We discuss the shift invariant properties of a new implementation of the Discrete Wavelet Transform, which employs a dual tree of wavelet lters to obtain the real and imaginary parts of complex wavelet co-eecients. This introduces limited redundancy (2 m :1 for m-dimensional signals) and allows the transform to provide approximate shift invariance and directionally selective lters (properties l...

seismic waves are non-stationary due to its propagation through the earth. time-frequency transformsare suitable tools for analyzing non-stationary seismic signals. spectral decomposition can reveal thenon-stationary characteristics which cannot be easily observed in the time or frequency representationalone. various types of spectral decomposition methods have been introduced by some researche...

this study represents an intelligence procedure for diagnosis simultaneously avian newcastle disease virus, infection bronchitis virus and influenza using heart sound signal. for this aim, the chickens were divided into four groups. the first group was considered as control samples. the second, third and fourth groups were infected with newcastle disease virus, infection bronchitis and avian in...

The empirical mode decomposition (EMD) is a powerful tool for non-stationary signal analysis. It has been used successfully for sound and vibration signals separation and time-frequency representation. Linear time-frequency analysis (TFA) is another powerful tool for non-stationary signal. Linear TFAs, e.g. short-time Fourier transform (STFT) and wavelet transform (WT), depend linearly upon the...

there are two methods for identifying formation interface in oil wells: core analysis, which is a precise approach but costly and time consuming, and well logs analysis, which petrophysists perform, which is subjective and not completely reliable. in this paper, a novel coupled method was proposed to detect the formation interfaces using gr logs. second approximation level (a2) of gr log gained...

‎There are different feature extraction methods in brain-computer interfaces (BCI) based on Steady-State Visually Evoked Potentials (SSVEP) systems‎. ‎This paper presents a comparison of five methods for stimulation frequency detection in SSVEP-based BCI systems‎. ‎The techniques are based on Power Spectrum Density Analysis (PSDA)‎, ‎Fast Fourier Transform (FFT)‎, ‎Hilbert‎- ‎Huang Transform (H...

Weak suction and large vibrations indicate an Induced Draft Fan (IDF) problem. The Fast Fourier Transform (FFT) method cannot be applied to non-stationary vibration signals. Therefore, this study aims analyze signals for IDF at start-up so that the source of damage can found. research process begins with a brief measurement both bearing locations horizontal axial axes. Processing signal from us...