49 research outputs found

    On the investigation of cloud-based mobile media environments with service-populating and QoS-aware mechanisms

    Get PDF
    Recent advances in mobile devices and network technologies have set new trends in the way we use computers and access networks. Cloud Computing, where processing and storage resources are residing on the network is one of these trends. The other is Mobile Computing, where mobile devices such as smartphones and tablets are believed to replace personal computers by combining network connectivity, mobility, and software functionality. In the future, these devices are expected to seamlessly switch between different network providers using vertical handover mechanisms in order to maintain network connectivity at all times. This will enable mobile devices to access Cloud Services without interruption as users move around. Using current service delivery models, mobile devices moving from one geographical location to another will keep accessing those services from the local Cloud of their previous network, which might lead to moving a large volume of data over the Internet backbone over long distances. This scenario highlights the fact that user mobility will result in more congestion on the Internet. This will degrade the Quality of Service and by extension, the Quality of Experience offered by the services in the Cloud and especially multimedia services that have very tight temporal constraints in terms of bandwidth and jitter. We believe that a different approach is required to manage resources more efficiently, while improving the Quality of Service and Media Service Delivery in which services run on localised public Clouds and are capable of populating other public Clouds in different geographical locations depending on service demands and network status. Using an analytical framework, this paper argues that as the demand for specific services increases in a location, it might be more efficient to move those services closer to that location. This will prevent the Internet backbone from experiencing high traffic loads due to multimedia streams and will offer service pr- viders an automated resource allocation and management mechanism for their services

    Transjugular Intrahepatic Portosystemic Shunts With Covered Stents Increase Transplant-Free Survival of Patients With Cirrhosis and Recurrent Ascites

    Get PDF
    BACKGROUND & AIMS: There is controversy over the ability of transjugular intrahepatic portosystemic shunts (TIPS) to increase survival times of patients with cirrhosis and refractory ascites. The high rate of shunt dysfunction with the use of uncovered stents counteracts the benefits of TIPS. We performed a randomized controlled trial to determine the effects of TIPS with stents covered with polytetrafluoroethylene in these patients. METHODS: We performed a prospective study of 62 patients with cirrhosis and at least 2 large-volume paracenteses within a period of at least 3 weeks; the study was performed at 4 tertiary care centers in France from August 2005 through December 2012. Patients were randomly assigned to groups that received covered TIPS (n = 29) or large-volume paracenteses and albumin as necessary (LVP+A, n = 33). All patients maintained a low-salt diet and were examined at 1 month after the procedure then every 3 months until 1 year. At each visit, liver disease-related complications, treatment modifications, and clinical and biochemical variables needed to calculate Child-Pugh and Model for End-Stage Liver Disease scores were recorded. Doppler ultrasonography was performed at the start of the study and then at 6 and 12 months after the procedure. The primary study end point was survival without a liver transplant for 1 year after the procedure. RESULTS: A higher proportion of patients in the TIPS group (93%) met the primary end point than in the LVP+A group (52%) (P = .003). The total number of paracenteses was 32 in the TIPS group vs 320 in the LVP+A group. Higher proportions of patients in the LVP+A group had portal hypertension-related bleeding (18% vs 0%; P = .01) or hernia-related complications (18% vs 0%; P = .01) than in the TIPS group. Patients in LVP+A group had twice as many days of hospitalization (35 days) as the TIPS group (17 days) (P = .04). The 1-year probability of remaining free of encephalopathy was 65% for each group. CONCLUSIONS: In a randomized trial, we found covered stents for TIPS to increase the proportion of patients with cirrhosis and recurrent ascites who survive transplantation-free for 1 year, compared with patients given repeated LVP+A. These findings support TIPS as the first-line intervention in such patients. ClinicalTrials.gov ID: NCT00222014

    Comparative epigenetic analysis of tumour initiating cells and syngeneic EPSC-derived neural stem cells in glioblastoma

    Get PDF
    Epigenetic mechanisms which play an essential role in normal developmental processes, such as self-renewal and fate specification of neural stem cells (NSC) are also responsible for some of the changes in the glioblastoma (GBM) genome. Here we develop a strategy to compare the epigenetic and transcriptional make-up of primary GBM cells (GIC) with patient-matched expanded potential stem cell (EPSC)-derived NSC (iNSC). Using a comparative analysis of the transcriptome of syngeneic GIC/iNSC pairs, we identify a glycosaminoglycan (GAG)-mediated mechanism of recruitment of regulatory T cells (Tregs) in GBM. Integrated analysis of the transcriptome and DNA methylome of GBM cells identifies druggable target genes and patient-specific prediction of drug response in primary GIC cultures, which is validated in 3D and in vivo models. Taken together, we provide a proof of principle that this experimental pipeline has the potential to identify patient-specific disease mechanisms and druggable targets in GBM

    The distortion principle for insurance pricing: properties, identification and robustness

    Get PDF
    Distortion (Denneberg in ASTIN Bull 20(2):181–190, 1990) is a well known premium calculation principle for insurance contracts. In this paper, we study sensitivity properties of distortion functionals w.r.t. the assumptions for risk aversion as well as robustness w.r.t. ambiguity of the loss distribution. Ambiguity is measured by the Wasserstein distance. We study variances of distances for probability models and identify some worst case distributions. In addition to the direct problem we also investigate the inverse problem, that is how to identify the distortion density on the basis of observations of insurance premia

    Advances in Vehicular Ad-hoc Networks (VANETs): challenges and road-map for future development

    Get PDF
    Recent advances in wireless communication technologies and auto-mobile industry have triggered a significant research interest in the field of vehicular ad-hoc networks (VANETs) over the past few years. A vehicular network consists of vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) communications supported by wireless access technologies such as IEEE 802.11p. This innovation in wireless communication has been envisaged to improve road safety and motor traffic efficiency in near future through the development of intelligent transportation system (ITS). Hence, governments, auto-mobile industries and academia are heavily partnering through several ongoing research projects to establish standards for VANETs. The typical set of VANET application areas, such as vehicle collision warning and traffic information dissemination have made VANET an interesting field of mobile wireless communication. This paper provides an overview on current research state, challenges, potentials of VANETs as well as the ways forward to achieving the long awaited ITS

    Tournures infinitives et antériorité

    No full text

    The integration of UAVs to the C-ITS stack

    No full text
    Abstract In this paper, we conceptualise and propose integrating UAVs with Intelligent Transportation Systems (ITS) based on using the Cooperative-ITS (C-ITS) framework. We start by discussing the state of the art and pinpointing some of the reasons for integration and the applications that the envisaged integration would enable. Next, we recall the critical aspects of the state of the art C-ITS connectivity and discuss how seamless integration of UAVs into C-ITS can be achieved. Notably, we show that encapsulation of UAVs in C-ITS does not imply significant changes for the currently existing mechanisms and data formats. Finally, we discuss some of the open research challenges related to the integration and operation of the integrated systems and pinpoint some mechanisms which can help to address these

    Live Video Streaming in Vehicular Networks

    No full text
    corecore