the speech enhancement techniques are often employed to improve the quality and intelligibility of the noisy speech signals. this paper discusses a novel technique for speech enhancement which is based on singular value decomposition. this implementation utilizes a genetic algorithm based optimization method for reducing the effects of environmental noises from the singular vectors as well as t...

| In this tutorial paper, we review fundamentals of oscillator phase noise emphasizing its physical picture based on the concept of phase di®usion. This review is intended to provide an essential understanding of phase noise rather than a comprehensive phase noise modeling. We then summarize several phase noise reduction techniques for various types of oscillators. Index Terms|oscillators, phas...

this paper tries to determine efficiency of noise control method using fuzzy logic and based on collected data. from among various methods of noise control in workplace, sex methods (enclosure, installing noise absorber, enclosure and absorber, active, and administrative control, and personal protective equipment) were typically selected based on experts' judgment. for each of selected control ...

in this paper, a new high dynamic range digitally-controlled oscillator (dco) for all-dpll systems is proposed. the proposed dco is based on using a δς modulator as a digital-to-analog converter. using δς dac can provide a very high resolution (18-bit) control on the dco. the δς dac output is a 2-level pulse signal that needs to be filtered for cancelling the out of band shaped noise. the used ...

This article presents a wide-band suppression technique of flicker phase noise (PN) by means gate–drain shift in transformer-based complementary oscillator. We identify that after naturally canceling its second-harmonic voltage the operation itself, third-harmonic current entering capacitive path is now main cause asymmetry rising and falling edges, leading to <inline-formula xmlns:mml="http://...

Switched Biasing is presented as a technique for reducing the 1/f noise in MOSFETS. It exploits an intriguing physical effect: cycling a MOS transistor from strong inversion to accumulation reduces its 1/f noise!! The history of the discovery of the effect and the main experimental results obtained so far will be reviewed. Keywords—1/f noise, noise reduction, CMOS, oscillators, phase noise.

A noise reduction scheme for long haul fiber amplitude modulation (AM) systems is proposed and analyzed. Such systems suffer from intensity noise which results from interference between the (twice) Rayleigh scattered light and the directly transmitted beam. This interference converts the fundamental phase noise of the laser to intensity noise. We show that a strong phase modulation of the outpu...

introduction: one of the major problems in the development of nuclear medicine images is the presence of noise. the noise level in nuclear medicine images is usually reduced by the analysis of imaging data in a fourier transform environment. the main drawback of this environment belongs to low signal to noise ratio in high frequencies because removing noise frequencies may remove data and times...