Search for dissertations about: "dictionary learning"

Showing result 1 - 5 of 6 swedish dissertations containing the words dictionary learning.

  1. 1. Sparse Modeling of Grouped Line Spectra

    University dissertation from Centre for Mathematical Sciences, Lund University

    Author : Ted Kronvall; Lunds universitet.; Lund University.; Lund University.; [2015]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; line spectra; parameter estimation; convex optimization; group-sparsity; block-sparsity; dictionary learning; ADMM; adaptive penalty; total variation; multi-pitch estimation; chroma; audio processing; TDOA; near-field localization; amplitude modulation;

    Abstract : This licentiate thesis focuses on clustered parametric models for estimation of line spectra, when the spectral content of a signal source is assumed to exhibit some form of grouping. Different from previous parametric approaches, which generally require explicit knowledge of the model orders, this thesis exploits sparse modeling, where the orders are implicitly chosen. READ MORE

  2. 2. Parameter Estimation - in sparsity we trust

    University dissertation from Mathematical Statistics, Centre for Mathematical Sciences, Lund University

    Author : Johan Swärd; Lunds universitet.; Lund University.; Lund University.; [2017]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Parameter estimation; Sparse models; Convex optimization; Symbolic Periodicity; Alternating direction method of multipliers ADMM ; Covariance fitting; multi-pitch estimation problem; Off-grid estimation; Dictionary learning; Atomic norm; Sampling schemes;

    Abstract : This thesis is based on nine papers, all concerned with parameter estimation. The thesis aims at solving problems related to real-world applications such as spectroscopy, DNA sequencing, and audio processing, using sparse modeling heuristics. READ MORE

  3. 3. Unsupervised feature learning applied to condition monitoring

    University dissertation from Luleå University of Technology

    Author : Sergio Martín del Campo Barraza; Luleå tekniska universitet.; [2017]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industrial Electronics; Industriell elektronik;

    Abstract : Improving the reliability and efficiency of rotating machinery are central problems in many application domains, such as energy production and transportation. This requires efficient condition monitoring methods, including analytics needed to predict and detect faults and manage the high volume and velocity of data. READ MORE

  4. 4. Speech Enhancement Using Nonnegative MatrixFactorization and Hidden Markov Models

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Nasser Mohammadiha; KTH.; [2013]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Speech enhancement; noise reduction; nonnegative matrix factorization; hidden Markov model; probabilistic latent component analysis; online dictionary learning; super-Gaussian distribution; MMSE estimator; temporal dependencies; dynamic NMF;

    Abstract : Reducing interference noise in a noisy speech recording has been a challenging task for many years yet has a variety of applications, for example, in handsfree mobile communications, in speech recognition, and in hearing aids. Traditional single-channel noise reduction schemes, such as Wiener filtering, do not work satisfactorily in the presence of non-stationary background noise. READ MORE

  5. 5. Towards autonomous condition monitoring sensor systems

    University dissertation from Luleå tekniska universitet

    Author : Sergio Martín del Campo Barraza; Luleå tekniska universitet.; [2015]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Industrial Electronics; Industriell elektronik;

    Abstract : Rolling element bearings are used to carry load and reduce friction between moving parts in rotating machines, which play a central role in society and industry, for example in the transportation and energy sectors. It is essential to monitor and maintain the condition of bearings such that machines can operate efficiently and any failures resulting in unplanned stoppages are avoided. READ MORE