Search results for "Statistica"

Merging Features from Green's Functions and Time Dependent Density Functional Theory: A Route to the Description of Correlated Materials out of Equil…

2016

We propose a description of nonequilibrium systems via a simple protocol that combines exchange-correlation potentials from density functional theory with self-energies of many-body perturbation theory. The approach, aimed to avoid double counting of interactions, is tested against exact results in Hubbard-type systems, with respect to interaction strength, perturbation speed and inhomogeneity, and system dimensionality and size. In many regimes, we find significant improvement over adiabatic time dependent density functional theory or second Born nonequilibrium Green's function approximations. We briefly discuss the reasons for the residual discrepancies, and directions for future work.

Suite of Statistical Models Forecasting Latvian GDP

2014

Abstract We develop a suite of statistical models to forecast Latvian GDP. We employ various univariate and multivariate econometric techniques to obtain short-term GDP projections and to assess the performance of the models. We also comprise the information contained in components of GDP and obtain short-term GDP projections from disaggregated perspective. We run out-of-sample forecasting procedures to evaluate GDP projections and to assess forecasting accuracy of all individual statistical models. We conclude that factor and bridge models are among the best individually performing models in the suite. Forecasting accuracy obtained using disaggregated models of factor and bridge models is …

Statistical analyses on the essential oil of italian coriander (coriandrum sativum L.) fruits of different ages and origins

2002

Thirty-one samples of Coriandrum sativum L. fruits, of different origin, year of cultivation (harvest) and crop management systems were subjected to volatile component analysis by combining Head Space Solid Phase Microextraction (HS-SPME) with GC/MS. In order to determine the importance of the major sources of volatile variability, some statistical analyses, including Cluster Analysis (CA) and Principal Component Analysis (PCA), were performed on the obtained data. The compounds, which gave the main contribution to the partition and classification of the original data, were α-pinene, p-cymene, γ-terpinene and linalool. The age of the fruits, which ranged from 1–16 years, seemed to generate …

Tourist Behaviour Predictors: a Focus on Organised Vs. Independent Tourism.

2013

la situazione socio-economica della regione Sicilia nella prospettiva del Partenariato Euromediterraneo

2005

Armonizzazione fra economia e modelli di sviluppo

2014

Il contributo propone un'analisi critica dei problemi relativi al processi di integrazione euromediterranea in una prospettiva di economia dello sviluppo .

Measuring the perceived value of rural tourism: a field survey in the western Sicilian agritourism sector

2016

Rural tourism constitutes a valuable tool for the sustainable development of many rural areas. This paper examines the concept of perceived value in rural tourism. A quantitative field survey was carried out in some main Western Sicilian holiday farms (agritourisms) during the Spring 2014. A theoretical model of the tourists’ perceived value in this specific context was developed and validated, using a 22-item scale. Using Partial Least Squares Path Modelling a theoretical structural model of the multidimensional structure of the RTPV was tested, assessing intensity and direction of the causal relationships among RTPV and its dimensions. Five dimensions were identified as forming the constr…

Numerical validation of an approximate formulation for the design of TLCD

2013

IS FAMILY HEALTH DETERMINANT? A GENDER-SPECIFIC MULTILEVEL ANALYSIS IN ITALY

2011

Background: The traditional model of the ltalian family, the married couple with children, is suffering a declining trend and many other family types are imposing. The aim of this paper is (i) to assess the role of family structure as determinant of perceived health and (ii) to investigate the existence of a geographical gradient of health. Methods: The study is based on data taken from the 2004 EU-SILC survey of Eurostat and regards people living in ltaly, aged 25 years and over. Results: Living alone or in an extended family with-out children is perceived an adverse health determinant for both sexes. Living in a traditional family with two children is protective for women health. The nort…

A distribution curves comparison approach to analyze the university moving students performance

2018

Da qualche anno anche l’Italia sta assistendo a un flusso migratorio di studenti, che da un povero Sud si dirige verso un più ricco Nord. Se un tempo la migrazione avveniva nel momento di cercare lavoro, adesso questa è anticipata da studenti che ritengono di avere meggiore successo se conseguono il titolo al Nord. L’obiettivo di questo studio è verificare la sensazione empirica secondo la quale in realtà gli studenti che restano per iscriversi alla Laurea Magistrale hanno un percorso simile rispetto a quelli che si iscrivono a un percorso magistrale del Nord. Considerate diverse misure di performance, e svolto i confronti attraverso una nuova procedura di raffronto tra curve di distribuzio…