Results 211 to 220 of about 971,936 (265)

Improved C-scan imaging using a Bayesian approach

2010 IEEE International Ultrasonics Symposium, 2010
Conventional ultrasonic C-scan imaging in composite materials typically employs peak amplitude extraction where the obtained image quality is extremely dependent on the gate setup on the ultrasonic acquisition hardware. Additionally structural noise created by scattering phenomenon is often high enough to bury meaningful reflection echoes, due to the ...
K. S. Ho, S. G. Pierce, M. H. Li, G. Hayward, M. T. H. Sultan   +4 more
openaire   +1 more source

Blind image-deconvolution for ultrasonic C-scans

AIP Conference Proceedings, 2001
Ultrasonic C-scan images suffer from the problem of gating truncations, blurring due to quantization and squaring distortion, and noise. In this work the H∞ identification strategy is presented to restore the image without any prior information about the distortion and noise, hence the scheme is called blind deconvolution.
openaire   +1 more source

Phased subarrays for low cost C-Scan applications

IEEE Ultrasonics Symposium, 2005., 2006
The performance of subarray processing as a means of reducing overall beamforming computational load for a low cost C-Scan imaging device is analyzed. Unlike the case encountered in B-Mode imaging, the C-Scan format is characterized by a large channel count (4096 in this case) and very short data record lengths. Additionally, unlike the case in B-Mode,
Y. Li, T.N. Blalock, W.F. Walker, J.A. Hossack   +3 more
openaire   +1 more source

Multi channel high-T/sub c/ scanning SQUID microscope

IEEE Transactions on Appiled Superconductivity, 2003
We have constructed and tested a multichannel scanning SQUID microscope. An array of up to 8 high-T/sub c/ YBCO SQUIDs are mounted on a single chip at the end of a 77 K cold finger. Each SQUID loop measures 30 /spl mu/m by 60 /spl mu/m, and the SQUID's are spaced by about 200 /spl mu/m.
J. Matthews, S.Y. Lee, F.C. Wellstood, A.F. Gilbertson, G.E. Moore, S. Chatraphorn   +5 more
openaire   +1 more source

Vibro-Acoustography: Speckle Free Ultrasonic C-Scan

2002
In an in vitro experiment the acoustic emission characteristics of broken and intact struts on BSCC valves exhibited different frequency responses and different vibro-acoustography images. The images indicated that the vibration modes of the object could be deduced in addition to the structural integrity of the object.
James F. Greenleaf, Mostafa Fatemi, Randall R. Kinnick   +2 more
openaire   +1 more source

C-scan enhancement using recursive subspace deconvolution

AIP Conference Proceedings, 2002
C-scan images are formed by mapping the windowed A-scan energy levels into pixel values. This operation limits the resolution of the resulting image due to the blurring effect of squared summations and the mechanical positioning resolution. However, one feature that is found in all such images that they are usually scanned in a raster scanning fashion (
openaire   +1 more source

Research of Ultrasonic C-scan Imaging Lateral Resolution

2019 IEEE International Conference on Mechatronics and Automation (ICMA), 2019
Aiming at the problem of reflective C-scan imaging lateral resolution, this paper proposes to use the right-angle crack reflection method to measure the lateral resolution of ultrasonic transducers. According to the theoretical sound field distribution at the focal plane of the ultrasonic transducer, the corresponding line response function and the ...
Ran Liu, Qinxue Pan, Dingguo Xiao, Pengzhi Ma, Ming Cheng   +4 more
openaire   +1 more source

Fabrication of a novel C-scan photoacoustic imaging camera

2015 IEEE Biomedical Circuits and Systems Conference (BioCAS), 2015
Our objective is to provide researchers with an inexpensive and fast photoacoustic imaging (PAI) device for exvivo studies. We implement this using an acoustic lens based focusing idea together with photoacoustic technology, resulting in a prototype imaging system. A complete photoacoustic imaging system simulation modeling is presented.
Bhargava Chinni, Vikram Dogra, Zichao Han, Navalgund Rao, Pedro Vallejo, Wayne Knox, Julie Bentley, Ronald Wood   +7 more
openaire   +1 more source

Screening of Metal Matrix Composites Using Ultrasonic C-Scans

Journal of Composites Technology and Research, 1989
Ultrasonic C-scans can be used to find some types of defects in continuous fiber-reinforced metal matrix composites such as boron/aluminum composites. These defects are related to the fatigue behavior and fracture location of each inspected specimen. The C-scan technique determined the relative amount of defects in boron/aluminum composites.
GP Sendeckyj, SS Wang, W Steven Johnson, WW Stinchcomb, WS Johnson   +4 more
openaire   +1 more source

Cornea curvature measurement using single shot C-scan OCT

SPIE Proceedings, 2007
A novel method is presented for the evaluation of object shapes. The method has applicability in the measurement of the cornea curvature. An en-face OCT system using a multiple delay element in the reference path of the interferometer is proposed. This method allows detection of the polar variations of the cornea curvature from a single en-face OCT ...
Lucian Plesea, Marta Gomez, Adrian Gh. Podoleanu   +2 more
openaire   +1 more source