Sökning: "model resolution"

Visar resultat 1 - 5 av 933 avhandlingar innehållade orden model resolution.

  1. 1. Improvement and Assessment of Two-Dimensional Resistivity Models Derived from Radiomagnetotelluric and Direct-Current Resistivity Data

    Författare :Thomas Kalscheuer; Laust B. Pedersen; Christopher Juhlin; Roland Roberts; Heinrich Brasse; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Electromagnetic geophysics; radiomagnetotellurics; direct-current resistivity; displacement currents; dielectric effect; non-linearity; inversion; regularization; two-dimensional model; model variance; model resolution; data resolution; Geophysics; Geofysik;

    Sammanfattning : Two-dimensional (2-D) models of electrical resistivity are improved by jointly inverting radiomagnetotelluric (RMT) and direct-current resistivity (DCR) data or by allowing for displacement currents in the inversion of RMT data collected on highly resistive bedrock. Uniqueness and stability of the 2-D models are assessed with a model variance and resolution analysis that allows for the non-linearity of the inverse problem. LÄS MER

  3. 2. Neural limits of visual resolution

    Författare :Zoran Popovic; Göteborgs universitet; []
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; cell separation; cortical magnification; detection; estimated receptive field; high-pass filtered optotypes; nyquist limit; psychophysics; resolution; ganglion cells;

    Sammanfattning : Aims: The aim of this thesis was to formulate a model of retinal neural circuitry in humans based on morphological estimates of retinal cone and ganglion cell populations, to compare results based on this model to psychophysical measurements of visual resolution and identify the retinal neural factors that limit visual resolution.Materials & Methods: Total displacement of central ganglion cells from foveal cones was obtained by estimating the length of fibers of Henle in four human retinas along the nasal or vertical hemi-meridians. LÄS MER

  4. 3. Model Based Coding : Initialization, Parameter Extraction and Evaluation

    Författare :Zhengrong Yao; Haibo Li; Ralf Schäfer; Umeå universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Model-based coding; Motion estimation; Vision based tracking; Initialization; Analysis-by-Synthesis; Texture mapping; Active tracking.; Signalbehandling; Signal processing; Signalbehandling; Signal Processing; signalbehandling;

    Sammanfattning : This thesis covers topics relevant to model-based coding. Model-based coding is a promising very low bit rate video coding technique. The idea behind this technique is to parameterize a talking head and to extract and transmit the parameters describing facial movements. At the receiver, the parameters are used to reconstruct the talking head. LÄS MER

  5. 4. Model on Demand : Algorithms, Analysis and Applications

    Författare :Anders Stenman; Fredrik Gustafsson; Lennart Ljung; Linköpings universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : System identification deals with the problem of estimating models of dynamical systems from observed data. In this thesis, we focus on the identification of nonlinear models, and, in particular, on the situation that occurs when a very large amount of data is available. LÄS MER

  7. 5. Controlled Source Radiomagnetotelluric (CSRMT) Applications in Environmental and Resource Exploration

    Författare :Nazli Ismail; Laust Pedersen; Bulent Tezkan; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetotelluric; radio magnetotelluric; controlled-source tensor magnetotelluric; plane wave; near surface geophysics; sediment; fracture zone; inversion; forward modelling; near field effect; two-dimensional model; three-dimensional model; resolution; Geophysics; Geofysik; Earth Sciences with Specialization Environmental Analysis; geovetenskap med inriktning mot miljöanalys; Hydrology; hydrologi; mineralogi; petrologi och tektonik; Mineral Chemistry; Petrology and Tectonics;

    Sammanfattning : An integrated use of radio magnetotelluric (RMT) and controlled source tensor magnetotelluric (CSTMT) measurements, the so-called CSRMT method, has been employed in environmental and resource exploration studies. A number of case histories, including a groundwater investigation in glacial deposits, a study of fracture zones for geotechnical purposes and a mining exploration study of a copper deposit, are presented in this thesis in order to illustrate the usefulness and capability of the CSRMT method. LÄS MER