Search for dissertations about: "noise reduction"

Showing result 16 - 20 of 294 swedish dissertations containing the words noise reduction.

  2. 16. Reduction of Audible Noise of a Traction Motor at PWM Operation

    Author : Hanna Amlinger; Ines Lopez Arteaga; Siv Leth; Wolfgang Kropp; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; electromagnetic noise; pulse width modulation PWM ; switching frequency; traction motor; Vehicle and Maritime Engineering; Farkostteknik;

    Abstract : A dominating source for the radiated acoustic noise from a train at low speeds is the traction motor. This noise originates from electromagnetic forces acting on the structure resulting in vibrations on the surface and thus radiated noise. It is often perceived as annoying due to its tonal nature. READ MORE

  4. 17. Noise reduction of speech signals with wavelets

    Author : Henrik Storm; Göteborgs universitet; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES;

    Abstract : .... READ MORE

  5. 18. Counteracting Acoustic Disturbances in Human Speech Communication

    Author : Nils Westerlund; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speech Enhancement; Noise Reduction; Hearing Aids; Adaptive Feedback Control; Ear-Mic; Active Noise Control;

    Abstract : A signal can be said to be any information bearing unit or action carrying a message from a sender to a receiver. This definition covers a vast number of human and non-human actions, ranging from flirtation to satellite communication. This thesis deals with increasing the quality of one of the most ubiquitous human-to-human signals: Speech. READ MORE

  6. 19. Substrate Noise Coupling in Mixed-Signal Integrated Circuits: Compact Modeling and Grounding Strategies

    Author : Simon Kristiansson; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; active noise reduction; substrate noise coupling modeling; elliptic integrals.; grounding resistance; Mixed-signal integrated circuits; z-parameter; substrate resistance; surface potential;

    Abstract : Integration of digital and analog circuits on the same chip is the result of the microelectronic industry's strive for low-cost, small, hand-held products. However, these mixed-signal circuits can experience interference problems; digital circuits inject noise into the substrate which is transmitted throughout the chip and received by sensitive analog circuits. READ MORE

  7. 20. Large Eddy Simulation for the Analysis of Supersonic Jet Noise Suppression Devices

    Author : Markus Olander Burak; Chalmers tekniska högskola; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; fluidic injection; mixer-ejector; jet noise; Kirchhoff; forward flight effects; LES; acoustic liner; supersonic turbulent jets; broadband time-domain impedance boundary condition; chevrons; shock-associated noise; CAA; aeroacoustics;

    Abstract : Stricter noise regulations for commercial and military aircraft have increased interest in noise reduction techniques within the aerospace industry. To meet the requirements, new noise suppression technologies have to be developed and numerical methods need to be validated and possibly improved for the correct assessment of these technologies. READ MORE