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 “"Non-stationary signals"”.
-
Advancing Fluorescence Fluctuation Microscopy in Living Cells: From Non-stationary Signals to Ternary Protein Interactions
… loss, or photodepletion. This loss leads to a non-stationary signal, which is incompatible with the implicit assumption of a stationary process in conventional FFS theory. We addressed this issue by introducing a new analysis approach that serves as a foundation for extending FFS to …
-
Condition Monitoring Techniques for Wind Turbines
… techniques for the detection of faults in non-stationary signals. Work is supported throughout by information from wind turbine operators and their experiences of variable speed, variable load wind turbines in the field. Experimental work is carried out on a condition monitoring test rig …
-
Advanced and complete functional series time-dependent ARMA (FS-TARMA) methods for the identification and fault diagnosis of non-stationary stochastic structural systems
Non-stationary signals, that is signals with time-varying (TV) statistical properties, are commonly encountered in engineering practice. The vibration responses of structures, such as traffic-excited bridges, robotic devices, rotating machinery, and so on, constitute typical examples of …
-
Detection of Rotor and Load Faults in BLDC Motors Operating Under Stationary and Non-Stationary Conditions
… current. As most BLDC applications involve non-stationary operating conditions, the diagnosis of rotor faults in non-stationary conditions forms the third and most important part of this research. Several signal processing techniques are reviewed to analyze non-stationary signals. Three new …
-
Wavelets and filter banks: New results and applications
… a new technique for time-scale analysis of non-stationary signals. Wavelet analysis uses orthonormal bases in which computations can be done efficiently with multirate systems known as filter banks. This thesis develops a comprehensive set of tools for (multidimensional) multirate signal …
-
COMPARISON ON DIFFERENT DISCRETE FRACTIONAL FOURIER TRANSFORM (DFRFT) APPROACHES
… are suitable for dealing with various types of non-stationary signals. Taking advantage of the properties and non-stationary features of linear chirp signals in the Fourier transform domain, several methods of extraction and parameter estimation for chirp signals are proposed, and a comparative …
-
Time-Frequency Analysis and Filtering based on the Short-Time Fourier Transform
… the most widely used method for the analysis of signals whose spectral content varies with time. Recent application examples of the STFT and its variants – e.g. the squared magnitude of the STFT known as the spectrogram – include signal denoising, instantaneous frequency estimation, and speech …
-
Non-contract Estimation of Respiration and Heartbeat Rate using Ultra-Wideband Signals
The use of ultra-wideband (UWB) signals holds great promise for remote monitoring of vital-signs which has applications in the medical, for first responder and in security. Previous research has shown the feasibility of a UWB-based radar system for respiratory and heartbeat rate estimation. Some …
-
Electrophysiological Recording of the Brain, Visualization, Prediction, and Interconnectivity
… way to visualize the time-frequency content of non-stationary signals with higher resolution than previously possible. The use of Wigner-Ville distribution together with chirplet decomposition allows a clearer visualization in terms of both the temporal and frequency details with detail higher …
-
Optimization of the assessment of cerebral autoregulation in neurocritical care unit
… the system being analysed is linear and the signals are stationary, with the announcement of non-stationary characteristic of CA, a more robust method, in particular suitable for non-stationary signal analysis, needs to be explored. Objectives and Methods This thesis addresses three primary …
-
Time-Varying Autoregressive Model Based Signal Processing with Applications to Interference Rejection in Spread Spectrum Communications
… signal processing methods for rapidly varying non-stationary signals based on time-varying autoregressive (TVAR) modeling, and to apply such methods to frequency-modulated (FM) interference rejection in direct-sequence spread spectrum (DSSS) communications. For fast varying non-stationary …
-
Improved Intermittent Clutter Filtering For Wind Profiler Radar
… signal processing is not able to deal with these signals in an efficient way, because the model assumption on which the processing is based is violated. With the development of sophisticated mathematical tools for the analysis of non-stationary signals in the last two decades and a better …
-
On characterisation and decomposition of internet traffic dynamics
… has identified the existence of highly non-stationary traffic characteristics on a volume aggregate and protocol-oriented basis. By virtue of this outcome, this work contributes to the applicability of energy TF distributions for the explicit traffic characterisation task of …
-
The application of advanced signal processing techniques to the condition monitoring of electrical machine drive systems
… machine diagnostic variables behave typically as non-stationary signals. Therefore, it is difficult distinguishing fault conditions from normal operating conditions using steady-state analysis techniques. The most popular of these steady-state techniques employs the Fourier Transform as the …
-
The application of advanced signal processing techniques to the condition monitoring of electrical machine drive systems
… machine diagnostic variables behave typically as non-stationary signals. Therefore, it is difficult distinguishing fault conditions from normal operating conditions using steady-state analysis techniques. The most popular of these steady-state techniques employs the Fourier Transform as the …