Population ageing and public pension reforms in a small open economy

This paper aims to address the issue of public pension reforms under demographic ageing that is likely to occur in Europe over the next 50 years. Three possible scenarios are analysed in a Blanchard OLG framework. These include: i) a decrease both in public pensions and the lump sum labour income tax, ii) a decrease both in public pensions and the distortionary corporate tax, iii) an increase in the retirement age. The analysis focuses on the effects of these fiscal policies on key economic variables such as consumption, private and public debt, output and wages. Quantitative experiments assess the impact of different fiscal policies in terms of public debt sustainability but most importantly suggest policies that smooth the transition of the economy to the new equilibrium. The main results suggest that the adverse effects of pension reforms on consumption are moderated when they are accompanied by appropriate taxation policies. In particular, when the tax response is rapid most of the adverse movement in consumption is avoided while public and national debt reach lower equilibrium levels

Fiscal variables and bond spreads: evidence from eastern European countries and Turkey

We investigate the impact of fiscal variables on bond yield spreads relative to US Treasury bonds in the Czech Republic, Hungary, Poland, Russia and Turkey from May 1998 to December 2007. To account for the importance of market expectations we use projected values for fiscal and macroeconomic variables generated from Consensus Economics Forecasts. Moreover, we compare results from panel regressions with those from country (seemingly unrelated regression) estimates, and conduct analogous regressions for a control group of Latin American countries. We find that the role of the individual explanatory variables, including the importance of fiscal variables, varies across countries. JEL Classification: C33, E43, E62, H62Budget deficits, determination of interest rates, Eastern European countries, Fiscal Policy

Fiscal variables and bond spreads: evidence from eastern European countries and Turkey

We investigate the impact of fiscal variables on bond yield spreads relative to US Treasury bonds in the Czech Republic, Hungary, Poland, Russia and Turkey from May 1998 to December 2007. To account for the importance of market expectations we use projected values for fiscal and macroeconomic variables generated from Consensus Economics Forecasts. Moreover, we compare results from panel regressions with those from country (seemingly unrelated regression) estimates, and conduct analogous regressions for a control group of Latin American countries. We find that the role of the individual explanatory variables, including the importance of fiscal variables, varies across countries

ClassCut for Unsupervised Class Segmentation

Abstract. We propose a novel method for unsupervised class segmentation on a set of images. It alternates between segmenting object instances and learning a class model. The method is based on a segmentation energy defined over all images at the same time, which can be optimized efficiently by techniques used before in interactive segmentation. Over iterations, our method progressively learns a class model by integrating observations over all images. In addition to appearance, this model captures the location and shape of the class with respect to an automatically determined coordinate frame common across images. This frame allows us to build stronger shape and location models, similar to those used in object class detection. Our method is inspired by interactive segmentation methods [1], but it is fully automatic and learns models characteristic for the object class rather than specific to one particular object/image. We experimentally demonstrate on the Caltech4, Caltech101, and Weizmann horses datasets that our method (a) transfers class knowledge across images and this improves results compared to segmenting every image independently; (b) outperforms Grabcut [1] for the task of unsupervised segmentation; (c) offers competitive performance compared to the state-of-the-art in unsupervised segmentation and in particular it outperforms the topic model [2].

Dynamical mean-field theory of indirect magnetic exchange

To analyze the physical properties arising from indirect magnetic exchange between several magnetic adatoms and between complex magnetic nanostructures on metallic surfaces, the real-space extension of dynamical mean-field theory (R-DMFT) appears attractive as it can be applied to systems of almost arbitrary geometry and complexity. While R-DMFT describes the Kondo effect of a single adatom exactly, indirect magnetic (RKKY) exchange is taken into account on an approximate level only. Here, we consider a simplified model system consisting of two magnetic Hubbard sites ("adatoms") hybridizing with a non-interacting tight-binding chain ("substrate surface"). This two-impurity Anderson model incorporates the competition between the Kondo effect and indirect exchange but is amenable to an exact numerical solution via the density-matrix renormalization group (DMRG). The particle-hole symmetric model at half-filling and zero temperature is used to benchmark R-DMFT results for the magnetic coupling between the two adatoms and for the magnetic properties induced in the substrate. In particular, the dependence of the local adatom and the nonlocal adatom-adatom static susceptibilities as well as the magnetic response of the substrate on the distance between the adatoms and on the strength of their coupling with the substrate is studied. We find both, excellent agreement with the DMRG data even on subtle details of the competition between RKKY exchange and the Kondo effect but also complete failure of the R-DMFT, depending on the parameter regime considered. R-DMFT calculations are performed using the Lanczos method as impurity solver. With the real-space extension of the two-site DMFT, we also benchmark a simplified R-DMFT variant.Comment: 14 pages, 8 figure

Xtru3D: Single-View 3D Object Reconstruction from Color and Depth Data

D object reconstruction from single image has been a noticeable research trend in recent years. The most common method is to rely on symmetries of real-life objects, but these are hard to compute in practice. However, a large class of everyday objects, especially when manufactured, can be generated by extruding a 2D shape through an extrusion axis. This paper proposes to exploit this property to acquire 3D object models using a single RGB+Depth image, such as those provided by available low-cost range cameras. It estimates the hidden parts by exploiting the geometrical properties of everyday objects, and both depth and color information are combined to refine the model of the object of interest. Experimental results on a set of 12 common objects are shown to demonstrate not only the effectiveness and simplicity of our approach, but also its applicability for tasks such as robotic grasping.The research leading to these results has been funded by the HANDLE European project (FP7/2007-2013) under grant agreement ICT 231640-http://www.handle-project.eu.Publicad

Nonequilibrium effects due to charge fluctuations in intrinsic Josephson systems

Nonequilibrium effects in layered superconductors forming a stack of intrinsic Josephson junctions are investigated. We discuss two basic nonequilibrium effects caused by charge fluctuations on the superconducting layers: a) the shift of the chemical potential of the condensate and b) charge imbalance of quasi-particles, and study their influence on IV-curves and the position of Shapiro steps.Comment: 17 pages, 2 figures, revised version slightly shortene

Deep Learning for Vanishing Point Detection Using an Inverse Gnomonic Projection

We present a novel approach for vanishing point detection from uncalibrated monocular images. In contrast to state-of-the-art, we make no a priori assumptions about the observed scene. Our method is based on a convolutional neural network (CNN) which does not use natural images, but a Gaussian sphere representation arising from an inverse gnomonic projection of lines detected in an image. This allows us to rely on synthetic data for training, eliminating the need for labelled images. Our method achieves competitive performance on three horizon estimation benchmark datasets. We further highlight some additional use cases for which our vanishing point detection algorithm can be used.Comment: Accepted for publication at German Conference on Pattern Recognition (GCPR) 2017. This research was supported by German Research Foundation DFG within Priority Research Programme 1894 "Volunteered Geographic Information: Interpretation, Visualisation and Social Computing

Charge-imbalance effects in intrinsic Josephson systems

We report on two types of experiments with intrinsic Josephson systems made from layered superconductors which show clear evidence of nonequilibrium effects: 1. In 2-point measurements of IV-curves in the presence of high- frequency radiation a shift of the voltage of Shapiro steps from the canonical value hf/(2e) has been observed. 2. In the IV-curves of double-mesa structures an influence of the current through one mesa on the voltage measured on the other mesa is detected. Both effects can be explained by charge-imbalance on the superconducting layers produced by the quasi-particle current, and can be described successfully by a recently developed theory of nonequilibrium effects in intrinsic Josephson systems.Comment: 8pages, 9figures, submitted to Phys. Rev.

Field-aligned current associated with low-latitude plasma blobs as observed by the CHAMP satellite

Here we give two examples of low-latitude plasma blobs accompanied by linearly polarized perpendicular magnetic deflections which imply that associated field-aligned currents (FACs) have a 2-D sheet structure located at the blob walls. The estimated FAC density is of the order of 0.1 μA/m<sup>2</sup>. The direction of magnetic deflections points westward of the magnetic meridian and there is a linear correlation between perpendicular and parallel variations. All these properties are similar to those of equatorial plasma bubbles (EPBs). According to CHAMP observations from August 2000 to July 2004, blobs show except for these two good examples no clear signatures of 2-D FAC sheets at the walls. Generally, perpendicular magnetic deflections inside blobs are weaker than inside EPBs on average. Our results are consistent with existing theories: if a blob exists, (1) a significant part of EPB FAC will be closed through it, exhibiting similar perpendicular magnetic deflection inside EPBs and blobs, (2) the FAC closure through blobs leads to smaller perpendicular magnetic deflection at its poleward/downward side, and (3) superposition of different FAC elements might result in a complex magnetic signature around blobs