Search results for "correlation"

Search for collectivity with azimuthal J/ψ -hadron correlations in high multiplicity p–Pb collisions at √sNN = 5.02 and 8.16 TeV

2018

We present a measurement of azimuthal correlations between inclusive J/ψ and charged hadrons in p–Pb collisions recorded with the ALICE detector at the CERN LHC. The J/ψ are reconstructed at forward (p-going, ) and backward (Pb-going, ) rapidity via their decay channel, while the charged hadrons are reconstructed at mid-rapidity (). The correlations are expressed in terms of associated charged-hadron yields per J/ψ trigger. A rapidity gap of at least 1.5 units is required between the trigger J/ψ and the associated charged hadrons. Possible correlations due to collective effects are assessed by subtracting the associated per-trigger yields in the low-multiplicity collisions from those in the…

Nonequilibrium Green's function approach to strongly correlated few-electron quantum dots

2009

The effect of electron-electron scattering on the equilibrium properties of few-electron quantum dots is investigated by means of nonequilibrium Green's function theory. The ground and equilibrium states are self-consistently computed from the Matsubara (imaginary time) Green's function for the spatially inhomogeneous quantum dot system whose constituent charge carriers are treated as spin-polarized. To include correlations, the Dyson equation is solved, starting from a Hartree-Fock reference state, within a conserving (second-order) self-energy approximation where direct and exchange contributions to the electron-electron interaction are included on the same footing. We present results for…

2019

Aims To report corneal topometric and aberrometric values in mucopolysaccharidosis (MPS) and to investigate their correlation with biomechanical corneal parameters. Methods One randomly chosen eye of 20 MPS patients with no to moderate corneal clouding and one eye of 23 healthy controls with comparable age were prospectively included into this study. Corneal surface regularity was assessed by index of surface variance (ISV), -vertical asymmetry (IVA), -height asymmetry (IHA), -height decentration (IHD); keratoconus index (KI), central keratoconus index (CKI) and Zernike indices of anterior and posterior corneal surface using Scheimpflug imaging (Pentacam). Corneal resistance factor (CRF) an…

Estructura dimensional de las competencias del siglo XXI en los estudiantes universitarios de educación

2018

La nueva Sociedad del Conocimiento requiere nuevas competencias, que son conocidas como Competencias del siglo XXI. Estas competencias se subdividen en competencias de pensamiento y competencias de orden superior en tecnologías de información y comunicación. El objetivo de este artículo es determinar la estructura dimensional de las competencias del siglo XXI, junto con los factores personales clave en este sentido. Se trata de un estudio correlacional, basado en un diseño de encuesta, cuya muestra está constituida por estudiantes de los grados de Pedagogía y Educación Social de la Universidad de Valencia, seleccionados por muestreo no probabilístico y accidental, recogiendo la información …

Predicting the structure and vibrational frequencies of ethylene using harmonic and anharmonic approaches at the Kohn–Sham complete basis set limit

2016

In this work, regular convergence patterns of the structural, harmonic, and VPT2-calculated anharmonic vibrational parameters of ethylene towards the Kohn–Sham complete basis set (KS CBS) limit are demonstrated for the first time. The performance of the VPT2 scheme implemented using density functional theory (DFT-BLYP and DFT-B3LYP) in combination with two Pople basis sets (6-311++G** and 6-311++G(3df,2pd)), the polarization-consistent basis sets pc-n, aug-pc-n, and pcseg-n (n = 0, 1, 2, 3, 4), and the correlation-consistent basis sets cc-pVXZ and aug-cc-pVXZ (X = D, T, Q, 5, 6) was tested. The BLYP-calculated harmonic frequencies were found to be markedly closer than the B3LYP-calculated h…

Feature Ranking of Large, Robust, and Weighted Clustering Result

2017

A clustering result needs to be interpreted and evaluated for knowledge discovery. When clustered data represents a sample from a population with known sample-to-population alignment weights, both the clustering and the evaluation techniques need to take this into account. The purpose of this article is to advance the automatic knowledge discovery from a robust clustering result on the population level. For this purpose, we derive a novel ranking method by generalizing the computation of the Kruskal-Wallis H test statistic from sample to population level with two different approaches. Application of these enlargements to both the input variables used in clustering and to metadata provides a…

Influence of the concentration of oxygen on the swimming path of Brachionus plicatilis (Rotifera)

1993

Brachionus plicatilis females were maintained for > 24 hours in water where the concentration of oxygen was precisely controlled (spherical flasks with ≥ 6 mg 1−1 or < 0.5 mg 1−1; food = dead Tetraselmis sp.). Each female was randomly taken from one flask and quickly placed in an observation chamber containing the same experimental conditions. The swimming path was videotaped (5 minutes); then the size of the female was measured. The tape was analyzed by automatic tracking (25 x, y coordinates of the center of the animal, in a 512 × 512 pixels space). The swimming path was analyzed for ~45 females in both treatments. The speed (mm s−1 body length−1) was calculated for all trajectories, or o…

A numerical recipe for the computation of stationary stochastic processes' autocorrelation function

2023

Many natural phenomena exhibit a stochastic nature that one attempts at modeling by using stochastic processes of different types. In this context, often one is interested in investigating the memory properties of the natural phenomenon at hand. This is usually accomplished by computing the autocorrelation function of the numerical series describing the considered phenomenon. Often, especially when considering real world data, the autocorrelation function must be computed starting from a single numerical series: i.e. with a time-average approach. Hereafter, we will propose a novel way of evaluating the time-average autocorrelation function, based on the preliminary evaluation of the quantit…

Maternal literacy teaching, causal attributions and children’s literacy skills in Finnish-speaking and language minority families

2016

Abstract This study investigated the effect of mothers’ (language minority group mothers, LM, n = 49, and Finnish speaking mothers, MP, n = 368) literacy teaching at home, and mothers’ causal attributions of their children’s (mean age 11.48 years) literacy skills at fourth grade in Finland. For Finnish speaking mothers, results showed a negative correlation between the amount of literacy taught at home and children’s performance on reading tests i.e., more teaching was associated with poorer performance and vice versa. Also, the more MP mothers measured their children’s success by their ability, the better their children performed in reading comprehension tests. In the LM group, maternal li…

Time resolved confocal luminescence investigations on reverse proton exchange Nd : LiNbO3 channel waveguides

2009

In this work we report on the time and spatial resolved fluorescence of Neodymium ions in LiNbO(3) channel waveguides fabricated by Reverse Proton Exchange. The analysis of the fluorescence decay curves obtained with a sub-micrometric resolution has evidenced the presence of a relevant fluorescence quenching inside the channel waveguide. From the comparison between diffusion simulations and the spatial dependence of the (4)F(3/2) fluorescence decay rate we have concluded that the observed fluorescence quenching can be unequivocally related to the presence of H+ ions in the LiNbO(3) lattice. Nevertheless, it turns out that Reverse Proton Exchange guarantees a fluorescence quenching level sig…