Fiscal shocks and budget balance persistence in the EU countries from Central and Eastern Europe

This paper analyses the time series properties of the fiscal balance in the 10 EU countries from Central and Eastern Europe. The persistence of shocks in the variable has been analysed by means of unit root tests that account for the possibility of non-linearities and structural changes. The results of the linear and non-linear unit root tests find only mild evidence in favour of the stationarity hypothesis, with asymmetric effects present in a few cases. After controlling for structural changes in the data generation process, the results point to stochastic stationarity of the series. Thus, in spite relatively steady headline figures, the public balance processes exhibit substantial instability in the EU countries from Central and Eastern Europe.Unit roots, structural breaks, budget balance, EU

Parallel Graph Transformation for Model Simulation applied to Timed Transition Petri Nets

Proceedings of the Workshop on Graph Transformation and Visual Modelling Techniques (GT-VMT 2004)This work discusses the use of parallel graph transformation systems for (multi-formalism) modeling and simulation and their implementation in the meta-modeling tool AToM3. As an example, a simulator for Timed Transition Petri Nets (TTPN) is modeled using parallel graph transformation.This work has been partially sponsored by the SEGRAVIS network and the Spanish Ministry of Science and Technology (TIC2002-01948)

Automatic vertebrae localization from CT scans using volumetric descriptors

The localization and identification of vertebrae in spinal CT images plays an important role in many clinical applications, such as spinal disease diagnosis, surgery planning, and post-surgery assessment. However, automatic vertebrae localization presents numerous challenges due to partial visibility, appearance similarity of different vertebrae, varying data quality, and the presence of pathologies. Most existing methods require prior information on which vertebrae are present in a scan, and perform poorly on pathological cases, making them of little practical value. In this paper we describe three novel types of local information descriptors which are used to build more complex contextual features, and train a random forest classifier. The three features are progressively more complex, systematically addressing a greater number of limitations of the current state of the art.Postprin

Unit Labour Costs and the Dynamics of Output and Unemployment in the South ern European Crisis Countries

The GIPS countries, the south ern European crisis countries, have seen depressed output dynamics and high unemployment rates during the great recession following the 2007 - 2008 financial crisis . Th is paper considers the effects of measures that seek to improve competitiveness by reducing real unit labour costs. The results are deriv ed in structural vector autoregressive models for each of t he GIPS counties as well as two reference countries , Germany and the Netherlands. The responses of output and unemployment to innovations in real unit labour costs are economically and statistically significant for Germany and the Netherlands, whereas the responses are typically muted and imprecise estimated for the GIPS countries. The small and uncertain effects raise doubts regarding the efficacy of measures that seek to lower real unit labour costs in the GIPS countrie

Phasemeter core for intersatellite laser heterodyne interferometry: modelling, simulations and experiments

Inter satellite laser interferometry is a central component of future space-borne gravity instruments like LISA, eLISA, NGO and future geodesy missions. The inherently small laser wavelength allows to measure distance variations with extremely high precision by interfering a reference beam with a measurement beam. The readout of such interferometers is often based on tracking phasemeters, able to measure the phase of an incoming beatnote with high precision over a wide range of frequencies. The implementation of such phasemeters is based on all digital phase-locked loops, hosted in FPGAs. Here we present a precise model of an all digital phase locked loop that allows to design such a readout algorithm and we support our analysis by numerical performance measurements and experiments with analog signals.Comment: 17 pages, 6 figures, accepted for publication in CQ

Ab initio thermodynamics of hydrocarbons relevant to graphene growth at solid and liquid Cu surfaces

Using ab initio thermodynamics, the stability of a wide range of hydrocarbon adsorbates under various chemical vapor deposition (CVD) conditions (temperature, methane and hydrogen pressures) used in experimental graphene growth protocols at solid and liquid Cu surfaces has been explored. At the employed high growth temperatures around the melting point of Cu, we find that commonly used thermodynamic models such as the harmonic oscillator model may no longer be accurate. Instead, we account for the translational and rotational mobility of adsorbates using a recently developed hindered translator and rotator model or a two-dimensional ideal gas model. The thermodynamic considerations turn out to be crucial for explaining experimental results and allow us to improve and extend the findings of earlier theoretical studies regarding the role of hydrogen and hydrocarbon species in CVD. In particular, we find that smaller hydrocarbons will completely dehydrogenate under most CVD conditions. For larger clusters our results show that metal-terminated and hydrogen-terminated edges have very similar stabilities. While both cluster types might thus form during the experiment, we show that the low binding strength of clusters with hydrogen-terminated edges could result in instability towards desorption

Computational design of chemical nanosensors: Transition metal doped single-walled carbon nanotubes

We present a general approach to the computational design of nanostructured chemical sensors. The scheme is based on identification and calculation of microscopic descriptors (design parameters) which are used as input to a thermodynamic model to obtain the relevant macroscopic properties. In particular, we consider the functionalization of a (6,6) metallic armchair single-walled carbon nanotube (SWNT) by nine different 3d transition metal (TM) atoms occupying three types of vacancies. For six gas molecules (N_{2}, O_{2}, H_{2}O, CO, NH_{3}, H_{2}S) we calculate the binding energy and change in conductance due to adsorption on each of the 27 TM sites. For a given type of TM functionalization, this allows us to obtain the equilibrium coverage and change in conductance as a function of the partial pressure of the "target" molecule in a background of atmospheric air. Specifically, we show how Ni and Cu doped metallic (6,6) SWNTs may work as effective multifunctional sensors for both CO and NH_{3}. In this way, the scheme presented allows one to obtain macroscopic device characteristics and performance data for nanoscale (in this case SWNT) based devices.Comment: Chapter 7 in "Chemical Sensors: Simulation and Modeling", Ghenadii Korotcenkov (ed.), 47 pages, 22 figures, 10 table

Biparental inbreeding depression, genetic relatedness and progeny vigor in a wind-pollinated treeline species in Argentina

Spatially restricted gene flow and resulting spatial genetic structure are generally considered as being the primary controlling factors in the dynamics of biparental inbreeding depression in a wide range of plant species. However, wind-pollinated angiosperm trees have not been adequately studied in this respect. The present study analyses the relationships between parental genetic similarity, outcrossing distances and progeny vigour in Polylepis australis (Rosaceae), a wind-pollinated treeline species endemic to Argentina. We investigated whether spatial genetic structuring occurs in anthropogenically fragmented P. australis woodlands of the Córdoba Mountains. We also performed a controlled crossing experiment using pollen collected from different distances. Genetic variability (using RAPD-PCR) and vigour (survival and N metabolism capacity) of the resulting progeny were contrasted with progeny from unmanipulated flowers. We found a continuous decrease in parental genetic similarity with spatial distance among mates and an increase in genetic variability, survival and N metabolism capacity in the progeny produced from pollen at increasing distances. However, our further results suggest fragment connectivity in P. australis through effective long-distance pollen-mediated gene flow with no effective inbreeding depression problems observed under present day conditions.Fil: Seltmann, Peggy. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Hensen, Isabell. Martin-Luther-University Halle-Wittenberg; AlemaniaFil: Renison, Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones Biológicas y Tecnológicas. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales. Instituto de Investigaciones Biológicas y Tecnológicas; ArgentinaFil: Wesche, Karsten. University of Göttingen; AlemaniaFil: Ploch, Sebastián. University of Hohenheim; AlemaniaFil: Rondan Dueñas, Juan. Universidad Nacional de Córdoba; ArgentinaFil: Cocucci, Andrea Aristides. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Jung, Klaus. Helmholtz Centre for Environmental Research-UFZ; Alemani

Termination Criteria for Model Transformation

Nowadays the usage of model transformations in software engineering has become widespread. Considering current trends in software development such as model driven development (MDD), there is an emerging need to develop model manipulations such as model evolution and optimisation, semantics definition, etc. If a model transformation is described in a precise way, it can be analysed lateron. Models, especially visual models, can be described best by graphs, due to their multi-dimensional extension. Graphs can be manipulated by graph transformation in a rule-based manner. Thus, we specify model transformation by graph transformation. This approach offers visual and formal techniques in such a way that model transformations can be subjects to analysis. Various results on graph transformation can be used to prove important properties of model transformations such as its functional behaviour, a basic property for computations. Moreover, certain kinds of syntactical and semantical consistency properties can be shown on this formal basis