Sequentially Triggered Star Formation in OB Associations

We discuss observational evidence for sequential and triggered star formation in OB associations. We first review the star formation process in the Scorpius-Centaurus OB association, the nearest OB association to the Sun, where several recent extensive studies have allowed us to reconstruct the star formation history in a rather detailed way. We then compare the observational results with those obtained for other OB associations and with recent models of rapid cloud and star formation in the turbulent interstellar medium. We conclude that the formation of whole OB subgroups (each consisting of several thousand stars) requires large-scale triggering mechanisms such as shocks from expanding wind and supernova driven superbubbles surrounding older subgroups. Other triggering mechanisms, like radiatively driven implosion of globules, also operate, but seem to be secondary processes, forming only small stellar groups rather than whole OB subgroups with thousands of stars.Comment: Invited talk at the IAU Symposium 237: "Triggered Star Formation in a Turbulent ISM", Prague, Czech Republic, August 200

Revitalizing Multilateral Governance at the World Trade Organization Report of the High-Level Board of Experts on the Future of Global Trade Governance. Bertelsmann Policy Brief 2018

If international trade is not governed by rules, mere might dictates what is right. The World Trade Organization (WTO) serves as a place where trade policy issues are addressed, disputes arbitrated, legal frameworks derived and enforced. Through these functions, the WTO ensures that the rules of trade policy are inspired by fairness and reciprocity rather than national interest. It is more important than ever to vitalize the global public good that it rep-resents against various threats that have been undermining it. Therefore, the Global Economic Dynamics project of the Bertelsmann Stiftung has called into life a High-Level Board of Experts on the Future of Global Trade Governance. Composed of eminent experts and seasoned trade diplomats, it elaborated a series of feasible policy recommendations that will increase the effectiveness and sali-ence of the WTO. We hope that this Report provides helpful suggestions in a time marked by increasing trade disputes and protectionism and instead contributes to stronger multilateral institutions and fora.1 The Bertelsmann Stiftung owes a debt of gratitude to Prof Bernard Hoekman, the Chairman of the Expert Board and author of this report. His invaluable expertise and experience, guidance and ability to bridge controversial opinions have been crucial in defining the work of the Board. We would also like to express our sincere thanks to all our Board Members, who generously contributed their expertise, time and networks. Without their dedication, this Report would not have been possible. Finally, we would like to thank Robert Koopman and Aik Hoe Lim of the WTO for their support throughout the whole process and Christian Bluth of Bertelsmann Stiftung for managing this common endeavour

Revitalizing Multilateral Governance at the World Trade Organization Policy Brief based on the Report of the High-Level Board of Experts on the Future of Global Trade Governance. Bertelsmann Policy Brief 2018

If international trade is not governed by rules, mere might dictates what is right. The World Trade Organization (WTO) serves as a place where trade policy issues are addressed, disputes arbitrated, legal frameworks derived and enforced. Through these functions, the WTO ensures that the rules of trade policy are inspired by fairness and reciprocity rather than national interest. It is more important than ever to vitalize the global public good that it represents against various threats that have been undermining it. Therefore, the Global Economic Dynamics project of the Bertelsmann Stiftung has called into life a High- Level Board of Experts on the Future of Global Trade ominant view among the members of the Expert Board. Members of the Board participated in meetings on a Governance. Composed of eminent experts and seasoned trade diplomats, it elaborated a series of feasible policy recommendations that will increase the effectiveness and salience of the WTO. We hope that this Report provides helpful suggestions in a time marked by increasing trade disputes and protectionism and instead contributes to stronger multilateral institutions and fora

Economic Integration and the Welfare State

Wirtschaftsintegration, Sozialstaat, Mobilität, Europäische Wirtschafts- und Währungsunion, Economic integration, Welfare state, Mobility, European Economic and Monetary Union

Energy-based comparison between the Fourier--Galerkin method and the finite element method

The Fourier-Galerkin method (in short FFTH) has gained popularity in numerical homogenisation because it can treat problems with a huge number of degrees of freedom. Because the method incorporates the fast Fourier transform (FFT) in the linear solver, it is believed to provide an improvement in computational and memory requirements compared to the conventional finite element method (FEM). Here, we systematically compare these two methods using the energetic norm of local fields, which has the clear physical interpretation as being the error in the homogenised properties. This enables the comparison of memory and computational requirements at the same level of approximation accuracy. We show that the methods' effectiveness relies on the smoothness (regularity) of the solution and thus on the material coefficients. Thanks to its approximation properties, FEM outperforms FFTH for problems with jumps in material coefficients, while ambivalent results are observed for the case that the material coefficients vary continuously in space. FFTH profits from a good conditioning of the linear system, independent of the number of degrees of freedom, but generally needs more degrees of freedom to reach the same approximation accuracy. More studies are needed for other FFT-based schemes, non-linear problems, and dual problems (which require special treatment in FEM but not in FFTH).Comment: 24 pages, 10 figures, 2 table

Human-like Walking with Compliant Legs

This work presents a novel approach to robotic bipedal walking. Based on the bipedal spring-mass model, which is known to closely describe human-like walking behavior, a robot has been designed that approaches the ideal model as closely as possible. The compliance of the springs is controllable by means of variable stiffness actuators. The controllable stiffness allows the gait to be stabilized against external disturbances

Enantiomer fractions instead of enantiomer ratios

The use of enantiomer ratios (ERs) to indicate the relative amounts of a pair of enantiomers in a sample has some disadvantages. Enantiomer fractions (EFs) are proposed as all alternative expression to eliminate the difficulties. (C) 2000 Elsevier Science Ltd

Stickiness of Commercial Virtual Communities

The recent merging of the electronic market arena has enabled the creation of new environments in which consumers can interact with each other online – Commercial Virtual Communities (CVC). The strategic question facing internet businesses today is what are the components of the glue that makes consumers stay and return to websites in general and to CVCs in particular, i.e. how can one increase the stickiness of a CVC? This paper provides an insight into the nature of CVCs and the factors that drive their stickiness. The resulting framework is evaluated with the help of a survey among CVC experts. The results of the survey are presented.economics of technology ;