Sökning: "sparse"

Visar resultat 21 - 25 av 507 avhandlingar innehållade ordet sparse.

  1. 21. Sparse Modeling of Grouped Line Spectra

    Författare :Ted Kronvall; Statistical Signal Processing Group; []
    Nyckelord :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;

    Sammanfattning : 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. LÄS MER

  3. 22. On the Measurement of Model Fit for Sparse Categorical Data

    Författare :Katrin Kraus; Dag Sörbom; Ghazi Shukur; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; goodness-of-fit; sparseness; model fit; categorical data; fit statistic; sparse contingency table; Statistics; Statistik;

    Sammanfattning : This thesis consists of four papers that deal with several aspects of the measurement of model fit for categorical data. In all papers, special attention is paid to situations with sparse data. LÄS MER

  4. 23. Van der Waals density-functional description of polymers and other sparse materials

    Författare :Jesper Kleis; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; softmatter; Density functional theory; polyethylene; van der Waals interaction; polymer crystal; nanotubes; DFT; sparse material systems; polymer interactions; polymer structure;

    Sammanfattning : Polymers are abundant in nature --- rubber, tar and latex have been known to mankind for thousands of years. Early in the 20th century, a systematic synthesis of polymers was developed, but the great potential of synthesized polymers was recognized first during World War II. LÄS MER

  5. 24. Parameter Estimation and Filtering Using Sparse Modeling

    Författare :Ashkan Panahi; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; sparsity based tracking; Sparsity based techniques; off-grid effect; parameter estimation; continuous basis pursuit; compressed sensing;

    Sammanfattning : Sparsity-based estimation techniques deal with the problem of retrieving a data vector from an undercomplete set of linear observations, when the data vector is known to have few nonzero elements with unknown positions. It is also known as the atomic decomposition problem, and has been carefully studied in the field of compressed sensing. LÄS MER

  7. 25. Socio-economic dynamics in sparse regional structures

    Författare :Örjan Pettersson; Ulf Wiberg; Umeå universitet; []
    Nyckelord :SAMHÄLLSVETENSKAP; SOCIAL SCIENCES; Northern Sweden; Norrland; Sparsely populated areas; Countryside; Rural change; Regional development; Forestry; Population; Welfare; Glesbygd-- Sverige -- Norrland; Regional utveckling-- Sverige -- Norrland; Norrland-- sociala förhållanden; Norrland-- ekonomiska förhållanden;

    Sammanfattning : The aim of the thesis is to describe and analyse socio-economic changes in northern Sweden. Focus is on the period 1985-2000. LÄS MER