Sökning: "virtual photons"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden virtual photons.

  1. 1. Aspects of QCD and the Photon Structure

    Författare :Christer Friberg; Teoretisk partikelfysik - Geonomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; High energy interactions; QCD; Photons; Monte Carlo Event Generator; Leptoquarks; Colour Connections; cosmic rays; Kosmisk strålning; högenergi; Fysicumarkivet A:2000:Friberg;

    Sammanfattning : In a single theoretical framework, real and virtual photon interactions are modeled for gamma-p and gamma-gamma collisions. The description covers aspects from the production of jets to total cross sections, where special emphasis is put on the range of uncertainty in the modeling of a resolved photon component. LÄS MER

  3. 2. Study of Two-Photon processes at low Q2 using the VSAT calorimeter in the DELPHI experiment

    Författare :Pavel Tyapkin; Partikel- och kärnfysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; högenergi; QCD; STIC; VSAT; DELPHI; LEP; antitag; double tag; single tag; photon structure function; hadronic cross-section; virtual photons; two-photon; gamma-gamma; Kosmisk strålning; cosmic rays; High energy interactions; PHOJET; TWOGAM; PYTHIA; VDM; GSP; Fysicumarkivet A:2004:Tyapkin;

    Sammanfattning : The study is based on data collected at the LEP II accelerator during the second period of the Large Electron-Positron collider operations (1996-2000). During that time the DELPHI (DEtector with Lepton, Photon and Hadron Identification) experiment collected about 90 Gb of data on tape corresponding to 687-691 pb-1 of luminosity. LÄS MER

  4. 3. Verification of Dose Calculation Algorithms in Treatment Planning Systems for External Radiation Therapy: A Monte Carlo Approach

    Författare :Elinore Wieslander; Lund Medicinsk strålningsfysik; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; radiologi; tomografi; medicinsk instrumentering; radiotherapy; dose calculation algorithm; verification; Monte Carlo calculation; electron beam; photon beam; Clinical physics; radiology; tomography; medical instrumentation; Klinisk fysiologi; treatment planning system;

    Sammanfattning : This thesis presents a new verification concept, the virtual accelerator, for dose calculation algorithms used in treatment planning systems (TPSs) for external beam radiotherapy. The algorithm input data required to implement a treatment unit in the TPS are generated by Monte Carlo simulations as are the beam reference data needed for the subsequent evaluation of the dose calculation algorithm. LÄS MER

  5. 4. Towards Fully Dynamic Surface Illumination in Real-Time Rendering using Acceleration Data Structures

    Författare :Pierre Moreau; Parallella System; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Computer graphics; Real-time; Ray tracing; Caustics; Global illumination;

    Sammanfattning : The improvements in GPU hardware, including hardware-accelerated ray tracing, and the push for fully dynamic realistic-looking video games, has been driving more research in the use of ray tracing in real-time applications. The work described in this thesis covers multiple aspects such as optimisations, adapting existing offline methods to real-time constraints, and adding effects which were hard to simulate without the new hardware, all working towards a fully dynamic surface illumination rendering in real-time. LÄS MER

  7. 5. Biological Inspired Deformable Image Sensor

    Författare :Wei Wen; Khatibi Siamak; Coleman Sonya; Blekinge Tekniska Högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; image sensor; pixel form; sub-arrangements; fill factor; square image; hexagonal image; deformable sensor; quality assessment.;

    Sammanfattning : Nowadays, cameras are everywhere thanks to the tremendous progress on sensor technology. However, their performance is far away from what we experience by our eyes. LÄS MER