Now showing 1 - 10 of 27
  • Publication
    Exploiting context information for identification of relevant experts in collaborative workplace-embedded e-learning environments
    ( 2007)
    Lokaiczyk, R.
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    Godehardt, E.
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    Faatz, A.
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    Goertz, M.
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    Kienle, A.
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    Wessner, M.
    ;
    Ulbrich, A.
    This work introduces an approach to discover collaboration partners and adequate advising experts in a workplace-embedded collaborative e-learning environment. Based on existing papers dealing with work task and user context modelling, we propose the following steps towards a successful collaboration initiation. In the beginning, the user's current process task needs to be identified (1). Taking into account the knowledge about the current process, availability of experts as well as organizational and social distance, relevant experts regarding the actual work task of the learner are pre-selected by the environment (2). Depending on the pre-selection and users' preferences, the potential collaboration partners are displayed in an expert list (3). That way, the learner is able to initiate beneficial collaborations, whose transcripts are used to enhance the existing knowledge base of learning documents (4).
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    Watermarking-based digital audio data authentication
    ( 2003)
    Steinebach, M.
    ;
    Dittmann, J.
    Digital watermarking has become an accepted technology for enabling multimedia protection schemes. While most efforts concentrate on user authentication, recently interest in data authentication to ensure data integrity has been increasing. Existing concepts address mainly image data. Depending on the necessary security level and the sensitivity to detect changes in the media, we differentiate between fragile, semifragile, and content-fragile watermarking approaches for media authentication. Furthermore, invertible watermarking schemes exist while each bit change can be recognized by the watermark, which can be extracted and the original data can be reproduced for high-security applications. Later approaches can be extended with cryptographic approaches like digital signatures. As we see from the literature, only few audio approaches exist and the audio domain requires additional strategies for time flow protection and resynchronization. To allow different security levels, we have to identify relevant audio features that can be used to determine content manipulations. Furthermore, in the field of invertible schemes, there are a bunch of publications for image and video data but no approaches for digital audio to ensure data authentication for high-security applications. In this paper, we introduce and evaluate two watermarking algorithms for digital audio data, addressing content integrity protection. In our first approach, we discuss possible features for a content-fragile watermarking scheme to allow several postproduction modifications. The second approach is designed for high-security applications to detect each bit change and reconstruct the original audio by introducing an invertible audio watermarking concept. Based on the invertible audio scheme, we combine digital signature schemes and digital watermarking to provide a public verifiable data authentication and a reproduction of the original, protected with a secret key.
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    Towards UML-G: A UML profile for modelling groupware
    ( 2002)
    Rubart, J.
    ;
    Dawabi, P.
    Groupware is explicitly designed to support the cooperation among group members. The implementation of cooperation-aware groupware is supported by several object-oriented toolkits and frameworks, but there is no unified way to model applications built on top of these. We propose UML- G as an extensible UML profile for modelling groupware and want the community to contribute to it. We identify groupware specific modelling needs related to shared data modelling. Since these needs are not addressed by standard UML, we define UML-G's shared data modelling part. Usage scenarios demonstrate how UML-G can be used to assist groupware modelling. UML-G supports explicit modelling of groupware related needs. Moreover, a shared understanding between developers is backed, which abstracts from the implementation. In addition, CASE tool support for UML-G strengthens its practical relevance.
  • Publication
    Design Challenges for an Integrated Disaster Management Communication and Information System
    ( 2002)
    Meissner, A.
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    Luckenbach, T.
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    Risse, T.
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    Kirste, T.
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    Kirchner, H.
    Disaster response and recovery efforts require timely interaction and coordination of public emergency services in order to save lives and property. Today, IT is used in this field only to a limited extent, but there is a tremendous potential for increasing efficiency and effectiveness in coping with a disaster. In this paper we sketch requirements and innovative technology for an integrated disaster management communication and information system, addressing in particular network, configuration, scheduling and data management issues during the response and recovery phases.
  • Publication
    Roomware-moving toward ubiquitous computers
    ( 2002)
    Tandler, P.
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    Streitz, N.
    ;
    Prante, T.
    Collaboration between users and environments with multiple interconnected devices will determine, to a large degree, approaches to work and everyday activities. An example of this type of device is roomware, or computer-augmented objects resulting from the integration of room elements, such as walls, doors, and furniture, with computer- based information devices. The roomware components that we have developed at Fraunhofer IPSI support the vision of a future where our surroundings act as an information interface, and the computer as a device disappears from our perception. Three main observations influenced the creation of roomware components: the growing importance of information technology; the need to integrate information technology with the environment in which it is used; and the recognition that new work practices will emerge to cope with the increasing rate of the innovation.
  • Publication
    EQUAL: Towards an inclusive design approach to novice programming languages and computing environments for native users
    ( 2002)
    Basawaraj, P.
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    Maetzel, K.
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    Neuhold, E.J.
    In the current textual programming languages (conventional, novice, etc.) and programming paradigms (e.g., procedural, declarative, functional etc.), the programming constructs, semantic concepts, and syntactic elements are based on English paradigm and implemented using ASCII character sets, seriously limiting the universal access to programming and computing skills. Especially, nonEnglish speaking native users (students, adults etc.) from nonEnglish speaking geographical regions, including visually challenged users, encounter serious cognitive, semantic and syntactic difficulties in understanding and translating their programming plans into the syntax and semantics of English based paradigm of a programming language. The authors have developed an inclusive, universal design framework with flexible cognitive, semantic and syntactic, and cultural adaptations in the textual languages and their compilers/interpreters to satisfy the computing requirements of native users.
  • Publication
    A cooperative visual hypermedia approach to planning and conducting virtual meetings
    ( 2002)
    Wang, W.
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    Haake, J.M.
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    Rubart, J.
    Most distributed meeting support systems focus on meeting management and audio/video communication mechanisms. They provide little support for a flexible meeting process and a shared information space with structure- rich visual artifacts. A cooperative visual hypermedia system is developed to provide visual hypermedia artifacts for team members to manipulate in a distributed meeting. The visual hypermedia system is a hypermedia-based drawing system that integrates visual hypermedia artifacts and structures found in multiple hypertext domains. In addition, the visual hypermedia is integrated with process support for flexible meeting control and for easy setup of audio/video and application sharing communication channels. A use case is presented, which shows that using the cooperative visual hypermedia, distributed teams can perform many kinds of meetings, in the meantime, enjoying dedicated support for the planning, control, information management, and follow-up activities of a distributed meeting.