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Showing result 1 - 5 of 1670 swedish dissertations matching the above criteria.

  2. 1. The Frequency of the Frequency : On Hydropower and Grid Frequency Control

    Author : Linn Saarinen; Urban Lundin; Per Norrlund; Bengt Carlsson; Kjetil Uhlen; Uppsala universitet; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydropower; frequency control; governors; power system stability; inertia; primary control; Engineering Science with specialization in Science of Electricity; Teknisk fysik med inriktning mot elektricitetslära;

    Abstract : Variations in the electricity consumption and production connected to the power system have to be balanced by active control. Hydropower is the most important balancing resource in the Nordic system, and will become even more important as the share of variable renewable energy sources increases. READ MORE

  4. 2. Computer methods for voice analysis

    Author : Svante Granqvist; KTH; []
    Keywords : voice analysis; perceptual analysis; fundamental frequency; correlogram; aperiodicity; Fourier analysis; high-speed imaging; laryngoscopy; vocal fold vibration; voice accumulation.; TECHNOLOGY; TEKNIKVETENSKAP;

    Abstract : This thesis consists of five articles and a summary. Thethesis deals with methods for measuring properties of thevoice. The methods are all computer-based, but utilisedifferent approaches for measuring different aspects of thevoice. Paper I introduces the Visual Sort and Rate (VSR) method forperceptual rating of voice quality. READ MORE

  5. 3. Trapezius muscle fatigue and electromyographic frequency analysis

    Author : Tommy Öberg; Linköpings universitet; []
    Keywords : EMG; Spectrum; Frequency; Fatigue; Trapezius; Myalgia; MEDICINE; MEDICIN;

    Abstract : This study, comprising 6 separate articles, is concerned with different validity and reliability aspects of the electromyogram mean power frequency (MPF) as an estimator of localized musele fatigue in the trapezius muscle. A series of new, and partly controversial and problematic findings are reported. READ MORE

  6. 4. Discrete Stochastic Time-Frequency Analysis and Cepstrum Estimation

    Author : Johan Sandberg; Matematisk statistik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; ambiguity domain; time-frequency analysis; time-frequency representations; covariance function; non-stationary random processes; Speaker recognition; MFCC; cepstrum;

    Abstract : The theory of stochastic time-frequency analysis of non-stationary random processes has mostly been developed for processes in continuous time. In practice however, random processes are observed, processed, and interpreted at a finite set of time points. READ MORE

  7. 5. Time-Frequency Analysis in Attosecond Spectroscopy

    Author : Marcus Isinger; Atomfysik; []
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Attosecond; Spectroscopy; Time-Frequency; High-order harmonic generation; Rabitt; Interferometry;

    Abstract : This thesis deals with ultrafast dynamics of electronic processes in rare gas atoms. The processes we explore include photoemission, where we time the emission of electrons moving away from the atomic core following ionization by a photon; and auto-ionization, where the atom spontaneously releases an electron wave-packet following photo-excitation. READ MORE