Search results for "stochastic"

ORDINAL MEASUREMENTS WITH INTERVAL CONSTRAINTS IN THE EIA PROCESS FOR SITING A WASTE STORAGE AREA

2009

We describe application of multicriteria decision analysis (MCDA) in the Environmental Impact Assessment (EIA) procedure for siting a waste storage area. The world’s largest biofuel-based combined heat and power (CHP) plant was built in Pietarsaari, Finland. The plant produces certain byproducts, such as flue dust and bottom ash, which need to be processed and stored to prevent releases to the environment. Different storage sites will have different impacts on people, nature, and the economy. Cardinal measurement of the different impacts was considered too costly. Instead, ordinal measurement of all criteria was applied; i.e., experts ranked the alternative storage sites according to each c…

Speed Stochastic Processes and Freeway Reliability Estimation: Evidence from the A22 Freeway, Italy

2013

In this paper, a criterion for predicting the reliability of freeway traffic flow is presented. The idea is based on an analysis of spot speed time series divided into sequences of events of random and homogeneous traffic processes. For each process, the flow rate and density were calculated; then the relationships between parameters of spot speed processes and vehicular density were obtained. Using these relationships and a simulation procedure for the spot speed process, a formulation for predicting the reliability of traffic flow moving along the offside lane on the freeway roadway was derived. Through this formulation and the measurements of flow rate and speed, the probability of insta…

Application of Monte Carlo technique to evaluate the power injectable on electrical grid by wind farms

2008

This paper is part of a research aimed at assessing the impact of wind generation on the transmission grid of Sicily, second among the Italian regions for wind power installed. To assess the maximum degree of wind generation penetrability in full compliance with the safe operation of the system, it seemed necessary to investigate the reports of contemporary winds and their territorial correlations when load assumes the peak or the minimum. Given the nature of the problem, it has been used a method of analysis based on the application of stochastic simulation techniques type Monte Carlo. In the paper, after describing the current state of wind energy generation in Sicily and development scen…

A predictive maintenance policy with imperfect monitoring

2010

For many systems,failure is a very dangerous or costly event. To reduce the occurrence of this event,it is necessary to implement a preventive maintenance policy to replace the critical elements before failure.Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life.To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure,condition based and,more recently,predictive maintenance policies have been proposed.This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost.By adopting a stoc…

Pollution and economic growth: a maximum likelihood estimation of environmental Kuznets curve

2011

As in Brock and Taylor (2011) in this paper we consider the importance of the relationship between the Environmental Kuznets Curve (EKC) Literature and the Economic Growth Theories. To address this issue we construct country production functions that directly incorporate CO2 emissions as input and estimate them using Stochastic Frontiers. This approach differs from that of Brock and Taylor (2011) but is similar to the one followed by Koop (1998). By introducing the environmental “bads” directly in the production function, we can analyse their contribution to total output growth. We highlight an important contribution of CO2 emissions to growth and find out that the EKC seems not to hold, at…

SIVS epidemic model with stochastic perturbation

2010

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.

Large-photon-number limit and the essential singularity in finite quantum electrodynamics

1976

It is shown that the essential singularity in finite quantum electrodynamics can be located by considering only those diagrams with a large number of photons exchanged in the single-fermion loop, without photons emitted and absorbed on a fermion line. (AIP)

Stochastic response determination of nonlinear oscillators with fractional derivatives elements via the Wiener path integral

2014

A novel approximate analytical technique for determining the non-stationary response probability density function (PDF) of randomly excited linear and nonlinear oscillators endowed with fractional derivatives elements is developed. Specifically, the concept of the Wiener path integral in conjunction with a variational formulation is utilized to derive an approximate closed form solution for the system response non-stationary PDF. Notably, the determination of the non-stationary response PDF is accomplished without the need to advance the solution in short time steps as it is required by the existing alternative numerical path integral solution schemes which rely on a discrete version of the…

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.