Sökning: "modulated noise"

Visar resultat 1 - 5 av 58 avhandlingar innehållade orden modulated noise.

1. 1. Human response to wind turbine noise : perception, annoyance and moderating factors

   Författare :Eja Pedersen; Sten Ljunggren; Högskolan i Halmstad; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Noise; Environmental exposure; Wind; Audio-visual interaction; Low-level noise exposure; NATURAL SCIENCES; NATURVETENSKAP; wind turbines; noise annoyance; sound perception; audio-visual interaction; low-level noise exposure;

   Sammanfattning : Aims: The aims of this thesis were to describe and gain an understanding of how people who live in the vicinity of wind turbines are affected by wind turbine noise, and how individual, situational and visual factors, as well as sound properties, moderate the response.Methods: A cross-sectional study was carried out in a flat, mainly rural area in Sweden, with the objective to estimate the prevalence of noise annoyance and to examine the dose-response relationship between A-weighted sound pressure levels (SPLs) and perception of and annoyance with wind turbine noise. LÄS MER

3. 2. 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

4. 3. Noise and Saturation Properties of Fiber Optical

   Författare :Per Kylemark; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear fiber optics; four-wave mixing; single-pumped; regeneration; saturation; dual-pumped; noise figure; parametric amplification;

   Sammanfattning : Fiber Optical Parametric Amplifiers (FOPAs) are based on a highly efficient Four-wave Mixing process in highly nonlinearfibers and have gained a lot of interest since it was shown that ahigh gain can be obtained. They are multi-functional devices thatare not only limited to amplifying signals, but their wide range ofapplicability also include wavelength conversion, pulse-generation,optical sampling and also regeneration at very high bit-rates. LÄS MER

5. 4. Stochastic Resonance and Noise-Assisted Signal Transfer : On Coupling Effects of Stochastic Resonators and Spectral Optimization of Fluctuations in Random Network Switches

   Författare :Peter Hammerstein; Claes Granqvist; Laszlo Kish; Hans Liljenström; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Engineering physics; stochastic resonance; nonlinear stochastic dynamics; noise and fluctuations; magnetic domains; Teknisk fysik; Engineering physics; Teknisk fysik;

   Sammanfattning : Recent research shows that noise or random fluctuations must not always be destructive in Nature by degrading system performance. On the contrary, in nonlinear systems they can synchronize systems or enhance the quality of signal transmission. The latter possibility is reported in the thesis. LÄS MER

7. 5. Nonlinear Characterisation and Modelling of Microwave Semiconductor Devices

   Författare :Mattias Thorsell; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; noise modelling; nonlinear measurement; active load-pull; noise measurement; thermal characterisation; AlGaN GaN HEMT; nonlinear modelling;

   Sammanfattning : There is an increasing need for more accurate models taking into account the nonlinearities and memory effects of microwave transistors. The memory effects are especially important for transistor technologies suffering from relatively large low frequency dispersion, such as GaN baed HEMTs. LÄS MER