Search results for "Statistica"

The ALHAMBRA survey: evolution of galaxy clustering since z∼1

2014

We study the clustering of galaxies as function of luminosity and redshift in the range $0.35 < z < 1.25$ using data from the Advanced Large Homogeneous Area Medium Band Redshift Astronomical (ALHAMBRA) survey. The ALHAMBRA data used in this work cover $2.38 \mathrm{deg}^2$ in 7 independent fields, after applying a detailed angular selection mask, with accurate photometric redshifts, $��_z \lesssim 0.014 (1+z)$, down to $I_{\rm AB} < 24$. Given the depth of the survey, we select samples in $B$-band luminosity down to $L^{\rm th} \simeq 0.16 L^{*}$ at $z = 0.9$. We measure the real-space clustering using the projected correlation function, accounting for photometric redshifts uncert…

THE ALHAMBRA SURVEY: EVOLUTION OF GALAXY SPECTRAL SEGREGATION

2016

arXiv:1601.03668v1

Euclid preparation: XI. Mean redshift determination from galaxy redshift probabilities for cosmic shear tomography

2021

Ilbert, O., et al. (Euclid Collaboration)

Measuring galaxy segregation with the mark connection function

2010

(abridged) The clustering properties of galaxies belonging to different luminosity ranges or having different morphological types are different. These characteristics or `marks' permit to understand the galaxy catalogs that carry all this information as realizations of marked point processes. Many attempts have been presented to quantify the dependence of the clustering of galaxies on their inner properties. The present paper summarizes methods on spatial marked statistics used in cosmology to disentangle luminosity, colour or morphological segregation and introduces a new one in this context, the mark connection function. The methods used here are the partial correlation functions, includi…

Temporal trends of heavy metals in sediment core from the gulf of Palermo (Sicily, Italy)

2009

The evaluation of long–term heavy metal concentrations in the Gulf of Palermo was carried out in this study. Measurements of Cr, Cu, Hg, Pb and Zn concentrations were performed by atomic absorption spectrophotometry (AAS) on dated fractions of a sediment core, dated by the 210Pbex method. They are found to cover a time period from 1951 to 2004. The constant sedimentation rate model was used for dating. Specific activities of 137Cs have also been measured in the sediment core sections as a check of the time scale derived by the 210Pbex method. A time-series analysis based on temporal decomposition was used in order to investigate the presence of heavy metal pollution trend. The additive comp…

A software tool via web for the statistical data analysis

2006

The spread of Internet and the growing demand of services from the web users have changed and are still changing the way to organize the work or tthe study. Nowadays, the main part of information and many services are on the web and the software is going toward the same direction: in fact, the use of software implemented via web is ever-increasing, with a client-server logic that enables the "centralized" use of software installed on a server. In this paper we describe the structure and the running of R-php, an environment for statistical analysis, freely accessible and attainable through the World Wide Web, based on the statistical environment R. R-php is based on two modules: a base modul…

Statistical Information and Local Tourism

2013

Overview and prerequisites of well-functioning Latvian national innovation system

2013

Analysis and understanding of the national innovation system can help policy-makers to identify strategies for improving innovative performance and overall competitiveness of the national economy. Nowadays we know too little about how to identify and measure specific problems in the system (if at all possible), despite several attempts to define them. Until now, little analysis on the Latvian innovation system was made. The paper aims to analyse the Latvian national innovation system and to provide a factors of well-functioning Latvian national innovation system. This research gives a possibility to researchers and policy-makers to investigate the mismatch between policies and problems and …

Statistical validation of investment decisions and transactions in financial markets

Inferring directionality of coupled dynamical systems using Gaussian process priors: Application on neurovascular systems

2022

Dynamical system theory has recently shown promise for uncovering causality and directionality in complex systems, particularly using the method of convergent cross mapping (CCM). In spite of its success in the literature, the presence of process noise raises concern about CCM's ability to uncover coupling direction. Furthermore, CCM's capacity to detect indirect causal links may be challenged in simulated unidrectionally coupled Rossler-Lorenz systems. To overcome these limitations, we propose a method that places a Gaussian process prior on a cross mapping function (named GP-CCM) to impose constraints on local state space neighborhood comparisons. Bayesian posterior likelihood and…