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Multiresolution geometrical-acoustics modeling
The Journal of the Acoustical Society of America, 2008Geometrical-acoustics (GA) modeling techniques assume that surfaces are large relative to the wavelengths of interest. For a given scenario, practitioners typically create a single 3D model with large, flat surfaces that satisfy the assumption over a broad range of frequencies. Such geometric approximations lead to errors in the spatial distribution of
Benjamin Markham, Paul Calamia
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Geometrical Acoustic Propagation with Frequency Dependence
The Journal of the Acoustical Society of America, 1968One characteristic of geometrical-acoustic solutions is their frequency independence. Geometrical acoustics stems from the solution of the eikonal equation, which is a form of the wave equation in the limit of infinite frequency. Since the effects of the medium and the boundary conditions on the acoustic fields are definitely frequency dependent, it is
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Geometrical Acoustics at Microwave Frequencies
1972Abstract : The purpose of this investigation is to study focusing and deflection of microwave acoustic bulk wave and surface wave beams in inhomogeneous anisotropic solids and to evaluate potential device application of these effects. Initially, the emphasis was on strictly geometrical effects and on inhomogeneities induced by means of magnetic and ...
S. Farnow, B. A. Auld
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Geometrical Acoustics. WKB Approximation
1990The importance of geometrical acoustics, or the ray method, in studying sound fields in inhomogeneous media can hardly be exaggerated. Regardless of the physical nature of the waves considered, this approach is also often referred to as geometrical optics or the eikonal approximation.
Leonid M. Brekhovskikh, Oleg A. Godin
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Automatic person recognition by acoustic and geometric features
Machine Vision and Applications, 1995This paper describes a multisensorial person-identification system in which visual and acoustic cues are used jointly for person identification. A simple approach, based on the fusion of the lists of scores produced independently by a speaker-recognition system and a face-recognition system, is presented.
Roberto Brunelli +3 more
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2019
The analytical methods of the previous chapters enable predictions of the sound field in an enclosure accounting for numerous geometric and material details of the boundary conditions. In practice however, many acoustical spaces of interest have far too many geometric complexities to permit meaningful predictions of a sound field.
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The analytical methods of the previous chapters enable predictions of the sound field in an enclosure accounting for numerous geometric and material details of the boundary conditions. In practice however, many acoustical spaces of interest have far too many geometric complexities to permit meaningful predictions of a sound field.
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Inhomogeneous absorption and geometric acoustics
The Journal of the Acoustical Society of America, 1998The conventional formulation of geometric acoustics in the presence of inhomogeneous (spatially varying) absorption is examined. This formulation is found to fail under conditions of multipath propagation, because interference between ray paths is not taken into account when the absorptive losses are calculated.
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Multispectral acoustic investigation of a thyroid geometrical model
2010 Annual International Conference of the IEEE Engineering in Medicine and Biology, 2010The aim of this paper is to present a new noninvasive method for investigating the homogeneity of the thyroid gland geometric model. The amplitude of reflected signal depends on the shape, size and homogeneity of the object investigated acoustic as well as the signal frequency emitted by generator.
G V, Gavriloaia, M-R, Gavriloaia
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Dependence of acoustic levitation capabilities on geometric parameters
Physical Review E, 2002A two-cylinder model incorporating boundary element method simulations is developed, which builds up the relationship between the levitation capabilities and the geometric parameters of a single-axis acoustic levitator with reference to wavelength. This model proves to be successful in predicting resonant modes of the acoustic field and explaining ...
W J, Xie, B, Wei
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Use of Splines and Numerical Integration in Geometrical Acoustics
The Journal of the Acoustical Society of America, 1970Two contributions are made to ray-theory techniques for propagation through continuously stratified media. The first makes use of spline polynomials to approximate speed of sound profiles smoothly. The second eliminates the singularity occurring in the usual range integral.
Moler, C. B., Solomon, L. P.
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