Search results for "C22"
showing 5 items of 35 documents
Testing for hysteresis in unemployment in OECD countries. New evidence using stationarity panel tests with breaks†
2006
This paper tests hysteresis effects in unemployment using panel data for 19 Organization for Economic Co-operation and Development (OECD) countries covering the period 1956–2001. The tests exploit the cross-sectional variations of the series, and additionally, allow for a different number of endogenous breakpoints in the unemployment series. The critical values are simulated based on our specific panel sizes and time periods. The findings stress the importance of accounting for exogenous shocks in the series and support the natural-rate hypothesis of unemployment for the majority of the countries analysed.
THE 1-HARMONIC FLOW WITH VALUES IN A HYPEROCTANT OF THE N-SPHERE
2014
We prove the existence of solutions to the 1-harmonic flow — that is, the formal gradient flow of the total variation of a vector field with respect to the [math] -distance — from a domain of [math] into a hyperoctant of the [math] -dimensional unit sphere, [math] , under homogeneous Neumann boundary conditions. In particular, we characterize the lower-order term appearing in the Euler–Lagrange formulation in terms of the “geodesic representative” of a BV-director field on its jump set. Such characterization relies on a lower semicontinuity argument which leads to a nontrivial and nonconvex minimization problem: to find a shortest path between two points on [math] with respect to a metric w…
Assessing the Open Trenches in Screening Railway Ground-Borne Vibrations by Means of Artificial Neural Network
2009
Reducing ground borne vibrations in urban areas is a very challenging task in railway transportation. Many mitigation measures can be considered and applied; among these open trenches are very effective. This paper deals with the study of the effect, in terms of reduction of vertical and horizontal displacements and velocities, of the open trenches. 2D FEM simulations have been performed and several open trench configurations have been analysed varying the main geometric features such as width and depth, distance from the rail, thickness of the soil layer over the rigid bedrock, type of the ground, ratio between the depth of the trench, and the thickness of the soil layer. For quantifying t…
An Examination of Tourist Arrivals Dynamics Using Short-Term Time Series Data: A Space—Time Cluster Approach
2013
The purpose of this study is to examine the development of Italian tourist areas ( circoscrizioni turistiche) through a cluster analysis of short time series. The technique is an adaptation of the functional data analysis approach developed by Abraham et al (2003), which combines spline interpolation with k-means clustering. The findings indicate the presence of two patterns (increasing and stable) averagely characterizing groups of territories. Moreover, tests of spatial contiguity suggest the presence of ‘space–time clusters’; that is, areas in the same ‘time cluster’ are also spatially contiguous. These findings appear to be more robust in particular for those series characterized by an…
STATE AID POLICY BETWEEN COMPETITION AND ECONOMIC GROWTH: THE IMPACT OF STATE AID TO R&D ON GDP IN THE EU MEMBER STATES
2012
The paper focuses on the analysis of the relationship between state aid to R&D and economic growth, measured by GDP level, providing empirical evidence of a correlation between these variables. Using a methodology which combines the regression technique and Granger causality, we found that GDP represents a significant causal determinant of state aid, while the correlation the variables considered is positive and statistically significant, suggesting that, in spite of disparities between Member States, government support through state aid to R&D has evolved from maintaining undistorted competition to the possibility to act as an incentive for the economic growth in the EU.