In this paper, guided wave health monitoring in plate structure for detection of nonlinear contact scatter is conduct using vibration modulation technique. By time-frequency analysis of modulated guided wave series, the nonlinear responses at frequency of vibration are extracted out and used for defect imaging. It is shown that the nonlinear guided wave imaging method based on vibration modulat...

We discuss the most common types of weight functions in harmonic analysis and how they occur in time-frequency analysis. As a general rule, submultiplicative weights characterize algebra properties, moderate weights characterize module properties, Gelfand-Raikov-Shilov weights determine spectral invariance, and Beurling-Domar weights guarantee the existence of compactly supported test functions.

Re ection patterns play an important role in seismic sequence stratigraphy, therefore making their quantitative description essential for the construction and validation of sequence stratigraphic models from seismic data. The characteristics of a seismic re ection pattern can be elicited from the data by representing the data as a joint function of time and frequency. Developments in the eld of...

This lecture continues the presentation of how to perform Dataflow Frequency Analysis [5] on the folded DAG structure generated via the Larus algorithm for collecting a whole-program path. The frequency-analysis technique can be applied to the class of bi-distributive dataflowanalysis problems. This lecture formalizes the technique of generating dataflow-frequency facts by traversing the DAG re...

This paper investigated the use of instantaneous frequency (IF) instead of power amplitude and power spectrum in side-channel analysis. By opposition to the constant frequency used in Fourier Transform, instantaneous frequency reflects local phase differences and allows detecting frequency variations. These variations reflect the processed binary data and are hence cryptanalytically useful. IF ...

AbstraciThe following is a presentation of echo detection techniques based on time-frequency signal analysis for the measuring of thickness in thin multilayer structures. These techniques are shown to provide high-resolution signal characterization in a time-frequency space, and good noise rejection performance. In particular, the Short-Time Fourier Transform, the Gabor expansion, the Cross-Amb...

A new numerical method of frequency analysis is described, designed mainly to search for discrete frequencies in a time series. An integral transform is applied twice to the data for different reference times. A complex amplitude within a selected narrow frequency band is obtained for each transform. The frequency is then determined from the phase change of the complex amplitude over the differ...