We study a stationary random ®eld model that is composed of a signal of an unknown number of sine and cosine functions, and a coloured noise. This model has been used in image analysis and modelling spatial data, and is useful for signal extraction in the presence of coloured noise. The problem is to estimate the number of unknown frequencies and the unknown frequencies. The analogous time seri...

Compressive sampling is a well-known approach to reconstruct sparse signals based on a limited number of measurements. In spectrum sensing applications for cognitive radio though, only reconstruction of the power spectrum of the signal is required, instead of the signal itself. In this paper, we present a new method for power spectrum reconstruction based on samples produced by a sub-Nyquist ra...

Modal parameters can reflect the dynamic characteristics of structure and be used to control vibration. To identify operational modal linear slow-time-varying structures only from non-stationary vibration response signals, a method based on moving window locality preserving projections (MWLPP) algorithm is proposed. Based theory “time freeze”, selects fixed length takes displacement signal in e...

condition monitoring of bldc motors due to their important applications is gaining more and more significance. rotor eccentricity is one of the most important sources of faults in these motors. up to now, detection methods of this fault under nonstationary conditions are limited to complicated and time-consuming methods using wavelets and cohen class algorithms which are difficult to implement ...

A signal is stationary if its statistical characteristics do not change with time. Signals of practical interest often do not comply with this requirement [1]. It has been quit difficult to satisfactorily handle non-stationary signals using conceptualizations based on stationarity, as it is assumed, for example, by classical Fourier transform. Nonstationary signals justify the need for joint ti...

The early cytokines production in response to live logarithmic and stationary phase promastigotes of Leishmania major was examined on the peripheral blood cells of the healthy individuals. Whole blood cultures were stimulated by either logarithmic or stationary phase promastigotes. IFN- and IL-10 productions were assessed by specific sandwich ELISA. The results showed that the logarithmic prom...

the early cytokines production in response to live logarithmic and stationary phase promastigotes of leishmania major was examined on the peripheral blood cells of the healthy individuals. whole blood cultures were stimulated by either logarithmic or stationary phase promastigotes. ifn- and il-10 productions were assessed by specific sandwich elisa. the results showed that the logarithmic prom...

At present, in the feature extraction of non-stationary vibration signals, many timefrequency analytic methods have emerged to meet the further need of non-stationary signal analysis such as Wavelet Transform (WT), Short Time Fourier Transform (STFT), WignerVille Distribution (WVD), Empirical Mode Decomposition (EMD), Ensemble Empirical Mode Decomposition (EEMD) and so on. However, these time-f...

Cognitive radio is an emerging technology proposing the concept of dynamic spectrum access as a solution to the looming problem of spectrum scarcity caused by the growth in wireless communication systems. Under the proposed concept, nonlicensed, secondary users (SU) can access spectrum owned by licensed, primary users (PU) so long as interference to PU are kept minimal. Spectrum sensing is a cr...

Abstract – Nonparametric density estimation is considered for a discretely observed stationary continuous-time process. For each of three given time sampling procedures either random or deterministic, we establish that histograms and frequency polygons can reach the same optimal L2-rates as in the independent and identically distributed case. Moreover, thanks to a suitable “high frequency” samp...