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 20 of 49 for “"time-frequency analysis"”.
-
Statistical time-frequency analysis
Time-frequency representations (TFRs), such as the short-time Fourier transform, the wavelet transform, and the Wigner distribution, represent signal characteristics jointly in time and frequency and provide a versatile set of tools for the analysis and processing of nonstationary signals. Recent …
-
Transfer function estimation using time-frequency analysis
… transfer function estimate despite noisy data, a time-frequency analysis approach to system identification has been developed. The method is based on the observation that for a linear system, an input at a given frequency should result in a response at the same frequency, and a time localized …
-
Time frequency analysis techniques in terahertz pulsed imaging
… imaging data are unusual in that an entire time series is `behind' every pixel of the image. While resulting in rich data sets, this high dimensionality necessitates some form of distillation or extraction of pertinent features before images can be formed. Within this thesis the technology …
-
Time-frequency analysis techniques for non-intrusive load monitoring
The work in this thesis examines time-frequency analysis techniques and in particular the wavelet transform to extract the features contained within the electrical load signals. A novel approach that is based on wavelet design was utilized to generate a wavelet library which was used to match each …
-
Time-frequency analysis of Lamb waves using the Morlet wavelet transform
Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2000.
-
Joint time-frequency analysis and filtering of single trial event-related potentials.
… an event-related potential is typically several times less than the background EEG. The background EEG has the effect of obscuring the ERP and therefore appropriate signal processing is required for its recovery. Traditionally ERPs are estimated using the synchronised averaging of several single …
-
Impact of missed beats on heart rate variability using time-frequency analysis
… beats and ectopic beats can occur. In this study analysis of missed beats is performed using time-frequency analysis. Some of the patient's data had missed beats. Fourier spectral analysis was first applied to the missed beats during the resting state. The impact of missed beats using Fourier …
-
Time-Frequency Analysis and Filtering based on the Short-Time Fourier Transform
The joint time-frequency (TF) domain provides a convenient platform for signal analysis by involving the dimension of time in the frequency representation of a signal. A straightforward way to acquire localized knowledge about the frequency content of the signal at different times is to perform the …
-
Fixed-wing Classification through Visually Perceived Motion Extraction with Time Frequency Analysis
… object based on its unique motion profile over time, using signal classification techniques. The study is not limited to just unmanned aircraft, but includes full scale aircraft in the simulated dataset used to provide a representative set of aircraft scale and motion.
-
Study of Wavepacket Dynamics in Rubidium Vapor by Means of Time-Frequency Analysis
… number densities of the excited states. The frequency spectrum of the UV/violet signal intensity, recorded while varying the pump-probe time delay, shows the presence of quantum beats between energy levels involved in the FWM process. The time-frequency analysis of that temporal UV/violet …
-
Real Time Frequency Analysis of Signals From Lasso Catheter For Radiofrequency Ablation During Atrial Fibrillation
Real time spectrum analysis of signals obtained through lasso catheter during radiofrequency ablation of pulmonary vein was performed to determine the channel with dominant frequency. Threshold algorithm was used for signals which could be classified as type I and type II AF. Type III AF Signals …
-
A look at T1 and Tb theorems on non-homogeneous spaces through time-frequency analysis
… function $b$. In this dissertation, we apply time-frequency analysis to T1 theorem and Tb theorem. In particular, the theory of tiles and trees is used to prove T1 theorem on non-homogeneous spaces. This provides an alternative and a more visualized point of view to some parts of the proof. We …
-
Time-frequency Analysis of Doppler Ultrasound Blood Flow Signals: An Investigation into Automated Diagnosis of Vascular Disease
This study investigated an automated classification and diagnosis process for Doppler ultrasound blood flow signals to support clinical decision making. This process is used in this study to diagnose the severity of vascular disease in the lower limb. The study reviewed the existing methods for …
-
The Behavioral and Electrophysiological Effects of Discrimination and Inhibition Training on Visual Selective Attention: an ERP and Time-Frequency Analysis
… associated with stimuli processing. Behavioral analysis revealed a reduction in both Garner interference [F(1,33)=6.85, p=0.01] and Congruity effect [<em>F</em>(2,66)= 4.35, <em>p</em>=.02] after inhibition training, indicating better conflict resolution. Neural analyses revealed that the …
-
Theory and Application of Joint Time-Frequency Analysis On Health Monitoring of Electric Cable and Guided-Waves Detection of Structural Corrosion
… repair expenses. In both applications, joint time-frequency analysis is found to be an effective tool. </p> <p> The Joint Time-Frequency Domain Reflectometry (JTFDR) which is based on time-frequency cross-correlation function is applied to health monitoring of XLPE, EPR and SIR insulated …
-
Shear Madness: Signal-Dependent and Metaplectic Time-Frequency Representations
Time-frequency representations are multidimensional transformations that indicate the joint time-frequency content of a signal. Representations such as the wavelet transform, the short-time Fourier transform, and the Wigner distribution have proven to be powerful tools for signal analysis and …
-
Analysis and techniques for non-intrusive appliance load monitoring.
… is to investigate the effectiveness of the analysis methods and techniques used in load disaggregation using a single point sensing. Time-frequency analysis methods such as Wavelet transforms are carefully examined and machine learning classifiers are used to develop the appropriate …
Page 1 of 3