12 research outputs found

    Mobility Management in beyond 3G-Environments

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    Beyond 3G-environments are typically defined as environments that integrate different wireless and fixed access network technologies. In this paper, we address IP based Mobility Management (MM) in beyond 3G-environments with a focus on wireless access networks, motivated by the current trend of WiFi, GPRS, and UMTS networks. The GPRS and UMTS networks provide countrywide network access, while the WiFi networks provide network access in local areas such as city centres and airports. As a result, mobile end-users can be always on-line and connected to their preferred network(s), these network preferences are typically stored in a user profile. For example, an end-user who wishes to be connected with highest bandwidth could be connected to a WiFi network when available and fall back to GPRS when moving outside the hotspot area.\ud In this paper, we consider a combination of MM for legacy services (like web browsing, telnet, etc.) using Mobile IP and multimedia services using SIP. We assume that the end-user makes use of multi-interface terminals with the capability of selecting one or more types of access networks\ud based on preferences. For multimedia sessions, like VoIP or streaming video, we distinguish between changes in network access when the end-user is in a session or not in a session. If the end-user is not in a session, he or she needs to be able to start new sessions and receive invitations for new sessions. If the end-user is in a session, the session needs to be handed over to the new access network as seamless as possible from the perspective of the end-user. We propose an integrated but flexible solution to these problems that facilitates MM with a customizable transparency to applications and end-users

    Samenwerken en zakendoen via het Internet

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    In de Internetwereld zien we een nieuwe paradigma ontstaan: de ‘retailer’. Ook al is niet helemaal duidelijk wie deze rol gaat invullen, duidelijk is wel dat eindgebruikers een Ă©Ă©nduidige ingang wensen voor een scala aan diensten. Transparantie van, onder andere, kosten is hierbij gewenst. Een dienstenaanbieder wil zich ook niet langer zorgen hoeven maken over generieke functionaliteit zoals authenticiteit en autorisatie van gebruikers, transacties, ‘application hosting’, betaling, of andere zaken die de zogenoemde retailer voor hem kan oplossen. Zo’n retailer past in een dienst-, in plaats van productgerichte aanpak. Het retailer paradigma wordt ondersteund door technische ontwikkelingen rondom het ASP model, de programmeertaal Java, ‘interoperabiliteit’, component software (hergebruik) en ‘netwerkcomputers’. Gebaseerd op het bovenstaande paradigma heeft FRIENDS een geĂŻntegreerd platform ontwikkeld dat ondersteuning biedt aan zowel eindgebruikers, als ontwikkelaars, als aanbieders van on-line gedistribueerde diensten

    B Cells Migrate into Remote Brain Areas and Support Neurogenesis and Functional Recovery after Focal Stroke in Mice

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    Lymphocytes infiltrate the stroke core and penumbra and often exacerbate cellular injury. B cells, however, are lymphocytes that do not contribute to acute pathology but can support recovery. B cell adoptive transfer to mice reduced infarct volumes 3 and 7 d after transient middle cerebral artery occlusion (tMCAo), independent of changing immune populations in recipient mice. Testing a direct neurotrophic effect, B cells cocultured with mixed cortical cells protected neurons and maintained dendritic arborization after oxygen-glucose deprivation. Whole-brain volumetric serial two-photon tomography (STPT) and a custom-developed image analysis pipeline visualized and quantified poststroke B cell diapedesis throughout the brain, including remote areas supporting functional recovery. Stroke induced significant bilateral B cell diapedesis into remote brain regions regulating motor and cognitive functions and neurogenesis (e.g., dentate gyrus, hypothalamus, olfactory areas, cerebellum) in the whole-brain datasets. To confirm a mechanistic role for B cells in functional recovery, rituximab was given to human CD20+ (hCD20+) transgenic mice to continuously deplete hCD20+-expressing B cells following tMCAo. These mice experienced delayed motor recovery, impaired spatial memory, and increased anxiety through 8 wk poststroke compared to wild type (WT) littermates also receiving rituximab. B cell depletion reduced stroke-induced hippocampal neurogenesis and cell survival. Thus, B cell diapedesis occurred in areas remote to the infarct that mediated motor and cognitive recovery. Understanding the role of B cells in neuronal health and disease-based plasticity is critical for developing effective immune-based therapies for protection against diseases that involve recruitment of peripheral immune cells into the injured brain

    A 2-D weighing procedure for two-way communication

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    New coding schemes for the binary multiplying channel, based on a 2-D weighing procedure, are discussed

    Near Real-Time Detection of Misinformation on Online Social Networks

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    In this paper, we focus on the automatic detection of misinformation articles on online social networks. We study micro-blog posts that propagate news articles and classify these articles as misinformation or trusted information. We do this by extracting a comprehensive set of network and linguistic features and propose a deep learning model that combines both feature types. Experiments on real data demonstrate that our proposed method detects misinformation with an accuracy of 93% in near-real time. Moreover, we compare network and linguistic features with respect to the earliness of detection and combine these features with temporal information about diffusion patterns. We find that combining both feature types is optimal for the detection of misinformation articles in near-real time.</p

    Mobility management for SIP sessions in a heterogeneous network environment

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    The next generation of communication networks is expected to create a heterogeneous network environment encompassing an ever-increasing number of different access networks and end-user terminals that will enable the introduction of and provide access to numerous feature-rich end-user services. It is essential that end users be able to roam from one access network to another if they are to enjoy a seamless roaming experience, which is especially important for multimedia applications such as voice, audio, and video. This paper describes how to make such a roaming experience possible in multimedia applications based on Session Initiation Protocol (SIP). It also describes several mobility management solutions and compares the suitability of SIP sessions for roaming across General Packet Radio Service (GPRS), Universal Mobile Telecommunications System (UMTS), and wireless local area network (WLAN) networks. The comparison is based on the implementation of a prototype. The advantages and disadvantages of each mobility management solution are discussed, as are the issues encountered during the implementation of the prototype. © 2004 Lucent Technologies Inc

    Near Real-Time Detection of Misinformation on Online Social Networks

    No full text
    In this paper, we focus on the automatic detection of misinformation articles on online social networks. We study micro-blog posts that propagate news articles and classify these articles as misinformation or trusted information. We do this by extracting a comprehensive set of network and linguistic features and propose a deep learning model that combines both feature types. Experiments on real data demonstrate that our proposed method detects misinformation with an accuracy of 93% in near-real time. Moreover, we compare network and linguistic features with respect to the earliness of detection and combine these features with temporal information about diffusion patterns. We find that combining both feature types is optimal for the detection of misinformation articles in near-real time

    The cost-utility of stepped-care algorithms according to depression guideline recommendations - Results of a state-transition model analysis.

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    Evidence-based clinical guidelines for major depressive disorder (MDD) recommend stepped-care strategies for sequencing evidence-based treatments conditional on treatment outcomes. This study aims to evaluate the cost-effectiveness of stepped care as recommended by the multidisciplinary clinical guideline vis-Ă -vis usual care in the Netherlands
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