Search results for "equation"
showing 10 items of 4219 documents
Estimating the safety performance function for urban unsignalized four-legged one-way intersections in Palermo, Italy
2014
Abstract Starting from consideration that urban intersections are sites with promise for safety and operational improvements, the paper describes the steps taken to develop a crash predictive model for estimating the safety performance of urban unsignalized intersections located in Palermo, Italy. The focus is on unsignalized four-legged one-way intersections widespread in Italian downtowns. The sample considered in the study consist of 92 intersections in Palermo, Italy. For the study were collected crashes occurred in the sites during the years 2006-2012, geometric design and functional characteristics and traffic flow. Results showed that data were overdispersed and NB1 distributed. In o…
Variational parabolic capacity
2015
We establish a variational parabolic capacity in a context of degenerate parabolic equations of $p$-Laplace type, and show that this capacity is equivalent to the nonlinear parabolic capacity. As an application, we estimate the capacities of several explicit sets.
Testing the nature of the Λ(1520)-resonance in proton-induced production
2006
The $\Lambda(1520)$ resonance has been recently studied in a unitarized coupled channel formalism with $\pi\Sigma(1385)$, $K\Xi(1530)$, $\bar{K}N$ and $\pi\Sigma$ as constituents blocks. We provide a theoretical study of the predictions of this model in physical observables of the $pp\to pK^+K^-p$ and $pp\to pK^+\pi^0\pi^0\Lambda$ reactions. In particular, we show that the ratio between the $\pi^0\pi^0\Lambda$ and $K^-p$ mass distributions can provide valuable information on the ratio of the couplings of the $\Lambda(1520)$ resonance to $\pi\Sigma(1385)$ and $\bar{K}N$ that the theory predicts. Calculations are done for energies which are accessible in an experimental facility like COSY at …
EMU and Trade Revisited: Long-Run Evidence Using Gravity Equations
2013
In this paper, we present evidence of the long-run effect of the euro on trade for the twelve initial EMU countries for the period 1967–2008 from a double perspective. First, we pool all the bilateral combinations of trade flows among the EMU countries in a panel cointegration gravity specification. Second, we estimate a gravity equation for each of the EMU members vis-a-vis the other eleven partners. We apply panel cointegration techniques based on factor models that account for cross-dependence and structural breaks. Whereas the joint gravity equation provides evidence on the aggregate effect of the euro on intra-European trade, by isolating the individual countries, we assess which of th…
Human capital and the intertemporal substitution for leisure: empirical evidence for Spain
2022
AbstractIn this paper we provide the first estimate of the intertemporal substitution for leisure in Spain, accounting for the impact of human capital accumulation. This would allow uncovering whether the intertemporal labour supply of Spanish workers is affected by human capital. Our empirical strategy consists of estimating the equation for the intertemporal substitution of leisure with and without accounting for human capital, what allows to detect hypothetical estimation biases associated to omitting the impact of human capital. To that end, we build a pseudo-panel data set combining the Spanish Family Expenditure Survey and the Labour Survey over the period 1987–1997. While the model t…
Shape optimization in contact problems : Approximation and numerical realization
1987
The optímal shape design of a two-dimensíonal elastic body on rigid foundatíon is analyzed. The relation between the continuous problem and the díscrete problem achieved by FEM is presented. A numerícal realization together wíth the sensítivity analysís is given. Several numerical examples to illustrate the practícal use of the methods are presented. peerReviewed
ADI schemes for valuing European options under the Bates model
2018
This paper is concerned with the adaptation of alternating direction implicit (ADI) time discretization schemes for the numerical solution of partial integro-differential equations (PIDEs) with application to the Bates model in finance. Three different adaptations are formulated and their (von Neumann) stability is analyzed. Ample numerical experiments are provided for the Bates PIDE, illustrating the actual stability and convergence behaviour of the three adaptations. peerReviewed
Structural Parameters under Partial Least Squares and Covariance-Based Structural Equation Modeling : A Comment on Yuan and Deng (2021)
2023
In their article, Yuan and Deng argue that a structural parameter under partial least squares structural equation modeling (PLS-SEM) is zero if and only if the same structural parameter is zero under covariance-based structural equation modeling (CB-SEM). Yuan and Deng then conclude that statistical tests on individual structural parameters assessing the null hypothesis of no effect can achieve the same purpose in CB-SEM and PLS-SEM. Our response to their article highlights that the relationship they find between PLS-SEM and CB-SEM structural parameters is not universally valid, and that consequently, tests on individual parameters in CB-SEM and PLS-SEM generally do not fulfill the same pur…
Partial-order reduction for parity games and parameterised Boolean equation systems
2022
AbstractIn model checking, reduction techniques can be helpful tools to fight the state-space explosion problem. Partial-order reduction (POR) is a well-known example, and many POR variants have been developed over the years. However, none of these can be used in the context of model checking stutter-sensitive temporal properties. We propose POR techniques for parity games, a well-established formalism for solving a variety of decision problems, including model checking. As a result, we obtain the first POR method that is sound for the full modal $$\upmu $$ μ -calculus. We show how our technique can be applied to the fixed point logic called parameterised Boolean equation systems, which pro…
A CNN Adaptive Model to Estimate PM10 Monitoring
2006
In this work we introduce a model for studying the distribution and control of atmospheric pollution from PM10. The model is based on the use of a cellular neural network (CNN) and more precisely on the integration of the mass-balance equation; at the same time it simulates the scenario regarding a planar grid describing the whole studied area (the city of Palermo) by means of a CNN and a set of Bayesian networks. The CNN allows us to define a grid system whose dynamic evolution is a redefinition of the diffusion equation that considers contributions coming from near cells for each element of the grid. Dynamics of each cell is influenced by meteorological effects and by parameters related t…