Enhancing the Digital Backchannel Backstage on the Basis of a Formative User Study

Contemporary higher education with its large audiences suffers from passivity of students. Enhancing the classroom with a digital backchannel can contribute to establishing and fostering active participation of and collaboration among students in the lecture. Therefore, we conceived the digital backchannel Backstage specifically tailored for the use in large classes. At an early phase of development we tested its core functionalities in a small-scale user study. The aim of the study was to gain first impressions of its adoption, and also to form a basis for further steps in the conception of Backstage. Regarding adoption we particularly focused on how Backstage influences the participants' questioning behavior, a salient aspect in learning. We observed that during the study much more questions were uttered on Backstage than being asked without backchannel support. Regarding the further development of Backstage we capitalized on the participants' usability feedback. The key of the refinement is the integration of presentation slides in Backstage, which leads to an interesting reconsideration of the user interactions of Backstage

Providing guidance on Backstage, a novel digital backchannel for large class teaching

Many articles in the last couple of years argued that it is necessary to promote the active participation of students in lectures with large audiences. One approach to make students actively participate in a lecture is to use a digital backchannel, i.e. a computer-mediated communication platform that allows students to exchange ideas and opinions, without disrupting the lecturer’s discourse. Though, a digital backchannel, in order to be most helpful for learning, have to address the need for guidance of the users interacting. The article presents Backstage, a digital backchannel for large class lectures, and shows how it provides guidance for its users, i.e. the students but also the lecturer. Structural guidance is provided by aligning the usually incoherent backchannel discourse with the presentation slides that are integrated in the backchannel’s user interface. The alignment is thereby asserted by carefully designed backchannel workflows. The article also discusses the guidance of a student’s substantial involvement in both the frontchannel and the backchannel by means of scripts. Through the interactions of guided individuals a social guidance may emerge, leading to a collectively regulated backchannel

Combining Higher Order Reflections with Diffractions without Explosion of Computation Time: The Sound Particle Radiosity Method

The simulation of sound propagation in large rooms and urban environments is mainly performed by geometric simulation methods like ray tracing or the Sound Particle Simulation Method (SPSM). Hence, a severe deficiency is that wave effects are not included, especially if screening or diffraction effects are important. A method to introduce diffraction is the Uncertainty relation Based Diffraction (UBD) model, which has been successfully evaluated recently. To find close edges as sources of diffraction, a subdivision of the room into convex subspaces is performed by virtual walls. However, this causes a recursive split-up of Sound Particles (SPs) at each diffraction event. This effect should be compensated by a reunification of SPs. Therefore, the Sound Particle Radiosity (SPR) has been found that combines the SPSM with an advantage of the radiosity method: the re-unification of sound energy that uses a discretization of the surface into small patches. Now, SPR has been extended to 3D for the first time. To increase the available memory and to decrease the computation time, a parallelization has been implemented for the first time. First results indicate that the discretization of the virtual walls into patches yields additional but tolerable errors in the simulation of diffraction. However, even in 2D, SPR requires a huge memory. To solve this problem in 3D remains a great challenge, even more for more complex rooms. Also a method for a convex subdivision to 3D still has to be found

Entwicklung eines stufenübergreifenden Qualitätssicherungssystems für die ökologische Ernährungswirtschaft unter besonderer Berücksichtigung der Kommunikations- und Organisationsstrukturen

Im Rahmen des Projektes wurden Konzepte zur Lösung drängender Probleme im Bereich Qualitätssicherung in der Ökologischen Lebensmittelwirtschaft erarbeitet. Dazu wurden Strukturen geschaffen, die es erlaubten die Fachleute der Branche in die Problemanalyse und Lösungserarbeitung einzubeziehen. Durch die intensive Einbindung der Akteure konnte gewährleistet werden, dass die erarbeiteten Konzepte von hoher Relevanz für die Branche und direkt umsetzbar sind. Neben der Erarbeitung von Konzepten war deren Abstimmung mit Branchenvertretern und der Wissenstransfer der Ergebnisse ein Schwerpunkt des Projektes. Die Analyse der Kommunikations- und Organisationsstrukturen der Branche gab Hinweise darauf, welche Akteure von besonderer Relevanz sind, welche Kommunikationsmittel genutzt werden und wo Lücken in den Organisationsstrukturen bestehen. Das Projekt hat im Bereich Kontaminationen von Öko-Lebensmitteln mit Pflanzenschutzmittelrückständen Konzepte erarbeitet, die eine Reduktion der Einträge in Erzeugung und Verarbeitung ermöglichen. Die rechtliche Situation bei Haftungsfragen wurde in leicht verständlicher Form aufgearbeitet. Mit der Kommentierung des Anhang III Nr. 9 der EU-Öko-Verordnung wurden Vorschläge zur effizienten Verbesserung der Kontrollen vorgelegt und Grundlagen geschaffen, um die Auslegung des Gesetzes in EU und Bundesländern zu harmonisieren. Im Bereich Gentechnik wurde ein Konzept zur Verbraucherinformation erarbeitet, welches von den Akteuren der Branche umgesetzt wurde. Erarbeitet wurden weiterhin konkrete Vorschläge für die Weiterentwicklung der gesetzlichen Rahmenbedingungen im Gentechnikbereich, um die Ökologische Lebensmittelwirtschaft in ihrem Bestand zu sichern. Von der angestrebten „Koexistenz“ gehen erhebliche Gefahren für diesen Wirtschaftsbereich aus. Die Erstellung einer „Handlungsempfehlung zur Umsetzung von Maßnahmen der Warenrückverfolgbarkeit und Herkunftssicherung in Unternehmen der Ökologischen Lebensmittelwirtschaft“ ist Hauptergebnis in einem weiteren Bereich des Projekts. Mit dem erarbeiteten Krisenmanagementplan steht der Branche künftig ein Instrument zur Verfügung, den kommunikativen Teil einer Krise koordiniert zu bewältigen

Increased magnetocrystalline anisotropy in epitaxial Fe-Co-C thin films with spontaneous strain

Rare earth free alloys are in focus of permanent magnet research since the accessibility of the elements needed for nowadays conventional magnets is limited. Tetragonally strained iron-cobalt (Fe-Co) has attracted large interest as promising candidate due to theoretical calculations. In experiments, however, the applied strain quickly relaxes with increasing film thickness and hampers stabilization of a strong magnetocrystalline anisotropy. In our study we show that already 2 at% of carbon substantially reduce the lattice relaxation leading to the formation of a spontaneously strained phase with 3 % tetragonal distortion. In these strained (Fe$_{0.4}$Co$_{0.6}$)$_{0.98}$C$_{0.02}$ films, a magnetocrystalline anisotropy above 0.4 MJ/m$^3$ is observed while the large polarization of 2.1 T is maintained. Compared to binary Fe-Co this is a remarkable improvement of the intrinsic magnetic properties. In this paper, we relate our experimental work to theoretical studies of strained Fe-Co-C and find a very good agreement.Comment: 19 pages, 6 figure

Uncovering sustainability concerns in software product lines

Sustainable living, i.e., living within the bounds of the available environmental, social, and economic resources, is the focus of many present-day social and scientific discussions. But what does sustainability mean within the context of Software Engineering? In this paper we undertake a comprehensive analysis of 8 case studies to address this question within the context of a specific SE approach, Software Product Line Engineering (SPLE). We identify the sustainability-related characteristics that arise in present-day studies that apply SPLE. We conclude that technical and economic sustainability are in prime focus on the present SPLE practice, with social sustainability issues, where they relate to organisations, also addressed to a good degree. On the other hand, the issues related to the personal sustainability are less prominent, and environmental considerations are nearly completely amiss. We present feature models and cross-relations that result from our analysis as a starting point for sustainability engineering through SPLE, suggesting that any new development should consider how these models would be instantiated and expanded for the intended socio-technical system. The good representation of sustainability features in these models is also validated with two additional case studies