Search for dissertations about: "focal fields"

Showing result 1 - 5 of 16 swedish dissertations containing the words focal fields.

2. 1. The long-term decline of the grey-sided vole (Clethrionomys rufocanus) in boreal Sweden: importance of focal forest patch and matrix

   Author : Pernilla Christensen; Birger Hörnfeldt; Rolf A. Ims; Umeå universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; : Destructive sampling; high quality habitat; focal habitat; landscape; habitat fragmentation; threshold; clear-cut; patch size and quality; long-term time-series; Terrestrial ecology; Terrestisk ekologi;

   Abstract : There has been a long-term decline in number of cyclic vole populations in boreal Sweden since the 1970s. Several hypotheses have been suggested to explain this decline. Commonly for C. glareolus, C. READ MORE

4. 2. Miniaturized Hard Waveguides in Multifunction Array Antennas

   Author : Malcolm Ng Mou Kehn; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; interlaced arrays; Floquet theorem; reflector antennas; focal plane array; multifunction antennas; miniaturized waveguides; multilayer structures; spectral domain technique; periodic structures; aperture reuse; method of moments; soft and hard surfaces; array antennas;

   Abstract : Recent advances in technologies of wireless communications systems have led to an increasing desire for several antennas performing diverse functions at different frequencies to be integrated into a common radiating aperture. This gives rise to the so-called multifunction antenna, which affords the saving of scarce premium real estate and can alleviate problems arising from excessive antenna protrusions in aspects such as aerodynamics, aesthetics, and stealth capability in military applications. READ MORE

5. 3. Mm-wave Radio Astronomy Instrumentation for the Onsala Space Observatory and SEST

   Author : Nicholas D. Whyborn; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mm-wave receiver; phase retrieval holography; focal plane imaging array; radio astronomy instrumentation; SIS mixer;

   Abstract : The thesis presents work done in developing instrumentation for mm- and submm-wave radio astronomy. The work described is in several fields. The greater part of the thesis is concerned with sensitive heterodyne receivers and in particular the cryogenically cooled mixers. In paper A the SEST telescope and its observing system are described. READ MORE

6. 4. Laser-Driven Plasma Waves for Particle Acceleration and X-ray Production

   Author : Guillaume Genoud; Atomfysik; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Laser plasma acceleration of electrons and protons; laser-wakefield acceleration; plasma waves; plasma-wiggler radiation; betatron radiation; laser guiding; laser pointing stabilisation;

   Abstract : This thesis presents experimental results related to laser plasma accelerators. These rely on very different principles from conventional particle accelerators. READ MORE

7. 5. Gröbner Basis Methods for Minimal Problems in Computer Vision

   Author : Henrik Stewenius; Matematik LTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; computer vision; minimal problems; gröbner basis; Matematik; Teknik; Mathematics; Technological sciences;

   Abstract : A method is presented for building solvers for classes of multivariate polynomial equations. The method is based on solving an analogous template problem over a finite field, and then using the elimination order established for this problem for the original class of problems. READ MORE