Search results for "standard deviation"
showing 10 items of 282 documents
Gas sensors arrays (electronic noses) : a study about the speed/accuracy ratio
2000
Abstract New Fingerprint Mass Spectra (FMS) systems claim for a higher precision, a reduced analysis time, and a lower drift, compared with Gas Sensors Arrays ‘Electronic Noses’. We demonstrated in this study that metal oxide gas sensors may have highly improved performances for both accuracy and run time, when used in optimum conditions. The different noise components were quantified referring to popular words (equivalent of ethanol concentration) using the transfer function of the sensor. It was pointed out that sample surrounding greatly affects the noise level, and that the signal-to-noise ratio may be dramatically increased, reducing the distortion generally assessed between sensor and…
Performances of neural networks for deriving LAI estimates from existing CYCLOPES and MODIS products
2008
International audience; This paper evaluates the performances of a neural network approach to estimate LAI from CYCLOPES and MODIS nadir normalized reflectance and LAI products. A data base was generated from these products over the BELMANIP sites during the 2001-2003 period. Data were aggregated at 3 km x 3 km, resampled at 1/16 days temporal frequency and filtered to reject outliers. VEGETATION and MODIS reflectances show very consistent values in the red, near infrared and short wave infrared bands. Neural networks were trained over part of this data base for each of the 6 MODIS biome classes to retrieve both MODIS and CYCLOPES LAI products. Results show very good performances of neural …
Observation of Higgs boson production in association with a top quark pair at the LHC with the ATLAS detector
2018
Physics letters / B 784, 173 - 191 (2018). doi:10.1016/j.physletb.2018.07.035
The bending triad of the quasi-spherical top molecule SO2F2 in the 550 cm(-1) region
2006
International audience; The analysis of the v(3)/v(7)/v(9) bending triad of SO2F2 has been recently performed with the Watson's Hamiltonian up to octic terms employing 79 rovibrational parameters but including only the first order Coriolis interaction terms, fixed to ab initio values [H. Burger, J. Demaison, F. Hegelund, L. Margules, I. Merke, J. Mol. Struct. 612 (2002) 133-141]. Since SO2F2 is a quasi-spherical top, it can also be considered as derived from the SO42- sulfate ion. We have thus developed a new tensorial formalism in the O(3) > Td > C2v group chain [M. Rotger, V. Boudon, M. Loete, J. Mol. Spectrosc. 216 (2002) 297-307]. This approach allows a systematic development of rovibra…
Stochastic seismic analysis of offshore towers
1984
After a brief review of the main problems and the most common analysis methods for offshore structures, a method of analysis for offshore towers submerged in water and subjected to strong earthquake motions is proposed. Nonlinear drag effects as well as random non-stationary seismic excitations are considered by means of a linearization technique based on a particular step-by-step procedure. Using a discrete lumped-mass model, the standard deviations of nodal displacements and velocities are evaluated. The probability of not exceeding a defined threshold of nodal displacements is also computed.
Flow-injection spectrophotometric determination of amino acids based on an immobilised copper(II) -zincon system
1993
Abstract The flow-injection spectrophotometric determination of different amino acids was carried out by reaction with copper(II) ions entrapped in a polymeric material and filling a packed-bed reactor; the released copper(II), complexed with the amino acid, reacted with zincon in a basic medium producing a blue colour that was monitored at 600 nm. The method was applied to determine the contents of different amino acids in pharmaceutical formulations. The calibration graph for glycine was linear over the range 0.5–20 μg ml −1 with a relative standard deviation of 0.8% ( n = 6) at 10 μg ml −1 and a sample throughput of 108 h −1 .
Effect of traditional, microwave and industrial cooking on inositol phosphate content in beans, chickpeas and lentils
2003
An high-performance liquid chromatography method for determining inositol phosphate fractions was adapted to legumes. The validity of the method was assessed by estimating the following analytical parameters: linearity (linear response between 125 and 5000 microg inositol hexaphosphate (IP(6))/ml); instrumental precision and method precision (relative standard deviation, %) were 1.9% (IP(6)) for instrumental, and 2.5% (IP(6)) and 8.2% (IP(5)) for method precision. An accuracy was estimated by percentage recovery (72 +/- 3%). The application of this method to raw, conventional, microwave-cooked and ready-to-eat beans, chickpeas and lentils gave IP(6) contents ranging from 0.63 g/100 g dry ma…
Memory‐type control charts for censored reliability data
2023
Control charts are commonly used to monitor a process to detect undesirable changes. The main goal of this work is to propose exponentially weighted moving average (EWMA) and cumulative sum (CUSUM) control charts to track a process by utilizing type-I censored generalized exponential (GE) distributed data. In particular, the censored data are replaced with the conditional expected value (CEV). A comparison between CUSUM and CUSUM ignoring unobserved covariates (CUSUM-IUC) charts is also a part of this study. The GE distribution is considered due to its application in reliability analysis. The performance of the charts is evaluated by using the average run length along with the standard devi…
Characterizing Cavities in Model Inclusion Fullerenes: A Comparative Study
2001
Abstract: The fullerene-82 cavity is selected as a model system in order to test several methods for characterizing inclusion molecules. The methods are based on different technical foundations such as a square and triangular tessellation of the molecular surface, spherical tessellation of the molecular surface, numerical integration of the atomic volumes and surfaces, triangular tessellation of the molecular surface, and cubic lattice approach to the molecular volume. Accurate measures of the molecular volume and surface area have been performed with the pseudorandom Monte Carlo (MCVS) and uniform Monte Carlo (UMCVS) methods. These calculations serve as a reference for the rest of the meth…
<title>Additional usage possibilities for the computerized Hess screen</title>
2003
The purpose of the study was to work out a method how to use the computerized Hess screen in proximal vergence measurements. Proximal vergence or vergence due to knowledge of nearness is one of four independent components making up the total vergence response. Proximal vergence is expressed as a ratio - proximal convergence/test distance (PC/T). The computerized Hess screen is usually used to detect and to measure an ocular misalignment in patients with paralytic strabismus in different directions of gaze. The computerized Hess screen can be used to assess PC/T ratio in different directions of gaze, providing the open-loop disparity vergence and accommodation systems and assuming that tonic…