Search results for "convergence"

Beyond second-order convergence in simulations of binary neutron stars in full general relativity

2014

Despite the recent rapid progress in numerical relativity, a convergence order less than the second has so far plagued codes solving the Einstein-Euler system of equations. We report simulations of the inspiral of binary neutron stars in quasi-circular orbits computed with a new code employing high-order, high-resolution shock-capturing, finite-differencing schemes that, for the first time, go beyond the second-order barrier. In particular, without any tuning or alignment, we measure a convergence order above three both in the phase and in the amplitude of the gravitational waves. Because the new code is able to calculate waveforms with very small phase errors already at modest resolutions,…

Collegial or Managerial? Academics' Conceptions of Quality in English and Finnish Universities

2009

Two specific forms of quality are identified: Type I, which has a managerial focus and stresses fitness for purpose and accountability, and Type II, which is collegial and concerned with enhancement. Through an analysis of the literature on quality in higher education and small-scale empirical research with a sample of academic staff, this article compares conceptions of quality assurance in the English and Finnish higher education systems. The authors highlight the similarities and differences in the two countries and possible reasons for them. Over time the blend of managerial and collegial approaches to quality has come to favour the former but much more so in England than in Finland, wh…

Mating (marriage) patterns and economic development

2011

This paper looks at the relationship between economic development and mating (marriage) patterns in the very long run. For this purpose we introduce the Goldin and the Kuznets curves which relate female labour and income inequality with economic development respectively. To some extent, the Goldin and the Kuznets curves have followed opposite paths, which in turn, could illustrate how economic development has had an impact on mating (marriage) patterns, and thus household formation. Convergence in mating patterns among hunter-gatherers across societies vanished after the Neolithic revolution. Then, African polygyny and the ‘European’ marriage pattern developed into the most significant exce…

Road to unity? : Nordic economic convergence in the long run

2022

This study examines Nordic economic convergence from the sixteenth to twentieth century respective of the economic leaders, in effect the UK before 1914 and USA thereafter. The paper uses a novel approach of combining the analysis of both GDP and wages. The examination of real GDP per capita suggests that there was a catch-up process in play, both with the economic leaders and among the Nordic states, from the early nineteenth century onwards. However, the examination of the adjusted silver wages suggests convergence among the Nordic economies by the end of the eighteenth century. Therefore, we argue, no single Nordic Model emerged from these development patterns, even though the Nordic sta…

On Legal Cooperation and the Dynamics of Legal Convergence

2010

In this paper, we study the dynamics of legal convergence and the comparison between the different instruments of legal convergence based on cooperative strategies (i.e., harmonization and unification) or not. To study these questions we use a model with two nation-states which is inspired in part by that used in Carbonara and Parisi (2008) where preferences of each nation-state are such that it is costly to change the law, but it is also costly to have a different legal system from the other nation-state. We show that legal unification could be achieved in the long-run through small step by step changes despite the existence of huge harmonization costs in the short run. We also show that l…

Technological differences and convergence in the OECD

2000

Abstract. In this paper we test the homogeneity of the technological parameters among OECD countries, which is the maintained hypothesis in most of the empirical growth literature. We first identify differences in the constant term of the convergence equation estimated for the OECD 1960/1990 sample using a fixed- effects estimator. Then we provide a formal test of the homogeneity of technological parameters across groups of countries. We identify at least two different groups within the OECD, with significantly different technologies. Convergence within each group is fast, supporting the notion of club convergence. Nevertheless, the implausible parameter values obtained for the leading tech…

Mapping discounted and undiscounted Markov Decision Problems onto Hopfield neural networks

1995

This paper presents a framework for mapping the value-iteration and related successive approximation methods for Markov Decision Problems onto Hopfield neural networks, for both discounted and undiscounted versions of the finite state and action spaces. We analyse the asymptotic behaviour of the control sets and we give some estimates on the convergence rate for the value-iteration scheme. We relate the convergence properties on an energy function which represents the key point in mapping Markov Decision Problems onto Hopfield networks. Finally, an application from queueing systems in communication networks is taken into consideration and the results of computer simulation of Hopfield netwo…

Direct perturbation theory in terms of energy derivatives: scalar-relativistic treatment up to sixth order.

2011

A formulation of sixth-order direct perturbation theory (DPT) to treat relativistic effects in quantum-chemical calculations is presented in the framework of derivative theory. Detailed expressions for DPT6 are given at the Hartree-Fock level in terms of the third derivative of the energy with respect to the relativistic perturbation parameter defined as λ(rel)=c(-2). They were implemented for the computation of scalar-relativistic energy corrections. The convergence of the scalar-relativistic DPT expansion is studied for energies and first-order properties such as dipole moment and electric-field gradient within the series of the hydrogen halides (HX, X = F, Cl, Br, I, and At). Comparison …

Boundary regularity and the uniform convergence of quasiconformal mappings

1979

Visual Servoing Based on Shifted Moments

2015

Over the past decade, image moments have been exploited in several visual servoing schemes for their ability to represent object regions, objects defined by contours or a set of discrete points. Moments have also been useful to achieve control decoupling properties and to choose a minimal number of features to control the whole degrees of freedom (DOFs) of a camera. However, the choice of moment-based features to control the rotational motions around the $x$ -axis and $y$ -axis simultaneously with the translational motions along the same axis remains a key issue. In this paper, we introduce new visual features computed from low-order “shifted moments invariant.” Importantly, they allow us 1…