The aim of this paper is to minimize output phase noise for the pure signal synthesis in the frequency synthesizers. For this purpose, first, an exact mathematical model of phase locked loop (PLL) based frequency synthesizer is described and analyzed. Then, an exact closed-form formula in terms of synthesizer bandwidth and total output phase noise is extracted. Based on this formula, the phase ...

introduction hippocampus is a well-defined brain region involved in learning and memory. in spite of the existing reports on hippocampal-dependent memory impairment due to noise stress, to our knowledge, there is no study on the effect of noise stress on the size of hippocampus. the present study aimed to investigate the likely effects of chronic noise exposure on learning and the size of rat h...

the presence of noise in geophysical measurements has undesirable effects on the seismic data. one of the important problems in seismic data processing is attenuation of the noise to the desired form and keeping the original signal. contamination of seismic data with noise prevents obtaining a proper image of geological structures and seismic data interpretation. in some of the receivers the no...

unknown noise and artifacts present in medical signals with  non-linear fuzzy filter will be estimate and then removed. an adaptive neuro-fuzzy interference system which has a nonlinear  structure presented  for the noise function prediction by before samples. this paper is about a neuro-fuzzy method to estimate unknown noise of electrocardiogram (ecg) signal. adaptive neural combined with fuzz...

the effect of vanillin on the corrosion behavior of aa6061 al alloy in 3.5% nacl solution wasinvestigated using potentiodynamic polarization and electrochemical noise (en) techniques. vanillinoffers interesting possibilities for corrosion inhibition due to its nontoxicity and high solubility inaqueous media. the best inhibition effect at 200 ppm vanillin was a marked characteristic of theinhibi...

although there are many methods for image denoising, but partial differential equation (pde) based denoising attracted much attention in the field of medical image processing such as magnetic resonance imaging (mri). the main advantage of pde-based denoising approach is laid in its ability to smooth image in a nonlinear way, which effectively removes the noise, as well as preserving edge throug...

this paper presents a new control structure to reduce torque ripple in switched reluctance motor. although srm possesses many advantages in motor structure, it suers from large torque ripple that causes some problems such as vibration and acoustic noise. in this paper another control loop is added and torque ripple is de ned as an objective function. by using fuzzy sliding mode strategy, the dc...

background : cement industry has many process units. basically all of these units can be considered as a source of noise. since noise pollution is defined based on its offensive hearing effects, the importance of the noise sources depends directly on the number of workers in the unit.   materials and methods : an experimental study has been done at tehran cement factory to recognize and analyze...