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Your search keyword '"Katakura, Kageyoshi"' showing total 40 results
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40 results on '"Katakura, Kageyoshi"'

2. Full-circular surface acoustic wave excitation for high resolution acoustic microscopy using spherical lens and time gate technology

Author

Ishikawa, Isao, Katakura, Kageyoshi, and Ogura, Yukio

Subjects
Acoustic surface waves -- Models, Attenuation -- Models, Ultrasonics -- Models, Acoustic imaging -- Models, Business, Electronics, Electronics and electrical industries
Abstract

The mechanism of full-circular surface acoustic wave excitation was investigated using spherical lens assembly and time gate technology. In addition, the shape of the point spread function was analyzed. Signal taking-in time was varied with a fixed gate width under the condition where the focus of an acoustic lens was set inside the sample. Experimental results showed that three types of images were obtained separately, namely, the surface reflection wave image, the surface acoustic wave image and combination images based on the interference of the surface reflection wave with surface acoustic waves.

Published
1999

3. A method of ultrasonic 3-D computed velocimetry

Author

Ogura, Yukiko, Katakura, Kageyoshi, and Okujima, Motoyoshi

Subjects
Ultrasound imaging -- Research, Fluid dynamics -- Research, Biological sciences, Business, Computers, Health care industry
Abstract

A method of ultrasonic three-dimensional (3-D) vector velocimetry, which is derived by extending the previously proposed two-dimensional (2-D) vector velocimetry, is presented. In the proposed method, the three vector components of velocity to be measured are defined as the velocity in the beam axial direction, and angle velocities in two transverse directions. To derive the three components of velocity, signals detected by a 2-D array transducer are first 2-D Fourier transformed in the spatial domain parallel to the 2-D array transducer and then are one-dimensional (1-D) Fourier transformed in the time domain. The advantage of the proposed method is that it uses a linear signal processing, so it can simultaneously measure individual velocities of multiple scatterers. Computer simulations clearly demonstrate the effectiveness of the proposed method. Index Terms - Flow imaging, ultrasonic velocimetry.

Published
1997

4. Ultrasonic vector velocity measurement by projection computed velocimetry

Author

Katakura, Kageyoshi and Okujima, Motoyoshi

Subjects
Ultrasonics -- Research, Fourier transformations -- Usage, Business, Electronics, Electronics and electrical industries
Abstract

A new method for measuring complete vector components of target velocity is discussed. Velocity resolution of this method with rectangular windows are estimated to be 1/(kappaTW) in axial velocity component and 2.3/(kappaTW) in lateral velocity component. Numerical simulation demonstrates the features of this method which are beneficial in the presence of multiple targets.

Published
1995

16. Advances in underwater acoustic video camera

Author

Matsumoto, Sayuri, primary, Hirabayashi, Taketsugu, additional, Shirai, Kazuhiro, additional, Tanaka, Toshinari, additional, Yoshie, Muneo, additional, Katakura, Kageyoshi, additional, and Takahashi, Koji, additional

Published
2015
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30. On ultrasonic methods for measurement of the nonlinear parameter B/A in fluid-like media.

Author

Cain, Charles A., Nishiyama, Hisashi, and Katakura, Kageyoshi

Abstract

A composite waveform consisting of the sum of a low-frequency pump sinusoid and a higher frequency probe results in phase modulation of the probe by the pump in nonlinear media. The phase deviation in the probe at the pump frequency can be measured directly or inferred from measurement of the magnitude of the resulting sum or difference sidebands. The phase deviation (or sideband magnitude) increases linearly with pump pressure and with the slope as a function of the nonlinearity of the medium, thus providing a means for determination of B/A. [ABSTRACT FROM AUTHOR]

Published
1986
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