The admission of accession countries to an enlarged monetary union: a tentative assessment

The enlargement of the European monetary union to include the accession countries (ACs) will not lead to higher average inflation in the enlarged euro area, but only to inflation redistribution across countries if continuity of the monetary policy framework is preserved. In the short term, unanticipated shocks to the real exchange rate may instead affect aggregate inflation if member countries' economic structure differs. When comparing welfare, inflation and output stabilisation, we find that the size, differences in economic structure and the variance-covariance matrix of supply and real exchange rate shocks play a key role. The numerical results indicate that the implications for the euro area are significant only if we assume a strong real exchange rate appreciation and if ACs are weighted in terms of purchasing power parity standards. In the event of real exchange rate or country-specific supply shocks in ACs, the consequences would be limited for both the current and the enlarged euro area, but sizeable for ACs themselves. JEL Classification: E52, E58, F33, F40Accession Countries, Balassa-Samuelson Effect, European Monetary Union, Exchange Rate Regimes, monetary policy

The Eastward Enlargement of the European Monetary Union

The enlargement of the European monetary union to include new EU Member States (NMs) will not lead to higher expected inflation in the enlarged euro area, but only to some redistribution of inflation at the country level, if the policy framework of the monetary authority remains invariant. Shocks to the real exchange rate may affect instead aggregate inflation, if member countries' economic structure differs. The numerical results indicate that the impact on steady state inflation of the current euro area is limited if participating countries are weighted on the basis of nominal GDP and if the upward pressure on the real exchange rate is postulated to be in line with most estimates of the Balassa-Samuelson effect. In the event of real exchange rate or country-specific supply shocks in NMs, the consequences are found to be limited for the current and the enlarged euro area, but sizeable for the NMs themselves.EMU; enlargement; East-Central Europe

Welfare implications of joining a common currency

This paper examines the welfare implications of a country joining a currency union as opposed to operating in a flexible exchange rate regime. At the country level, the suboptimal response to domestic and foreign shocks and the inability of setting inflation at the desired level may be offset by a positive impact on potential output. We show that for entry to be welfare enhancing, the potential output gain must be the larger, the smaller the country, the larger the difference between the standard deviation of supply shocks across the participating countries, the smaller the correlation of countries’ supply shocks and the larger the variance of real exchange rate shocks. JEL Classification: E52, E58, F33, F40Balassa-Samuelson Effect, Currency union, monetary policy, Welfare

Scanning integer points with lex-inequalities: A finite cutting plane algorithm for integer programming with linear objective

We consider the integer points in a unimodular cone K ordered by a lexicographic rule defined by a lattice basis. To each integer point x in K we associate a family of inequalities (lex-cuts) that defines the convex hull of the integer points in K that are not lexicographically smaller than x. The family of lex-cuts contains the Chvatal-Gomory cuts, but does not contain and is not contained in the family of split cuts. This provides a finite cutting plane method to solve the integer program min{cx : x \in S \cap Z^n }, where S \subset R^n is a compact set and c \in Z^n . We analyze the number of iterations of our algorithm.Comment: 16 pages, 1 figur

Sensitivity-Based Model of Low Voltage Distribution Systems with Distributed Energy Resources

A key issue in Low Voltage(LV) distribution systems is to identify strategies for the optimal management and control in the presence of Distributed Energy Resources (DERs). To reduce the number of variables to be monitored and controlled, virtual levels of aggregation, called Virtual Microgrids (VMs), are introduced and identified by using new models of the distribution system. To this aim, this paper, revisiting and improving the approach outlined in a conference paper, presents a sensitivity-based model of an LV distribution system, supplied by a Medium/Low Voltage (MV/LV) substation and composed by several feeders, which is suitable for the optimal management and control of the grid and for VM definition. The main features of the proposed method are: it evaluates the sensitivity coefficients in a closed form; it provides an overview of the sensitivity of the network to the variations of each DER connected to the grid; and it presents a limited computational burden. A comparison of the proposed method with both the exact load flow solutions and a perturb-and-observe method is discussed in a case study. Finally, the method is used to evaluate the impact of the DERs on the nodal voltages of the network

Harmonic Distortion Reduction of Transformer-Less Grid-Connected Converters by Ellipsoidal-Based Robust Control

A photovoltaic generator connected to a large network and supplying a nonlinear load (source of harmonics) injects distorted current into the grid. This manuscript presents an invariant-ellipsoid set design of a robust controlled active power filter to inject current into the large grid with minimum total harmonic distortion (THD). The nonlinear load current is considered an external disturbance to minimize its effect on the injected grid current. Moreover, the large grid is modeled as a fixed voltage source in a series with a Thevenin impedance whose value changes within an interval. Using the invariant-ellipsoid technique, the problem is cast as a robust disturbance-rejection tracking control. The volume of the ellipsoid is minimized, which results in minimizing the effect of disturbance on system performance and keeping the trajectories as close as possible to the origin. The design is cast into a set of nonlinear matrix inequalities that are linearized by fixing a scalar. The resulting convex optimization is solved iteratively by linear matrix inequalities (LMIs). The simulation and experimental findings show that the proposed design is successful in reducing THD injected into the grid when grid impedance is uncertain and variable loads are applied (balanced and unbalanced cases)

Density Distribution Maps: A Novel Tool for Subcellular Distribution Analysis and Quantitative Biomedical Imaging

open5noSubcellular spatial location is an essential descriptor of molecules biological function. Presently, super-resolution microscopy techniques enable quantification of subcellular objects distribution in fluorescence images, but they rely on instrumentation, tools and expertise not constituting a default for most of laboratories. We propose a method that allows resolving subcellular structures location by reinforcing each single pixel position with the information from surroundings. Although designed for entry-level laboratory equipment with common resolution powers, our method is independent from imaging device resolution, and thus can benefit also super-resolution microscopy. The approach permits to generate density distribution maps (DDMs) informative of both objects’ absolute location and self-relative displacement, thus practically reducing location uncertainty and increasing the accuracy of signal mapping. This work proves the capability of the DDMs to: (a) improve the informativeness of spatial distributions; (b) empower subcellular molecules distributions analysis; (c) extend their applicability beyond mere spatial object mapping. Finally, the possibility of enhancing or even disclosing latent distributions can concretely speed-up routine, large-scale and follow-up experiments, besides representing a benefit for all spatial distribution studies, independently of the image acquisition resolution. DDMaker, a Software endowed with a user-friendly Graphical User Interface (GUI), is also provided to support users in DDMs creation.openIlaria De Santis; Michele Zanoni; Chiara Arienti; Alessandro Bevilacqua; Anna TeseiIlaria De Santis; Michele Zanoni; Chiara Arienti; Alessandro Bevilacqua; Anna Tese