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Report Usability Test BigBlueButton 2.4
No full textUpon request from the university’s center for digital teaching (virtUOS), students at Osnabrück University tested functionalities in BigBlueButton which are often used in seminars in a usability test with student participants, and additionally surveyed participants’ general impression of the usability of BBB. This report summarizes the observations that were made during this test and introduces possible redesigns for those UI sections which regularly caused friction for test participants
Cyberwar Grundlagen Methoden Beispiele
Get PDFDer Cyberwar (Cyberkrieg) ist die kriegerische Auseinandersetzung mit den Mitteln der Informationstechnologie. Dieses Arbeitspapier unternimmt eine aktuelle Bestandsaufnahme und geht auf die theoretischen und praktischen Probleme ein. In der Praxis ist der Cyberwar ein integraler Bestandteil militärischen Handelns, lässt sich jedoch nicht ganz von der Spionage trennen, da das Eindringen in und Aufklären von gegnerischen Systemen wesentlich für das weitere Vorgehen ist. Nach einem Überblick über Angriffsmethoden, Angreifer (Advanced Persistent Threats), Spionagetools, Cyberwaffen und der Cyberverteidigung liegt ein besonderes Augenmerk auf der Einordnung von Cyberangriffen (Attribution) und der Smart Industry (Industrie 4.0). Anschließend werden die Cyberwar-Strategien der USA, Chinas, Russlands und weiterer führender Akteure besprochen. Weitere Kapitel befassen sich der Künstlichen Intelligenz, der Smart Industry, smarten Systemen und biologischen Anwendungen
Model-Driven Code Generation of Safety Mechanisms
Get PDFSafety-critical systems are systems in which failure may lead to serious harm for humans or the environment. Due to the nature of these systems, there exist regulatory standards that recommend a set of safety mechanisms that should be included in these systems, e.g., IEC 61508. However, these standards offer little to no implementation assistance for these mechanisms. This thesis provides such development assistance, by proposing an approach for the automatic generation of safety mechanisms via Model-Driven Development (MDD). Such an automation of previously manual activities has been known to increase developer productivity and to reduce the number of bugs in the implementation. In the context of safety-critical systems, the latter also means an improvement in safety. The approach introduces a novel way to define safety requirements as structured sentences. This structure allows for the automatic parsing of these requirements in order to subsequently generate software-implemented safety mechanisms, as well as to initially configure hardware-implemented safety mechanisms. The generation approach for software-implemented safety mechanisms uses Unified Modeling Language (UML) stereotypes to represent these mechanisms in the application model. Automated model-to-model transformations parse this model representation and realize the safety mechanisms within an intermediate model. From this intermediate model, code may be generated with simple 1:1 mappings. For the generation of hardware-implemented safety mechanisms, this thesis introduces a novel Graphical User Interface (GUI) tool for representing the configuration of hardware interfaces. A template-based code snippet repository is used for generating the code responsible for the configuration of the hardware-implemented safety mechanisms. The presented approach is validated by applying it to the development of a safety-critical fire detection application example. Furthermore, the runtime overhead of the respective transformation steps of the code generation process is measured. The results indicate a linear scalability and a runtime that is no impediment to the workflow of the developer. Furthermore, the memory and runtime overhead of the generated code is evaluated. The results show that the inclusion of a single safety mechanism for a single system element has a negligible overhead. However, the relative overhead indicates that the application of safety mechanisms should be limited to those system elements that are strictly safety-critical, as their arbitrary application to all system elements would have large effects on the runtime and memory usage of the application
Frauen und lixae im militärischen Umfeld. Bemerkungen zum Fundplatz Kalkriese im Jahre 11 nach Beginn der archäologischen Forschungen
No full textFrauen und lixae im militärischen Umfeld. Fundplatz Kalkriese im Jahre 11 nach Beginn der archäologischen
Forschungen. Seit den ersten archäologischen Sondierungen und Prospektionen im Jahr 1987 vermehren sich die eindeutigen Hinweise auf den geschichtsträchtigen Boden am Kalkrieser Berg. Funde und Befunde haben die Geschichte um die ausgedehnten römisch-germanischen Grenz- und Interessenkonflikte und, basierend auf den numismatischen Forschungsergebnissen, vornehmlich die Ereignisse des Jahres 9 n.Chr. in das Blickfeld der wissenschaftlichen Untersuchungen gerückt. Die vielgesuchte Örtlichkeit der Niederlage römischer Truppen im Kampf gegen verbündete germanische Stammesverbände scheint am Kalkrieser Berg tangiert zu sein. Initiiert und in Szene gesetzt durch den Fundplatz auf dem Oberesch wird dem Besuchenden das Areal bei Kalkriese unter dem Slogan "Varusschlacht" präsentiert. ..
Real-Time Monitoring the Growth of Epitaxial CoxFe3−xO4 Ultrathin Films on Nb-Doped SrTiO3(001) via Reactive Molecular Beam Epitaxy by Means of Operando HAXPES
Get PDFIn this work, we present a comprehensive study on real-time monitoring the growth of epitaxial CoxFe3−xO4 thin films grown on SrTiO3(001) substrates via reactive molecular beam epitaxy. The growth process was monitored during evaporation by means of time resolved operando hard X-ray photoelectron spectroscopy (HAXPES). We prepared ultrathin ferrite films using different oxygen partial pressures, showing pure metallic, light oxidic, and cobalt ferrite-like growth. Additional X-ray diffraction measurements confirm HAXPES results
Intercalation-free, fast switching of mesoporous antimony doped tin oxide with cathodically coloring electrochromic dyes
Get PDFMesoporous nanoparticle layers of transparent conductive oxides (TCOs) with anchored organic dyes are of great interest for electrochromic applications. Herein, we prepared mesoporous layers of antimony doped tin oxide (ATO) consisting of only 5 nm large particles with a low Sb concentration (2% antimony). The particles were prepared via a modified synthesis procedure based on hexahydroxostannate and pure Sb(V) hexahydroxoantimonate(V). We show that the ATO layers benefit from using a non-intercalating electrolyte such as tetrabutylammonium perchlorate (TBAP) compared to lithium perchlorate. Especially in the negative potential range, negative side effects, such as degradation due to lithium intercalation, are reduced. Furthermore, comparing the behavior of particles with varying antimony doping concentrations showed that the particles doped with 2% Sb are most suitable with respect to their conductivity and transparency. When modified with an electrochromic dye (viologen), the hybrid electrodes allow fully reversible (de)coloration with the non-intercalating electrolyte. Similar viologen/TiO2 electrodes on the other hand show severely restricted performance with the non-intercalating electrolyte as the oxidation of the dye is partially inhibited. Finally, we built a full electrochromic device composed of two ATO electrodes, each bearing a different electrochromic dye with TBAP as the electrolyte. Despite the dense morphology of the layers due to the small particle size as well as the large size of the electrolyte cation, the device displays remarkable switching times below 0.5 s
Neprilysins regulate muscle contraction and heart function via cleavage of SERCA-inhibitory micropeptides
Get PDFMuscle contraction depends on strictly controlled Ca2+ transients within myocytes. A major player maintaining these transients is the sarcoplasmic/endoplasmic reticulum Ca2+ ATPase, SERCA. Activity of SERCA is regulated by binding of micropeptides and impaired expression or function of these peptides results in cardiomyopathy. To date, it is not known how homeostasis or turnover of the micropeptides is regulated. Herein, we find that the Drosophila endopeptidase Neprilysin 4 hydrolyzes SERCA-inhibitory Sarcolamban peptides in membranes of the sarcoplasmic reticulum, thereby ensuring proper regulation of SERCA. Cleavage is necessary and sufficient to maintain homeostasis and function of the micropeptides. Analyses on human Neprilysin, sarcolipin, and ventricular cardiomyocytes indicates that the regulatory mechanism is evolutionarily conserved. By identifying a neprilysin as essential regulator of SERCA activity and Ca2+ homeostasis in cardiomyocytes, these data contribute to a more comprehensive understanding of the complex mechanisms that control muscle contraction and heart function in health and disease
Effectiveness of a teaching unit on the willingness to consume insect-based food – An intervention study with adolescents from Germany
No full textThis study investigated the effect of a four-lesson teaching unit titled “Entomophagy and Sustainability” on the willingness of adolescents in Germany to consume insect-based food (N = 114; MAge = 15.77 years; SDAge = 1.12 years; female = 58.8%). The main aim of the study was to test whether the teaching unit can induce long-term changes in selected nutritional-psychological factors (food disgust, food neophobia, food technology neophobia), attitudes, knowledge, and the willingness to consume insect-based food. For this purpose, a paper-pencil questionnaire was conducted immediately before (pre-test), immediately after (post-test), and approximately six weeks after (follow-up test) the teaching unit. Although significant changes in food disgust, food neophobia, food technology neophobia, attitudes, and knowledge were recorded, adolescents’ willingness to consume insect-based food was not significantly increased. Attitudes were identified as the strongest predictor of adolescents’ willingness to consume, while knowledge was not a significant predictor. Conclusions and recommendations that can be applied to other educational interventions are provided to increase the effectiveness of the teaching unit
Zum Verhältnis von Angst und Politik in Zeiten von Corona
Get PDFBeitrag im Jahrbuch der Osnabrücker Friedensgespräche 202
»Oma, was ist ein Schneemann?« – Diskussion zum Thema Klimagerechtigkeit
Get PDFTextdokumentation zur Podiumsveranstaltung der Osnabrücker Friedensgespräche am 19. Nov. 201