268 research outputs found
The discursive appeal to solidarity and partisan journalism in Europe's migration crisis
The article analyses the discursive appeal to solidarity in the mass media during the unfolding of Europe's migration crisis. Solidarity was claimed by numerous actors in the public discourse to legitimise political decisions and mobilise public opinion. While it seems that the call for solidarity was shared by many actors, media studies show the "partisan journalism" of media outlets. Thus, the political orientation of media outlets influences their coverage of public debates. Hence, to what extent do different quality newspapers cover the same solidarity claims in times of crisis? In order to answer this question, the crisis coverage of two German and two Irish newspapers with centre-left and centre-right political orientations is examined via the discourse network methodology. Germany is selected due to high political parallelism and a strong affectedness by the crisis, while Ireland is selected because of low political parallelism and a weak affectedness by the migration crisis. The findings demonstrate that partisan journalism persists during Europe's migration crisis. Especially German party actors are present in both countries, underpinning the central position of Germany. Regarding the appeal to solidarity, political solidarity claims prevail in all four newspapers, indicating the political-institutional asymmetry in the Common European Asylum System. The study contributes to the strategic framing of concepts in public debates and demonstrates that the left-right distinction of media outlets is hardly affected by the migration crisis
Transient amplitude behavior analysis of nonlinear power ultrasonic transducers with application to ultrasonic squeeze film levitation
In this article, force and self-excitation driving methods for ultrasonic transducers are compared with each other in sense of their transient amplitude behavior in the presence of nonlinearities. An equivalent circuit transducer model is simplified to a series oscillator. The simplified model is averaged by the Van der Pol method in order to reduce the system at hand to its amplitude dynamics. The transient amplitude behavior of both driving methods is presented in an analytical form. At high vibration amplitudes, the system's natural frequency varies due to the nonlinear stiffness of the piezoelectric material and the vibration amplitude is likely to break down due to the jump phenomena. Therefore, the averaged models are extended by the nonlinear effects. From the amplitude behavior analysis of both systems, it follows that self-excitation is the preferable driving method in sense of obtaining a high operation bandwidth and a stable oscillation. © The Author(s) 2012
On the maximum damping performance of piezoelectric switching techniques
Synchronized switch damping on inductor offers a high damping performance in a broad frequency range. It consists of an inductor and resistor in a serial configuration, which are connected and disconnected from the piezoceramics in an alternating manner by a switch. When the switch is triggered by the vibration itself, it adapts to different excitation frequencies especially in the low frequency range. This article presents a detailed study of the damping performance of the synchronized switch damping on inductor technique. Calculations are performed in a normalized way. The optimal tuning of synchronized switch damping on inductor network parameters is derived, and the corresponding maximum damping performance is obtained. The results are further compared to standard linear inductance-resistance networks. For a validation of the theoretical results, measurements on a clamped beam test rig are performed. Therefore, the synchronized switch damping on inductor circuit is realized as a synthetic impedance in a DSpace environment. The measurement results are in good agreement with the theoretical calculations. © The Author(s) 2012
What the new German government means for the country’s European policy
How will German European policy change under the country’s new government? Drawing on new data, Ann-Kathrin Reinl and Stefan Wallaschek show that the three coalition partners – the Social Democrats (SPD), Greens, and the Free Democrats (FDP) – are not nearly as close to each other on EU issues as one might assume. Much will depend on how the government can reconcile the pro-EU positions of the Greens with the soft Euroscepticism of the FDP
Modeling of ultrasonic processes utilizing a generic software framework
Modeling of ultrasonic processes is typically characterized by a high degree of complexity. Different domains and size scales must be regarded, so that it is rather difficult to build up a single detailed overall model. Developing partial models is a common approach to overcome this difficulty. In this paper a generic but simple software framework is presented which allows to coupe arbitrary partial models by slave modules with well-defined interfaces and a master module for coordination. Two examples are given to present the developed framework. The first one is the parameterization of a load model for ultrasonically-induced cavitation. The piezoelectric oscillator, its mounting, and the process load are described individually by partial models. These partial models then are coupled using the framework. The load model is composed of spring-damper-elements which are parameterized by experimental results. In the second example, the ideal mounting position for an oscillator utilized in ultrasonic assisted machining of stone is determined. Partial models for the ultrasonic oscillator, its mounting, the simplified contact process, and the workpiece's material characteristics are presented. For both applications input and output variables are defined to meet the requirements of the framework's interface.DF
Solidarity in the Public Sphere: A Discourse Network Analysis of German Newspapers (2008-2017)
Multiple crises in the EU have sparked a renaissance of the concept of solidarity. However, discursive approaches to solidarity and the public understanding of solidarity have hardly received scholarly attention. Empirical research on solidarity is rather centered on welfare institutions as well as on individual attitudes and behavior. To shed new light on solidarity in public discourse, we investigate in which policy fields the term is most often used, which actors refer to it and how different types of solidarity are covered in the German public discourse. We investigate the coverage of solidarity in four German newspapers (Die Welt, Frankfurter Allgemeine Zeitung, Süddeutsche Zeitung, Die Tageszeitung) from 2008 to 2017. By deploying the discourse network methodology with 306 claims in 230 news articles, we analyze the co-occurrence of actors and issues over time. Our results indicate a varying set of issues in which solidarity occurs, a rather stable actor visibility, across time and a context-dependent use of different types of solidarity. Government actors, civil society actors as well as citizens drive the solidarity discourse showing that institutional as well as non-institutional actors make use of solidarity in their public actions regarding political protest, financial issues and migration. The study provides novel insights into the interdependence of actor and issue visibility and sheds new light on solidarity in media discourses
Special Issue on IWPMA (International Workshop on Piezoelectric Materials and Applications in Actuators) 2019
[No abstract available
Continuation methods for lab experiments of nonlinear vibrations
In this work, we will give an overview of our recent progress in experimental continuation. First, three different approaches are explained and compared which can be found in scientific papers on the topic. We then show S-Curve measurements of a Duffing oscillator experiment for which we derived optimal controller gains analytically. The derived formula for stabilizing PD-controller gains makes trial and error search for suitable values unnecessary. Since feedback control introduces higher harmonics in the driving signal, we consider a harmonization of the forcing signal. This harmonization is important to reduce shaker-structure interaction in the treatment of nonlinear frequency responses. Finally, the controlled nonlinear testing and harmonization is enhanced by a continuation algorithm adapted from numerical analysis and applied to a geometrically nonlinear beam test rig for which we measure the nonlinear forced response directly in the displacement-frequency plane
EUropa auf dem Weg zu einem besseren EUropa? Antoine Vauchez und Ulrike Guérot über die Europäische Union
Antoine Vauchez: Europa demokratisieren. Hamburg: Hamburger Edition 2016. 9783868542967 +++ Ulrike Guérot: Warum Europa eine Republik werden muss!: Eine politische Utopie. Bonn: Dietz Verlag 2016. 978-3-8012-0479-
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