Technical and Didactical Scenarios of Student-centered Teaching and Learning

In this paper we envision didactical concepts for university education based on self-responsible and project-based learning and outline principles of adequate technical support. We use the scenario technique describing how a fictive student named Anna organizes her studies of informatics at a fictive university from the first days of her studies to make a career for herself.(DIPF/Orig.)

Internetbasierte Wissensorganisation in der Lehrerbildung

In diesem Artikel geht es um die internetbasierte Wissensorganisation von multimedialen Lerninhalten. Die Lernenden in der Lehrerausbildung sollen nicht allein eine rezeptive Rolle bei der Nutzung multimedialer Inhalte einnehmen, sondern sie werden aufgefordert, eine aktive Rolle bei der Erstellung von Inhalten zu übernehmen. Dabei wird die Trennung zwischen dem Autor auf der einen Seite und dem Leser bzw. Nutzer von Inhalten auf der anderen Seite aufgebrochen. Basis ist die Auseinandersetzung mit konkreten Lehr-/Lern-Situationen über die Nutzung von Video- und Audiosequenzen (Situated Learning). Eine internetbasierte Wissensbasis mit multimedialen Inhalten ist dabei der Ausgangspunkt, um die individuelle Wissensorganisation in der Lehrerbildung zu unterstützen. Exemplarisch werden diese Aspekte einer internetbasierten Wissensorganisation an dem Projekt MaDiN deutlich gemacht (MathematikDidaktik im Netz). Ohne detailliert auf die in MaDiN aufgebaute Wissensbasis einzugehen, geht es in diesem Artikel um allgemeine Methoden, internetbasiertes Wissensmanagement in die Lehrerbildung zu integrieren. Im Rahmen des vom Bundesministerium für Wissenschaft und Forschung mit 1,6 Millionen Euro geförderten Projektes zum Aufbau einer Wissensbasis mit mathematischen und mathematikdidaktischen Inhalten (Primarstufe, Sekundarstufe I und II) wurde eine spezielle Methode zur internetbasierten Wissensorganisation entwickelt. Das Konzept einer internetbasierten Wissensorganisation hat einen konstruktivistischen Hintergrund. Die Umsetzung in der Lehrerbildung erfolgt über ein Autorensystem, mit dem der Nutzer ein Werkzeug zur Online-Strukturierung personalisierter Lerninhalte besitzt.(DIPF/Orig.)

Strategisches Management von virtuellen Hochschulen. Positionierung auf dem Bildungsmarkt

Die Euphorie über die Zukunft virtueller Hochschulen trägt den realen Gegebenheiten nicht Rechnung. Der erhoffte Wandel virtueller Hochschulprojekte von technologieorientierten Informatikprojekten zu marktorientierten Bildungdienstleistern ist bislang ausgeblieben. Dieser Zusammenhang erfordert eine systematische Analyse der strategischen Positionierungen von Präsenz- und Fernhochschulen und von virtuellen Hochschulprojekten. Ausgehend von den Überlegungen des Wettbewerbskonzepts von M. E. Porter und der Systemtriade von B. R. Clark werden die strategischen Differenzen zwischen den Akteuren der Hochschullehre (Ministerien, Rektoraten und Professoren) und den virtuellen Hochschulprojekten aufgearbeitet. Diese Überlegungen basieren auf einer umfangreichen empirischen Erhebung der strategischen Positionierung deutscher Hochschulen und ihrer Bewertung des Nutzenpotenzials virtueller Hochschullehre. Aufgrund der Ergebnisse dieser empirischen Erhebungen werden Gestaltungsempfehlungen zur strategischen Positionierung virtueller Hochschulen entwickelt. Die Integration virtueller Lehre in die Hochschulen ist an folgende Prämissen geknüpft: Für eine nachhaltige Integration virtueller Hochschulprojekte in die Hochschulen muss die strategische Relevanz virtueller Hochschullehre in den Zielen und Strategien der Hochschulen verankert sein. Die Finanzierung virtueller Hochschulprojekte sollte durch die Steuerungslogik der „State Authority“ oder des „Market“ organisiert sein. Eine ausschließliche Finanzierung innerhalb der Steuerungslogik der „Academic Oligarchy“ ist kontraproduktiv für eine nachhaltige Integration. Zwischen den Ministerien und den Hochschulen besteht eine strategische Differenz in der Einschätzung der zukünftigen Relevanz von Fernstudiengängen und der Bedeutung von Effizienz und Wirtschaftlichkeit in der Hochschullehre. Unter den gegebenen Rahmendingungen sollten virtuelle Hochschulprojekte eine Differenzierungs- und/oder Nischenstrategie wählen. (DIPF/Orig.)

Inter-Packet Symbol Approach To Reed-Solomon FEC Codes For RTP-Multimedia Stream Protection

This paper presents an alternative Forward Error Correction scheme, based on Reed-Solomon codes, with the aim of protecting the transmission of RTP-multimedia streams: the inter-packet symbol approach. This scheme is based on an alternative bit structure that allocates each symbol of the Reed-Solomon code in several RTP-media packets. This characteristic permits to exploit better the recovery capability of Reed-Solomon codes against bursty packet losses. The performance of our approach has been studied in terms of encoding/decoding time versus recovery capability, and compared with other proposed schemes in the literature. The theoretical analysis has shown that our approach allows the use of a lower size of the Galois Fields compared to other solutions. This lower size results in a decrease of the required encoding/decoding time while keeping a comparable recovery capability. Finally, experimental results have been carried out to assess the performance of our approach compared to other schemes in a simulated environment, where models for wireless and wireline channels have been considered.

Generating multimedia presentations that summarize the behavior of dynamic systems using a model-based approach

This article describes a knowledge-based method for generating multimedia descriptions that summarize the behavior of dynamic systems. We designed this method for users who monitor the behavior of a dynamic system with the help of sensor networks and make decisions according to prefixed management goals. Our method generates presentations using different modes such as text in natural language, 2D graphics and 3D animations. The method uses a qualitative representation of the dynamic system based on hierarchies of components and causal influences. The method includes an abstraction generator that uses the system representation to find and aggregate relevant data at an appropriate level of abstraction. In addition, the method includes a hierarchical planner to generate a presentation using a model with dis- course patterns. Our method provides an efficient and flexible solution to generate concise and adapted multimedia presentations that summarize thousands of time series. It is general to be adapted to differ- ent dynamic systems with acceptable knowledge acquisition effort by reusing and adapting intuitive rep- resentations. We validated our method and evaluated its practical utility by developing several models for an application that worked in continuous real time operation for more than 1 year, summarizing sen- sor data of a national hydrologic information system in Spain.

A linear chained approach for service invocation in IP multimedia subsystem.

IP Multimedia Subsystem (IMS) is considered to provide multimedia services to users through an IP-based control plane. The current IMS service invocation mechanism, however, requires the Serving-Call Session Control Function (S-CSCF) invokes each Application Server (AS) sequentially to perform service subscription pro?le, which results in the heavy load of the S-CSCF and the long session set-up delay. To solve this issue, this paper proposes a linear chained service invocation mechanism to invoke each AS consecutively. By checking all the initial Filter Criteria (iFC) one-time and adding the addresses of all involved ASs to the ?Route? header, this new approach enables multiple services to be invoked as a linear chain during a session. We model the service invocation mechanisms through Jackson networks, which are validated through simulations. The analytic results verify that the linear chained service invocation mechanism can effectively reduce session set-up delay of the service layer and decrease the load level of the S-CSCF

A New Approach for Video Adaptation through Overlay Services Networks

Video adaptation is an extensively explored content providing technique aimed at appropriately suiting several usage scenarios featured by different network requirements and constraints, user`s terminal and preferences. However, its usage in high-demand video distribution systems, such as CNDs, has been badly approached, ignoring several aspects of optimization of network use. To address such deficiencies, this paper presents an approach for implementing the adaptation service by exploring the concept of overlay services networks. As a result of demonstrate the benefits of this proposal, it is made a comparison of this proposed adaptation service with other strategies of video adaptation.

Multimedia fate modeling and comparative impact on freshwater ecosystems of pharmaceuticals from biosolids-amended soils

This study modeled the impact on freshwater ecosystems of pharmaceuticals detected in biosolids following application on agricultural soils. The detected sulfonamides and hydrochlorothiazide displayed comparatively moderate retention in solid matrices and, therefore, higher transfer fractions from biosolids to the freshwater compartment. However, the residence times of these pharmaceuticals in freshwater were estimated to be short due to abiotic degradation processes. The non-steroidal anti-inflammatory mefenamic acid had the highest environmental impact on aquatic ecosystems and warrants further investigation. The estimation of the solid-water partitioning coefficient was generally the most influential parameter of the probabilistic comparative impact assessment. These results and the modeling approach used in this study serve to prioritize pharmaceuticals in the research effort to assess the risks and the environmental impacts on aquatic biota of these emerging pollutants.

Scheduling IP traffic in multimedia-enabled PROFIBUS networks

Technological developments are pulling fieldbus networks to support a new wide class of applications, such as industrial multimedia applications. To enable its use in this kind of applications the TCP/IP suite of protocols can be integrated within a fieldbus stack, leading to a dual-stack approach that is briefly outlined in the paper. One important requirement that must be fulfilled by this approach is that the hard real-time guarantees provided to the control-related traffic ("native" fieldbus traffic) are kept. At the same time it must also provide the desired quality of service (QoS) to IP applications. The focus of the paper is on how, in such a dual-stack approach, QoS can be efficiently provided to IP applications requiring quasi-constant bandwidth.

Automatic musical instrument recognition for multimedia indexing

Trabalho apresentado no âmbito do Mestrado em Engenharia Informática, como requisito parcial para obtenção do grau de Mestre em Engenharia Informática

Relational navigation and archiving of multimedia information for contemporary dance

Dissertação para obtenção do Grau de Mestre em Engenharia Informática

Adaptive intelligent agent approach to guide the web navigation on the PLAN-G distance learning platform

Hypermedia systems based on the Web for open distance education are becoming increasinglypopular as tools for user-driven access learning information. Adaptive hypermedia is a new direction in research within the area of user-adaptive systems, to increase its functionality by making it personalized [Eklu 961. This paper sketches a general agents architecture to include navigationaladaptability and user-friendly processes which would guide and accompany the student during hislher learning on the PLAN-G hypermedia system (New Generation Telematics Platform to Support Open and Distance Learning), with the aid of computer networks and specifically WWW technology [Marz 98-1] [Marz 98-2]. The PLAN-G actual prototype is successfully used with some informatics courses (the current version has no agents yet). The propased multi-agent system, contains two different types of adaptive autonomous software agents: Personal Digital Agents {Interface), to interacl directly with the student when necessary; and Information Agents (Intermediaries), to filtrate and discover information to learn and to adapt navigation space to a specific student

Improved Privacy-Preserving P2P Multimedia Distribution Based on Recombined Fingerprints

Peer-reviewed