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ÐMultiaspect target identification is effected by fusing the features extracted from multiple scattered waveforms; these waveforms are characteristic of viewing the target from a sequence of distinct orientations. Classification is performed in the maximum-likelihood sense, which we show, under reasonable assumptions, can be implemented via a hidden Markov(More)
The performance of an inversion algorithm is investigated when applied to measured displacement data for a determination of the material parameters /sup /spl lambda/+2/spl mu////sub /spl rho// (longitudinal wave velocity squared) and /sup /spl mu////sub /spl rho// (shear wave velocity squared) throughout an inhomogeneous test phantom. The vector(More)
The static thermal sensitivity of the optical phase in bare and jacketed fibers has been studied both analytically and experimentally. Taking into account the exact fiber composition and geometry, the strains have been determined from the thermally induced stresses using the appropriate boundary conditions, and the resulting phase shift has been calculated.(More)
A zero-power ballast control system that could be used to float and submerge a device solely using a gas source was built and tested. This system could be used to convey sensors, data loggers, and communication devices necessary for water quality monitoring and other applications by periodically maneuvering up and down a water column. Operational parameters(More)
We present a novel extension of standard magnetic resonance elastography (MRE) measurement and analysis methods, which is applicable in cases where the medium is characterized by waveguides or fiber bundles (i.e., muscle) leading to constrained propagation of elastic waves. As a demonstration of this new method, MRI is utilized to identify the pathways of(More)
In this paper, we present a formulation and numerical simulation for the noninvasive determination of the material parameter ratios (i.e., the Lame parameters divided by density) of an isotropic, inhomogenous elastic medium subject to time harmonic vibration. Given a knowledge of the displacements throughout the medium, a novel implementation of a(More)
Intensity modulation induced by microbending in multimode fibers is considered as a transduction mechanism for detecting environmental changes such as pressure, temperature, acceleration, and magnetic and electric fields. A generic microbend sensor has been defined and studied, and its components, such as sensing fiber, light source, optical fiber leads,(More)
In this paper, the feasibility of extending previously described magnetic resonance elastography (MRE) dynamic displacement (and associated elasticity) measurement techniques, currently used successfully in tissue, to solid materials which have much higher shear rigidity and much lower nuclear spin densities, is considered. Based on these considerations,(More)
A method for detecting sound using a single step-index multimode fiber is presented. The detected signal results from differences in acoustically induced phase shifts between two different waveguide modes propagating in the fiber. The relative sensitivity of this technique compared with a two-path interferometer was experimentally determined and agreed with(More)
The nondestructive evaluation inversion and generalized force-mapping techniques developed and demonstrated for isotropic thin plates by Bucaro et al. [(2004). "Detection and localization of inclusions in plates using inversion of point actuated surface displacements," J. Acoust. Soc. Am. 115, 201-206] are extended to the case of orthotropic plates. The(More)