Search results for "stochastic"

Design Of TLCD under random loads: a new formulation

2012

A Stochastic Decision Process Model for Optimization of Railway and Tramway Track Maintenance by means of Image Processing Technique

2013

One of the key targets for an efficient transport network management is the search for proper maintenance policies to guarantee acceptable safety and quality standards in the travel and to optimize available resource allocation. Methodologically, the proposed model presented in this paper uses the stochastic dynamic programming and in particular Markov decision processes applied to the rail wear conditions for the railway and tramway network. By performing the integrated analysis of the classes of variables which characterize the rail quality (in terms of safety), the proposed mathematical approach allows to find the solutions to the decision-making process related to the probability of det…

Decoupling on the Wiener space and variational estimates for BSDEs

2015

Analysis of the Effects of Reservoir Operating Scenarios on Downstream Flood Damage Risk Using an Integrated Monte Carlo Modelling Approach

2023

The aim of this study is to analyse the effects of reservoir operating scenarios, for flood damage evaluation downstream of a dam, using a Monte Carlo bivariate modelling chain. The proposed methodology involves a stochastic procedure to calculate flood hydrographs and the evaluation of the consequent flood inundation area by applying a 2D hydraulic model. These results are used to estimate the inundation risk and, as consequence, the relative damage evaluation under different water level conditions in an upstream reservoir. The modelling chain can be summarized as follows: single synthetic stochastic rainfall event generation by using a Monte Carlo procedure through a bivariate copulas ana…

The uncertainty of the energy demand in existing mediterranean urban blocks

2013

The objective of the paper is to describe a stochastic model that has been developed to obtain load profiles for household electricity. For the study, several profiles have been generated in order to simulate the electrical demand of a residential building block or neighbourhood and evaluate the uncertainty of its energy use. The paper is divided in three different parts: development of the model, validation and determination of the uncertainty demand. In the first parts the basis of the model and how it works is explained. The second one represents the validation of the model, the input data and its results. The last step is focused on a statistical analysis of the electricity demand of a …

BEMOD: A DSGE Model for the Spanish Economy and the Rest of the Euro Area

2006

In this paper we present the theoretical foundations and the simulation results obtained with a new dynamic general equilibrium model developed at the Banco de España for the Spanish economy and the rest of Euro area. The model is designed to help in simulating the effect of alternative shocks on the main aggregate variables. The main contributions of this work from a theoretical perspective are the modelling of a monetary union composed of two regions, the inclusion of housing as a durable good with its own sector of production and the degree and detail of the disaggregation considered for each country in the model, which replicates the Quarterly National Accounts. On the empirical side, t…

The Joint Distribution Criterion and the Distance Tests for Selective Probabilistic Causality

2010

A general definition and a criterion (a necessary and sufficient condition) are formulated for an arbitrary set of external factors to selectively influence a corresponding set of random entities (generalized random variables, with values in arbitrary observation spaces), jointly distributed at every treatment (a set of factor values containing precisely one value of each factor). The random entities are selectively influenced by the corresponding factors if and only if the following condition, called the joint distribution criterion, is satisfied : there is a jointly distributed set of random entities, one entity for every value of every factor, such that every subset of this set that corr…

Smart Cities and Eu growth strategy: a Comparison among European Cities

2015

The level of interest in smart cities has been growing during these last years. The academic literature (Holland, 2008; Caragliu et al., 2009, Nijkamp et al., 2011 and Lombardi et al., 2012) has identified a number of factors that characterise a city as smart, such as economic development, business-friendly, environmental sustainability, social innovation, information and knowledge process, and human and social capital. Thus, the smartness concept is strictly linked to urban efficiency in a multifaceted way as well as to citizens’ wellbeing through the use of appropriate technologies. Instead, from a “political perspective” smartness is mainly related to the ability of using ICT (Informatio…

Can the adaptive Metropolis algorithm collapse without the covariance lower bound?

2011

The Adaptive Metropolis (AM) algorithm is based on the symmetric random-walk Metropolis algorithm. The proposal distribution has the following time-dependent covariance matrix at step $n+1$ \[ S_n = Cov(X_1,...,X_n) + \epsilon I, \] that is, the sample covariance matrix of the history of the chain plus a (small) constant $\epsilon>0$ multiple of the identity matrix $I$. The lower bound on the eigenvalues of $S_n$ induced by the factor $\epsilon I$ is theoretically convenient, but practically cumbersome, as a good value for the parameter $\epsilon$ may not always be easy to choose. This article considers variants of the AM algorithm that do not explicitly bound the eigenvalues of $S_n$ away …

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…