Search results for " NOISE"
showing 10 items of 659 documents
Transient dynamics in driven long Josephson junctions.
2013
The switching time from the superconductive metastable state of a long Josephson junction (LJJ)[1] is computationally analyzed in the framework of the perturbed sine-Gordon equation. The model includes an external bias current term and a stochastic noise source, i.e. a Lévy noise term. The effects of this noise on the mean escape time (MET) from the superconductive state are analyzed. The investigation is performed by considering a wide range of values of system parameters and different noise statistics: Gaussian, Cauchy-Lorentz and Lévy-Smirnov[2]. We found evidence of well known noise induced phenomena on the MET behavior, that is the noise enhanced stability (NES) and resonant activation…
A Social Spider Optimisation Algorithm for 3D Unmanned Aerial Base Stations Placement
2020
International audience; In recent years, the use of drones as aerial base stations (ABS) has attracted the attention of both scientific and industrial communities as a promising solution to enhance the network coverage. However, their deployment brings out many challenges and restrictions. In this work, we model a realistic, constrained scenario where unmanned aerial vehicles (UAVs) are used as ABSs along with traditional ground base stations (GBSs) to extend their coverage. We propose a scalable and efficient social spider optimization (SSO) algorithm that determines the placement of UAVs and their association with both user equipments (UEs) and GBSs. Extensive computational experiments we…
Accelerated Aging and Age-Related Diseases (CVD and Neurological) due to Air Pollution and Traffic Noise Exposure
2021
The World Health Organization estimates that only approximately 25% of diversity in longevity is explained by genetic factors, while the other 75% is largely determined by interactions with the physical and social environments. Indeed, aging is a multifactorial process that is influenced by a range of environmental, sociodemographic, and biopsychosocial factors, all of which might act in concert to determine the process of aging. The global average life expectancy increased fundamentally over the past century, toward an aging population, correlating with the development and onset of age-related diseases, mainly from cardiovascular and neurological nature. Therefore, the identification of de…
Noise annoyance is associated with depression and anxiety in the general population : the contribution of aircraft noise
2015
BACKGROUND: While noise annoyance has become recognized as an important environmental stressor, its association to mental health has hardly been studied. We therefore determined the association of noise annoyance to anxiety and depression and explored the contribution of diverse environmental sources to overall noise annoyance. PATIENTS AND METHODS: We investigated cross-sectional data of n = 15.010 participants of the Gutenberg Health Study (GHS), a population-based, prospective, single-center cohort study in Mid-Germany (age 35 to 74 years). Noise annoyance was assessed separately for road traffic, aircraft, railways, industrial, neighborhood indoor and outdoor noise ("during the day"; "i…
Early Alterations of Endothelial Nitric Oxide Synthase Expression Patterns in the Guinea Pig Cochlea After Noise Exposure.
2019
Constitutively expressed endothelial nitric oxide synthase (eNOS) is supposed to play a role in noise-induced nitric oxide (NO)-production. It is commonly known that intense noise exposure results in inducible NOS (iNOS) expression and increased NO-production, but knowledge about a contribution of the eNOS isoform is still lacking. Effects of noise exposure on eNOS immunolabeling were determined in male guinea pigs ( n=24). For light microscopic analysis, 11 animals were exposed to 90 dB for 1 hr and 6 animals were used as controls. After exposure, eNOS immunostaining was performed on paraffin sections, and the staining intensities were quantified for 4 cochlear regions. For electron micro…
Coronary CT angiography using iterative reconstruction vs. filtered back projection: evaluation of image quality.
2014
To compare image quality of iterative reconstruction algorithm(IRIS) vs. standard filtered back projection(FBP) reconstruction in CT Coronary Angiography (CTCA).Thirty-four consecutive patients underwent CTCA for suspected or known CAD with Dual-Source CT (DSCT-Flash, Siemens). All datasets were reconstructed with 0.75/0.4 and 0.6/0.4 mm slice thickness/increment, using three standard FBP kernels (B26-B30-B46) and three comparable IRIS algorithms (I26-I30-I46). Vascular attenuation and noise were measured. CT vascular attenuation values [HU] were measured in: ascending aorta (Ao), right (RCA) and left (LCA) coronary artery, respectively. Signal-to-noise (SNR) and contrast-to-noise (CNR) rat…
Associations of long-term exposure to air pollution and road traffic noise with cognitive function : an analysis of effect measure modification
2017
Background: Adverse effects of traffic-related air pollution (AP) and noise on cognitive functions have been proposed, but little is known about their interactions and the combined effect of co-exposure. Methods: Cognitive assessment was completed by 4086 participants of the population-based Heinz Nixdorf Recall cohort study using five neuropsychological subtests and an additively calculated global cognitive score (GCS). We assessed long-term residential concentrations for size-fractioned particulate matter (PM) and nitrogen oxides with land use regression. Road traffic noise (weighted 24-h (LDEN) and night-time (LNIGHT) means) was assessed according to the EU directive 2002/49/EC. Linear r…
Behavioural and biochemical stress responses of Palinurus elephas after exposure to boat noise pollution in tank
2014
This study examined the effects of boat noise on the behavioural and biochemical parameters of the Mediterranean spiny lobster (Palinurus elephas).The experiment was conducted in a tank equipped with a video and audio recording system. 18 experimental trials, assigned to boat noise and control conditions, were performed using lobsters in single and group of 4 specimens. After a 1. h habituation period, we audio- and video-recorded the lobsters for 1. h. During the experimental phase, the animals assigned to the boat groups were exposed to boat noise pollution (a random sequence of boat noises). Exposure to the noise produced significant variations in locomotor behaviours and haemolymphatic …
Mathematical models for the diffusion magnetic resonance signal abnormality in patients with prion diseases
2014
In clinical practice signal hyperintensity in the cortex and/or in the striatum on magnetic resonance (MR) diffusion-weighted images (DWIs) is a marker of sporadic Creutzfeldt–Jakob Disease (sCJD). MR diagnostic accuracy is greater than 90%, but the biophysical mechanisms underpinning the signal abnormality are unknown. The aim of this prospective study is to combine an advanced DWI protocol with new mathematical models of the microstructural changes occurring in prion disease patients to investigate the cause of MR signal alterations. This underpins the later development of more sensitive and specific image-based biomarkers. DWI data with a wide a range of echo times and diffusion weightin…
Contrast sensitivity of the visual system in speckle imagery
1994
The contrast sensitivity function (CSF) of the whole visual system is determined with the use of coherent diffuse illumination. This function provides supplementary data about the effect of speckle on the ability of the visual system to perceive the spatial information contained in an image. The results show that speckle not only prevents perception of the finest details (highest frequencies) but also reduces the visibility of lower frequencies (especially where contrast is low). The difference between the CSF's determined with and without speckle is quantitatively very important. And the ratio between the two CSF's is a measure of the retinal ability to perceive contrast in the presence of…