131,277 research outputs found

    Using the Internet to improve university education

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    Up to this point, university education has largely remained unaffected by the developments of novel approaches to web-based learning. The paper presents a principled approach to the design of problem-oriented, web-based learning at the university level. The principles include providing authentic contexts with multimedia, supporting collaborative knowledge construction, making thinking visible with dynamic visualisation, quick access to content resources via information and communication technologies, and flexible support by tele-tutoring. These principles are used in the MUNICS learning environment, which is designed to support students of computer science to apply their factual knowledge from the lectures to complex real-world problems. For example, students may model the knowledge management in an educational organisation with a graphical simulation tool. Some more general findings from a formative evaluation study with the MUNICS prototype are reported and discussed. For example, the students' ignorance of the additional content resources is discussed in the light of the well-known finding of insufficient use of help systems in software applications

    Towars web site user's profile: log file analysis.

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    The Internet is a remote, innovative, extremely dynamic and widely accessible communication medium. As in all other human communication formats, we observe the development and adoption of its own language, inherent to its multimedia aspects. The Embrapa Satellite Monitoring is using the Internet as a dissemination medium of its research results and interaction with clients, partners and web site users for more than one decade. In order to evaluate the web site usage and performance of the e-communication system the Webalizer software has been used to track and to calculate statistics based on web server log file analysis. The objective of the study is to analyze the data and evaluate the indicators related to requests origin (search string, country, time), actions performed by users (entry pages, agents) and system performance (error messages). It will help to remodel the web site design to improve the interaction dynamics and also develop a customized log file analyser. This tool would retrieve coherent and real information

    The Design of a System Architecture for Mobile Multimedia Computers

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    This chapter discusses the system architecture of a portable computer, called Mobile Digital Companion, which provides support for handling multimedia applications energy efficiently. Because battery life is limited and battery weight is an important factor for the size and the weight of the Mobile Digital Companion, energy management plays a crucial role in the architecture. As the Companion must remain usable in a variety of environments, it has to be flexible and adaptable to various operating conditions. The Mobile Digital Companion has an unconventional architecture that saves energy by using system decomposition at different levels of the architecture and exploits locality of reference with dedicated, optimised modules. The approach is based on dedicated functionality and the extensive use of energy reduction techniques at all levels of system design. The system has an architecture with a general-purpose processor accompanied by a set of heterogeneous autonomous programmable modules, each providing an energy efficient implementation of dedicated tasks. A reconfigurable internal communication network switch exploits locality of reference and eliminates wasteful data copies

    Ubiquitous Sensor Networks in IMS: an Ambient Intelligence Telco Platform

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    Ubiquitous Sensor Network (USN) concept describes the integration of heterogeneous and geographically dispersed Wireless Sensor and Actuator Networks (WS&AN) into rich information infrastructures for accurate representation and access to different dynamic user’s physical contexts. This relatively new concept envisions future Sensor-Based Services leading to market disruptive innovations in a broad range of application domains, mainly personal (lifestyle assistants), community (professional users) and industrial domains. The support for this broad range of innovative Ambient Intelligence services urgently demands a standardized access to different WS&AN, and Telco Operators have an opportunity to lead this technological challenge as they evolve towards future Next-Generation Networks. Telefónica Research and Development is a leading innovation company that provides communication services for businesses and consumers. Networks and Service Platforms is a major Telefónica I+D innovation area where new Service Architectures and Platforms concepts are essential for the development of services with a high differentiation value. This contribution describes Telefónica I+D activities directed to the design of an Ambient Intelligence Platform integrating USN concepts over NGN architectures. In our view IP Multimedia Subsystem (IMS) concepts can enable and promote a first generation of Sensor-Based Services where multimedia interactive sessions are enriched with contextual information from WS&ANs. To this end three major design criteria are addressed at three different levels. At the application layer, OMA Service Environment and OGC Sensor Web Enablement are combined to define a specific USN Service Enabler. At the communication, management and control level WS&AN Gateways are defined for integrating WS&ANs infrastructures into all-IP IMS environments. While at the lower level, data and meta-data exchanges with different WS&ANs entities are homogeneously represented using OGC® SensorML standard. Finally this paper concludes by discussing some preliminary business opportunities we foresee for the proposed Platform

    Dynamic interactive learning systems

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    A cross-layer approach to enhance QoS for multimedia applications over satellite

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    The need for on-demand QoS support for communications over satellite is of primary importance for distributed multimedia applications. This is particularly true for the return link which is often a bottleneck due to the large set of end-users accessing a very limited uplink resource. Facing this need, Demand Assignment Multiple Access (DAMA) is a classical technique that allows satellite operators to offer various types of services, while managing the resources of the satellite system efficiently. Tackling the quality degradation and delay accumulation issues that can result from the use of these techniques, this paper proposes an instantiation of the Application Layer Framing (ALF) approach, using a cross-layer interpreter(xQoS-Interpreter). The information provided by this interpreter is used to manage the resource provided to a terminal by the satellite system in order to improve the quality of multimedia presentations from the end users point of view. Several experiments are carried out for different loads on the return link. Their impact on QoS is measured through different application as well as network level metrics

    Design of a shared whiteboard component for multimedia conferencing

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    This paper reports on the development of a framework for multimedia applications in the domain of tele-education. The paper focuses on the protocol design of a specific component of the framework, namely a shared whiteboard application. The relationship of this component with other components of the framework is also discussed. A salient feature of the framework is that it uses an advanced ATM-based network service. The design of the shared whiteboard component is considered representative for the design as a whole, and is used to illustrate how a flexible protocol architecture utilizing innovative network functions and satisfying demanding user requirements can be developed

    Perceived quality of multimedia educational content: A cognitive style approach

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    This is the post-print version of the Article. The oficial published version can be accessed from the link below - Copyright, 2006 SpringerCognitive styles influence the way how humans process information, with previous research demonstrating that they have significant effects on student learning in multimedia environments. On the other hand, the perceptual quality of the human multimedia experience is notoriously difficult to measure. In this paper, we report the results of an empirical study, which investigated the relationship between user cognitive styles and perceptual multimedia quality, in which users had the possibility to specify their desired Quality of Service settings — in terms of frame rates and color depth. Results show that whilst color choice is impacted by a participant's cognitive style, such Quality of Service parameters do not significantly affect perceived multimedia quality, and that users do not necessarily choose optimum presentation settings to enhance their perceived enjoyment and assimilation of multimedia informational content

    Octopus - an energy-efficient architecture for wireless multimedia systems

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    Multimedia computing and mobile computing are two trends that will lead to a new application domain in the near future. However, the technological challenges to establishing this paradigm of computing are non-trivial. Personal mobile computing offers a vision of the future with a much richer and more exciting set of architecture research challenges than extrapolations of the current desktop architectures. In particular, these devices will have limited battery resources, will handle diverse data types, and will operate in environments that are insecure, dynamic and which vary significantly in time and location. The approach we made to achieve such a system is to use autonomous, adaptable modules, interconnected by a switch rather than by a bus, and to offload as much as work as possible from the CPU to programmable modules that is placed in the data streams. A reconfigurable internal communication network switch called Octopus exploits locality of reference and eliminates wasteful data copies
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