Results 151 to 160 of about 147,257 (198)
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Acoustical determinations of bubble-size spectra
The Journal of the Acoustical Society of America, 1977The exact integration of the equations for acoustical cross sections of bubbles is considered to show when the dependence of the bubble number on radius can be determined by scatter and attenuation experiments in a liquid containing a broad spectrum of bubble radii.
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Spectra of laser acoustic signals in water
2011 International Conference on Electric Information and Control Engineering, 2011To get the spectra of laser acoustic signal (LAS) in water induced by CO2 laser pulse, and the relation to the parameters of laser pulse (LP). A peak-tail approximation of the actual CO2 LP is used to get the theoretical thermoelastic LAS, after FFT(Fast Fourier Transformation), the affection of the waveform parameters to the LAS spectra is given.
Chen Qingming, Cheng Zuhai, Zhu Haihong
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Acoustic measures of lake community size spectra
Canadian Journal of Fisheries and Aquatic Sciences, 2016Acoustic methods were tested as an alternative to catch data to measure size spectra of freshwater fish communities in Lac du Bonnet (LdB), Manitoba, Canada. Eleven daytime hydroacoustic surveys conducted in 2011 and 2012 enabled length-frequency spectra of fish communities to be calculated within LdB.
Laura J. Wheeland, George A. Rose
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Transient Response Spectra of Coupled Acoustical Resonators
The Journal of the Acoustical Society of America, 1966The maximum absolute pressure magnification of a Helmholtz resonator for an excitation of one cycle of a sine wave is 3.14, occurring when the natural period of the system is equal to the excitation period. When two resonators are coupled together, the response is a function of two uncoupled natural frequencies and a coupling frequency of the system ...
N. N. Reddy, Richard L. Lowery
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Estimating sea surface spectra with acoustic tomography
The Journal of the Acoustical Society of America, 1986A technique for estimating space- and time-varying sea surface spectra using acoustic tomography is described. The technique uses acoustic (mode and/or ray) phase or travel time perturbations as data for the inversions. The inverse problems for spatially homogeneous and spatially nonhomogeneous frequency-directional wave spectra are discussed ...
James H. Miller +2 more
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Spectra of ion acoustic plasma instability
The Physics of Fluids, 1977An experimental study of ion acoustic plasma turbulence in a collision-dominated positive column is presented. Linear theory predictions, which include ion Landau damping and the effects of a dc electric field, are shown to agree with measured values of convective growth rates.
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Production of directionally limited acoustic power spectra
The Journal of the Acoustical Society of America, 1991Apparatus 10 (FIG. 1(a)) for providing acoustic power spectra, all defined over a frequency band from signals received in a predetermined time interval, for individually identifiable directions comprises a pair of arrays 11, 11' of omnidirectional microphone elements 12.
Michael J. Greenwood +1 more
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Off-resonance contributions to acoustical bubble spectra
The Journal of the Acoustical Society of America, 1989Comparisons of experimental optical and acoustical bubble size spectra disagree in size distribution at the low end of the spectrum. Previous methods of obtaining acoustic bubble size information relied strictly on resonant acoustical scattering and absorption theory.
Kerry Commander, Elan Moritz
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Electroacoustic contingency management of the acoustic spectra of speech
Journal of Communication Disorders, 1975Three studies involving the manipulation of the acoustic spectrum of speech are described. An array of electronic equipment was set up which signaled the presence or absence of certain frequency characteristics of speech. Subjects (Ss) were given feedback for production of speech containing targeted frequencies.
Fitch, James L., Terrio, Leelen M.
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Learning-Based Acoustic Source Localization Using Directional Spectra
2019 IEEE 8th International Workshop on Computational Advances in Multi-Sensor Adaptive Processing (CAMSAP), 2019This paper proposes to use directional spectra as new features for manifold-learning-based acoustic source localization. We claim that directional spectra not only contain directional information, but are rather discriminative for different positions in a reverberant enclosure.
Andreas Brendel +3 more
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