Browse Conferences
Measurement of grain size in metals by acoustic scattering provides improved quality
The principle of the measurement technique is the scattering of ultrasound by discontinuities in the metal. Ultrasound in metals is dissipated by internal friction and scattered by discontinuities in the metallic structure. The grains or cr...
Acoustic detection of physiological change within the thorax
This paper presents the initial results of the development of a non-invasive, in vivo method for the detection of physiological changes within the thorax. An acoustic method is used; where, by generating a variable frequency acoustic in the...
Recent progress in acoustic imaging and microanalysis of new materials and devices by scanning acoustic microscopy
The authors describe acoustic characterisation techniques and then, in order to improve the quality of materials to detect defects or to determine elastic constants, we report some new qualitative and quantitative results obtained in many f...
Thermoelastic nondestructive evaluation of carbon fibre reinforced composites using an intensity modulated power laser beam
Carbon fibre reinforced composite plates can be inspected using laser generated ultrasound. In this paper, we propose a thermoelastic method using an Ar ion laser that produces images of subsurface defects in composite plates without mechan...
Ocean botton recognition from acoustic reflection data
In this paper we present an algorithm for the density and sound speed reconstruction of a two-layered bottom consisting of a fluid sediment layer over a fluid substrate of semi-infinite extend. The thickness of the sediment as well as the a...
Quantitative correlation of acoustical and light microscopy
A new method has been developed to correlate acoustical spectral parameters and histology at a microscopic scale. The local acoustical parameters of a section of 250 mu m thickness are correlated to histological parameters of an adjacent se...
Ray approximation approach for ocean tomography
In this paper, an approach to ocean acoustic tomography is considered. The aim is to derive from the ray approximation a full-determined inverse algorithm, which may bring out an expected estimate of sound-speed perturbations. Simulation il...
A hybrid model for propagation and scattering in a robotic acoustic imaging system
The authors have been working on a system based on transmission line matrix modelling (TLM). This formed part of a research program to develop sensing systems in advanced manufacturing using airborne ultrasound. A modelling system was requi...
Using acoustic cats eyes to improve mobile robot navigation
The processes of navigation and guidance of a mobile robot depend on inferences made from sensor measurements. These inferences become computationally more feasible, more reliable, and more accurate as the reliability and accuracy of the se...
A new real-time ultrasonic imaging system
Present day imaging systems exhibit many problems, such as, low temporal and lateral resolution, operator dependence, high cost and complexity etc. The new system described is an attempt to address these problems by combining the desirable ...