1,677 research outputs found
The potential growth of the Belgian economy and its determinants
The potential growth path of the economy is at the centre of various fundamental economic questions, particularly in connection with the conduct of monetary policy and the management of public finances. It also determines the progress of living standards, so that the adverse population prospects confronting the European economies have rekindled interest in the subject. The first chapter of the article reports on the developments recorded over the past twenty years, using a method derived from the one adopted by the EC and based on the use of a production function. The role played by the three determinants â labour, capital and total factor productivity â is discussed, focusing on the case of the Belgian economy while comparing the results with those recorded in the EU-15. With potential growth averaging 2.2 p.c. for the private sector and 2.1 p.c. in the whole economy, Belgium is in the middle group of European countries. A growth breakdown between labour volume and labour productivity is proposed in chapter 2. Belgiumâs advantages and disadvantages are assessed, not only in comparison with the EU-15 average but also in relation to the United States. Particular attention is drawn to the divergent picture in terms of productivity on the two continents. The improving performance in the United States in this respect contrasts with the deceleration recorded in Europe. The slowdown was also experienced in Belgium although, in the past ten years, the weaker growth in labour productivity here was due essentially to a slower increase in capital intensity. Having diminished between 1985 and 1995, the growth of total factor productivity, which in principle measures the overall productive capacity of the economy, stabilised at a level above the European average and close to that of the United States. This relatively good performance could be due to the fairly widespread use of ICT, as Belgiumâs investment expenditure on this item is greater than that of the majority of European countries. The highly skilled labour force provides additional support for total factor productivity, although its impact has not been quantified in the case of Belgium. Expenditure on research and development could also yield substantial productivity returns. Particular efforts in these three fields, in a context within which market forces provide appropriate incentives to the economic agents, could hold possibilities for enhancing productivity growth. This could contribute to stimulate growth in view of the anticipated adverse demographic developments in the coming decades, that will also require raising the rates of participation in the labour market.potential output, labour productivity, growth accounting, total factor productivity
A methodology for the classification of convective structures using meteorological radar: Application to heavy rainfall events on the Mediterranean coast of the Iberian Peninsula
During the period 1996â2000, forty-three heavy rainfall events have been detected in the Internal Basins of Catalonia (Northeastern of Spain). Most of these events caused floods and serious damage. This high number leads to the need for a methodology to classify them, on the basis of their surface rainfall distribution, their internal organization and their physical features. The aim of this paper is to show a methodology to analyze systematically the convective structures responsible of those heavy rainfall events on the basis of the information supplied by the meteorological radar. The proposed methodology is as follows. Firstly, the rainfall intensity and the surface rainfall pattern are analyzed on the basis of the raingauge data. Secondly, the convective structures at the lowest level are identified and characterized by using a 2-D algorithm, and the convective cells are identified by using a 3-D procedure that looks for the reflectivity cores in every radar volume. Thirdly, the convective cells (3-D) are associated with the 2-D structures (convective rainfall areas). This methodology has been applied to the 43 heavy rainfall events using the meteorological radar located near Barcelona and the SAIH automatic raingauge network
Radar analysis of the life cycle of Mesoscale Convective Systems during the 10 June 2000 event
International audienceThe 10 June 2000 event was the largest flash flood event that occurred in the Northeast of Spain in the late 20th century, both as regards its meteorological features and its considerable social impact. This paper focuses on analysis of the structures that produced the heavy rainfalls, especially from the point of view of meteorological radar. Due to the fact that this case is a good example of a Mediterranean flash flood event, a final objective of this paper is to undertake a description of the evolution of the rainfall structure that would be sufficiently clear to be understood at an interdisciplinary forum. Then, it could be useful not only to improve conceptual meteorological models, but also for application in downscaling models. The main precipitation structure was a Mesoscale Convective System (MCS) that crossed the region and that developed as a consequence of the merging of two previous squall lines. The paper analyses the main meteorological features that led to the development and triggering of the heavy rainfalls, with special emphasis on the features of this MCS, its life cycle and its dynamic features. To this end, 2-D and 3-D algorithms were applied to the imagery recorded over the complete life cycle of the structures, which lasted approximately 18 h. Mesoscale and synoptic information were also considered. Results show that it was an NS-MCS, quasi-stationary during its stage of maturity as a consequence of the formation of a convective train, the different displacement directions of the 2-D structures and the 3-D structures, including the propagation of new cells, and the slow movement of the convergence line associated with the Mediterranean mesoscale low
A prospective longitudinal study of perceived infant outcomes at 18-24 months: Neural and psychological correlates of parental thoughts and actions assessed during the first month postpartum
The first postpartum months constitute a critical period for parents to establish an emotional bond with their infants. Neural responses to infant-related stimuli have been associated with parental sensitivity. However, the associations among these neural responses, parenting, and later infant outcomes for mothers and fathers are unknown. In the current longitudinal study, we investigated the relationships between parental thoughts/actions and neural activation in mothers and fathers in the neonatal period with infant outcomes at the toddler stage. At the first month postpartum, mothers (n=21) and fathers (n=19) underwent a neuroimaging session during which they listened to their own and unfamiliar babyâs cry. Parenting-related thoughts/behaviors were assessed by interview twice at the first month and 3-4 months postpartum and infantsâ socioemotional outcomes were reported by mothers and fathers at 18-24 months postpartum. In mothers, higher levels of anxious thoughts/actions about parenting at the first month postpartum, but not at 3-4 months postpartum, were associated with infantâs low socioemotional competencies at 18-24 months. Anxious thoughts/actions were also associated with heightened responses in the motor cortex and reduced responses in the substantia nigra to own infant cry sounds. On the other hand, in fathers, higher levels of positive perception of being a parent at the first month postpartum, but not at 3-4 months postpartum, were associated with higher infant socioemotional competencies at 18-24 months. Positive thoughts were associated with heightened responses in the auditory cortex and caudate to own infant cry sounds. The current study provides evidence that parental thoughts are related to concurrent neural responses to their infants at the first month postpartum as well as their infantâs future socioemotional outcome at 18-24 months. Parent differences suggest that anxious thoughts in mothers and positive thoughts in fathers may be the targets for parenting-focused interventions very early postpartum
Estimation of convective precipitation: the meteorological radar versus an automatic rain gauge network
The estimation of convective precipitation and its contribution to total precipitation is an important issue both in hydrometeorology and radio links. The greatest part of this kind of precipitation is related with high intensity values that can produce floods and/or damage and disturb radio propagation. This contribution proposes two approaches for the estimation of convective precipitation, using the β parameter that is related with the greater or lesser convective character of the precipitation event, and its time and space distribution throughout the entire series of the samples. The first approach was applied to 126 rain gauges of the Automatic System of Hydrologic Information of the Internal Basins of Catalonia (NE Spain). Data are series of 5-min rain rate, for the period 1996-2002, and a long series of 1-min rain rate starting in 1927. Rainfall events were classified according to this parameter. The second approach involved using information obtained by the meteorological radar located near Barcelona. A modified version of the SCIT method for the 3-D analysis and a combination of different methods for the 2-D analysis were applied. Convective rainfall charts and β charts were reported. Results obtained by the rain gauge network and by the radar were compared. The application of the β parameter to improve the rainfall regionalisation was demonstrated
Two-dimensional cellular automata and the analysis of correlated time series
Correlated time series are time series that, by virtue of the underlying
process to which they refer, are expected to influence each other strongly. We
introduce a novel approach to handle such time series, one that models their
interaction as a two-dimensional cellular automaton and therefore allows them
to be treated as a single entity. We apply our approach to the problems of
filling gaps and predicting values in rainfall time series. Computational
results show that the new approach compares favorably to Kalman smoothing and
filtering
Continuous stochastic Schrodinger equations and localization
The set of continuous norm-preserving stochastic Schrodinger equations
associated with the Lindblad master equation is introduced. This set is used to
describe the localization properties of the state vector toward eigenstates of
the environment operator. Particular focus is placed on determining the
stochastic equation which exhibits the highest rate of localization for wide
open systems. An equation having such a property is proposed in the case of a
single non-hermitian environment operator. This result is relevant to numerical
simulations of quantum trajectories where localization properties are used to
reduce the number of basis states needed to represent the system state, and
thereby increase the speed of calculation.Comment: 18 pages in LaTeX + 6 figures (postscript), uses ioplppt.sty. To
appear in J. Phys.
Towards a Reproducible Pan-European Soil Erosion Risk Assessment - RUSLE
Soil is a valuable, non-renewable natural resource that offers a multitude of ecosystems goods and services. Given the increasing threat of soil erosion in Europe and the implications this has on future food security and water quality, it is important that land managers and decision makers are provided with accurate and appropriate information on the areas more prone to erosion phenomena. The present study shows an attempt to locate, at regional scale, the most sensitive areas and to highlight any changes of soil erosion trends with climate change. The choice of the input datasets is crucial as they have to offer the most homogeneous and complete covering at the pan-European level and to allow the produced information to be harmonized and easily validated. The model is based on available datasets (HWSD, SGDBE, SRTM, CLC and E-OBS) and The Revised Universal Soil Loss Equation (RUSLE) is used because of its ïŹexibility and least data demanding. A signiïŹcant effort has been made to select the better simpliïŹed equations to be used when a strict application of the RUSLE model was not possible. In particular for the computation of the Rainfall Erosivity factor a validation based on measured precipitation time series (having a temporal resolution of 10-15 minutes) has been implemented to be easily reproducible. The validation computational framework is available as free software. Designing the computational modeling architecture with the aim to ease as much as possible the future reuse of the model in analyzing climate change scenarios has also been a challenging goal of the research
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