. Rolich ◽  
Anatoliy V. Dunayev ◽  
Keyword(s):  
Spectral Analysis ◽  
Educational Institution ◽  
Injection Pressure ◽  
Measuring System ◽  
Research Purpose ◽  
Flexible Structure ◽  
Multichannel System ◽  
Vibration Sensors ◽  
The Fourier Transform ◽  
Wavelet Transformations

At the CR-Jet 4E stand, the vibroacoustic signals of BOSCH injectors were studied using a multichannel system with a flexible structure in the BGATU Educational Institution. They were processed in the Mathcad system with spectral analysis and wavelet transformations in MATLAB programs. (Research purpose) The research purpose is in analyzing the vibration characteristics of BOSCH injectors, identifying possible malfunctions and predict their service life. (Materials and methods) The article presents testing results of a new and working nozzle at an injection pressure of 158, 200 and 1000 bar. In five tests it were used the MPU6050 vibration sensors, the INMP621 microphone, and the temperature sensor. The vibration signals were displayed along the xyz axes according to the amplitude-frequency response with the Fourier transform. (Results and discussion) The article presents graphs of wavelet transformations and amplitude-frequency characteristics from five binary files of accelerometer signals and sound files of injectors. The article presents the accelerometer signals on the y-axis at the top of the graphs, the spectrum of their constancy in the middle, and the scalogram at the bottom. For worn-out injectors, the spectrum of constancy is less expressed, the main signal peaks are in the frequencies of 150 and 300 hertz, they are less than in the new nozzle, and the amplitudes are higher up to 800 units. For the new nozzle, the uniform peaks are less than 200 units. The acoustic amplitude of the worn–out nozzle is 150 units, and the new one at frequencies up to 250 hertz is up to 120 units. (Conclusion) Studies of BOSCH injectors with signal processing in the Mathcad system, followed by spectral analysis and wavelet transformations using the MATLAB software package, have shown that the worn-out injectors are characterized by a less expressed spectrum of oscillation constancy. The research goals have not been achieved, but they deepen the traditional diagnosis.

DIAGNOSTICS WITH A MULTI-CHANNEL MEASURING SYSTEM WITH A FLEXIBLE STRUCTURE OF BOSCH INJECTORS

2021 ◽  
Vol 1 (142) ◽  
pp. 55-64
Author(s):  
Aleksandr Zheshko ◽  
◽  
Viktor Tarasenko ◽  
Oleg Rolich ◽  
Anatoliy Dunayev ◽  
...  
Keyword(s):  
Spectral Analysis ◽  
Educational Institution ◽  
Injection Pressure ◽  
Measuring System ◽  
Research Purpose ◽  
Flexible Structure ◽  
Multichannel System ◽  
Vibration Sensors ◽  
The Fourier Transform ◽  
Wavelet Transformations

At the CR-Jet 4E stand, the vibroacoustic signals of BOSCH injectors were studied using a multichannel system with a flexible structure in the BGATU Educational Institution. They were processed in the Mathcad system with spectral analysis and wavelet transformations in MATLAB programs. (Research purpose) The research purpose is in analyzing the vibration characteristics of BOSCH injectors, identifying possible malfunctions and predict their service life. (Materials and methods) The article presents testing results of a new and working nozzle at an injection pressure of 158, 200 and 1000 bar. In five tests it were used the MPU6050 vibration sensors, the INMP621 microphone, and the temperature sensor. The vibration signals were displayed along the xyz axes according to the amplitude-frequency response with the Fourier transform. (Results and discussion) The article presents graphs of wavelet transformations and amplitude-frequency characteristics from five binary files of accelerometer signals and sound files of injectors. The article presents the accelerometer signals on the y-axis at the top of the graphs, the spectrum of their constancy in the middle, and the scalogram at the bottom. For worn-out injectors, the spectrum of constancy is less expressed, the main signal peaks are in the frequencies of 150 and 300 hertz, they are less than in the new nozzle, and the amplitudes are higher up to 800 units. For the new nozzle, the uniform peaks are less than 200 units. The acoustic amplitude of the worn-out nozzle is 150 units, and the new one at frequencies up to 250 hertz is up to 120 units. (Conclusion) Studies of BOSCH injectors with signal processing in the Mathcad system, followed by spectral analysis and wavelet transformations using the MATLAB software package, have shown that the worn-out injectors are characterized by a less expressed spectrum of oscillation constancy. The research goals have not been achieved, but they deepen the traditional diagnosis.

Medical Image Compression Using Integer Wavelet Transformations

2011 ◽  
pp. 277-286
Author(s):  
B. Ramakrishnan ◽  
N. Sriraam
Keyword(s):  
Wavelet Transform ◽  
Wavelet Transforms ◽  
Medical Images ◽  
Lossy Compression ◽  
Data Sets ◽  
Optimal Method ◽  
Medical Image Compression ◽  
Integer Wavelet ◽  
Wavelet Transformations ◽  
Lossless And Lossy Compression

In this chapter, we have focused on compression of medical images using integer wavelet transforms. Lifting transforms such as S, TS, S+P(B), S+P(C), 5/3, 2+@, 2, 9/7-M and 9/7-F transforms are used to evaluate the performances of lossless and lossy compression. Four medical images, namely, MRI, CT, ultrasound, and angiograms are used as test data sets. It is found from the experiments that, among the different transforms, the 9/7-M wavelet transform is identified as the optimal method for lossless and lossy compression of medical images.

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