The NASA goal of reducing external aircraft noise by 10 dB in the near-term presents the acoustics community with an enormous challenge. This report identifies technologies with the greatest potential to reduce airframe noise. Acoustic and aerodynamic effects will be discussed, along with the likelihood of industry accepting and implementing the different technologies. We investigate the lower ...

We present an exemplar-based method for noise reduction using missing data imputation: A noise-corrupted word is sparsely represented in an over-complete basis of exemplar (clean) speech signals using only the uncorrupted time-frequency ele­ ments of the word. Prior to recognition the parts of the spectro­ gram dominated by noise are replaced by clean speech estimates obtained by projecting the...

background: noise as a most common harmful physical agent in workplaces has some effects on the exposed persons such as hearing threshold reduction, increasing blood pressure, and interference with the speech. the adverse side-effect of noise is one of the scientific areas that have seldom been considered by researchers. the aim of this study was to investigate the effects of occupational noise...

Introduction: SPECT is a diagnostic imaging technique the main disadvantage of which is the existence of Poisson noise. So far, different methods have been used by scientists to improve SPECT images. The Wavelet Transform is a new method for de-noising which is widely used for noise reduction and quality enhancement of images. The purpose of this paper is evaluation of noise reduction in SPECT ...

We present an optical flow based method for noise reduction in image sequences. To prevent artefacts caused by optical flow imperfections, we propose a method to estimate these imperfections. We use the estimation to adaptively choose either a temporal or a spatial based noise reduction algorithm to be applied in different image zones. Our results have shown that an important noise reduction ca...

The estimation of the standard deviation of noise contaminating an image is a fundamental step in wavelet-based noise reduction techniques. The method widely used is based on the mean absolute deviation (MAD). This model-based method assumes specific characteristics of the noise-contaminated image component. Three novel and alternative methods for estimating the noise standard deviation are pro...

We propose a new image denoising method with shrinkage. In the proposed method, small blocks in an input image are projected to the space that makes projection coefficients sparse, and the explicitly evaluated sparsity degree is used to control the shrinkage threshold. On average, the proposed method obtained higher quantitative evaluation values (PSNRs and SSIMs) compared with one of the state...

This paper deals with a noisy speech enhancement technique based on the fusion of auditory and visual information. We first present the global structure of the system, and then we focus on the tool we used to melt both sources of information. The whole noise reduction system is implemented in the context of vowel transitions corrupted with white noise. A complete evaluation of the system in thi...