Search for dissertations about: "Christian Bohm"

Showing result 1 - 5 of 10 swedish dissertations containing the words Christian Bohm.

  2. 1. Methods and some applications of depth selective conversion electron Mössbauer spectroscopy

    Author : Christian Bohm; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : Depth selective conversion electron Mössbauer spectroscopy (DCEMS) is a method by which it is possible to non-destructively study iron containing surfaces in the region 0-1000 Ä using the Mössbauer effect. The parameters whose depth behavior can be determined are the familiar Mössbauer parameters: chemical shifts, magnetic hyperfine and quadrupole splitting. READ MORE

  4. 2. Detector Considerations for Time-of-Flight in Positron Emission Tomography

    Author : Florian Bauer; Christian Bohm; Magnus Dahlbom; Stockholms universitet; []
    Keywords : MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; Positron Emission Tomography; Time of Flight; Depth of Interaction; LSO; Radiological physics; Radiofysik; Medical Radiation Physics; medicinsk strålningsfysik;

    Abstract : Positron-Emission-Tomography (PET) is a modern imaging technique in nuclear medicine providing quantitative 3D distribution of a radioactive tracer substance in the human body. The gamma-detector is the first link in the chain of components that constitutes a PET. READ MORE

  5. 3. FPGA based data acquistion and digital pulse processing for PET and SPECT

    Author : Abdel Kader Bousselham; Christian Bohm; Ulf Bäverstam; Stockholms universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Digital signal processing; positron emission tomography; single photon computed tomography; field programmable gate arrays; digital signal processors; digital data acquisition; free running clock sampling; Physics; Fysik; Physics; fysik;

    Abstract : The most important aspects of nuclear medicine imaging systems such as Positron Emission Tomography (PET) or Single Photon Emission Computed Tomography (SPECT) are the spatial resolution and the sensitivity (detector efficiency in combination with the geometric efficiency). Considerable efforts have been spent during the last two decades in improving the resolution and the efficiency by developing new detectors. READ MORE

  6. 4. Feature Extraction for Low-Frequency Signal Classification

    Author : José Chilo; Thomas Lindblad; Christian Bohm; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; infrasound; seismic signals; feature extraction; wavelets; fingerprints; mining; multimodal data space; Atomic physics; Atomfysik; Electronics;

    Abstract : The development of the International Monitoring System (IMS) for the verification of the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) has led to a rapid revival of interest in infrasound. Furthermore, the installation of low-frequency sensors at seismic sites has increased in recent years, providing researchers with large and heterogeneous data-sets in near real-time. READ MORE

  7. 5. Filtering extracting features from infrasound data

    Author : José Chilo; Thomas Lindblad; Christian Bohm; KTH; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; infrasound; seismic signals; feature extraction; wavelets; fingerprints; mining; magnetometer; Physics; Fysik; Electronics;

    Abstract : The goal of the research presented in this thesis is to extract features, to filter and get fingerprints from signals detected by infrasound, seismic and magnetic sensors. If this can be achieved in a real time system, then signals from various events can be detected and identified in an otherwise torrent data. READ MORE