Browsing Faculty - Engineering and Computer Science by Issue Date
Now showing items 1-20 of 42
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The method of the local parabolic approximation for rough surface scattering
(Journal of the Acoustical Society of America, 1993-10)A method for evaluation of scattering from rough surfaces which is similar to the Kirchhoff approximation is considered. However, it is based on a local parabolic approximation of the surface irregularities rather than a ... -
Acoustic scattering from a fluid-elastic solid interface using the small slope approximation
(Journal of the Acoustical Society of America, 1994-09)In this paper the small slope approximation is applied to acoustic scattering from a randomly rough fluid–elastic?solid interface. Expressions for the zeroth?, first?, and second?order bistatic scattering cross sections ... -
An investigation of the small slope approximation for scattering from rough surfaces: Part I: Theory
(Journal of the Acoustical Society of America, 1995-04)The small slope approximation (SSA) of Voronovich [Sov. Phys. JETP 62, 65–70 (1985)] is a promising method for application to scattering from many natural surfaces. The theory gives a systematic expansion that can be ... -
Application of the perfectly matched layer (PML) absorbing boundary condition to elastic wave propagation
(Journal of the Acoustical Society of America, 1996-11)A method is presented for application of the perfectly matched layer (PML) absorbing boundary condition (ABC) to the P?SV velocity–stress finite?difference method. The PML consists of a nonphysical material, containing ... -
An investigation of the small slope approximation for scattering from rough surfaces: Part II: Numerical studies
(Journal of the Acoustical Society of America, 1997-05)The small slope approximation (SSA) of Voronovich [Sov. Phys. JETP 62, 65–70 (1985)] is a promising method for modeling wave scattering from rough surfaces. The SSA T-matrix series, which can be interpreted as an expansion ... -
A finite-difference time-domain solution to scattering from a rough pressure-release surface
(Journal of the Acoustical Society of America, 1997-12)The finite-difference time-domain (FDTD) method is a numerical technique that makes no explicit physical approximations to the underlying problem. The quality of a FDTD-based solution typically is determined by the ... -
Implementation of transparent sources embedded in acoustic finite-difference time-domain grids
(Journal of the Acoustical Society of America, 1998-01)The finite-difference time-domain (FDTD) method is a simple but powerful numerical method which has been used to perform a wide variety of complex simulations. One of the considerations in using this method is modeling the ... -
Inverse imaging of the breast with a material classification technique
(Journal of the Acoustical Society of America, 1998-03)In recent publications [Chew et al., IEEE Trans. Blomed. Eng. BME-9, 218–225 (1990); Borup et al., Ultrason. Imaging14, 69–85 (1992)] the inverse imaging problem has been solved by means of a two-step iterative method. In ... -
A comparison of material classification techniques for ultrasound inverse imaging
(Journal of the Acoustical Society of America, 2002-01)The conjugate gradient method with edge preserving regularization (CGEP) is applied to the ultrasoundinverse scattering problem for the early detection of breast tumors. To accelerate image reconstruction, several different ... -
A conjugate gradient-neural network technique for ultrasound inverse imaging
(World Scientific Publishing, 2002-06)In this paper, a new technique for solving the two-dimensional inverse scattering problem for ultrasound inverse imaging is presented. Reconstruction of a two-dimensional object is accomplished using an iterative algorithm ... -
A numerical study of conjugate gradient directions for an ultrasound inverse problem
(World Scientific Publishing, 2004-12)In ultrasound inverse problems, the integral equation can be nonlinear, ill-posed, and computationally expensive. One approach to solving such problems is the conjugate gradient (CG) method. A key parameter in the CG method ... -
Comparison of the reflectance and Crystal Violet assays for measurement of biofilm formation by Enterococcus
(Biofilms, 2005-07)In previous work, we described a protocol for measuring biofilm formation on opaque and non-opaque surfaces using reflected light. In the present work, we used the reflectance assay to assess biofilm formation for 14 strains ... -
Optical reflectance assay for the detection of biofilm formation
(Journal of Biomedical Optics, 2005-08)We describe the protocol for an inexpensive and nondestructive optical reflectance assay for the measurement of biofilm formation. Reflectance data are obtained using an Ocean Optics !Dunedin, Florida" USB 2000 spectrometer ... -
Validation of mixed-genome microarrays as a method for genetic discrimination
(Applied and Environmental Microbiology, 2007-03)Comparative genomic hybridizations have been used to examine genetic relationships among bacteria. The microarrays used in these experiments may have open reading frames from one or more reference strains (whole-genome ... -
A Java-based tool for the design of classification microarrays
(Oxford University Press, 2008-08)Classification microarrays are used for purposes such as identifying strains of bacteria and determining genetic relationships to understand the epidemiology of an infectious disease. For these cases, mixed microarrays, ... -
A practical cross section for scattering from rough surfaces at very low grazing angles in both the forward and backward directions
(Taylor and Francis, 2009-08)In this paper we develop an extension of the small slope approximation (SSA) for scattering from randomly rough Dirichlet surfaces, which includes some multiple scattering. This extension is designated by SSA+. We focus ... -
BlaCMY-2 positive Inc A/C plasmids from Escherichia coli and Salmonella enterica are a distinct component of a larger lineage of plasmids
(Antimicrobial Agents and Chemotherapy, 2009-11)Large multidrug resistance plasmids of the A/C incompatibility complex (IncA/C) have been found in a diverse group of Gram-negative commensal and pathogenic bacteria. We present three completed sequences from IncA/C plasmids ... -
Improved identification of epidemiologically related strains of Salmonella enterica by use of a fusion algorithm based on pulsed-field gel electrophoresis and multiple-locus variable-number tandemrepeat analysis
(Journal of Clinical Microbiology, 2010-11)Pulsed-field gel electrophoresis (PFGE) and multiple-locus variable-number tandem-repeat analysis (MLVA) are used to assess genetic similarity between bacterial strains. There are cases, however, when neither of these ... -
The SSA+ for scattering from dielectric surfaces at very low grazing angles
(Taylor and Francis, 2011-02)In this paper we develop an extension of the small slope approximation (SSA) for scattering from randomly rough Dirichlet surfaces, which includes some multiple scattering. This extension is designated by SSA+. We focus ... -
Genotypic-phenotypic discrepancies between antibiotic resistance characteristics of Escherichia coli from calves in high and low antibiotic use management settings
(Applied and Environmental Microbiology, 2011-05)We hypothesized that bacterial populations growing in the absence of antibiotics will accumulate more resistance gene mutations than bacterial populations growing in the presence of antibiotics. If this is so, the prevalence ...