Search results for " MODELLI"

Technical assessment and evaluation of environmental models and software: Letter to the Editor

2011

International audience; This letter details the collective views of a number of independent researchers on the technical assessment and evaluation of environmental models and software. The purpose is to stimulate debate and initiate action that leads to an improved quality of model development and evaluation, so increasing the capacity for models to have positive outcomes from their use. As such, we emphasize the relationship between the model evaluation process and credibility with stakeholders (including funding agencies) with a view to ensure continued support for modelling efforts. Many journals, including EM&S, publish the results of environmental modelling studies and must judge the w…

Modelling PM10 Crisis Peaks Using Multi-agent Based Simulation: Application to Annaba City, North-East Algeria

2015

The paper describes a MAS (multi-agent system) simulation approach for controlling PM10 (Particulate Matter) crisis peaks. A dispersion model is used with an Artificial Neural Network (ANN) to predict the PM10 concentration level. The dispersion and ANN models are integrated into a MAS system. PM10 source controllers are modelled as software agents. The MAS is composed of agents that cooperate with each other for reducing their emissions and control the air pollution peaks. Different control strategies are simulated and compared using data from Annaba (North-East Algeria). The simulator helps to compare and assess the efficiency of policies to control peaks in PM10.

Probabilistic stability analysis of social obesity epidemic by a delayed stochastic model

2014

Abstract Sufficient conditions for stability in probability of the equilibrium point of a social obesity epidemic model with distributed delay and stochastic perturbations are obtained. The obesity epidemic model is demonstrated on the example of the Region of Valencia, Spain. The considered nonlinear system is linearized in the neighborhood of the positive point of equilibrium and a sufficient condition for asymptotic mean square stability of the zero solution of the constructed linear system is obtained.

Caratterizzazione morfologica e idraulica dei rill rilevati nell'area sperimentale di Masse

2012

Nella memoria sono riportati i risultati di un’analisi finalizzata alla validazione in ambiente Umbro di modelli per la quantificazione e la caratterizzazione morfologico-idraulica delle formazioni rill. A tale scopo sono state utilizzate le misure effettuate presso la stazione sperimentale per il monitoraggio dei processi erosivi a scala di parcella in località Masse (Umbria). In seguito a due eventi erosivi (11-01-2010 e 16-05-2011) che hanno prodotto la formazione di rill, è stato effettuato il rilievo della morfologia (lunghezza e sezione) e del profilo degli stessi. Il database di Masse è stato utilizzato, in primo luogo, per la validazione della relazione di potenza che permette la st…

Volatility transmission patterns and terrorist attacks

2009

The objective of this study is to analyze volatility transmission between the US and Eurozone stock markets considering the effects of the September 11, March 11 and July 7 financial crises. In order to do this, we use a multivariate GARCH model and take into account the asymmetric volatility phenomenon, the non-synchronous trading problem and the crises themselves. Moreover, a graphical analysis of the Asymmetric Volatility Impulse-Response Functions (AVIRF) is introduced, which takes into consideration the crisis effect. Results suggest that there is bidirectional and asymmetric volatility transmission and show the different impact that terrorist attacks had on both markets. El objetivo d…

Sviluppi recenti e nuove tecnologie per la stima dei fabbisogni irrigui in ambiente mediterraneo

2008

B-0-(B)over-bar(0) mixing and decay constants with the non-perturbatively improved action

2001

Several quantities relevant to phenomenological studies of B-0-(B) over bar (0) mixing are computed on the lattice. Our main results are f(Bd) root(B) over cap (Bd) = 206(28) (14)(-00)(+31) MeV, xi = f(Bd) root(B) over capB(x)/f(Bd) root(B) over cap (Bd) = 1.16(7). We also obtain the related quantities f(Bs) root(B) over cap (Bs) - 237(18) (10)(-00)(+34) MeV, f(Bd) = 174(22)(-0-0-00)(+7+5+26) MeV, f(Bs) = 204(15)(-0-0-00)(+7+4+31) MeV, f(Bs)/f(Bd) = 1.17(4)(-1)(+0), f(Bd)/f(Ds) = 0.74(5). After combining our results with the experimental world average Deltam(d)((exp)), we predict Deltam(s) = 15.8(2.1)(3.3) ps(-1). We have also computed the relevant parameters for D-0-(D) over bar (0) mixing…

Numerical stochastic perturbation theory in the Schrödinger functional

2013

The Schr\"odinger functional (SF) is a powerful and widely used tool for the treatment of a variety of problems in renormalization and related areas. Albeit offering many conceptual advantages, one major downside of the SF scheme is the fact that perturbative calculations quickly become cumbersome with the inclusion of higher orders in the gauge coupling and hence the use of an automated perturbation theory framework is desirable. We present the implementation of the SF in numerical stochastic perturbation theory (NSPT) and compare first results for the running coupling at two loops in pure SU(3) Yang-Mills theory with the literature.

Delta M_K and epsilon_K in SUSY at the Next-to-Leading order

1998

We perform a Next-to-Leading order analysis of Delta S=2 processes beyond the Standard Model. Combining the recently computed NLO anomalous dimensions and the B parameters of the most general Delta S=2 effective Hamiltonian, we give an analytic formula for Delta M_K and epsilon_K in terms of the Wilson coefficients at the high energy scale. This expression can be used for any extension of the Standard Model with new heavy particles. Using this result, we consider gluino-mediated contributions to Delta S=2 transitions in general SUSY models and provide an improved analysis of the constraints on off-diagonal mass terms between the first two generations of down-type squarks. Finally, we improv…

Critical comments on EEG sensor space dynamical connectivity analysis

2019

Many different analysis techniques have been developed and applied to EEG recordings that allow one to investigate how different brain areas interact. One particular class of methods, based on the linear parametric representation of multiple interacting time series, is widely used to study causal connectivity in the brain. However, the results obtained by these methods should be interpreted with great care. The goal of this paper is to show, both theoretically and using simulations, that results obtained by applying causal connectivity measures on the sensor (scalp) time series do not allow interpretation in terms of interacting brain sources. This is because (1) the channel locations canno…