Zobrazeno 1 - 10
of 27
pro vyhledávání: '"Carl K. Frederickson"'
Autor:
Brian H. Houston, Alain R. Berdoz, Larry A. Kraus, Steve W. Liskey, Philip A. Frank, Carl K. Frederickson, Steve Stanic, Erik C. Porse, Harry J. Simpson
Publikováno v:
The Journal of the Acoustical Society of America. 121:85-97
Shallow-water propagation experiments were carried out in St. Andrews Bay, Florida. These investigations used a vertical one-dimensional synthetic array measurement system where two hydrophones incrementally mapped the acoustic pressure from 2m below
Autor:
Carl K. Frederickson, E. H. Grissinger, D.C. Sokol, James M. Sabatier, J.C. Shipps, M.J.M. Römkens
Publikováno v:
Soil Technology. 8:259-274
An acoustic technique for evaluating soil physical properties is described and tested in model porous materials. A probe microphone is used to measure the acoustic signal attenuation and phase speed. Emphasis is on the probe construction, insertion i
Publikováno v:
The Journal of the Acoustical Society of America. 99:1326-1332
Acoustic measurements in and above porous materials (500‐μm‐diam glass beads) have been used to determine rigid‐frame porous medium parameters. The propagation constant for the acoustic signal propagating through the air in the pores was calcu
Publikováno v:
Applied Acoustics. 45:283-296
The sound field within a layered porous granular medium may be explored by means of suitably protected probe microphones. The field within a system consisting of a granular surface layer above a thick porous substrate with considerably higher flow re
An improved procedure for the determination of ground parameters using level difference measurements
Publikováno v:
The Journal of the Acoustical Society of America. 94:396-399
Attenborough has developed a theory to predict the ground impedance from four physical parameters; the flow resistivity (σ), the tortuosity (T), the porosity (Ω), and the pore shape factor (sp). This theory has been used to determine the flow resis
Publikováno v:
The Journal of the Acoustical Society of America. 92:2869-2877
An experiment was performed to image the acoustical diffraction pattern decorating the transverse cusp caustic. In the vicinity of the cusp point, the wave field is described by the Pearcey function P(w2,w1). The wave field was formed by reflecting s
Autor:
Larry A. Kraus, Harry J. Simpson, Carl K. Frederickson, Steve Stanic, Brian H. Houston, Alain R. Berdoz, Philip A. Frank, Steve W. Liskey
Publikováno v:
The Journal of the Acoustical Society of America. 114(3)
Acoustic bottom penetration experiments were carried out in a medium-grain sandy bottom at a site in St. Andrews Bay, Florida. These investigations used a new buried, vertical, one-dimensional synthetic array system where a small hydrophone was water
Publikováno v:
Oceans '99. MTS/IEEE. Riding the Crest into the 21st Century. Conference and Exhibition. Conference Proceedings (IEEE Cat. No.99CH37008).
Finding and identifying objects in littoral waters is of growing interest. Although current acoustic based systems can readily detect objects sifting proud, identification is considerably more difficult. For a buried target, even detection may prove
Publikováno v:
The Journal of the Acoustical Society of America. 136:2126-2126
New software has been developed to evaluate the Pearcey function P±(w1,w2)= ∫(-∞)∞ exp[±i(s4/4 + w2s2/2 + w1s)]ds. This describes the diffraction pattern of a transverse cusp caustic. Run-time comparisons between different coding environments
Autor:
Carl K. Frederickson, Forrest McDougal
Publikováno v:
The Journal of the Acoustical Society of America. 136:2127-2127
An impedance tube has been used to make measurements of the acoustic impedance of porous samples. Porous with designed porosities and tortuosities have been produced using 3D printing. Measured impedances are compared to calculated values.