Conventional vibration signals processing techniques are most suitable for stationary processes. However, most mechanical faults in machinery reveal themselves through transient events in vibration signals. That is, the vibration generated by industrial machines always contains nonlinear and nonstationary signals. It is expected that a desired time-frequency analysis method should have good com...

The constant center frequency to bandwidth ratio (Q-factor) of wavelet transforms provides a very natural representation for audio data. However, invertible have either required non-uniform decimation -- leading irregular data structures that are cumbersome work with or require excessively high oversampling unacceptable computational overhead. Here, we present novel strategy leads stable repres...

We give a new characterization of the Gelfand triple of function spaces in (S0, L, S′ 0) by means of a family of time-frequency localization operators. The localization operators are defined by the short-time Fourier transform and determine the local time-frequency behavior, whereas the global timefrequency distribution is characterized by a sequence space norm. We also show that the alternativ...

Theoretical results have recently been established in non parametric entropy estimation, based on asymptotic properties of minimal spanning trees (MST). A new application is proposed for the automatic extraction of time-frequency skeletons in the case of multicomponent chirp-like signals. The proposed method makes use of local maxima of a timefrequency distribution (considered as realizations o...

A flexible system for timefrequency signal analysis is presented. It is based on the S-method, which has a significant advantage in implementation since it can involve, as a key intermediate step, the Shorttime Fourier transform or the Hartley transform, each widely studied and commonly used in practice. Signal invariant and signal dependent system forms are presented. Hardware design, for a fi...

Non-stationary signals are very common in nature, consider for example speech, music or heart rate. Using the concept of time-frequency analysis this thesis studies the performance of different time-frequency distributions of both simulated and real non-stationary signals. The signals studied are linear and non-linear frequency modulated (FM) signals. Two methods are studied to increase perform...

We used the Ultimatum Game to investigate two person social decision making. The Ultimatum Game offers the experimental model to estimate the fairness, mind reading, conflict between emotion and cognition, and strategic behavior. We recorded simultaneous activity of the EEG from 64 scalp electrodes in 26 healthy participants (13 pairs of proposers and responders) and estimated the timefrequency...

Harmonic structure can be easily recognized in the timefrequency representation of speech signals even in the diverse environment. The harmonicity is a measure of the completeness of harmonic structure. This paper extends the use of conventional harmonicity measure to the tasks of pitch estimation and voice activity detection. A set of hierarchical harmonicities, including grid, temporal, spect...

Local frequency and time averaging and differentiating operators, using three neighboring points of critical-band timefrequency plane, are used to process the plane prior to its use in TRAP-based ASR. In that way, five alternative TRAP-based ASR systems (the original one and the time/frequency integrated/differentiated ones)are created. We show that the frequency differentiating operator improv...

In this paper we introduce a new technique for blind source separation of speech signals. We focused on the temporal structure of signals which is not always the case in other major approaches. The idea is to apply the decorrelation method proposed by Molgedey and Schuster in timefrequency domain. We show some results of experiments with artificial data and speech data recorded in the real envi...