rdf-syntax-grammar
mods:
  schema location: http://www.loc.gov/mods/v3 http://www.loc.gov/standards/mods/v3/mods-3-2.xsd
  title info:
    title: Modeling aspects and computational methods for some recent problems of tomographic imaging
  name:
    name part: Allmaras, Moritz.
    role:
      role term: creator
  name:
    name part: Bangerth, Wolfgang
    role:
      role term: thesis advisor.
  name:
    name part: Kuchment, Peter
    role:
      role term: thesis advisor.
  type of resource: text
  genre: bibliography
  origin info:
    place:
      place term: txu
    date issued: 2012
    issuance: monographic
  language:
    language term: eng
  physical description:
    form: remote
    extent: 1 online resource.
  abstract: In this dissertation, two recent problems from tomographic imaging are studied, and results from numerical simulations with synthetic data are presented. The first part deals with ultrasound modulated optical tomography, a method for imaging interior optical properties of partially translucent media that combines optical contrast with ultrasound resolution. The primary application is the optical imaging of soft tissue, for which scattering and absorption rates contain important functional and structural information about the physiological state of tissue cells. We developed a mathematical model based on the diffusion approximation for photon propagation in highly scattering media. Simple reconstruction schemes for recovering optical absorption rates from boundary measurements with focused ultrasound are presented. We show numerical reconstructions from synthetic data generated for mathematical absorption phantoms. The results indicate that high resolution imaging with quantitatively correct values of absorption is possible. Synthetic focusing techniques are suggested that allow reconstruction from measurements with certain types of non-focused ultrasound signals. A preliminary stability analysis for a linearized model is given that provides an initial explanation for the observed stability of reconstruction. In the second part, backprojection schemes are proposed for the detection of small amounts of highly enriched nuclear material inside 3D volumes. These schemes rely on the geometrically singular structure that small radioactive sources represent, compared to natural background radiation. The details of the detection problem are explained, and two types of measurements, collimated and Compton-type measurements, are discussed. Computationally, we implemented backprojection by counting the number of particle trajectories intersecting each voxel of a regular rectangular grid covering the domain of detection. For collimated measurements, we derived confidence estimat…
  note: by Moritz Allmaras.
  note: "Major Subject: Mathematics"
  note: Electronic resource.
  note: Doctor of Philosophy Texas A&M University 2011 http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10397
  note: Includes bibliographical references.
  note: Text (Dissertation)
  subject:
    topic: Major mathematics
  subject:
    topic: Inverse problems
  subject:
    topic: Ultrasound modulated optical tomography
  subject:
    topic: Compton data
  subject:
    topic: Hybrid imaging
  subject:
    topic: Backprojection
  subject:
    topic: Nuclear source detection
  identifier: http://hdl.handle.net/1969.1/ETD-TAMU-2011-12-10397
  record info:
    record content source: TXA
    record creation date: 120320
    record change date: 20151202151854.0
    record identifier: in00002742109