Search results for "Spectral"
showing 10 items of 3116 documents
Signal characteristics of EMG during fatigue
1977
Electromyographic (EMG) activity of m. rectus femoris muscle was registered from young male and female subjects during maintained isometric knee extension at 60% of maximal voluntary contraction. The following EMG parameters were analyzed for the entire fatigue time: integrated EMG (IEMG), averaged motor unit potential (AMUP) and power spectral density function (PSDF). The results indicated a slight but continuous rise of IEMG during the fatigue period. AMUP showed sensitivity to fatigue with increase in amplitude, rise time, and number of spikes counted. PSDF was also easily affected by fatigue so that the total power density curve was shifted towards lower frequencies with a high frequenc…
Acoustics of snoring and automatic snore sound detection in children
2017
Objective Acoustic analyses of snoring sounds have been used to objectively assess snoring and applied in various clinical problems for adult patients. Such studies require highly automatized tools to analyze the sound recordings of the whole night's sleep, in order to extract clinically relevant snore- related statistics. The existing techniques and software used for adults are not efficiently applicable to snoring sounds in children, basically because of different acoustic signal properties. In this paper, we present a broad range of acoustic characteristics of snoring sounds in children (N = 38) in comparison to adult (N = 30) patients. Approach Acoustic characteristics of the signals we…
Bispectral index variations in patients with neurological deficits during awake carotid endarterectomy
2010
The bispectral index (BIS) is derived from the EEG and therefore may be useful to diagnose intraoperative cerebral ischaemia. This study was undertaken to investigate BIS changes in awake patients with and without neurological deficits during carotid endarterectomy under regional anaesthesia.Seventy consecutive carotid endarterectomies under regional anaesthesia were divided into two surgical groups: patients with and patients without neurological deficits. Patients' neurological status was evaluated and neurological deficits were compared with BIS values. Measurements were made at different surgical stages: baseline, after sedation, at the beginning of surgery, at preclamping, at the 3 min…
Effect of sport-tinted contact lenses for contrast enhancement on retinal straylight measurements
2008
PURPOSE: To investigate the effect of two tinted contact lenses (CL) designed for outdoor sports activity on the psychometric determination of retinal straylight using the compensation comparison method. METHODS: Thirteen emmetropic subjects were randomly fitted with two different tinted Nike Maxsight (Bausch & Lomb, Rochester, NY, USA) CL in one eye, while the contralateral eye was fitted with a clear lens made of the same material (Optima 38, Bausch & Lomb). Three valid straylight measurements were taken on each eye before and a few minutes after lens insertion, when lens stabilization had occurred. RESULTS: The subjects' mean straylight values were 0.90 +/- 0.09 at baseline and 0.95 +/- …
Genetic colour variation visible for predators and conspecifics is concealed from humans in a polymorphic moth
2022
The definition of colour polymorphism is intuitive: genetic variants express discretely coloured phenotypes. This classification is, however, elusive as humans form subjective categories or ignore differences that cannot be seen by human eyes. We demonstrate an example of a 'cryptic morph' in a polymorphic wood tiger moth (Arctia plantaginis), a phenomenon that may be common among well-studied species. We used pedigree data from nearly 20,000 individuals to infer the inheritance of hindwing colouration. The evidence supports a single Mendelian locus with two alleles in males: WW and Wy produce the white and yy the yellow hindwing colour. The inheritance could not be resolved in females as t…
Extracting science from Mössbauer spectroscopy on Mars
2003
[1] Deployment by the Mars Exploration Rovers of backscatter Mossbauer spectrometers offers an incredible opportunity to (1) elucidate the iron mineralogies of rocks, soils, and atmospheric dust and (2) gain insight into the physical event by which the mineralogy came into existence and consequently acquire information having potential for yielding ancient planetary history relevant to broad issues including the question of life. Determining the mineralogy is done by subjecting raw data to reduction algorithms and generating products known as Mossbauer parameters, which are highly characteristic. Mixed mineralogies are treated through deconvolution. Through being able to exploit Mossbauer m…
On simfitting MER Mössbauer data to characterize Martian hematite
2010
Mossbauer spectra of Eagle Crater outcrop rocks in Meridiani Planum were acquired by the Mars Exploration Rover (MER) Opportunity. Sixty spectra, containing ~20 to 60% hematite by area, were simultultaneously fit (simfit) in a self-consistent manner to a single chi-squared minimum, where relations among parameters from different spectra were defined for both sol (Martian day) and acquisition temperature (200–280 K). Different spectral models were compared, hematite being modeled optimally with two sextets. Sextet S1 (~35% of total sextet area) has narrower linewidths, a larger magnetic hyperfine field, and a quadrupole shift that changes smoothly from positive to negative values as the temp…
Convolutional Neural Networks for Multispectral Image Cloud Masking
2020
Convolutional neural networks (CNN) have proven to be state of the art methods for many image classification tasks and their use is rapidly increasing in remote sensing problems. One of their major strengths is that, when enough data is available, CNN perform an end-to-end learning without the need of custom feature extraction methods. In this work, we study the use of different CNN architectures for cloud masking of Proba-V multispectral images. We compare such methods with the more classical machine learning approach based on feature extraction plus supervised classification. Experimental results suggest that CNN are a promising alternative for solving cloud masking problems.
Multiplicity dependence of light (anti-)nuclei production in p–Pb collisions at sNN=5.02 TeV
2020
The measurement of the deuteron and anti- deuteron production in the rapidity range −1 < y < 0 as a function of transverse momentum and event multiplicity in p–Pb collisions at √sNN= 5.02 TeV is presented. (Anti-)deuterons are identified via their specific energy loss dE/dxand via their time-of-flight. Their production in p–Pb collisions is compared to pp and Pb–Pb collisions and is discussed within the context of thermal and coalescence models. The ratio of integrated yields of deuterons to protons (d/p) shows a significant increase as a function of the charged-particle multiplicity of the event starting from values similar to those observed in pp collisions at low multiplicities and appro…
Photoinduced mass transfer in amorphous As 2 S 3 films
2011
The surface relief grating formation in amorphous As2S3 films strongly depends on the polarization state of recording beams. The surface relief grating formation efficiency of s-s and p-p recording beam combination can be essentially enhanced by additional illumination with orthogonal polarization. It is shown that the direction of mass transport on the film surface is determined by the direction of light electric vector (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)