Sökning: "near-field localization"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden near-field localization.
1. Single layer near-field acoustic imaging in space-invariant reflective environments
Sammanfattning : The visualization of optical fields, or widely known as photography, is a common practice that can also be applied to acoustic fields. No less than three decades of research in acoustic imaging demonstrate its potential and relevance in plenty applications such as sound source identification and localization, as well as characterization of noise generation mechanisms. LÄS MER
2. Localization effects in ternary nitride semiconductors
Sammanfattning : InGaN based blue and near-ultraviolet light emitting diodes and laser diodes have been successfully commercialized for many applications such as general lighting, display backlighting and high density optical storage devices. Despite having a comparably high defect density, these devices are known for their efficient operation, which is attributed to localization in potential fluctuations preventing carriers from reaching the centers of nonradiative recombination. LÄS MER
3. Impact of carrier localization on recombination in InGaN quantum wells with nonbasal crystallographic orientations
Sammanfattning : The modern InGaN technology demonstrates high efficiencies only in the blue spectral region and low current operation modes. The growth of InGaN quantum wells (QWs) on nonbasal crystallographic planes (NBP) has potential to deliver high-power blue and green light emitting diodes and lasers. LÄS MER
4. Sparse Modeling of Grouped Line Spectra
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
5. Sparse Modeling Heuristics for Parameter Estimation - Applications in Statistical Signal Processing
Sammanfattning : This thesis examines sparse statistical modeling on a range of applications in audio modeling, audio localizations, DNA sequencing, and spectroscopy. In the examined cases, the resulting estimation problems are computationally cumbersome, both as one often suffers from a lack of model order knowledge for this form of problems, but also due to the high dimensionality of the parameter spaces, which typically also yield optimization problems with numerous local minima. LÄS MER
