Analysis of a high order Trace Finite Element Method for PDEs on level set surfaces

We present a new high order finite element method for the discretization of partial differential equations on stationary smooth surfaces which are implicitly described as the zero level of a level set function. The discretization is based on a trace finite element technique. The higher discretization accuracy is obtained by using an isoparametric mapping of the volume mesh, based on the level set function, as introduced in [C. Lehrenfeld, \emph{High order unfitted finite element methods on level set domains using isoparametric mappings}, Comp. Meth. Appl. Mech. Engrg. 2016]. The resulting trace finite element method is easy to implement. We present an error analysis of this method and derive optimal order $H^1(\Gamma)$-norm error bounds. A second topic of this paper is a unified analysis of several stabilization methods for trace finite element methods. Only a stabilization method which is based on adding an anisotropic diffusion in the volume mesh is able to control the condition number of the stiffness matrix also for the case of higher order discretizations. Results of numerical experiments are included which confirm the theoretical findings on optimal order discretization errors and uniformly bounded condition numbers.Comment: 28 pages, 5 figures, 1 tabl

The periodic b-equation and Euler equations on the circle

In this note we show that the periodic b-equation can only be realized as an Euler equation on the Lie group Diff(S^1) of all smooth and orientiation preserving diffeomorphisms on the cirlce if b=2, i.e. for the Camassa-Holm equation. In this case the inertia operator generating the metric on Diff(S^1) is given by A=1-d^2/dx^2. In contrast, the Degasperis-Procesi equation, for which b=3, is not an Euler equation on Diff(S^1) for any inertia operator. Our result generalizes a recent result of B. Kolev.Comment: 8 page

“The death of sympathy”: coal mining, workplace hazards, and the politics of risk in Britain, ca. 1970-1990

"Das Ende des Mitleids: Steinkohlebergbau, Gefahren am Arbeitsplatz und Risikopolitik in Großbritannien, ca. 1970-1990". This article employs the concept of risk as a lens through which to explore discursive constructions of the nature of coal mining and coal miners in the UK in the 1970s and 1980s. Drawing on a diverse primary source base, ranging from songs and poetry to parliamentary debates and government files, it contextualises and refines labour historian Dick Geary’s observation about the “death of sympathy” for the miners in the coal strike of 1984/85. It argues that over the course of the period, coal miners turned from an object of risk into its subject; they were transformed, in political discourse, from heroes and victims into enemies of the state and society. Although the notion that coal miners were a “special case” on account of the hazardous working conditions in which they laboured, continued to resonate in popular culture throughout the 1970s and 1980s, the political bargaining power of the “blood on the coal” argument became progressively eroded after its successful application in the strikes of 1972 and 1974. By the time of the strike of 1984/85, Conservative opponents of the miners’ cause had turned the argument on its head: The very hazardous working conditions were taken as proof of an obstinate refusal of the industry to go with the times. The real danger, they argued, were not health hazards, but the miners themselves

Vom Verlierer zum Gewinner – und zurück: der Coal Miner als Schlüsselfigur der britischen Zeitgeschichte

This article traces the cyclical trajectory of the British coal miner from the mid-1960s to the mid-1980s. Within less than one generation, the miner turned from doomed industrial proletarian to self-assured embodiment of the future back to doomed proletarian. The renaissance of King Coal in the 1970s proved short-lived, and yet it needs to be taken seriously if one is to understand the nature of the coal strike of 1984/85 and the rundown of the industry that followed. Indeed, the figure of the miner offers a lens for reconfiguring our understanding of the 1970s and British contemporary history more generally, as the article seeks to demonstrate both empirically and conceptually

Strategic Foresight in multinational enterprises – a case study on the Deutsche Telekom Laboratories

Strategic Foresight activities enable companies to use weak signals to identify opportunities and threats. Research on Strategic Foresight proposes different methods, discusses their implementation and gives recommendations on how to link Strategic Foresight with other functions in an organization. Based on a literature review, we define a generic framework for the management of Strategic Foresight activities on the strategic, tactical and operational level and identify and discuss actors, methods and systems of Strategic Foresight. Building on an in-depth case study of the Deutsche Telekom Laboratories we shed light on the implementation of Strategic Foresight activities. In the discussion we focus on the interaction of methods from Consumer Foresight and Technology Intelligence. Taking an example project, we explore how Strategic Foresight is used on the operational level of innovation management. We conclude that Strategic Foresight can successfully contribute to coping with uncertainty and complexity and can feed the front-end of innovation from the market (customer needs) and technology (realization opportunities) perspective.strategic foresight; consumer foresight; technology foresight; technology intelligence; market foresight; trend analysis; future studies; future analysis; telecommunication industry

Relative humidity as a new parameter in rheological testing

Besides temperature and pressure the water content of a sample as well as the relative humidity of the ambient air are important parameter influencing the rheological behavior of many complex fluids such as for example gels, biomaterials, polymeric systems, food products, and adhesives. The aim of this contribution is to introduce a newly designed environmental control chamber for the use with a rotational rheometer. A combination of a modified convection oven and an external humidity generator enables to work under defined relative humidity (RH) and temperature (T) in the ranges of RH = 5 to 95 % and T = 5 to 120°C. Traditional convection ovens are mainly equipped with electrical heaters. For lower temperatures a cold gas (e.g. LN2) is brought into the chamber and the oven heats against the cold gas. In the new humidity system the convection oven is based on Peltier elements allowing to set temperatures below ambient without the need of a cold gas as input to the oven chamber. In order to control the relative humidity a humidity sensor is located in the oven and the external humidity generator provides the needed moisture of the gas flowing into the chamber. The humidity sensor and the humidity generator are fully integrated into the operating software for the rheometer, allowing the programing of combinations of T and RH including ramps in RH at constant T or ramps in T at constant RH, respectively. Various standard geometries like parallel-plate, cone-and-plate, solid bar for torsional DMTA, extensional tools for extensional DMTA and steady extensional rheological testing, a ball on three plate geometry for tribological investigations, as well as a newly designed modified ring geometry can be used in the humidity system. The later consists of two hollow cylinders, which build a ring geometry. Because the upper cylinder has three rectangular notches only the sample below these notches is used to characterize the sample properties. Hence the characterized sample has a large surface to volume ratio, enabling a fast and homogeneous diffusion of moisture in the sample. Applications examples in the different geometries are presented and show the importance of the relative humidity on a broad variety of samples. The new humidity system allows an easy control of the relative humidity and makes this parameter readily available in advanced rheological testing

The Dynamics of Active Embedding and Field Structuration

This article examines how multinational corporations (MNCs) shape institutional conditions in emerging economies to secure access to high- skilled, yet lower-cost science and engineering talent. Based on two in-depth case studies of engineering offshoring projects of German automotive suppliers in Romania and China we analyze how MNCs engage in ‘active embedding’ by aligning local institutional conditions with global offshoring strategies and operational needs. MNCs thereby contribute to the structuration of field relations and practices of sourcing knowledge-intensive work from globally dispersed locations. Our findings stress the importance of institutional processes across geographic boundaries that regulate and get shaped by MNC activities