841 research outputs found
Uncovering the parliamentary roots of European social policy
No full textThe creation of a European social policy has been a long-held goal of many political actors across Europe. Drawing on a new book, Mechthild Roos shows how the early European Parliament was pivotal in establishing this social dimension to European policymaking
Studying the informal in European integration: a research guide
No full textThis chapter aims to offer a guide for scholars from both political science and history to the study of informality. It conceptualises informality and discusses a variety of theories, methods and source types on which an analysis of the informal can be based. The chapter starts off with an overview of the dominating definitions of informality. It focuses notably on works from political science, since most existing conceptualisations of informality in European integration have been undertaken by scholars within that discipline. However, the chapter also builds on historical research concerning informal aspects in European integration: even though these studies rarely conceptualise the study of informality, they offer important insights for instance into the interplay of formal and informal processes, as well as with regard to source material when it comes to tracing the seemingly invisible. The chapter addresses various issues arising in the process of studying the informal, such as pitfalls in terms of available or unavailable data. Finally, the chapter offers some guidance on where to look for informality in European integration, and how to structure a research agenda accordingly
How informality can play out in European integration
No full textThis concluding chapter argues that the ambition to study informality more systematically
should not be allowed to obscure the fact that historians have often already looked into
informal aspects of European integration, but refrained from claiming it openly. The point is
thus not to start studying informal aspects of European integration, but instead to do it
consciously, explicitly, and systematically. Based on the various contributions in this volume
as well as further historiographical examples, this chapter surveys the ways in which
informality can be defined, then provides some examples where informality can already be
found in the historiography of postwar European cooperation and integration, appraises how
the chapters in this volume can be categorised, and finally explores what this can indicate for
future research
Of treaties, conventions and habits: how informal integration interacts with formal integration
No full textLarge-Update Infeasible Interior-Point Methods for Linear Optimization
No full textRecently, C. Roos proposed a full-Newton step infeasible interior-point method (IIPM) for linear optimization (LO). Shortly afterwards, Mansouri and Roos presented a variant of this algorithm and Gu et al. a version with a simplified analysis. Roos' algorithm is a path-following method. It uses the so-called homotopy path as a guideline to an optimal solution. The algorithm has the advantage that it uses only full Newton steps (the step size is always 1, hence requires no computation), and its convergence rate is O(n), which coincides with the best known convergence rate for IIPMs. Apart from these nice features, the algorithm has the deficiency that it is a small-update method and hence it is too slow for practical purposes. In this thesis we design a large-update version of Roos' algorithm. We present a practically efficient implementation of (a variant of) the algorithm and compare its performance with that of the well- known LIPSOL package. The numerical results are promising as the iteration numbers of our algorithm are close to those of LIPSOL; in a few cases they outperform LIPSOL. Not surprisingly, as in large-update feasible interior-point methods (FIPMs), there is a gap between the practical and the theoretical behavior of our large-update IIPM. To be more precise, its theoretical convergence rate is O(n?n (log n)³) which is worse than the convergence rate of its full-Newton step variant. This phenomenon is well-known in the field of IPMs, and has been called the irony of IPMs: small-update methods have the best complexity results and are slow in practice, whereas large-update methods have worse complexity results and excellent performance in practice. For example, large-update FIPMs are by a factor worse than that of the full-Newton step FIPMs, i.e., O(?nlogn) versus O(?n). The thesis also contains a survey of IIPMs that have been presented by several authors in last two decades. It covers a wide range of methods, starting from Lustig's algorithm, to the infeasible potential-reduction methods of Mizuno, Kojima and Todd. We focus on convergence properties and polynomiality of the IIPMs presented in our survey.EWIElectrical Engineering, Mathematics and Computer Scienc
What's on a machine's mind? Models for reasoning with incomplete and uncertain knowledge
No full textElectrical Engineering, Mathematics and Computer Scienc
Counterexample to a Conjecture on an Infeasible Interior-Point Method
No full textIn [SIAM J. Optim., 16 (2006), pp. 1110–1136], Roos proved that the devised full-step infeasible algorithm has worst-case iteration complexity. This complexity bound depends linearly on a parameter , which is proved to be less than . Based on extensive computational evidence (hundreds of thousands of randomly generated problems), Roos conjectured that (Conjecture 5.1 in the above-mentioned paper), which would yield an iteration full-Newton step infeasible interior-point algorithm. In this paper we present an example showing that is in the order of , the same order as that proved in Roos's original paper. In other words, the conjecture is false.Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
Full-step interior-point methods for symmetric optimization
No full textIn [SIAM J. Optim., 16(4):1110--1136 (electronic), 2006] Roos proposed a full-Newton step Infeasible Interior-Point Method (IIPM) for Linear Optimization (LO). It is a primal-dual homotopy method; it differs from the classical IIPMs in that it uses only full steps. This means that no line searches are needed. In this thesis, we first present an improved full-Newton step IIPM for LO. Then, based on the properties of Euclidean Jordan algebras, we generalize the improved full-Newton step IIPM for LO to full Nesterov-Todd step (NT-step) IIPM for Symmetric Optimization (SO). Since the analysis requires a quadratic convergence result for the feasible case, primal-dual feasible IPMs with full steps are presented as well. Although our devised IIPMs admit the best known iteration bound, from a practical perspective they are not efficient. This is because they always perform according to their worst-case theoretical complexity bounds, which means that only tiny reductions of the so-called barrier parameter are admitted. As a remedy, we propose a more aggressive (adaptive) updating strategy. Finally, our full NT-step IIPM for SO is implemented with both standard and adaptive updates of the barrier parameter. The significant improvement in performance of the adaptive updating strategy over the original short updating strategy is illustrated. The algorithm with adaptive updates is also used to solve problems from the well known library SDPLIB [Optim. Methods Softw., 11/12(1-4):683--690, 1999] of test problems. The results are promising, and to some extend competing with SDPT3 [Math. Program., 95(2, Ser. B):189--217, 2003].Software TechnologyElectrical Engineering, Mathematics and Computer Scienc
Guest Post: Julia Roos' Response to Victoria Harris
No full textJulia Roos, the author of Weimar through the Lens of Gender, has asked the Weimar Studies Network to publish her response to Victoria Harris' review of her book in the current issue of German History. We happily comply with her request, as the support of a lively scholarly debate is the stated aim of this forum. However, the opinions expressed in the following text are those of the author, and do not necessarily reflect those of the editors. "Victoria Harris and I disagree in our evaluation ..
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