Sökning: "direction fields"

Visar resultat 1 - 5 av 143 avhandlingar innehållade orden direction fields.

  1. 1. Recognition of printed Sinhala characters by direction fields

    Författare :Hemakumar Lalith Premaratne; Högskolan i Halmstad; []

    Sammanfattning : Although substantial research has been carried out on Optical Character Recognition (OCR) where a printed or a handwritten document of script is read as an image and converted to the editable text format, for various languages during the last 30 years, majority of Brahmi descended south Asian scripts are yet to achieve a commercial OCR system.... LÄS MER

  2. 2. Investigations of auroral electric fields and currents

    Författare :Tommy Johansson; Göran Marklund; Kristina Lynch; KTH; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; auroral physics; auroral electric fields; auroral potential structures; auroral particle acceleration; Space physics; Rymdfysik;

    Sammanfattning : The Cluster spacecraft have been used to investigate auroral electric fields and field-aligned currents (FACs) at geocentric distances between 4 and 7 Re. The electric fields have been measured by the EFW instrument, consisting of two pairs of spherical probes, and the FACs have been calculated from measurements of the magnetic field by the FGM fluxgate magnetometer. LÄS MER

  3. 3. Multifont recognition System for Ethiopic Script

    Författare :Yaregal Assabie Lake; Josef Bigun; Högskolan i Halmstad; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Ethiopic character recognition; OCR; Multifont recognition; Amharic; Direction fields; Structural and syntactic pattern recognition; Image analysis; Bildanalys;

    Sammanfattning : In this thesis, we present a general framework for multi-font, multi-size and multi-style Ethiopic character recognition system. We propose structural and syntactic techniques for recognition of Ethiopic characters where the graphically comnplex characters are represented by less complex primitive structures and their spatial interrelationships. LÄS MER

  4. 4. Transport, Turbulence and Instabilities in Cosmic Magnetic Fields

    Författare :Giuseppe Di Bernardo; Göteborgs universitet; Göteborgs universitet; Gothenburg University; []
    Nyckelord :Cosmic Rays; Interstella Medium; Galactic Magnetic Fields; Magnetohydrodynamics Turbulence; Accretion Discs;

    Sammanfattning : This decade has seen a large number of space missions, which, alongside ground-based radio, optical and gamma-ray telescopes, have enabled a deep insight into the non-thermal astrophysical environments. Interstellar Medium (ISM), Supernovae Remnants (SNRs) and Black-Hole (BH) accretion discs (ADs) are only a few examples of natural habitat of interaction of relativistic particles and magnetic fields, largely mediated by the action of the turbulence. LÄS MER

  5. 5. Generation of magnetic fields in plasmas

    Författare :Nitin Shukla; Gert Brodin; Dusan Jovanovic; Umeå universitet; []

    Sammanfattning : Relativistic and non-relativistic plasma outflows are quite ubiquitous in astrophysical scenarios, as well as in laboratory plasmas. The propagation of relativistic and non- relativistic charged particle beams in background plasmas provides return currents in the opposite direction and interactions between the currents then drive several plasma instabilities involving the longitudinal (electrostatic instabilities) and trans- verse (electromagnetic instability) modes. LÄS MER