Sökning: "electromagnetic models"

Visar resultat 1 - 5 av 174 avhandlingar innehållade orden electromagnetic models.

  1. 1. Electromagnetic Interference in Distributed Outdoor Electrical Systems, with an Emphasis on Lightning Interaction with Electrified Railway Network

    Författare :Nelson Theethayi; Rajeev Thottappillil; Farhad Rachidi; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical engineering; Electromagnetic Compatibility EMC ; Lightning; Lightning Protection; Transmission Lines; Electromagnetic Wave Propagation; Underground Cables; Grounding; Electromagnetic Transients; Electromagnetic Interference; Shielding Effectiveness; Railway Systems; Elektroteknik; elektronik och fotonik; Electrical engineering; electronics and photonics; Elektroteknik; elektronik och fotonik;

    Sammanfattning : This thesis deals with the electromagnetic compatibility (EMC) problems of distributed electrical networks, especially that caused by lightning to electrified railway. Lightning transients were found to damage important devices that control train movements, causing traffic stoppage and delays. LÄS MER

  3. 2. Efficient Electromagnetic Induction Modelling : Adaptive mesh optimisation, advanced boundary methods and iterative solution techniques

    Författare :Laura M. Buntin; Thomas Kalscheuer; Gunilla Kreiss; Zhengyong Ren; Klaus Spitzer; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Applied geophysics; Electromagnetic theory; Numerical Modelling; Geo-Electromagnetics; Magnetotellurics; Controlled-source electromagnetics; Goal-oriented adaptive mesh refinement; Perfectly-matched layers; Iterative solution methods; Preconditioning; Geofysik med inriktning mot fasta jordens fysik; Geophysics with specialization in Solid Earth Physics;

    Sammanfattning : Forward modelling of electromagnetic induction data simulates the electric and magnetic fields within a computational domain for a given distribution of electromagnetic material properties and a given source of the electromagnetic field. The quantities of interest are the fields at receiver locations at the Earth's surface. LÄS MER

  4. 3. Synthetic-Aperture Radar Imaging of Forests in the VHF and UHF Bands: Electromagnetic Models and Data Analysis

    Författare :Björn Hallberg; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; image formation; biomass mapping; Synthetic-aperture radar SAR ; ionospheric propagation; electromagnetic models; forest monitoring; remote sensing;

    Sammanfattning : Synthetic-aperture radar (SAR) is a technique which can image the Earth’s surface, from a spaceborne or airborne platform, irrespective of daylight or cloud cover. During the last decades there has been an increasing interest in using SAR for estimation of forest parameters. LÄS MER

  5. 4. Design and Characterization of Functional Structures for Electromagnetic Waves

    Författare :Andreas Ericsson; Teoretisk elektroteknik; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electromagnetic scattering; functional structure; circular polarization selective structure; reflector antenna; electromagnetic absorber; radar cross section; compressive sensing; triaxial weave; homogenization; physical optics;

    Sammanfattning : This dissertation deals with design and characterization of functional structures for scattering of electromagnetic waves. An abundance of these structures can be found in nature, such as the structural coloration in the feathers of a peacock, the scales of butterflies and the shell of scarab beetles. LÄS MER

  7. 5. Automotive Electromagnetic Compatibility - Prediction and Analysis of Parasitic Components in Conductor Layouts

    Författare :Sabine Alexandersson; Industriell elektroteknik och automation; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Parasitic components; Electromagnetic Compatibility; Crosstalk; Electromagnetic simulations;

    Sammanfattning : The electronics in the automotive industry is facing a new era where safety critical functions are electrified, as for example drive-by-wire technology. At the same time as the number of electrical loads in the vehicles is increasing, the time to market is decreasing. LÄS MER