Time-Frequency Analysis
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Recent papers in Time-Frequency Analysis
Filter banks with fixed time-frequency resolution, such as the Short-Time Fourier Transform (STFT), are a common tool for many audio analysis and processing applications allowing effective implementation via the Fast Fourier Transform... more
Time-frequency distribution methods are being widely used for the analysis of a variety of biomedical signals. Recently, they have been applied also to study otoacoustic emissions (OAE's), the active acoustic response of the... more
This paper reports experimental research undertaken to study the effect of variation of inter-electrode distance on the Electromyogram (EMG). The experiments were conducted on ten healthy subjects and they performed isometric contraction... more
The purpose of the present communication is, after a brief outline of the use of simple surrogates as introduced so far for stationarity tests, to deal with constructions of surrogates in ''time-frequency domains''.... more
We present a new method for time-frequency representation (TFR), which combines the Fourier-Bessel (FB) transform and the Wigner-Ville distribution (WVD). The FB transform decomposes a multi-component signal into a number of... more
This paper introduces a new approach for setting streamflow-based river ecosystem management targets and this method is called the 'Range of Variability Approach' (RVA). The proposed approach derives from aquatic ecology theory concerning... more
Automatic network road extraction from high resolution remotely sensed images has been under study by computer scientists for over 30 years. In fact, Conventional methods to create and update road information rely heavily on manual work... more
Condition monitoring of voltage source inverters-fed induction motors is challenging since the influence of the supply complicates the use of methods valid for utility fed motors. Analysis of variance is performed over data obtained in a... more
Transformers are a major capital item and the cost of a failure is high both in direct costs and downtime. For this reason they are monitored using a variety of methods. Partial discharges in power transformers are often a predecessor of... more
The classic approach for estimating instantaneous parameters relies on using the Hilbert Transform (HT). The HT method extracts the instantaneous parameters by comparing the imaginary part with the real part of an analytical signal. The... more
Acoustical measures of vocal function are routinely used in the assessments of disordered voice, and for monitoring the patient's progress over the course of voice therapy. Typically, acoustic measures are extracted from sustained vowel... more
Stroke is a cardiovascular accident within the brain resulting in motor and sensory impairment in most of the survivors. A stroke can produce complete paralysis of the limb although sensory abilities are normally preserved. Functional... more
The electromyography (EMG) signals give information about different features of muscle function. Realtime measurements of EMG have been used to observe the dissociation between the electrical and mechanical measures that occurs with... more
This paper develops an overcomplete discrete wavelet transform (DWT) based on rational dilation factors for discrete-time signals. The proposed overcomplete rational DWT is implemented using self-inverting FIR filter banks, is... more
Vibration signals are considered as nonstationary signals with transients. Conventional harmonic Fourier analysis ®nds it dif®cult to model the vibration signals. In this paper, a novel approach using the global Fourier transforms and... more
The acoustic signature of an internal combustion (IC) engine contains valuable information regarding the functioning of its components. It could be used to detect the incipient faults in the engine. Acoustics-based condition monitoring of... more
The recovery of threatened and endangered species is complicated by the number, severity, and tractability of the threats facing each species. We investigated the nature and the treatment of threats in recovery plans for 181 threatened... more
Output-only algorithms are needed for modal identification when only structural responses are available. The recent years have witnessed the fast development of blind source separation (BSS) as a promising signal processing technique,... more
Response processing may comprise multiple systems working in parallel at different functional levels of performance monitoring. In time-frequency decompositions of response-locked event-related potentials from adults, a subprocess... more
Planetary gears are widely used in aeronautic and industrial applications that require compactness and high torque-to-weight ratios. Despite these advantages, the severe conditions under which such gears are typically used may lead to... more
An exact and general expression for the analytic wavelet transform of a real-valued signal is constructed, resolving the time-dependent effects of nonnegligible amplitude and frequency modulation. The analytic signal is first locally... more
Safety, reliability, efficiency and performance of rotating machinery in all industrial applications are the main concerns. Rotating machines are widely used in various industrial applications. Condition monitoring and fault diagnosis of... more
In recent years, the wavelet transform on the basis of multiresolution analysis has been considered as a concrete algorithm of an integral wavelet transform which performs a spectral analysis in time-frequency domain. On the other hand,... more
The aim of this paper is to apply a nonparametric methodology developped by Donoho, Mallat, von Sachs & Samuelides (2003) for estimating an autocovariance sequence to the statistical analysis of the return of securities and discuss the... more
The kurtogram is a fourth-order spectral analysis tool recently introduced for detecting and characterising nonstationarities in a signal. The paradigm relies on the assertion that each type of transient is associated with an optimal... more
Demodulation is an important issue in gearbox fault detection. Non-stationary modulating signals increase difficulties of demodulation. Though wavelet packet transform has better time-frequency localisation, because of the existence of... more
Digital effects are most of the time non-adaptive: they are applied with the same control values during the whole sound. Adaptive digital audio effects are controlled by features extracted from the sound itself. This means that both a... more
The aim of this study is to investigate the difference of EEG dynamics on navigation performance. A tunnel task was designed to classify subjects into allocentric or egocentric spatial representation users. Despite of the differences of... more
The S-transform combines properties of the short-time Fourier (STFT) and wavelet transforms. It preserves the phase information of a signal as in the STFT, while providing the variable resolution as in the wavelet transform. However, the... more
In the frequency analysis of hydrologic data, the frequency of occurrence of the observed distributions is important for the purpose of plotting observed data called the " plotting positions ". An acceptable determination of plotting... more
The study of phenological aspects of plants involves the observation, recording and interpretation of the timing of their life history events. This review considers the phenology of leafing, flowering and fruit production in a range of... more
Objectives: Analysis of event-related desynchronization (ERD) and event-related synchronization (ERS) often requires the investigation of diverse frequency bands. Such analysis can be difficult, especially when using multichannel data.... more
My assembled documents are ongoing works and are added to and expanded on, frequently, so reviewing the docs gives deeper understandings, and broadens the interconnections between many topics and subjects. These documents are intended to... more
When, in addition to the constant Doppler frequency shift induced by the bulk motion of a radar target, the target or any structure on the target undergoes micro-motion dynamics, such as mechanical vibrations or rotations, the... more
Prior to discussing the newly devised scheme for our universal Creational code that pertains to the new edifice of our universe and planetary consciousness mechanics such as the structure of our stargate system, portals, consciousness... more
Intensive storm rainfall induced flooding is one of the most severe and devastating natural disasters in arid regions. In recent years, urban expansion and consolidation, changing demographic features within floodplains makes the urban... more