By a News Reporter-Staff News Editor at Journal of Technology -- Investigators discuss new findings in Acoustic Research. According to news reporting from St. Louis, Missouri, by VerticalNews journalists, research stated, "This study is based on an extension of the concept of joint entropy of two random variables to continuous functions, such as backscattered ultrasound. For two continuous random variables, X and Y, the joint probability density p(x,y) is ordinarily a continuous function of x and y that takes on values in a two dimensional region of the real plane."
The news correspondents obtained a quote from the research from the Washington University School of Medicine, "However, in the case where X=f(t) and Y=g(t) are both continuously differentiable functions, X and Y are concentrated exclusively on a curve, ?(t)=(f(t),g(t)), in the x,y plane. This concentration can only be represented using a mathematically 'singular' object such as a (Schwartz) distribution. Its use for imaging requires a coarse-graining operation, which is described in this study. Subsequently, removal of the coarse-graining parameter is accomplished using the ergodic theorem. The resulting expression for joint entropy is applied to several data sets, showing the utility of the concept for both materials characterization and detection of targeted liquid nanoparticle ultrasonic contrast agents."
According to the news reporters, the research concluded: "In all cases, the sensitivity of these techniques matches or exceeds, sometimes by a factor of two, that demonstrated in previous studies that employed signal energy or alternate entropic quantities."
For more information on this research see: Joint entropy of continuously differentiable ultrasonic waveforms. The Journal of the Acoustical Society of America, 2013;133(1):283-300.
Our news journalists report that additional information may be obtained by contacting M.S. Hughes, Dept. of Medicine, Cardiology Division, Campus Box 8215, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, Missouri 63110-1093, United States. Additional authors for this research include J.E. McCarthy, J.N. Marsh and S.A Wickline.
Keywords for this news article include: Missouri, St. Louis, United States, Acoustic Research, North and Central America.
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