Search results for "Extrapolation"
showing 10 items of 150 documents
Rotational spectra of isotopic species of silyl fluoride. Part II: theoretical and empirical equilibrium structure
2010
Abstract The equilibrium structure of silyl fluoride, SiH 3 F, has been reinvestigated using both theoretical and experimental data. With respect to the former, quantum-chemical calculations at the coupled-cluster level have been employed together with extrapolation to the basis set limit, consideration of higher excitations in the cluster operator, and inclusion of core correlation as well as relativistic corrections ( r (Si–F) = 1.5911 A, r (Si–H) = 1.4695 A, and ∠FSiH = 108.30°). A semi-experimental equilibrium structure has been determined based on the available rotational constants for the various isotopic species of silyl fluoride ( 28 SiH 3 F, 28 SiD 3 F, 29 SiH 3 F, 29 SiD 3 F, 30 S…
Inferring True Species Richness and Complete Abundance Distribution in Six Reef-fish Communities from Red-sea, Using the Numerical Extrapolation of I…
2019
Even when ecological communities are incompletely sampled (which is most frequent in practice, at least for species-rich assemblages including many rare species), it remains possible to retrieve much more information than could be expected first, by applying numerical extrapolation to incomplete field data. Indeed, recently developed procedures of numerical extrapolation of partial samplings now allow to estimate, with fair accuracy, not only the number of the still unrecorded species but, moreover, the distribution of abundances of each of these unrecorded species, thereby making available the full range of the Species Abundance Distribution, despite dealing with incomplete data only. In t…
Discharge estimation combining flow routing and occasional measurements of velocity
2011
A new procedure is proposed for estimating river discharge hydrographs during flood events, using only water level data at a single gauged site, as well as 1-D shallow water modelling and occasional maximum surface flow velocity measurements. One-dimensional diffusive hydraulic model is used for routing the recorded stage hydrograph in the channel reach considering zero-diffusion downstream boundary condition. Based on synthetic tests concerning a broad prismatic channel, the “suitable” reach length is chosen in order to minimize the effect of the approximated downstream boundary condition on the estimation of the upstream discharge hydrograph. The Manning’s roughness coefficient is calibra…
Functional Extrapolations to Tame Unbound Anions in Density-Functional Theory Calculations
2019
Standard flavors of density-functional theory (DFT) calculations are known to fail in describing anions, due to large self-interaction errors. The problem may be circumvented using localized basis sets of reduced size, leaving no variational flexibility for the extra electron to delocalize. Alternatively, a recent approach exploiting DFT evaluations of total energies on electronic densities optimized at the Hartree-Fock (HF) level has been reported, showing that the self-interaction-free HF densities are able to lead to an improved description of the additional electron, returning affinities in close agreement with the experiments. Nonetheless, such an approach can fail when the HF densitie…
Estudio experimental comparado de marcadores bioquímicos en la infección por Fasciola hepatica y F. gigantica
2017
Fascioliasis is caused by the genetically and phenotypically very close Fasciola hepatica and F. gigantica. The latter, always considered secondary in human infection, appears nowadays increasingly involved in human endemic areas of Africa and Asia. Unfortunately, little is known about the pathogenicity of this liver fluke species, mainly due to difficulties assessing the moment of a patient's infection in the anamnesis and in the differential diagnosis with F. hepatica. This is the first experimental study comparing F. hepatica and F. gigantica in a long-term study of up to 24 weeks with genotypically and phenotypically standardised fluke strains in the same animal model host, the Guirra s…
An Emulator Toolbox to Approximate Radiative Transfer Models with Statistical Learning
2015
Physically-based radiative transfer models (RTMs) help in understanding the processes occurring on the Earth’s surface and their interactions with vegetation and atmosphere. When it comes to studying vegetation properties, RTMs allows us to study light interception by plant canopies and are used in the retrieval of biophysical variables through model inversion. However, advanced RTMs can take a long computational time, which makes them unfeasible in many real applications. To overcome this problem, it has been proposed to substitute RTMs through so-called emulators. Emulators are statistical models that approximate the functioning of RTMs. Emulators are advantageous in real practice because…
Mater semper certa est ? Passé, présent, avenir d'un adage, Actes du colloque de Dijon des 24-25 novembre 2016, K. Fiorentino et A. Fiorentino (dir.)…
2018
International audience; La preuve de la filiation maternelle, résumée par l’un des adages les plus connus en droit de la famille, Mater semper certa est, a pendant longtemps semblé être une évidence voulue par la nature, donc ne posant que peu de problème juridique, à l’inverse de la paternité. Pourtant, l’évidence a-t-elle toujours été aussi flagrante ? Pourquoi ressentir le besoin de forger un adage ? Quelle fut sa valeur et a-t-il toujours parfaitement reflété la réalité ? Force est de constater que si la maternité est certaine, la preuve de celle-ci se heurte à plusieurs difficultés tant matérielles que processuelles. Il s’agit donc ici de s’interroger sur la place accordée en droit à l…
La faune des insectes à larves fonceuses de mines foliaires : un pré-inventaire réalisé dans la partie bourguignonne du projet de Parc national des f…
2017
10 pages; National audience
Biodiversité : comment tirer le meilleur parti des inventaires incomplets : illustrations de la procédure d'extrapolation au moyen de quelques exempl…
2016
14 pages; National audience
Hadronic light-by-light contribution to $(g-2)_\mu$ from lattice QCD with SU(3) flavor symmetry
2020
We perform a lattice QCD calculation of the hadronic light-by-light contribution to $(g-2)_\mu$ at the SU(3) flavor-symmetric point $m_\pi=m_K\simeq 420\,$MeV. The representation used is based on coordinate-space perturbation theory, with all QED elements of the relevant Feynman diagrams implemented in continuum, infinite Euclidean space. As a consequence, the effect of using finite lattices to evaluate the QCD four-point function of the electromagnetic current is exponentially suppressed. Thanks to the SU(3)-flavor symmetry, only two topologies of diagrams contribute, the fully connected and the leading disconnected. We show the equivalence in the continuum limit of two methods of computin…