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Research describing the use of the Nakagami model for modeling the echo from breast tissue is presented. In particular the Nakagami distribution is investigated as a means of separating benign and malignant breast masses.

A general statistical model based on Nakagami distribution is explored as a means of describing the backscattered ultrasonic echo from tissues.

Presents a study which examined the statistics of the backscattered ultrasonic echo from tissue using Rayleigh, K and Nakagami distributions. Theoretical model; Computational approach; Results and conclusions.

Explores the possibility of enhancing the ability of Nakagami statistics for ultrasonic tissue characterization through the techniques of diversity and compounding. Definition of Nakagami distribution; Diagram of a diversity processor; Results from simulation of random numbers showing the validity of the analytical model for the parameters of the Nakagami model.

On-fiber devices are fabricated by removing the cladding over a short length of the multimode fiber and replacing it with an active medium like electrooptic or magnetooptic material When a field is applied, the index of this modified cladding goes up, leading to a redistribution of modal amplitudes, which may or may not he accompanied by optical power loss due to radiation modes. Significant optical power loss occurs when the induced index change is large while modal redistribution of amplitudes takes place with negligible power loss when the index change is very small. This modal redistribution has been investigated and expressions for the amplitude coupling coefficient related the modal amplitudes before and after the application of the field are derived. These coupling coefficients have been evaluated as a function of the induced index change in the cladding. The results indicate that this modal redistribution may be used as a sensing mechanism. [ABSTRACT FROM AUTHOR]

A double frequency method of measuring bubble size which has better spatial resolution than previous techniques, is described. Bubbles are insonified simultaneously by a swept, relatively low, ''pumping'' frequency near their resonance and a high ''imaging'' frequency. Theoretical expressions are derived for the sound scattered by a bubble under the influence of these two frequencies. Existence of sharp resonance behavior in the scattered sound at the sum frequency is shown both theoretically and experimentally. [ABSTRACT FROM AUTHOR]