1996 IEEE Ultrasonics Symposium. Proceedings最新文献

Linear feature enhancement by false color 伪色线性特征增强

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584313

R. Czerwinski, D.L. Jones, W. O’Brien

引用次数: 2

Measurements of pulse mode behavior in weakly-clad silica waveguides 弱包层硅波导中脉冲模式行为的测量

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584076

E. Verdonk

引用次数: 2

Comparison of contrast in backscatter and angular scatter ultrasonic images 后向散射与角向散射超声图像对比度的比较

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584344

J. Lacefield, O. V. von Ramm

引用次数: 0

Lead titanate based composition for multilayer actuators 多层执行器用钛酸铅基组合物

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584004

L. Pardo, W. Wolny, A. James, M. Calzada, M. Algueró, B. Jiménez

引用次数: 1

Blind deconvolution through parametric identification using second and fourth order cumulants 利用二阶和四阶累积量进行参数辨识的盲反卷积

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584075

T. Olofsson, Tadeusz Stepinski

{"title":"Blind deconvolution through parametric identification using second and fourth order cumulants","authors":"T. Olofsson, Tadeusz Stepinski","doi":"10.1109/ULTSYM.1996.584075","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584075","url":null,"abstract":"Deconvolution of signals that have been distorted by an ultrasonic transducer is usually made in order to obtain improved image resolution. In NDE applications efficient deconvolution would make possible comparison of images obtained using different transducers. Classical deconvolution methods are based on some a priori knowledge of the transducer. In blind deconvolution the distortion is estimated from the signals at hand and later on used in the deconvolution process. Both parametric and nonparametric methods are available. A standard parametric approach is to find the model that minimizes the squared prediction error. This method which is based on second order statistics has the disadvantage of not being able to correctly identify nonminimum-phase systems. An alternative method based on both second and fourth order cumulants, referred as to HOCM, is proposed to circumvent this problem. In order to see advantages and disadvantages with the proposed method comparisons are made with the prediction error method, PEM, and also with a nonparametric method. The nonparametric method is based on the complex cepstrum, and is known to be capable of identifying nonminimum-phase systems. The results presented in the paper show that the proposed method is capable of finding nonminimum-phase systems and therefore is a step towards identification of the true distorting system (transducer). The results are obtained using real and simulated ultrasonic data. The B-scans have been acquired in inspection of graphite-epoxy composite materials, and the simulated data is generated by a simple model of the layered structure materials.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"371 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125138318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Radio accessible SAW sensors for non-contact measurement of torque and temperature 无线电可达SAW传感器，用于非接触式测量扭矩和温度

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.583992

U. Wolff, F. Schmidt, G. Scholl, V. Magori

引用次数: 43

Ultrasonic characterization of aramid-epoxy/aluminum laminates from pulse-echo data 基于脉冲回波数据的芳纶-环氧树脂/铝层压板的超声表征

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584080

K. Hollman, C. Fortunko, D. Fitting

{"title":"Ultrasonic characterization of aramid-epoxy/aluminum laminates from pulse-echo data","authors":"K. Hollman, C. Fortunko, D. Fitting","doi":"10.1109/ULTSYM.1996.584080","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584080","url":null,"abstract":"The objectives of this study are to determine the through-thickness elastic coefficient of fiber-epoxy/metal laminates with ultrasonic measurements and to determine the elastic coefficients of the constituent layers. For the measurements, a broadband, piezopolymer, transmitting transducer is excited with the leading edge of a square wave. A specimen is aligned perpendicular to the transducer in an immersion tank. Signals reflected from the specimen are captured by the piezopolymer transducer and Fourier transformed. Signals transmitted through the specimen are captured by a hydrophone, and the first arrival of the signals is used to determine the average velocity through the laminate. For this study we consider four regimes. There is a static regime and a second regime where the wavelength of the ultrasound is much greater than the thickness of the laminate. In the third, intermediate wavelength regime the velocities and densities of the individual layers are determined using \"stop bands\" in the spectrum. Short-duration pulse determinations of the elastic stiffness coefficients are valid in the fourth, short wavelength regime. Elastic coefficients determined from pulse measurements compare favorably with predictions based on the assumption that velocities of the layers act in series as the sound travels through the laminate.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123787533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Homomorphic deconvolution of medical ultrasound images using a Bayesian model for phase unwrapping 基于贝叶斯相位展开模型的医学超声图像同态反卷积

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584301

G. Frolova, T. Taxt

{"title":"Homomorphic deconvolution of medical ultrasound images using a Bayesian model for phase unwrapping","authors":"G. Frolova, T. Taxt","doi":"10.1109/ULTSYM.1996.584301","DOIUrl":"https://doi.org/10.1109/ULTSYM.1996.584301","url":null,"abstract":"Radial homomorphic deconvolution algorithms for medical ultrasound images based on the complex cepstrum or the generalized cepstrum are the best of several cepstral deconvolution methods. However, the frequency domain phase unwrapping, which is an essential part of both methods, is sensitive to the stochastic noise that always degrades sensor data. The sensitivity causes variable spatial and gray scale resolution in image sequences following deconvolution. This paper introduces a robust Bayesian phase unwrapping method using a Markov random field model. The prior regularizing term accounts for the noise. The phase unwrapping is formulated as a least mean squares optimization problem. The optimization is done non-iteratively by solving a differential equation using the cosine transform. The ordinary complex cepstrum and the generalized cepstrum methods with the new phase unwrapping procedure were compared to the same methods with the standard phase unwrapping procedure, and to the logarithmic derivative cepstrum method. Both radial and lateral deconvolution were tested on several sequences of in vivo ultrasound images recorded with a 5.0 MHz or a 3.25 MHz probe. The homomorphic deconvolution methods, with the Markov model based phase unwrapping gave images with the same degree of deconvolution through the sequence and better spatial resolution and gray scale resolution than the old methods.","PeriodicalId":278111,"journal":{"name":"1996 IEEE Ultrasonics Symposium. Proceedings","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1996-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126602124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Experimental verification of the sectored annular phased array for MRI guided ultrasound surgery 扇形环形相控阵用于MRI引导超声手术的实验验证

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584228

T. Fjield, K. Hynynen

引用次数: 4

Assessment of wall velocity gradient and thrombi detection using test-phantom 壁速度梯度的评估和血栓的检测

1996 IEEE Ultrasonics Symposium. Proceedings Pub Date : 1996-11-03 DOI: 10.1109/ULTSYM.1996.584203

A. Nowicki, R. Olszewski, J. Etienne, P. Karłowicz, J. Adamus

引用次数: 0