Sökning: "Singular Value Decomposition"

Visar resultat 16 - 20 av 37 avhandlingar innehållade orden Singular Value Decomposition.

  1. 16. Synchronization and channel estimation in OFDM systems

    Författare :Jaap van de Beek; Luleå tekniska universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Signalbehandling; Signal Processing;

    Sammanfattning : This thesis addresses synchronization and channel estimation in OFDM communication systems. The joint maximum likliehood estimator of symbol time and carrier frequency offsets for OFDM systems using a cyclic prefix is presented. This estimator exploits the redundancy introduced by the prefix and does not require extra pilot information. LÄS MER

  3. 17. Hydrogeophysics of Tropical Africa : Recent advances and perspectives

    Författare :Elónio Muiuane; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : In the present work an attempt is made to put into perspective the hydrogeophysical investigations for rural water supply carried out over the last two decades in tropical Africa, paying special attention to groundwater targets in the weathered rocks in and above the crystalline basement. The applicability of geophysical techniques in groundwater investigations in tropical Africa, particularly the DC resistivity and electromagnetic techniques is discussed in the light of recent developments in instrumentation, data collection and interpretation procedures. LÄS MER

  4. 18. Algorithms in data mining : reduced rank regression and classification by tensor methods

    Författare :Berkant Savas; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; MATHEMATICS; MATEMATIK;

    Sammanfattning : In many fields of science, engineering, and economics large amounts of data are stored and there is a need to analyze these data in order to extract information for various purposes. Data mining is a general concept involving different tools for performing this kind of analysis. LÄS MER

  5. 19. 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

  7. 20. Dynamic Source Models of Icelandic Earthquakes and Teleseismic Tomograhy along the TOR array

    Författare :Z. Hossein Shomali; Göran Ekström; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; Geovetenskap; Earth sciences; Geovetenskap; Geofysik med inriktning mot seismologi; Geophysics with specialization in Seismology;

    Sammanfattning : This thesis describes new inversion-oriented methodological developments and their seismological applications. In the first study presented the dynamic source parameters of some local Icelandic earthquakes are studied by employing a time domain moment tensor inversion method. LÄS MER