Interactive free viewpoint video streaming using prioritized network coding

In free viewpoint applications, the images are captured by an array of cameras that acquire a scene of interest from different perspectives. Any intermediate viewpoint not included in the camera array can be virtually synthesized by the decoder, at a quality that depends on the distance between the virtual view and the camera views available at decoder. Hence, it is beneficial for any user to receive camera views that are close to each other for synthesis. This is however not always feasible in bandwidth-limited overlay networks, where every node may ask for different camera views. In this work, we propose an optimized delivery strategy for free viewpoint streaming over overlay networks. We introduce the concept of layered quality-of-experience (QoE), which describes the level of interactivity offered to clients. Based on these levels of QoE, camera views are organized into layered subsets. These subsets are then delivered to clients through a prioritized network coding streaming scheme, which accommodates for the network and clients heterogeneity and effectively exploit the resources of the overlay network. Simulation results show that, in a scenario with limited bandwidth or channel reliability, the proposed method outperforms baseline network coding approaches, where the different levels of QoE are not taken into account in the delivery strategy optimization.

Musiktraditionen im Kontext moderner Globalisierungsprozesse und globaler Denkkonzepte

The documentation of music cultures and the research in and on “classic” regions like India, Indonesia, and Sub-Saharan Africa still plays a central role within ethnomusicological research. However, given the increasing impact of global processes, the central guiding questions of the discipline have undergone profound changes in recent years. Approaches towards globalization are highly varied: One dominant perspective – which can be described as “skeptical” – has equated globalization with musical homogenization. This perspective is still apparent in approaches in European folk music research, which focus on the preservation of “traditional” cultures. Besides hyperglobal perspectives, which perceive the emergence of global networks (hypermedia, mass media, cultural organizations) as a positive development, one can predominantly observe the emergence of transformationalist approaches in recent decades: Global interconnectedness is viewed as a (neutrally perceived) basis for the emergence of new musical structures here. The transformation of the discipline is also apparent in the shift of the historical perspective. Comparative Musicology had already developed a global-historical perspective, which, however, became problematic due to the lack of contextualization. This might explain the subsequent distanced stance taken towards global concepts. Yet the focus on oral cultures also neglected deeper analysis of the historical dimension. At present, one can observe the emergence of a – albeit highly differentiated – change of perspective. While the Anglo-American approaches encourage the development of a specifically ethnomusicological-historical methodology, this separation between ethnomusicological and historical topics is perceived as racist in countries like South Africa. Starting out with an analysis of the concept of canonization in ethnomusicology, this article not only provides an overview of the aforementioned approaches and developments, but also discusses the integration of these processes into ethnomusicologically informed music pedagogical teaching material – within both a school and university context.

Virtual Patients in continuing medical education and residency training: a pilot project for acceptance analysis in the framework of a residency revision course in pediatrics.

AIM Virtual patients (VPs) are a one-of-a-kind e-learning resource, fostering clinical reasoning skills through clinical case examples. The combination with face-to-face teaching is important for their successful integration, which is referred to as "blended learning". So far little is known about the use of VPs in the field of continuing medical education and residency training. The pilot study presented here inquired the application of VPs in the framework of a pediatric residency revision course. METHODS Around 200 participants of a pediatric nephology lecture ('nephrotic and nephritic syndrome in children') were offered two VPs as a wrap-up session at the revision course of the German Society for Pediatrics and Adolescent Medicine (DGKJ) 2009 in Heidelberg, Germany. Using a web-based survey form, different aspects were evaluated concerning the learning experiences with VPs, the combination with the lecture, and the use of VPs for residency training in general. RESULTS N=40 evaluable survey forms were returned (approximately 21%). The return rate was impaired by a technical problem with the local Wi-Fi firewall. The participants perceived the work-up of the VPs as a worthwhile learning experience, with proper preparation for diagnosing and treating real patients with similar complaints. Case presentations, interactivity, and locally and timely independent repetitive practices were, in particular, pointed out. On being asked about the use of VPs in general for residency training, there was a distinct demand for more such offers. CONCLUSION VPs may reasonably complement existing learning activities in residency training.

Context Aware e-Learning Objects and their Types from the Perspective of the Object-Oriented Paradigm

The contribution of this article demonstrates how to identify context-aware types of e-Learning objects (eLOs) derived from the subject domains. This perspective is taken from an engineering point of view and is applied during requirements elicitation and analysis relating to present work in constructing an object-oriented (OO), dynamic, and adaptive model to build and deliver packaged e-Learning courses. Consequently, three preliminary subject domains are presented and, as a result, three primitive types of eLOs are posited. These types educed from the subject domains are of structural, conceptual, and granular nature. Structural objects are responsible for the course itself, conceptual objects incorporate adaptive and logical interoperability, while granular objects congregate granular assets. Their differences, interrelationships, and responsibilities are discussed. A major design challenge relates to adaptive behaviour. Future research addresses refinement on the subject domains and adaptive hypermedia systems.