Sökning: "echo"

Visar resultat 1 - 5 av 168 avhandlingar innehållade ordet echo.

  1. 1. On System Identification and Acoustic Echo Cancellation

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Per Åhgren; Peter Stoica; Peter Händel; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; acoustic echo cancellation; stereophonic acoustic echo cancellation; doubletalk detection; adaptive beamforming; adaptive filtering; system identification; recursive system identification; loudspeaker impulse response estimation; TECHNOLOGY Information technology Signal processing; TEKNIKVETENSKAP Informationsteknik Signalbehandling;

    Sammanfattning : The topic of acoustic echo cancellation has received a lot of interest over the years. Even though the topic is relatively old, the increasing demand for hands-free telephony has made it more important than ever before. LÄS MER

  2. 2. Impulse Response Identification Applied to Estimation of Event-Related Potentials and Non-Intrusive Echo Path Analysis

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Tomas Gänsler; [1996]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Robust; Transfer function; Double-talk; Echo Path; Anaesthesia; Nb-trough; single ERP; Impulse response; Event-related potential; Echo Canceller; Signal processing; Signalbehandling;

    Sammanfattning : This thesis consists of five parts in which problems in two fields, medical and telecommunication, have been studied. In the first part, a prediction algorithm, the Prony method, for estimation of frequencies and damping factors of sinusiods is developed for a coloured noise disturbance. LÄS MER

  3. 3. Nuclear Magnetic Resonance for Diffusion Imaging Development and evaluation of spin-echo-based pulse sequences for in vivo studies of water self-diffusion

    Detta är en avhandling från Department of Radiation Physics, Lund university

    Författare :Sara Brockstedt; [1998]
    Nyckelord :MEDICIN OCH HÄLSOVETENSKAP; MEDICAL AND HEALTH SCIENCES; perfusion fraction; electrocardiographic triggering; segmented EPI SEPI ; echo-planar imaging EPI ; fast spin-echo FSE ; spin-echo SE ; navigator echoes; phase corrections; diffusion; Magnetic resonance; MRI; ischaemic stroke; Medicine human and vertebrates ; Medicin människa och djur ;

    Sammanfattning : The interest in diffusion imaging with nuclear magnetic resonance techniques has increased during the last few years. The main reason is the possibility of early diagnosis of acute ischaemic stroke, at a time when conventional MR techniques and computerised tomography fail. LÄS MER

  4. 4. System Modeling Using Basis Functions and Application to Echo Cancelation

    Detta är en avhandling från Department of Radiation Physics, Lund university

    Författare :Lester S.H. Ngia; [2000]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Laguerre filters; Gauss-Newton algorithms; Levenberg-Marquard algorithms; room acoustics; separable nonlinear least-squares; adaptive filtering; off-line estimation; echo cancelation; on-line estimation; system modeling; neural net filters; Kautz filters; loudspeaker systems; steepest-descent algorithms; Hammerstein models;

    Sammanfattning : This thesis concerns modeling of linear and nonlinear dynamic systems, where the applied models can be described by basis function expansions. In the first part of the thesis, the investigated model (or filter) structures and parameter estimation algorithms are described. LÄS MER

  5. 5. Acoustic Noise and Echo Cancelling : Microphone Array Methods and Applications

    Detta är en avhandling från Lund/Karlskrona : University of Karlskrona/Ronneby - Lund University

    Författare :Mattias Dahl; ; [1997]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : This Licentiate thesis is divided into three parts corresponding to three different papers. There is one research report, one conference paper and one submitted journal paper. All three parts deal with acoustic echo and/or noise cancelling problems when using adaptive microphone arrays. LÄS MER