445 research outputs found

    A new flexible and modular QoS mapping framework based on psychophysics

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    Accounting for the perceiving conditions that make up the delivery environment of an application helps improve the efficiency of QoS provisioning systems. It is useless to transmit information whose absence cannot be noticed by the end-user under the actual perceiving conditions. Until now, QoS architectures mostly focused on the transport system and did not integrate the studies achieved in the psychophysics area. In this paper, we propose a QoS framework that accounts for the perceiving conditions. Moreover, our framework is both flexible - i.e., customizable at will by the manager - and modular, with a clear and fine-grained layering. New mechanisms and their supporting characteristics, such as experimental curves, may be very easily introduced and managed in the proposed architecture. A case study is carried out, which shows the applicability of the framework for a video-on-demand provisioning system

    Multimedia resources: An information model and its application to an MPEG2 video codec

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    Still today, diagnosing a problem with multimedia resources, such as video and sound cards, is insufficiently automated. These resources therefore cannot be accurately managed. One reason for this is the lack of their thorough modeling. In this paper, we fulfill this need, by proposing a generic information model, which we further apply to an MPEG2 video codec. We highlight the main characteristics of this kind of codec, identify parameters that influence these characteristics, and reveal some of the trade-offs that the application developer can consider in order to design efficient software for MPEG2 codecs. In addition to the benefits of this modeling for the user and the application developer, we also show how useful it could be for the providers of distribution services, such as live video transmission. These providers can use our model to achieve resource management on an end-to-end basis

    A generic service management architecture for multimedia multipoint communications

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    With rapid advances in multimedia processing technologies, and in high bandwidth network technologies, new kinds of multimedia applications are now emerging. These applications require real-time, multimedia, and multipoint interactions involving multiple communicating entities and leading to a need of more sophisticated communication control functionalities. In this paper, a generic integrated and flexible service management architecture for multimedia multipoint communications is proposed, which offers three main generic functions, namely Quality of Service (QoS) negotiation, QoS monitoring and control, and session management

    Contribution to national maritime development in Haiti

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    Service Management: From definition to information modeling

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    In this paper, we split the service management layer, as defined in the Telecommunication Management Network (TMN), into two sublayers, namely the service application management sublayer and the service network management sublayer. The former deals with managing the mapping of the non functional requirements into functional constraints over the telecommunication service of interest, while the second reveals the management details related to meeting the functional requirements over that service. At each sublayer, we propose an information model and emphasize the correspondence with the other sublayer

    Management of multimedia resources: from a generic information model to its application to an MPEG2 video codec

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    New open service architectures provide a management framework for telecommunications services, telecommunications networks and computing resources. However, the introduction of multimedia applications in these architectures will require the management of the underlying multimedia resources (e.g., codecs, converters, etc). Multimedia resources are the basic components that support multimedia communications. In this paper, we tackle this issue by proposing a generic management information model for multimedia resources and then instantiate it for the management of an MPEG2 video codec. This information model provides a data representation of the multimedia resources in order to manage them efficiently

    An Architecture for the Integration of Internet and Telecommunication Services

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    In this paper, we propose an architecture for hybrid services, i.e., services that span many network technologies, especially the PSTN and the Internet. These services will play an important role in the future, because they leverage on the existing infrastructures, rather than requiring brand-new and sophisticated mechanisms to be deployed. We explore a few issues related to hybrid services and propose a platform, as well as a set of components, to facilitate their creation and deployment. The existing infrastructure is only required to generate specific events when requests for hybrid services are detected. We present the design of s service layer, based on Java, that handles the treatment of these special requests. Our service layer is provided with a set of generic components realized as Java Beans. Hence, we can provide hybrid services without changing the existing infrastructure. We illustrate this strength of our architecture by discussing the call forwarding service

    Integration of Internet and Telecommunications- An Architecture for Hybrid Services

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    In this article, we propose an architecture for hybrid services, i.e., services that span many network technologies, such as the Public Switched Telephone Network (PSTN), cellular networks and networks based on the Internet Protocol (IP). These services will play an important role in the future because they leverage on the existing infrastructures, rather than requiring new and sophisticated mechanisms to be deployed. We explore a few issues related to hybrid services and propose a platform, as well as a set of components, to facilitate their creation and deployment. The existing infrastructure is only required to generate specific events when requests for hybrid services are detected. We present the design of a service layer, based on Java, that handles the treatment of these special requests. Our service layer is provided with a set of generic components realized according to the JavaBeans model. We illustrate the strength of our architecture by discussing two hybrid-service examples: a calendar service and a call forwarding service

    Oscillations in the expression of a self-repressed gene induced by a slow transcriptional dynamics

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    We revisit the dynamics of a gene repressed by its own protein in the case where the transcription rate does not adapt instantaneously to protein concentration but is a dynamical variable. We derive analytical criteria for the appearance of sustained oscillations and find that they require degradation mechanisms much less nonlinear than for infinitely fast regulation. Deterministic predictions are also compared with stochastic simulations of this minimal genetic oscillator

    Oscillations in the expression of a self-repressed gene induced by a slow transcriptional dynamics

    Get PDF
    We revisit the dynamics of a gene repressed by its own protein in the case where the transcription rate does not adapt instantaneously to protein concentration but is a dynamical variable. We derive analytical criteria for the appearance of sustained oscillations and find that they require degradation mechanisms much less nonlinear than for infinitely fast regulation. Deterministic predictions are also compared with stochastic simulations of this minimal genetic oscillator
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