Search results for "deviation"
showing 10 items of 367 documents
Multi-channel and multi-angle algorithms for estimating sea and land surface temperature with ATSR data
1996
Abstract A study has been carried out using LOWTRAN-7 simulations of the Along-Track Scanning Radiometer (ATSR) data at 11 and 12 μm wavelengths to compare the merits of the multi-angle technique with those of the currently used multi-channel technique (split-window method) to retrieve both sea surface temperature (SST) and land surface temperature (LST). To this end a simple single-channel double-angle viewing model is presented, which relates actual surface temperature to the two brightness temperatures measured from space in the two views of interest (ATSR nadir and forward). Subsequently, statistical retrieval coefficients for the double angle and split-window techniques are derived via…
Time, frequency and information domain analysis of short-term heart rate variability before and after focal and generalized seizures in epileptic chi…
2019
OBJECTIVE In this work we explore the potential of combining standard time and frequency domain indexes with novel information measures, to characterize pre- and post-ictal heart rate variability (HRV) in epileptic children, with the aim of differentiating focal and generalized epilepsy regarding the autonomic control mechanisms. APPROACH We analyze short-term HRV in 37 children suffering from generalized or focal epilepsy, monitored 10 s, 300 s, 600 s and 1800 s both before and after seizure episodes. Nine indexes are computed in time (mean, standard deviation of normal-to-normal intervals, root mean square of the successive differences (RMSSD)), frequency (low-to-high frequency power rati…
Land surface temperature retrieval from LANDSAT TM 5
2004
In this paper, three methods to retrieve the land surface temperature (LST) from thermal infrared data supplied by band 6 of the Thematic Mapper (TM) sensor onboard the Landsat 5 satellite are compared. The first of them lies on the estimation of the land surface temperature from the radiative transfer equation using in situ radiosounding data. The others two are the mono-window algorithm developed by Qin et al. [International Journal of Remote Sensing 22 (2001) 3719] and the single-channel algorithm developed by Jime´nez-Mun˜oz and Sobrino [Journal of Geophysical Research 108 (2003)]. The land surface emissivity (LSE) values needed in order to apply these methods have been estimated from a…
(Supplementary Table 1) 230Th/U results for stalagmite Cuba Grande (CG) from Pinar del Rio
2010
We present 22 U-series ages for a stalagmite from north-western Cuba based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) and thermal ionisation mass spectrometry (TIMS). Our results reveal that the stalagmite continuously grew within the last ~1400a. Low uranium content of the sample and thus, extremely low 230Th concentrations limit the precision and accuracy of 230Th/U-dating by TIMS. Samples measured by MC-ICPMS show a high variability of 232Th content along the growth axis with some sections significantly affected by initial 230Th from a detrital phase. An a-priori bulk earth ratio for (238U/232Th) cannot be used to accurately account for this initial 230Th.…
A GIS-based approach for gully erosion susceptibility modelling: a test in Sicily, Italy
2013
The aim of this study is to analyze the susceptibility conditions to gully erosion phenomena in the Magazzolo River basin and to test a method that allows for driving the factors selection. The study area is one of the largest (225 km2) watershed of southern Sicily and it is mostly characterized by gentle slopes carved into clayey and evaporitic sediments, except for the northern sector where carbonatic rocks give rise to steep slopes. In order to obtain a quantitative evaluation of gully erosion susceptibility, statistical relationships between the spatial distributions of gullies affecting the area and a set of twelve environmental variables were analyzed. Stereoscopic analysis of aerial …
Cuando el exceso de protección se convierte en un problema: factores globales que inciden en el desarrollo de riesgos en los adolescentes
2014
El presente artículo, reflexiona en torno al hecho común y cada vez más representativo sobre cómo adolescentes, que proceden de entornos familiares socialmente ajustados y envueltos en garantías, acaban siendo protagonistas de prácticas de riesgo que derivan en su propio deterioro. Podemos afirmar, que los nuevos tiempos amparados en las garantías de la globalización, han logrado adiestrar a estos nuevos adolescentes acomodados, socializados en espacios de bienestar, preservados ante cualquier contingencia y vacunados contra las inercias de la exclusión. Como decimos, los adolescentes viven con mucha protección y muchas posibilidades, pero estas garantías no evitan los problemas. Así, algun…
The topographic diagnosis of acquired nystagmus in brainstem disorders.
2002
Evidence is presented for a clinical classification of central vestibular syndromes according to the three major planes of action of the vestibulo-ocular reflex (VOR): yaw, pitch, and roll. The plane-specific vestibular syndromes are determined by ocular motor, postural, and perceptual signs. Yaw plane signs are horizontal nystagmus, horizontal past pointing, rotational and lateral body falls to the right or to the left, and horizontal deviation of perceived straight-ahead. Pitch plane signs are upbeat/downbeat nystagmus, forward/backward tilts and falls, and upward or downward deviations of the perceived horizontal. Roll plane signs are torsional nystagmus, skew deviation, ocular torsion, …
Apparent and Real Distribution in GPC (Experiments with PMMA Samples)
1971
Abstract Molecular weight distribution curves obtained by GPC are broadened if concentration and flow rate are fixed in the usual range. Therefore, the apparent nonuniformity U app of the samples is larger than the real non-uniformity U = (Mw/Mn) −1. For a number of fractionated and unfractionated samples of polymethyl methacrylate we determined M n and M w by osmotic, light-scattering, and viscosity measurements. Thus, the real value of U can be compared to U app obtained by GPC at different concentrations and flow rates, υ. The excess nonuniformity U exc is evaluated as function of concentration c, polydispersity, molecular weight, and flow rate. For c = 0 and υ = 0, U exc is not far from…
Modified Gaussian models applied to the description and deconvolution of peaks in chiral liquid chromatography.
2020
Abstract The description of the profiles of chromatographic peaks has been studied extensively, with a large number of proposed mathematical functions. Among them, the accuracy achieved with modified Gaussian models that describe the deviation of an ideal Gaussian peak as a change in the peak variance or standard deviation over time, has been highlighted. These models are, in fact, a family of functions of different complexity with great flexibility to adjust chromatographic peaks over a wide range of asymmetries and shapes. However, an uncontrolled behaviour of the signal may occur outside the region being fitted, forcing the use of different strategies to overcome this problem. In this wo…
Phase partitioning of aerosol particles in clouds at Kleiner Feldberg
1994
The partitioning of aerosol particles between cloud droplets and interstitial air by number and volume was determined both in terms of an integral value and as a function of size for clouds on Mt. Kleiner Feldberg (825 m asl), in the Taunus Mountains north-west of Frankfurt am Main, Germany. Differences in the integral values and the size dependent partitioning between two periods during the campaign were observed. Higher number and volume concentrations of aerosol particles in the accumulation mode were observed during Period II compared to Period I. In Period I on average 87 ± 11% (±one standard deviation) and 73 ± 7% of the accumulation mode volume and number were incorporated into cloud…