The Experts below are selected from a list of 312 Experts worldwide ranked by ideXlab platform
Robert R. Alfano - One of the best experts on this subject based on the ideXlab platform.
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True Scattering Coefficients of turbid media
Optical Tomography Photon Migration and Spectroscopy of Tissue and Model Media: Theory Human Studies and Instrumentation, 1995Co-Authors: X. Liang, Leming Wang, Robert R. AlfanoAbstract:Scattering Coefficients of two turbid media with the particle size varying from 0.45 micrometers to 10 micrometers have been measured from three time regions: ballistic, ballistic and snake, and steady state using a picosecond Kerr-Fourier imaging system. In all cases, the measured time- resolved Scattering Coefficients were found to be larger than the cw Scattering Coefficients.
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True Scattering Coefficients of turbid matter measured by early-time gating
Optics letters, 1995Co-Authors: Leming Wang, X. Liang, P. Galland, Robert R. AlfanoAbstract:The true Scattering Coefficients of turbid matter have been determined by use of picosecond time-resolved imaging. The Scattering Coefficients measured by the conventional cw collimation method were found to be smaller than those obtained from the early-time-sliced ballistic photons.
J E Roy - One of the best experts on this subject based on the ideXlab platform.
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a numerical technique for computing the values of plane wave Scattering Coefficients of a general scatterer
IEEE Transactions on Antennas and Propagation, 2009Co-Authors: J E RoyAbstract:The results of a numerical technique for computing the plane wave Scattering Coefficients of a general scatterer are presented. The technique is tailored herein to the case where the scatterer is a general slab and the technique is implemented with the FDTD method of the scattered field formulation. Since the technique relies on the use of a Maxwellian beam of dominant polarization as the excitation within the FDTD simulation, this paper presents also an improved scheme for synthesizing such a beam. Window averaging is also presented as a new scheme for mitigating the effects of aperture truncation. Validation of the technique revealed that the use of a non-Maxwellian Gaussian beam of uniform polarization produced erroneous values of the plane wave Scattering Coefficients. When used with a Maxwellian beam excitation, however, the technique showed to be trustworthy, stable and accurate, even for lossy media. Convergence test results revealed that the accuracy of the values of plane wave Scattering Coefficients decreased much faster as the conductivity of the medium increased than what would be expected from numerical anisotropy. Finally, poor accuracy results are reported when the scattered field illuminates strongly the edges or corners of the integration box around a finite-size slab.
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computing the effective complex permittivity of corrugated slabs by inverse Scattering under oblique incidence
IEEE Antennas and Propagation Society International Symposium, 2008Co-Authors: J E RoyAbstract:The numerical method presented herein attempts to equate the scatterer under test to a prescribed equivalent scatterer by adjusting some geometrical and/or constitutive parameters of the equivalent scatterer to reproduce the given values of plane-wave Scattering Coefficients of the scatterer under test as a function of the incidence angle. Hence, the equivalence is based on the assumption that two different scatterers could have exactly the same curves of plane-wave Scattering Coefficients as a function of the incidence angle. However, this is not generally the case because to be able to adjust independently all eight variables of the plane-wave Scattering Coefficients, namely the four magnitudes |RTM|, |RTE|, |TTM|, |TTE|, and the four phases angRTM, angRTE, angTTM, angTTE, would require at least eight degrees of freedom for each desired value of the incidence angle. In this paper, the equivalent scatterer is a uniform homogeneous isotropic slab, and the two degrees of freedom are the relative permittivity epsiv'r and the conductivity sigma. Hence, it is not always possible to make the values of plane-wave Scattering Coefficients for the uniform homogeneous isotropic slab be exactly equal to the given values of plane-wave Scattering coefficient as a function of the incidence angle by adjusting only the values of epsiv'r and sigma.
Leming Wang - One of the best experts on this subject based on the ideXlab platform.
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True Scattering Coefficients of turbid media
Optical Tomography Photon Migration and Spectroscopy of Tissue and Model Media: Theory Human Studies and Instrumentation, 1995Co-Authors: X. Liang, Leming Wang, Robert R. AlfanoAbstract:Scattering Coefficients of two turbid media with the particle size varying from 0.45 micrometers to 10 micrometers have been measured from three time regions: ballistic, ballistic and snake, and steady state using a picosecond Kerr-Fourier imaging system. In all cases, the measured time- resolved Scattering Coefficients were found to be larger than the cw Scattering Coefficients.
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True Scattering Coefficients of turbid matter measured by early-time gating
Optics letters, 1995Co-Authors: Leming Wang, X. Liang, P. Galland, Robert R. AlfanoAbstract:The true Scattering Coefficients of turbid matter have been determined by use of picosecond time-resolved imaging. The Scattering Coefficients measured by the conventional cw collimation method were found to be smaller than those obtained from the early-time-sliced ballistic photons.
Leland Timothy Long - One of the best experts on this subject based on the ideXlab platform.
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Spatial Distribution of Relative Scattering Coefficients Determined from Microearthquake Coda
Bulletin of the Seismological Society of America, 2000Co-Authors: Xiuqi Chen, Leland Timothy LongAbstract:A coda-envelope-inversion technique is developed to image the three- dimensional spatial distribution of relative Scattering Coefficients. The technique is applied to the Norris Lake Community, Georgia, earthquake swarm of 1993. The relative Scattering coefficient is the ratio of the Scattering coefficient to a regionally determined average used to normalize the coda amplitudes. The inversion problem was solved using the Algebraic Reconstruction Technique (ART) with the relative Scattering coefficient constrained to positive values. Although coda envelope inver- sion is based on the theory for single Scattering, we show that it may with a correction factor be used to characterize the distribution of relative Scattering Coefficients when multiple Scattering contributes significantly to the coda. The coda envelope inversion for the Norris Lake Community earthquake swarm revealed a highly nonuniform distribution of relative Scattering Coefficients. The zones of strong Scattering are correlated with the hypocenters and areas of rough topography. Moreover, at shallow depths the relative Scattering Coefficients are frequency dependent, with scattered energy increasing with frequency. We interpret this frequency dependence to imply that open fractures less than 250 m in length are responsible for strong Scattering in the coda of these shallow earthquakes. At greater depths, Scattering is independent of frequency and probably relates to velocity layering. A strong reflecting layer was identified at or below 7 km, which is consistent with the thrust plain identified in the Georgia COCORP reflection lines. The inhomogeneous distribution of Scattering strength obtained in this study argues strongly against the observation-based as- sumption that the Scattering structures are uniformly distributed in the crust.
X. Liang - One of the best experts on this subject based on the ideXlab platform.
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True Scattering Coefficients of turbid media
Optical Tomography Photon Migration and Spectroscopy of Tissue and Model Media: Theory Human Studies and Instrumentation, 1995Co-Authors: X. Liang, Leming Wang, Robert R. AlfanoAbstract:Scattering Coefficients of two turbid media with the particle size varying from 0.45 micrometers to 10 micrometers have been measured from three time regions: ballistic, ballistic and snake, and steady state using a picosecond Kerr-Fourier imaging system. In all cases, the measured time- resolved Scattering Coefficients were found to be larger than the cw Scattering Coefficients.
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True Scattering Coefficients of turbid matter measured by early-time gating
Optics letters, 1995Co-Authors: Leming Wang, X. Liang, P. Galland, Robert R. AlfanoAbstract:The true Scattering Coefficients of turbid matter have been determined by use of picosecond time-resolved imaging. The Scattering Coefficients measured by the conventional cw collimation method were found to be smaller than those obtained from the early-time-sliced ballistic photons.
