Acoustical Imaging - Powers, John P

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Résumé :
This volume contains forty-one papers presented at the Eleventh International Symposium on Acoustical Imaging held on 4-7 Ma~ in Monterey, California. The objective of this conference series is to bring together workers in diverse areas and applications of Acoustical Imaging for interaction and exchange of ideas. People working in other aspects of scalar wave theory and applications also benefit from this series. The papers presented here demonstrate continued growth in the activity of this field. In this conference there was emphasis on New Techniques, Acoustic Tomography, Tissue Characterization, Signal Processing, Inversion Techniques, and Transducers and Arrays. The success and stimulation of the conference and of the papers presented in this volume is owed, of course to the authors and participants. Many thanks are due to the authors and their co-workers for their diligence and enthusiasm in performing their research, preparing their manuscripts and presenting their results. The editor would like to express his appreciation to each and every one of them.

Sommaire:
Imaging Systems.- Scanning Acoustic Microscopy of Solid Objects Using Aspheric Lenses.- A Digital Processing System for Acousto-optic Visualization of Sound Fields.- Acoustical Imaging Using Focalization under Oblique Incidence through and Interface-Application to Non-destructive Testing.- Generation of Acoustical Images from the Absorption of Pulsed Microwave Energy.- A Thermoplastic Acoustical Holography Recording Device.- Two-dimensional Imaging with a High Resolution PVF2/Si Optically-scanned Receiving Transducer.- Tissue Characterization.- An Ultrasonic Determination of Cardiac Muscle Structures.- The Application of Diffraction Analysis to Liver and Thyroid Disease.- Tissue Parameter Measurement and Imaging.- Pulse Scattering in Dispersive Media.- An Absolute Measurement of Backscattering Coefficients for Excised Human Tissues and its Relevance to Abdominal Imaging.- Signal Processing Techniques.- The Design And Application of Software Filters to Improve Lateral Resolution in a B-mode Ultrasonogram.- Digital Filtering of Acoustic Images.- Two-dimensional Null Processing.- Acoustic Imaging in Marine Sediment: A Multiple Microprocessor Array Processor using the Trace Function.- Phase Error Reduction Method for a Towed Array.- Digital Enhancement of Ultrasonic Images and its Application to Non-destructive Testing of Composite Materials.- Preliminary Results of Computer Aided Acoustic Imaging.- An Optimum Ultrasonic Imaging System Using ARMA Processing.- Acoustical Tomography.- Ultrasonic Planar Scanned Tomography.- A Comparison of Born and Rytov Approximations in Acoustic Tomography.- Tomographie Evaluation of Sound Fields from Acousto-optic Data.- Effects of Diffraction on Ultrasonic Computer-Assisted Tomography.- Inversion Techniques.- An Exact Theory for Coherent Acoustic Probing.- Acoustical Holography Is, At Best, Only a Partial Solution to the Inverse Scattering Problem.- Inverse Scattering, Inverse Field, and Inverse Source Theory.- Wave Equations and Inverse Solutions for Soft Tissue.- Asymptotic Ultrasonic Inversion Based on Using More Than one Frequency.- Transducers and Arrays.- The Properties and Performance of a Si-PVF2 Optically Controlled Acoustic Point Source.- Effect of Mechanical Aberrations on the Resolution of Fresnel Zone Plate Transducers.- Sidelobe Reduction of the Ring Array for Use in Circularly Symmetric Imaging Systems.- Anomalous Quantization Error Lobes in Phased Array Images.- Multi-element Arrays for NDE Applications.- Study of the Normal Modes of Vibration of the Peizoelectric Transducers used in a Acoustic Imaging Applications.- New Techniques.- Linear Impulse Holography.- Acoustic Passive Remote Temperature Sensing.- The Speed of Sound as a Thermal Image CT Scan Parameter.- Focused Acoustic Beams for Accurate Phase Measurements.- High Resolution Ultrasonic Testing System Using Dynamic Focusing and Signal Correlation.- Eddy Current Phasography.- A 50 MHZ Synthetic Focus System.- Bibliographic Index.