Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
Results
Showing 1 to 15 of 15 for “"phase spectrum"”.
-
Phase Spectrum of the Visually Evoked EEG Response as a Measure of Latency.
The latency of evoked response waveforms has become an important clinical parameter. Latency is defined as the time between stimulus onset and a specific peak of the evoked response waveform. The latency of the visual evoked response (VER) waveform is a measure of neural conduction time in …
-
Data integration and visualization for systems biology data
… the highly responsive molecules (Chapter 3). The phase spectrum computed from the Fast Fourier transform of the time course data has been found to play more important roles than amplitude in the signal reconstruction. Phase spectrum analyses on in silico data created with two artificial …
-
Exploring the dimensionality of speech using manifold learning and dimensionality reduction methods
… derived from the conventional magnitude spectrum and less widely used phase spectrum are investigated. The manifold learning methods used in this study are locally linear embedding, Isomap, and Laplacian eigenmaps. The classic linear method, principal component analysis (PCA), is also …
-
Probabilistic generative modeling of speech
… Second, it has a well-designed model for the phase spectrum of speech, which has been hard to model and often neglected. Third, it models the AM-FM effects in speech, which are perceptually significant but often ignored in frame-based speech processing algorithms. Experiment shows that the …
-
Cross-Spectral Analysis For Spatial Point-Lattice Processes
… jumps that normally occur in the cross-spectral phase statistic is then proposed. Such adjustment is needed to enable us to calculate the slope of the phase spectrum which measures the shift between the two components. Several methods to calculate the slope are investigated. Asymptotic properties …
-
The mechanisms of reliable coding in mouse visual cortex
… training period. By perturbing the amplitude spectrum of these movies, I discovered that mice used structural information in the phase spectrum to discriminate between the different movies. This suggests that mice also use similar strategies as higher mammals for scene recognition. Inspired by …
-
Spectral discontinuity in concatenative speech synthesis – perception, join costs and feature transformations
… they are typically computed from the magnitude spectrum. However, the auditory system combines information relating to the magnitude spectrum, phase spectrum and spectral dynamics. The potential of phase and spectral dynamics as measures of spectral continuity were investigated. One widely …
-
Application of generative models in speech processing tasks
… Second, it has a well-designed model for the phase spectrum of speech, which has been hard to model and often neglected. Third, it models the AM-FM effects in speech, which are perceptually significant but often ignored in frame-based speech processing algorithms. Experiments show that the …
-
Quantitative Anisotropy Imaging based on Spectral Interferometry
… metrology of physical parameters. It can provide phase or optical path information of interest in single shot measurements with exquisite sensitivity and large dynamic range. As fast spectrometer became more available in 21st century, spectral interferometric techniques start to dominate over …
-
High-resolution infrared spectroscopy of large molecules and water clusters using quantum cascade lasers
… the purpose of obtaining a high-resolution gas phase spectrum of C60 for use in astronomical observations of this molecule. Details of the development of the spectrometer and initial results measuring methylene bromide are included as appendices in the dissertation. The spectrometer was used to …
-
Design, construction, and characterization of an ultra-sensitive, high-precision fast ion-beam spectrometer for the study of molecular ions
… acquisition of cold, rotationally-resolved, gas-phase spectra of molecular ions in the 2 - 5 μm region. For this dissertation in particular, the goal was to build an instrument able to acquire the uncooled, rotationally-resolved, gas-phase spectrum of N2+ in the near IR at 920 nm, using an ion …
-
Development of a quantum cascade laser based spectrometer for high-resolution spectroscopy of gas phase C60
… is to acquire a rotationally-resolved, cold, gas-phase spectrum of an infrared band of C60 around 8.5 μm. A high-resolution spectrum will be valuable from an applied astronomy and fundamental spectroscopy perspective. While there have been astronomical detections of C60 emission from thermal …
-
Radio Propagation Through Density Irregularities in the Auroral Ionosphere
… that distort the incident radio wave by inducing phase and amplitude fluctuations. These fluctuations are called<em> ionospheric</em><em> scintillation</em>. Scintillation effects can be detrimental to Global Navigation Satellite Systems (GNSS) such as Global Positioning System (GPS), but the …
-
Qualitative nichtlineare Zeitreihenanalyse mit Anwendung auf das Problem der Polbewegung
… des in der Arbeit eingeführten Begriffs des Phasensignals werden Testmöglichkeiten dargelegt und Beziehungen zwischen den nichtlinearen Eigenschaften der Zeitreihe und deren Phasenspektrum erforscht. Das Phasensignal wird aus dem Phasenspektrum der Zeitreihe hergeleitet und registriert …
-
High-Speed and Power Efficient Integrated Electro-Optic Modulators
… I have demonstrated a SOI platform-based optical phase shifter by combining the through and drop ports of a silicon add-drop MRR modulator. The measured intensity spectra for different bias voltages show that, our proposed phase shifter combining the through and the drop ports show ∼4.29 dB less …