Sökning: "noise modelling"

Visar resultat 11 - 15 av 203 avhandlingar innehållade orden noise modelling.

1. 11. Microwave characterisation of electrodes and field effect transistors based on graphene

   Författare :MICHAEL ANDERSSON; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Graphene; graphene electrodes; microwave amplifiers; noise measurements; microwave FETs; CVD graphene; noise modelling; FBARs.; nanofabrication; subharmonic resistive mixers; small-signal FET modelling;

   Sammanfattning : The isolation of the two-dimensional material graphene, a single hexagonal sheet of carbon atoms, is believed to trigger a revolution in electronics. Theory predicts unprecedented carrier velocities in ideal graphene, from which ultrahigh speed graphene field effect transistors (GFETs) are envisioned. LÄS MER

3. 12. Railway track dynamic modelling

   Författare :Blas Blanco; Leif Kari; Stefano Bruni; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Track modelling; Timoshenko element; local deformation; response discontinuity; distributed supports; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The railway vehicles are an increasing mean of transportation due to, its reduced impact on environment and high level of comfort provided. These reasons have contributed to settle a positive perception of railway traffic into the European society. LÄS MER

4. 13. On the Directivity of Railway Noise Sources

   Författare :Xuetao Zhang; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; railway traction noise; railway rolling noise; line source; railway aerodynamic noise; moving source; equivalent source line; De-Dopplerization; sound emission time; sound immission time; directivity; the Doppler factor;

   Sammanfattning : This dissertation deals with the directivity of railway noise. The directivity of railway noise is of particular importance when we have high-rise buildings close to the track, tunnel openings, partial barriers, or when we calculate the maximum sound pressure level during a pass-by based on the sound power level of the different sub-sources of a train. LÄS MER

5. 14. Modelling animal populations

   Författare :Åke Brännström; Umeå universitet; []
   Nyckelord :population model; stochastic population model; population dynamics; discrete time model; Beverton-Holt model; Skellam model; Hassell model; Ricker model; first principles; coupled map lattice; CML; area integral; square function; Mathematics; matematik;

   Sammanfattning : This thesis consists of four papers, three papers about modelling animal populations and one paper about an area integral estimate for solutions of partial differential equations on non-smooth domains. The papers are: I. Å. Brännström, Single species population models from first principles. LÄS MER

7. 15. Design, Modelling and Control of Electrical Machines - With Applications to Iron-powder Machines and Acoustic Noise

   Författare :David Martinez; Industriell elektroteknik och automation; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; BEM; induction machine; noise prediction; vector control; acoustic noise; HEV; series magnetization; leakage reduction; thermal model; FEM; MEC; claw-poles; SMC; slip-ring-less machine; sound intensity measurements; vibration; Electrical engineering; Elektroteknik;

   Sammanfattning : This thesis consists of two parts, the first dealing with the design of iron-powder synchronous machines, and the second with the analysis and prediction of the acoustic noise in electrical machines. In Part I, a 1.6 kW electrically magnetized claw-pole machine with magnetically conducting end-plates has been analyzed and a prototype tested. LÄS MER