Very large stochastic resonance gains in finite sets of interacting identical subsystems driven by subthreshold rectangular pulses

We study the phenomenon of nonlinear stochastic resonance (SR) in a complex noisy system formed by a finite number of interacting subunits driven by rectangular pulsed time periodic forces. We find that very large SR gains are obtained for subthreshold driving forces with frequencies much larger than the values observed in simpler one-dimensional systems. These effects are explained using simple considerations.Comment: 4 pages, 5 figures. to appear in Phys. Rev.

Estados Unidos y Europa en la posguerra fría : tres lecturas diferentes de un mismo período histórico

Este texto analiza el trato que se ha dado a la evolución de las relaciones transatlánticas en la literatura especializada en relaciones internacionales a nivel europeo y americano en el período comprendido entre enero de 1990 a diciembre de 2004Aquest text analitza el tracte que s'ha donat a l'evolució de les relacions transatlàntiques en la literatura especialitzada en relacions internacionals a nivell europeu i americà en el període comprès entre gener de 1990 a desembre de 200

L' administració de les aigües subterrànies a Catalunya: situació general i prospectiva

Les aigües subterrànies són analitzades des d'una perspectiva històrica tot abordant, de manera crítica i oberta, la problemàtica de les competències. En aquest sentit, es considera la unitat de conca com un principi negatiu per a una autonomia hidrològica plena. L'autor assenyala els objectius d'una política hidrològica catalana en aigües subterrànies i apunta les iniciatives més convenients per a impulsar una òptima gestió dels recursos hídrics subterranis (estalvi hídric, reutilització, recàrrega artificial,...

Decentralization and regional economic disparities

This paper analyses the impact of both fiscal and political decentralisation on regional productivity inequalities. The study of the influence of decentralisation on economic growth has received some attention in recent years, but very few studies deal with its impact on regional inequalities, both theoretically and empirically. In this paper, we analyse the relationship between different measures of regional inequalities in productivity, and several measures of political and fiscal decentralisation for a sample of 15 OECD countries. In order to control for other possible influences, we have also include in the analysis measures of public sector size and the type of party government. The results suggest a strong negative correlation between decentralisation, mainly fiscal decentralisation, and regional inequalities. Of course, much more analysis must be done before we can demonstrate such relationship. We hope that this paper will stimulate further research.

Mobility and regional inequality in the European Union: Implications for economic policy

The aim of this paper is to analyse the mobility of per capita income distribution in the European regions during the period 1977-1996. In doing so we will attempt highlight some aspects of the nature of interregional inequality. We also hope to draw inferences that might be applied by European regional policy makers. If, for example, there proves to be very little mobility, this might mean that the regional positions are consolidated. If this were the case, a belligerent regional policy could be introduced in order to reduce regional disparities. If, on the other hand, our results suggest that income variability accounts for most of the disparities, regional policy could be focused on the negative effects of economic cycles. In this case, a regional convergence policy might be made to take second place. Our methodological approach involves calculating indices commonly used in the dynamic income distribution literature, such as those of Theil, Atkinson and Shorrocks. These indices are calculated at different levels, both temporal and geographical, in order to discover different regional behaviour patterns throughout the study period.

Regional Productive Specialisation and Inequality in the European Union

This paper examines productive specialization in the regions of the European Union over the period 1977 to 1999 using the information provided by various methodological instruments. The results obtained reveal a process of convergence in regional productive structures during the twenty-three years considered. This has been due to the behavior of regions with high levels of specialization at the start of the period, whose productive structures have tended to shift to wards the European average overtime. The analysis carried out also high lights the major role played by regional size, level of development and geographical location in explaining specialization in the European context. Finally, the empirical evidence provided suggests that changes in regional productive structures are closely linked to the evolution of the spatial distribution of per capita income in the European Union. Keywords: Specialization, economic activity, regions, European Union. JEL Code: F15, R11, R12.

Overdamped Deterministic Ratchets Driven By Multifrequency Forces

We investigate a dissipative, deterministic ratchet model in the overdamped regime driven by a {\it rectangular force}. Extensive numerical calculations are presented in a diagram depicting the drift velocity as a function of a wide range of the driving parameter values. We also present some theoretical considerations which explain some features of the mentioned diagram. In particular, we proof the existence of regions in the driving parameter space with bounded particle motion possessing zero current. Moreover, we present an explicit analytical expression for the drift velocity in the adiabatic limit.Comment: 12 pages, 6 figure