Sökning: "Fractal analysis"

Visar resultat 16 - 20 av 49 avhandlingar innehållade orden Fractal analysis.

1. 16. Methods for Characterisation of Pressing Die Surfaces

   Författare :Johan C Berglund; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finish milling; scale-sensitive fractal analysis; surface characterisation; polishing; functional correlation; : pressing dies; functional filtration; surface roughness; functional surface;

   Sammanfattning : Design and manufacture of dies and moulds is a critical aspect of many production systems since the manufacturing and try-out of new dies and moulds often is essential in determining the lead-time and quality of a new production system. In the automotive industry, many new car models are introduced each year and for each of these models, a new set of pressing dies has to be designed and manufactured. LÄS MER

3. 17. Towards Topography Characterization of Additive Manufacturing Surfaces

   Författare :AMOGH VEDANTHA KRISHNA; Bengt Göran Rosén; Frederic Cabanettes; Högskolan i Halmstad; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laser-based Powder bed fusion; Fused deposition modeling; Structured light projection; Stylus profilometer; Multiple regression; Areal surface texture parameters; Profile parameters; Feature-based characterization; Power spectral density; Scale-sensitive fractal analysis; Confocal fusion; Additive manufacturing;

   Sammanfattning : Additive Manufacturing (AM) is on the verge of causing a downfall to conventional manufacturing with its huge potential in part manufacture. With an increase in demand for customized product, on-demand production and sustainable manufacturing, AM is gaining a great deal of attention from different industries in recent years. LÄS MER

4. 18. Sheet metal trimming dies – characterisation methods of geometry and surface topography and the influence on wear

   Författare :Per Jonsson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; finish milling; wear measurement; functional surface; trimming dies; scale-sensitive fractal analysis; surface roughness; polishing; surface characterisation; high strength steel; tool wear;

   Sammanfattning : In recent years, the life cycle of car models has decreased from 7 to 5 years and the volume sizes are becoming shorter in the automotive industry. The increasing number of car models introduced to the market means that a fewer number of parts must pay the costs for the tool/die design and manufacturing. LÄS MER

5. 19. Decoupling and Evaluation of Multiple Antenna Systems in Compact MIMO Terminals

   Författare :Hui Li; Sailing He; Cyril Luxey; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Multiple antennas; mutual coupling; compact antennas; frequency reconfigurable antennas; pattern reconfigurable antennas; meta-material antennas; mobile antennas; fractal antennas; collocated antennas; antenna measurement.;

   Sammanfattning : Research on multiple antenna systems has been a hot topic in recent years due to the demands for higher transmission rate and more reliable link in rich scattering environment in wireless communications. Using multiple antennas at both the transmitter side and the receiver side increases the channel capacity without additional frequency spectrum and transmitted power. LÄS MER

7. 20. Star clusters as engines of galaxy evolution

   Författare :Mattia Sirressi; Angela Adamo; Matthew Hayes; Paul Crowther; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Extragalactic astronomy; Galaxies; Star formation; Interstellar medium; Stellar feedback; Ultraviolet surveys; Hubble Space Telescope; Spectroscopy; Data analysis; Astronomy; astronomi;

   Sammanfattning : Feedback in star forming galaxies is the key process that regulates how many stars form given the available gas reservoir. The radiation, energy and momentum released by the stellar activity and the active galactic nuclei change the physical properties of the gas in the galaxy such as the ionisation state, the density and the kinematics. LÄS MER