Sökning: "Q Wang"

Hittade 5 avhandlingar innehållade orden Q Wang.

  1. 1. Enhanced block sparse signal recovery and bayesian hierarchical models with applications

    Författare :Jianfeng Wang; Jun Yu; Anders Garpebring; Jia Li; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetic resonance imaging; Bayesian hierarchical models; Weather Research and Forecasting; Compressive sensing; Block sparsity; Multivariate isotropic symmetric a-stable distribution; q-ratio block constrained minimal singular value;

    Sammanfattning : This thesis is carried out within two projects ‘Statistical modelling and intelligentdata sampling in Magnetic resonance imaging (MRI) and positron-emission tomography(PET) measurements for cancer therapy assessment’ and ‘WindCoE -Nordic Wind Energy Center’ during my PhD study. It mainly focuses on applicationsof Bayesian hierarchical models (BHMs) and theoretical developments ofcompressive sensing (CS). LÄS MER

  3. 2. Theoretical Design of Molecular Photonic Materials

    Författare :Yanhua Wang; Yi Luo; David Beljonne; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Optical property; Molecular material; Solvent environment; Nuclear vibrations; Aggregation effect; Theoretical chemistry; Teoretisk kemi;

    Sammanfattning : This thesis presents a theoretical study on optical properties of molecular materials. Special emphasis has been put on the influence of solvent environment, nuclear vibrations, and aggregation effects on molecular properties like linear and nonlinear polarizabilities, one- and two-photon absorption probabilities. LÄS MER

  4. 3. Fabrication and characterization of periodically poled KTB and RB-doped KTB for applications in the visible and UV

    Författare :Shunhua Wang; Fredrik Laurell; Peter Smith; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nonlinear optics; second-harmonic generation; quasi-phasematching; type-I QPM SHG; type-II QPM SHG; KTP; RKTP; periodic electric-field poling; Physics; Fysik;

    Sammanfattning : This thesis deals with the fabrication and the characterization of periodically-poled crystals for use in lasers to generate visible and UV radiation by second-harmonic generation (SHG) through quasi-phasematching (QPM). Such lasers are of practical importance in many applications like high-density optical storage, biomedical instrumentation, colour printing, and for laser displays. LÄS MER

  5. 4. Water density impact on water flow and mass transport in rock fractures

    Författare :Helen Winberg-Wang; Longcheng Liu; Ivars Neretnieks; Andrew Frampton; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Tracer experiments; solute transport in fractured rock; advection-diffusion experiments; repositories; equivalent flowrate.; Spårämnesexperiment; ämnestransport i bergssprickor; advektion och diffusionsexperiment; slutförvar; ekvivalent flöde.;

    Sammanfattning : One way of taking care of spent nuclear fuel is to place it in a geological repository. In Sweden, a three-barrier system is planned. The system is based on encapsulating the fuel in copper canisters. These are surrounded by bentonite clay and buried under 500 m of bedrock. LÄS MER

  7. 5. Functions of Generalized Bounded Variation

    Författare :Martin Lind; Viktor Kolyada; Peter Oswald; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bounded p-variation; generalized bounded variation; modulus of continuity; function spaces; embeddings; Matematik; Mathematics;

    Sammanfattning : This thesis is devoted to the study of different generalizations of the classical conception of a function of bounded variation.First, we study the functions of bounded p-variation introduced by Wiener in 1924. We obtain estimates of the total p-variation (1.. LÄS MER