262,015 research outputs found

    Augmentation of information in educational objects: Effectiveness of arrows and pictures as information for actions in instructional objects

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    The use of information and communication technology (ICT) in education is now central to facilitating links between learners, resources and instructors. Regardless of whether it is used in distance education or educational objects, ICT enables educators to package education opportunities in an increasing number of alternative ways so as best to meet the varying needs of the end user. Currently, one of the challenges that face instructors is to develop materials that enhance the learner-content interaction by reducing extraneous cognitive load while at the same time facilitating learning. This study explored the effectiveness of pictorial information and augmentation in instructions and educational objects. Dual coding theory is used to suggest that information that can be processed via separate but interconnected systems will facilitate faster processing and deeper learning of the information. University students were randomly assigned to six experimental conditions to perform a novel task using six different instruction manuals. A 3 (text, text-pictorial, text-pictorial-arrows) X 2 (picture of object vs. no picture of object) design was used to test whether augmenting text with pictorial information provided additional valuable information in instructional settings. Results partially support this multimedia effect; participants exhibited superior performance in a Text-Pictorial and Text-Pictorial-Arrows format over Text format. A picture of the object also facilitated superior performance on both the assembly and operating tasks, especially in a text format. Overall, combinations of text-pictorial and text-pictorial-arrows facilitated faster assembly and operation; they reduced errors, extra procedures, and unsuccessful assemblies (uncorrected errors). Results also support the idea that arrows convey unique types of information and function. In particular, arrows may attune people to important information and/or convey information movement that guides actions during tasks. Practical implications are discussed in relation to the type of information combinations that may lead to superior instructional design of instructional objects and research, including how to reduce errors of omission

    An integrated bandwidth allocation and admission control framework for the support of heterogeneous real-time traffic in class-based IP networks

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    The support of real-time traffic in class-based IP networks requires the reservation of resources in all the links along the end-to-end paths through appropriate queuing and forwarding mechanisms. This resource allocation should be accompanied by appropriate admission control procedures in order to guarantee that newly admitted real-time traffic flows do not cause any violation to the Quality of Service (QoS) experienced by the already established real-time traffic flows. In this paper we initially aim to highlight certain issues with respect to the areas of bandwidth allocation and admission control for the support of real-time traffic in class-based IP networks. We investigate the implications of topological placement of both the bandwidth allocation and admission control schemes. We show that the performance of bandwidth allocation and admission control schemes depends highly on the location of the employed procedures with respect to the end-users requesting the services and the various network boundaries (access, metro, core, etc.). Based on our results we conclude that the strategies for applying these schemes should be location-aware, because the performance of bandwidth allocation and admission control at different points in a class-based IP network, and for the same traffic load, can be quite different and can deviate greatly from the expected performance. Through simulations we also try to provide a quantitative view of the aforementioned deviations. Taking the implications of this “location-awareness” into account, we subsequently present a new Measurement-based Admission Control (MBAC) scheme for real-time traffic that uses measurements of aggregate bandwidth only, without keeping the state of any per-flow information. In this scheme there is no assumption made on the nature of the traffic characteristics of the real-time traffic flows, which can be of heterogeneous nature. Through simulations we show that the admission control scheme is robust with respect to traffic heterogeneity and measurement errors. We also show that our scheme compares favorably against other admission control schemes in the literature

    Cross layer techniques for flexible transport protocol using UDP-Lite over a satellite network

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    Traditional real-time multimedia and streaming services have utilised UDP over RTP. Wireless transmission, by its nature, may introduce a variable, sometimes high bit error ratio. Current transport layer protocols drop all corrupted packets, in contrast, protocols such as UDP-Lite allow error-resilient applications to be supported in the networking stack. This paper presents experimental quantitative performance metrics using H.264 and UDP Lite for the next generation transport of IP multimedia, and discusses the architectural implications for enhancing performance of a wireless and/or satellite environment

    Packet loss characteristics of IPTV-like traffic on residential links

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    Packet loss is one of the principal threats to quality of experience for IPTV systems. However, the packet loss characteristics of the residential access networks which carry IPTV are not widely understood. We present packet level measurements of streaming IPTV-like traffic over four residential access links, and describe the extent and nature of packet loss we encountered. We discuss the likely impact of these losses for IPTV traffic, and outline steps which can ameliorate this

    Experiences in deploying metadata analysis tools for institutional repositories

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    Current institutional repository software provides few tools to help metadata librarians understand and analyze their collections. In this article, we compare and contrast metadata analysis tools that were developed simultaneously, but independently, at two New Zealand institutions during a period of national investment in research repositories: the Metadata Analysis Tool (MAT) at The University of Waikato, and the Kiwi Research Information Service (KRIS) at the National Library of New Zealand. The tools have many similarities: they are convenient, online, on-demand services that harvest metadata using OAI-PMH; they were developed in response to feedback from repository administrators; and they both help pinpoint specific metadata errors as well as generating summary statistics. They also have significant differences: one is a dedicated tool wheres the other is part of a wider access tool; one gives a holistic view of the metadata whereas the other looks for specific problems; one seeks patterns in the data values whereas the other checks that those values conform to metadata standards. Both tools work in a complementary manner to existing Web-based administration tools. We have observed that discovery and correction of metadata errors can be quickly achieved by switching Web browser views from the analysis tool to the repository interface, and back. We summarize the findings from both tools' deployment into a checklist of requirements for metadata analysis tools

    Experiences in deploying metadata analysis tools for institutional repositories

    Get PDF
    Current institutional repository software provides few tools to help metadata librarians understand and analyze their collections. In this article, we compare and contrast metadata analysis tools that were developed simultaneously, but independently, at two New Zealand institutions during a period of national investment in research repositories: the Metadata Analysis Tool (MAT) at The University of Waikato, and the Kiwi Research Information Service (KRIS) at the National Library of New Zealand. The tools have many similarities: they are convenient, online, on-demand services that harvest metadata using OAI-PMH; they were developed in response to feedback from repository administrators; and they both help pinpoint specific metadata errors as well as generating summary statistics. They also have significant differences: one is a dedicated tool wheres the other is part of a wider access tool; one gives a holistic view of the metadata whereas the other looks for specific problems; one seeks patterns in the data values whereas the other checks that those values conform to metadata standards. Both tools work in a complementary manner to existing Web-based administration tools. We have observed that discovery and correction of metadata errors can be quickly achieved by switching Web browser views from the analysis tool to the repository interface, and back. We summarize the findings from both tools' deployment into a checklist of requirements for metadata analysis tools
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