Search results for "Function"
showing 10 items of 14432 documents
Modeling Return to Education in Heterogeneous Populations: An Application to Italy
2019
The Mincer human capital earnings function is a regression model that relates individual’s earnings to schooling and experience. It has been used to explain individual behavior with respect to educational choices and to indicate productivity on a large number of countries and across many different demographic groups. However, recent empirical studies have shown that often the population of interest embed latent homogeneous subpopulations, with different returns to education across subpopulations, rendering a single Mincer’s regression inadequate. Moreover, whatever (concomitant) information is available about the nature of such a heterogeneity, it should be incorporated in an appropriate ma…
Noise in ecosystems: a short review
2004
Noise, through its interaction with the nonlinearity of the living systems, can give rise to counter-intuitive phenomena such as stochastic resonance, noise-delayed extinction, temporal oscillations, and spatial patterns. In this paper we briefly review the noise-induced effects in three different ecosystems: (i) two competing species; (ii) three interacting species, one predator and two preys, and (iii) N-interacting species. The transient dynamics of these ecosystems are analyzed through generalized Lotka-Volterra equations in the presence of multiplicative noise, which models the interaction between the species and the environment. The interaction parameter between the species is random …
Origin of the large spectral shift in electroluminescence in a blue light emitting cationic iridium(III) complex
2007
A new, but archetypal compound [ Ir( ppy- F-2) (2)Me(4)phen] PF6, where ppy- F2 is 2-(2',4'- fluorophenyl) pyridine and Me(4)phen is 3,4,7,8- tetramethyl- 1,10- phenanthroline, was synthesized and used to prepare a solid-state light-emitting electrochemical cell (LEEC). This complex emits blue light with a maximum at 476 nm when photoexcited in a thin film, with a photoluminescence quantum yield of 52%. It yields an efficient single-component solid-state electroluminescence device with a current efficiency reaching 5.5 cd A(-1) and a maximum power efficiency of 5.8 Lm Watt(-1). However, the electroluminescence spectrum is shifted with respect to the photoluminescence spectrum by 80 nm resul…
An adaption mechanism for the error threshold of XCSF
2020
Learning Classifier System (LCS) is a class of rule-based learning algorithms, which combine reinforcement learning (RL) and genetic algorithm (GA) techniques to evolve a population of classifiers. The most prominent example is XCS, for which many variants have been proposed in the past, including XCSF for function approximation. Although XCSF is a promising candidate for supporting autonomy in computing systems, it still must undergo parameter optimization prior to deployment. However, in case the later deployment environment is unknown, a-priori parameter optimization is not possible, raising the need for XCSF to automatically determine suitable parameter values at run-time. One of the mo…
Electronic and magnetic structure ofLa0.875Sr0.125MnO3calculated by means of hybrid density-functional theory
2007
We present the results of ab initio calculations on magnetic and electronic structures of La1�xSrxMnO3 at low doping, x =1/8. Using the B3LYP hybrid exchange-correlation functional within the framework of densityfunctional theory, we predict a ferromagnetic ground state for La0.875Sr0.125MnO3 in both the low-temperature orthorhombic and the high-temperature pseudocubic phases. This is in contrast to its parent compound LaMnO3, for which we find in agreement with experiment the layered antiferromagnetic state to be the most stable one. The calculated density of states and bond population analysis suggest a tendency of formation of half-metallic spin states in the band gap of both structures.
Multi-modal search for multiobjective optimization: an application to optimal smart grids management
2012
This paper studies the possibility to use efficient multimodal optimizers for multi-objective optimization. In this paper, the application area considered for such new approach is the optimal dispatch of energy sources in smart microgrids. The problem indeed shows a non uniform Pareto front and requires efficient optimal search methods. The idea is to exploit the potential of agents in population-based heuristics to improve diversity in the Pareto front, where solutions show the same rank and are thus equally weighted. Since Pareto dominance is at the basis of the theory of multi-objective optimization, most algorithms show the non dominance ranking as quality indicator, with some problem i…
Assessing the Beneficial Effects of Economic Growth: The Harmonic Growth Index
2011
In this paper we introduce the multidimensional notion of harmonic growth as a situation of diffused well-being associated to an increase of per capita GDP. We say that a country experienced a harmonic growth if during the observed period all the key indicators, proxies of the endogenous and exogenous forces driving population well-being, show a significantly common pattern with the income dynamics. The notion is operationalized via an index of time series harmony which follows the functional data analysis approach. This Harmonic Growth Index (HGI) is based on comparisons between the coefficients from cubic B-splines interpolation. Such indices are then synthesized in order to provide the g…
The Severe Asthma Registry – German data
2018
Patients with severe persistent asthma represent the highest unmet medical need among the asthmatic population. To improve the understanding of underlying mechanisms and disease progression the German Asthma Net (GAN, www.german-asthma-net.de) launched a Severe Asthma Registry in December 2011. Enrolled patients undergo detailed clinical and physiologic evaluations, including patients’ medical history, allergy and lung function tests, blood analyses as well as past and concomitant medication and comorbidities. Patients are followed up every year. As of February 2018, 1097 subjects were recruited in Germany, Austria, and Slovenia. The mean age±SEM of the 839 German adult patients is 50.6±0.5…
Un programa de entrenamiento para familiares de pacientes con trastorno límite de la personalidad basado en la terapia dialéctica comportamental
2021
espanolLos familiares de pacientes con trastorno limite de la personalidad (TLP) experimentan ansiedad y depresion, y estan inmersos en un clima familiar disfuncional. Aunque existen tratamientos eficaces para el TLP, se ha prestado menos atencion a los familiares. El objetivo de este trabajo fue adaptar para familiares el entrenamiento grupal en habilidades de la terapia dialectica comportamental, en 14 sesiones. La muestra estuvo formada por 12 familiares: 50% madres, 41,7% padres y 8,3% parejas. Se evaluaron los niveles de depresion (BDI-II), ansiedad (OASIS) y emocion expresada (LEE-S) antes y despues de la intervencion. Los resultados indican que tras la intervencion se produce una mej…
Population analysis of pair densities. A study on cyclic systems
2000
Abstract Pair population analysis seems a reliable method for evaluating atomic valency states and bond orders from the MO wavefunction of molecular systems. A test on some cyclic organic systems was performed. The results confirm the capability of the method to provide a correct description of the molecules in terms of simple VB approach.