The Southern Annular Mode (SAM, also known as the Antarctic Oscillation—AAO) explains most of climate variability in Hemisphere. A ring pattern mean sea level pressure (MSLP) or 500 hPa geopotential height around Antarctica characterizes SAM. Differences MSLP values between SH mid and high latitudes define positive negative SAM phases with impacts on atmospheric circulation. Thus, investigating...

This article presents a polynomial-based image compression scheme, which consists of using the color model (YUV) to represent contents and two-dimensional polynomial coding (first-order) with variable block size according correlation between neighbor pixels. The residual part for all bands is analyzed into two parts, most important (big) part, least (small) parts. Due significant subjective imp...

Digital modulation signals such as FSK are time-varying signals that can he represented in the time-frequency representation. The smooth lag-windowed Wigner-Ville distribution (SLWWVD) is proposed as a method to obtain accurate time-frequency representation of FSK signals used in HF (High Frequency) radio communications. Unlike existing time-frequency distributions such as the windowed Wigner-V...

In this thesis, we study the representation of speech signals and the estimation of information-theoretical measures from observations containing features of the speech signal. The main body of the thesis consists of four research papers. Paper A presents a compact representation of the speech signal that facilitates perfect reconstruction. The representation is constituted of models, model par...

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 ...