Lehrszenarien-übergreifende Erzeugung und Verwendung Multimedialer Teachware

Das Erstellen multimedialer Lehrdokumente ist ein aufwendiger Prozeß. In der traditionellen Lehre werden für verschiedenen Lehrszenarien (Vorlesung, Nachbearbeitung durch den Studenten, etc.) oft unterschiedliche Dokumente erstellt, die denselben Stoff behandeln. Weiterhin entstehen während einer Vorlesung durch die Erklärungen des Dozenten implizit Dokumente, die auch in anderen Lehrszenarien sinnvoll eingesetzt werden können. In diesem Artikel wird beschrieben, wie die in Lehrveranstaltungen entstehenden Dokumente aufgezeichnet und auf einem Server bereitgestellt werden. Mit dem vorgestellten Verfahren können die Aufzeichnungen flexibel mit zusätzlichen multimedialen Inhalten zu einer Computer-Based-Training-Einheit verknüpft werden. Dadurch ist es möglich, Dokumente effektiv sowohl in synchronen als auch in asynchronen Lehrszenarien zu einzusetzen

Freestyle Learning – Das mediendidaktische Konzept

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Multimedia Applications of the Wavelet Transform

This dissertation investigates novel applications of the wavelet transform in the analysis and compression of audio, still images, and video. Most recently, some surveys have been published on the restoration of noisy audio signals. Based on these, we have developed a wavelet-based denoising program for audio signals that allows flexible parameter settings. The multiscale property of the wavelet transform can successfully be exploited for the detection of semantic structures in images: A comparison of the coefficients allows the extraction of a predominant structure. This idea forms the basis of our semiautomatic edge detection algorithm. Empirical evaluations and the resulting recommendations follow. In the context of the teleteaching project Virtual University of the Upper Rhine Valley (VIROR), many lectures were transmitted between remote locations. We thus encountered the problem of scalability of a video stream for different access bandwidths in the Internet. A substantial contribution of this dissertation is the introduction of the wavelet transform into hierarchical video coding and the recommendation of parameter settings based on empirical surveys. Furthermore, a prototype implementation proves the principal feasibility of a wavelet-based, nearly arbitrarily scalable application. Mathematical transformations constitute a commonly underestimated problem for students in their first semesters of study. Motivated by the VIROR project, we spent a considerable amount of time and effort on the exploration of approaches to enhance mathematical topics with multimedia; both the technical design and the didactic integration into the curriculum are discussed. In a large field trial on "traditional teaching versus multimedia-enhanced teaching", the objective knowledge gained by the students was measured. This allows us to objectively rate positive the efficiency of our teaching modules

Reference model for learning and educational methods for e-learning, knowledgemanagement and competencemanagement

In dieser Arbeit wurden Methoden aus den Bereichen E-Learning und Wissensmanagement anhand des Referenzmodells nach didaktischen Anforderungen, Wissens- und Managementprozessen kategorisiert, so dass sie sich für einen didaktischen Einsatz in Schule, Lehre, Aus- und Weiterbildung und zum persönlichen Wissensmanagement eignen. Des Weiteren wurden jeder Lehr-, Lern- und Wissensmethode spezifische Kompetenzen von Lehrenden und Lernenden zugeordnet, die bei Lernenden während der Anwendung dieser Methode entstehen können und beim Lehrenden zur erfolgreichen Anwendung vorhanden sein sollten. Die Herausforderung dieser Arbeit bestand somit auch darin, alle Komponenten von gezielten Lehr-, Lern- und Wissensprozessen und dem Aufbau von Kompetenzen in einem Referenzmodell für Bildungsmethoden zu berücksichtigen. Anhand des entwickelten Anwendungsmodells wird schließlich jede einzelne Methode beschrieben und kann im konkreten Einsatz auf ihre Tauglichkeit überprüft werden

Consistency Algorithms and Protocols for Distributed Interactive Applications

The Internet has a major impact not only on how people retrieve information but also on how they communicate. Distributed interactive applications support the communication and collaboration of people through the sharing and manipulation of rich multimedia content via the Internet. Aside from shared text editors, meeting support systems, and distributed virtual environments, shared whiteboards are a prominent example of distributed interactive applications. They allow the presentation and joint editing of documents in video conferencing scenarios. The design of such a shared whiteboard application, the multimedia lecture board (mlb), is a main contribution of this thesis. Like many other distributed interactive applications, the mlb has a replicated architecture where each user runs an instance of the application. This has the distinct advantage that the application can be deployed in a lightweight fashion, without relying on a supporting server infrastructure. But at the same time, this peer-to-peer architecture raises a number of challenging problems: First, application data needs to be distributed among all instances. For this purpose, we present the network protocol RTP/I for the standardized communication of distributed interactive applications, and a novel application-level multicast protocol that realizes efficient group communication while taking application-level knowledge into account. Second, consistency control mechanisms are required to keep the replicated application data synchronized. We present the consistency control algorithms “local lag”, “Timewarp”, and “state request”, show how they can be combined, and discuss how to provide visual feedback so that the session members are able to handle conflicting actions. Finally, late-joining participants need to be initialized with the current application state before they are able to participate in a collaborative session. We propose a novel late-join algorithm, which is both flexible and scalable. All algorithms and protocols presented in this dissertation solve the aforementioned problems in a generic way. We demonstrate how they can be employed for the mlb as well as for other distributed interactive applications