Multiple coverings with closed polygons

A planar set $P$ is said to be cover-decomposable if there is a constant $k=k(P)$ such that every $k$-fold covering of the plane with translates of $P$ can be decomposed into two coverings. It is known that open convex polygons are cover-decomposable. Here we show that closed, centrally symmetric convex polygons are also cover-decomposable. We also show that an infinite-fold covering of the plane with translates of $P$ can be decomposed into two infinite-fold coverings. Both results hold for coverings of any subset of the plane.Comment: arXiv admin note: text overlap with arXiv:1009.4641 by other author

Double or quits: should money found be risked?

This article examines social attitudes towards risk-preference and risk-aversion. First, we briefly discuss the theoretical approach to the analysis of risk-preference and risk-aversion that was developed within rational choice theory. Next, we present an approach to operationalise risk-preference using survey data. Our measurement of attitudes towards risk follows the usual strategy: respondents are asked to choose between a small amount of money they get for sure, and a large but risky amount. Drawing on the theoretical models and earlier empirical research, we formulate hypotheses about the social factors that have an impact on actual decision making in the situations under study. The hypotheses are tested using survey data. The article ends with a brief discussion. The novelty of our paper is that – to the best of our knowledge – neither previous Hungarian nor international research has attempted to examine attitudes towards risk using data from large-scale surveys

Liquidity Constraints and Consumer Impatience

In recent years significant changes have been observed in household saving and consumption behavior in several transition countries including Hungary. In the second half of the 1990s the financial saving rate fell markedly and household borrowing surged. These developments are not unique to Hungary, they correspond to the experience of other emerging countries, and they can be attributed above all to financial liberalization and modernization and the improving permanent income prospects of households, with prospective EU accession playing an important role in the improving income perception. We believe that declining saving rates and increasing indebtedness in accession countries will be important issues in the following years, even after joining the EU – as the example of less developed EU members shows. The phenomena of declining saving rates and increasing indebtedness are, of course, not unique to EU accession countries, they were observed in other emerging countries, too – e.g. in Latin America -, but these developments have special aspects in Eastern and Central Europe. One special aspect is prospective EU accession, which is perceived to be close and certain enough to contribute to the rise in future income expectations. Another special aspect is the reaction of other sectors of the economy to deteriorating net household position. Emerging market experience shows that declining household savings were offset by increasing corporate savings in some countries and by a rise in public savings in others (often along with a temporary deterioration of the current account). As Eastern and Central European countries wish to join the EMU as soon as possible, they will do their best to meet the Maastricht criteria, which involves limits on the budget deficit and public debt. This implies an additional incentive for the public sector to be the one that does the major adjustment to the decline in household saving rates in most accession countries. In this regard, we think that our paper is not only relevant for Hungary, but it has implication for other Eastern and Central European countries as well. The paper is organized as follows: Chapter 1 summarizes recent research on Hungarian household savings based both on macro indicators and survey data, while Chapter 2 gives a brief description of the evolution of Hungarian aggregate indicators for financial wealth, assets and liabilities. Chapter 3 analyzes data obtained from a special survey conducted in September 2000. The survey questions were supplied by the authors and were constructed to gain insight into prevailing liquidity constraints, consumer impatience, households’ attitude towards indebtedness, and to separate „financially relevant” households, i.e. households with financial assets and/or liabilities, because these are the groups that are most relevant for economic policymakers. The paper also contains estimations of the propensity to borrow. Based on the survey questions, special indicators, such as income tension, consumer impatience are constructed and used – among others - as explanatory variables in the regressions. The standard framework for analysis of household saving and consumption behavior is the life-cycle hypothesis. We do not aim to give a review of the life-cycle theory here, see Deaton (1992) or Browning and Lusardi (1996) for excellent surveys. Most empirical tests of the life-cycle hypothesis examine excess sensitivity and the significance of precautionary savings. Our paper has different aims, but it still relates to the life-cycle theory in several respects when we discuss the reasons for saving, consumer impatience, and the propensity to borrow.

The imperium of the Slovaks of the Great Hungarian Plain, 1918-1920

For the bigger part of the First World War, Slovaks emphasized their loyalty to the Hungarian government. From February 1918 on, the Slovak politicians started to activate themselves in the political life. Slovak political parties gathered to hold a confidential meeting on May 26, 1918, where the Slovak National Party was given a mandate for the central representation of the interests of Slovaks. On the other hand, the political climate only became favorable by the end of October 1918 in order to manifest this intention. Contemplating solutions and brooding no longer tying them up, they had a more pressing task at hand: to decide on the form of independent national life. The Slovaks of the Great Hungarian Plain tried to orient themselves, but the international political situation was changing permanently, and for this reason they could not get important information and decisions from abroad, which could help them to make their choice. Thus, they wavered between approaching Serbia, becoming an “independent republic" (The imperium of the Slovaks of the Great Hungarian Plain), and approaching Romania. Finally, the peace talks left the area of their settlements under Hungarian control, which resulted in the immediate exile of exposed individuals. The phrase “their own Slovak Imperium” provided an opportunity though for the occupying Romanian troops. According to Lajos Hrdlička, the occupying Romanian authorities were accommodating in every sense. They were offered a chance for an independent district, “okolie”, the “Imperium Slovenské” (The Imperium of the Slovaks). The Slovaks of Békés and Csanád counties remained inside the borders of mutilated Hungary. Romanian troops were tasked with the occupation of the areas of Békés and Csanád. They successfully began building their own little “imperium”, as the Romanians called it

Numerical investigation of the dynamics of linear spin ss fields on Kerr background I. Late time tails of spin s=±1,±2s = \pm 1, \pm 2 fields

The time evolution of linear fields of spin $s = \pm 1$ and $s = \pm 2$ on Kerr black hole spacetimes are investigated by solving the homogeneous Teukolsky equation numerically. The applied numerical setup is based on a combination of conformal compactification and the hyperbolic initial value problem. The evolved basic variables are expanded in terms of spin-weighted spherical harmonics which allows us to evaluate all the angular derivatives analytically, whereas the evolution of the expansion coefficients, in the time-radial section, is determined by applying the method of lines implemented in a fourth order accurate finite differencing stencil. Concerning the initialization, in all of our investigations single mode excitations---either static or purely dynamical type initial data---are applied. Within this setup the late time tail behavior is investigated. Due to the applied conformal compactification the asymptotic decay rates are determined at three characteristic locations---in the domain of outer communication, at the event horizon and at future null infinity---simultaneously. Recently introduced new type of `energy' and `angular momentum' balance relations are also applied in order to demonstrate the feasibility and robustness of the developed numerical schema, and also to verify the proper implementation of the underlying mathematical model.Comment: 38 pages, 5 figures, typos correcte

Customer Loyalty Problems in Retail Banking

According to analyses of the most business consulting companies (KPMG, Capgemini, Deloitte, TowerGroup, etc.) customers are discontented with the retail banking experience. To achieve higher business growth, banks must increase customer loyalty by delivering a distinctive experience that combines the right mix of convenience, value and service and forges an emotional bond with consumers. Winners will be those that transform themselves into customer-centric enterprises by having a clear vision of what they want to achieve, fully aligning business processes and IT infrastructure to achieve those goals and engaging their employees in the process. The first step to do it is the identification of customer satisfaction. This paper intends to reveal its essential elements.customer loyalty, customer attitudes, retail banking