How big is the elephant in the room? Estimated and actual IT costs in an online behaviour change trial

The practical and methodological challenges inherent in online behaviour change studies are both novel and complex. We relate our experiences of estimating and managing information technology (IT) research and intervention costs in an ongoing internet trial in the hope that others will find this information useful

A nonconforming pressure-robust finite element method for the Stokes equations on anisotropic meshes

Most classical finite element schemes for the (Navier-)Stokes equations are neither pressure-robust, nor are they inf-sup stable on general anisotropic triangulations. A lack of pressure-robustness may lead to large velocity errors, whenever the Stokes momentum balance is dominated by a strong and complicated pressure gradient. It is a consequence of a method, which does not exactly satisfy the divergence constraint. However, inf-sup stable schemes can often be made pressure-robust just by a recent, modified discretization of the exterior forcing term, using $\mathbf{H}(\operatorname{div})$-conforming velocity reconstruction operators. This approach has so far only been analyzed on shape-regular triangulations. The novelty of the present contribution is that the reconstruction approach for the Crouzeix-Raviart method, which has a stable Fortin operator on arbitrary meshes, is combined with results on the interpolation error on anisotropic elements for reconstruction operators of Raviart-Thomas and Brezzi-Douglas-Marini type, generalizing the method to a large class of anisotropic triangulations. Numerical examples confirm the theoretical results in a 2D and a 3D test case

A nonconforming pressure-robust finite element method for the Stokes equations on anisotropic meshes

Most classical finite element schemes for the (Navier--)Stokes equations are neither pressure-robust, nor are they inf-sup stable on general anisotropic triangulations. A lack of pressure-robustness may lead to large velocity errors, whenever the Stokes momentum balance is dominated by a strong and complicated pressure gradient. It is a consequence of a method, which does not exactly satisfy the divergence constraint. However, inf-sup stable schemes can often be made pressure-robust just by a recent, modified discretization of the exterior forcing term, using H(div)-conforming velocity reconstruction operators. This approach has so far only been analyzed on shape-regular triangulations. The novelty of the present contribution is that the reconstruction approach for the Crouzeix--Raviart method, which has a stable Fortin operator on arbitrary meshes, is combined with results on the interpolation error on anisotropic elements for reconstruction operators of Raviart--Thomas and Brezzi--Douglas--Marini type, generalizing the method to a large class of anisotropic triangulations. Numerical examples confirm the theoretical results in a 2D and a 3D test case

The influence of the layer sizes on the conversion regimes realizing at layered composite synthesis

The composite materials with different structure find a variety of applications. However, the peculiarities of the propagation of chemical reactions between structural elements during composite material synthesis are poorly studied. This paper suggests a model describing the conjugation of structure composite elements using a solid phase reaction at the ignition from a free surface. It was established that depending on the relation between layer sizes, various conversion regimes between inert materials are observed. The regimes differ in temperature values in the reaction zone, heterogeneities of temperature field and reaction zone thickness. Relation between thermophysical properties and thicknesses of layers can both promote reaction and retard it

Mit Selbstkritik durch den Mediendschungel. Die Strukturen des deutschen Medienjournalismus und das Selbstverständnis der Medienredakteure

Die Medien sind heute allgegenwärtig - sei es in Gesellschaft und Politik, sei es in Wirtschaft oder Kultur. Das Schlagwort von der Mediengesellschaft vermag den beachtlichen Bedeutungsaufschwung, den die Medien, allen voran das Fernsehen, während der letzten Jahre erfahren haben, anzudeuten: Die Medien moderieren den gesellschaftlichen Diskurs; sie vermitteln Politik und sii:J.d damit zu einem absolut notwendigen "Unterpfand der Demokratie"! geworden. Daneben hat sich die Medienindustrie zu einer gigantischen Wachstumsbranche entwickelt, die pro Jahr immense Summen umsetzt und in Zeiten einer weitläufig stagnierenden Ökonomie gegen den allgemeinen Trend sogar Arbeitsplätze schafft. Der Wirkungskreis der Medien reicht aber über die Bereiche Politik und Wirtschaft weit hinaus - die Medien haben sich in der modernen Gesellschaft zur sprichwörtlichen "Bewusstseinsindustrie" entwickelt: Sie sind es, die unseren Alltag bestimmen_ Sie prägen unsere Gedanken und Vorstellungen. Sie beeinflussen unser Verhalten und unsere Gewohnheiten. Damit hat die Welt der Medien, erneut allen voran das Fernsehen, eine "weitreichende Definitionsmacht über die Wirklichkeit gewonnen", und das nicht nur nach Auffassung des hier zitierten französischen Soziologen und Fernsehkritikers Pierre Bourdieu. (...) EnglishThomas Linke/Daniela Pickl: Self-critical journalism in the media-jungleDuring the last decade the media scene in Germany has been so widely diversificated that it is often called a media-jungle. The media themselves, now, reacted to this tendency by more and more making their own scene to a subject matter. In this way, a new kind of journalism emerged: media-journalism. While university studies on this topic in general are still in the beginnings, at the faculty for Journalism II of the Catholic University of Eichstärt in the Wintersemester 1998/99 two degree dissertations were written: one as an opinion poll and one as an analysis of content. In the opinion poll editors of all media sections in Germany were especially questioned concerning their self-understanding while the content analysis tried to find out about the quality of media-reporting in selected newspapers. Both researches concentrated on the question which conception of media-journalism is favoured in Germany. The answer was alike in both cases: Most frequently the integrational approach is chosen collecting all media themes on one page. On second place follows the crossection model: distributing media themes - either by purpose or due to financial and personal circumstances - all over the issue. In addition, in Germany at present a positive tendency is to be found: More and more newspapers install own media editors.

Meta-descent for Online, Continual Prediction

This paper investigates different vector step-size adaptation approaches for non-stationary online, continual prediction problems. Vanilla stochastic gradient descent can be considerably improved by scaling the update with a vector of appropriately chosen step-sizes. Many methods, including AdaGrad, RMSProp, and AMSGrad, keep statistics about the learning process to approximate a second order update---a vector approximation of the inverse Hessian. Another family of approaches use meta-gradient descent to adapt the step-size parameters to minimize prediction error. These meta-descent strategies are promising for non-stationary problems, but have not been as extensively explored as quasi-second order methods. We first derive a general, incremental meta-descent algorithm, called AdaGain, designed to be applicable to a much broader range of algorithms, including those with semi-gradient updates or even those with accelerations, such as RMSProp. We provide an empirical comparison of methods from both families. We conclude that methods from both families can perform well, but in non-stationary prediction problems the meta-descent methods exhibit advantages. Our method is particularly robust across several prediction problems, and is competitive with the state-of-the-art method on a large-scale, time-series prediction problem on real data from a mobile robot.Comment: AAAI Conference on Artificial Intelligence 2019. v2: Correction to Baird's counterexample. A bug in the code lead to results being reported for AMSGrad in this experiment, when they were actually results for Ada

Direct deposit of catalyst on the membrane of direct feed fuel cells

An improved direct liquid-feed fuel cell having a solid membrane electrolyte for electrochemical reactions of an organic fuel. Catalyst utilization and catalyst/membrane interface improvements are disclosed. Specifically, the catalyst layer is applied directly onto the membrane electrolyte