Sökning: "Spectral density"
Visar resultat 1 - 5 av 197 avhandlingar innehållade orden Spectral density.
1. Some Contributions to Filtering, Modeling and Forecasting of Heteroscedastic Time Series
Sammanfattning : Heteroscedasticity (or time-dependent volatility) in economic and financial time series has been recognized for decades. Still, heteroscedasticity is surprisingly often neglected by practitioners and researchers. This may lead to inefficient procedures. LÄS MER
2. ROBUST DETECTION AND SPECTRAL ANALYSIS OF SIGNALS WITH APPLICATIONS IN SPECTROSCOPY
Sammanfattning : Modern spectroscopic techniques, such as nuclear quadrupole resonance (NQR), nuclear magnetic resonance (NMR), and Raman spectroscopy, rely heavily on statistical signal processing systems for decision making and information extraction. The first part of this thesis introduces novel robust algorithms for detection, estimation, and classification of signals obtained through these spectroscopic techniques. LÄS MER
3. Multi-spectral analysis of fine scale aurora
Sammanfattning : The Aurora Borealis is the visible manifestation of the complex plasma interaction between the solar wind and the Earth's magnetosphere and ionosphere. Ground based and in situ measurements demonstrate a prevalence of dynamic fine structure within auroral displays, with spatial scales down to tens of metres and time variations occurring on a fraction of a second. LÄS MER
4. Analysis and Design of Spatially-Coupled Codes with Application to Fiber-Optical Communications
Sammanfattning : The theme of this thesis is the analysis and design of error-correcting codes that are suitable for high-speed fiber-optical communication systems. In particular, we consider two code classes. The codes in the first class are protograph-based low-density parity-check (LDPC) codes which are decoded using iterative soft-decision decoding. LÄS MER
5. Noise Applications in Light Water Reactors with Traveling Perturbations
Sammanfattning : Neutron noise induced by perturbations traveling with the coolant of light water reactors (LWRs) is investigated. Different methods to simulate the effect of propagating perturbations are considered. The studies are performed in both open- and closed-loop systems and summarized in three chapters. LÄS MER