Magnetotellurics is an exploration method which is based on measurement of natural electric and magnetic fields of the Earth and is increasingly used in geological applications, petroleum industry, geothermal sources detection and crust and lithosphere studies. In this work, discrete wavelet transform of magnetotelluric signals was performed. Discrete wavelet transform decomposes signals into coefficients in multi-scales. noise and signal portions are separable in multi-scale mode. Therefore, noise can be discarded in each scale; a threshold value is constructed dependent to coefficients of the scale then, the noise coefficients are discarded by thresholding the coefficients with the proper values. Proportional threshold values can be used to remove white and 1/f noise from time series. After that, a new signal is constructed using clean coefficients. This method is widely used in various fields of sciences from image processing to seismic studies. This work tried to show the effectiveness of this technique in decreasing pervasive noise from magnetotelluric signals. The results emphasized the advantageous effect of wavelet techniques in magnetotelluric data noise removing process.

The main purpose of this paper is to introduce a new method to analyze the effects of the white and Colored noise perturbations on the robotic arms. To show the efficiency of the presented idea the simplest manipulator, two link robotic arm, is considered. Most previous noise analyses of manipulators are done using mechanical or electrical modeling. Applying exact kinematic equations of the robots is the novelty of the proposed research. For this purpose, by adding white and Colored noise terms in each angle function of the robotic arm, the end effector linear velocity is studied. Also, mechanical variation's effect on the final velocity in noisy space is considered. The longer the length of the links, the more the noise effect. Analysis of simulation results shows that the root mean square error in 2nd order is more than when angle functions are of the first order. Also, the mean square error is less when Colored noise is added in comparison to the white noise. The Matlab programming is used to perform numerical examples to show the efficiency and accuracy of the presented idea.

In this work, aluminum electrode was Colored with Eriochrom black, using frequency electrochemical noise analysis technique of the FFT impedance response, corrosion resistance of the Colored electrode in 0.1 M sulfuric acid solution have been investigated. Scanning Electron Microcopy, also used for monitoring the electrodes surfaces. The electrochemical noise analysis FFT impedance measurements showed that under some applied conditions, coloring aluminum with Eriochrom black could reduce corrosion resistance of aluminum. Where it was realized that application a potential ramp (in range of 0 to 3000 mV) produces an oxidation response associated with a significant noise in the FFT spectrum for the Colored aluminum. The noise magnitude in the spectrum strongly depends on the applied conditions during anodizing, coloring and sealing stages. The noise analysis of the impedance and SEM images of the surface Colored aluminum, showed a correlation between the number of pitting and the noise in the impedance of the surface.

In this paper, a new method for determining the number of coherent/correlated signals in the presence of Colored noise is proposed which is based on the Eigen Increment Threshold (EIT) method. First, we present a new approach which combines EIT criterion and eigenvalue correction. The simulation results show that the new method estimates the number of noncoherent signals in the presence of Colored noise with higher detection probability respect to MDL, AIC, EGM and conventional EIT. In addition, to apply the proposed EIT algorithm to detect the number of sources in the case of coherent and/or correlated sources, a spatial smoothing preprocessing is added. In this case, simulation results show 100% detection probability for signal to noise ratios greater than -5dB. Final version of the proposed EIT-based method is a simple and efficient way to increase the detection probability of EIT method in the presence of Colored noise considering either coherent/correlated or noncoherent sources.