3,333 research outputs found

    Tag-based Recommender System for Context-Aware Content Dissemination in Opportunistic Networks

    Get PDF
    Content dissemination in opportunistic networks is a hot research topic that attracted a lot of interest in the last few years. The key idea is to optimise the diffusion of content among nodes in opportunistic networks to ensure that users are always able to obtain the most relevant items according to their interests. The classical approach is to statically define a set of interests for each user, and make sure that they receive items matching those interests. In this paper, we propose a novel approach, based on the dynamic and automatic identification of interests. To do so, we exploit the tags that users assign to the items they create, and the tags of the items that they download. We model these actions through a folksonomy and the related tripartite graph, with different nodes for users, items, and tags. We use this graph as the basis for identifying the relevance of the items. Specifically, we use a tag-based recommender system on the graph, called PLIERS, that is able to calculate the relevance of an item for a certain user, with respect to the items that are already linked to this user. We validate our approach through a series of simulations. We emulate the presence of a variable number of agents which randomly move, create and tag items, and possibly encounter other agents. Each agent maintains a tripartite graph locally, representing its actions, and it integrates this graph with information received from other encountered nodes. The agents use PLIERS on their local graph to assess the relevance of the items they find, and they decide whether these items are relevant for them or not. We evaluate the accuracy of the results by comparing the recommendations on the local graphs with the relevance of the items (calculated through PLIERS) on a global graph obtained by merging together all the local graphs of the nodes. This graph represents the complete knowledge of all actions in the network and it allows us to obtain the best possible recommendations for a target user, that could be obtained if all the nodes had the full knowledge of the actions of other nodes. The results indicate that the recommendations on the local graph are accurate and that the local knowledge of nodes reaches the global knowledge in the network through a sufficiently high number of contacts

    The energy center initiative at politecnico di torino: practical experiences on energy efficiency measures in the municipality of torino

    Get PDF
    Urban districts should evolve towards a more sustainable infrastructure and greener energy carriers. The utmost challenge is the smart integration and control, within the existing infrastructure, of new information and energy technologies (such as sensors, appliances, electric and thermal power and storage devices) that are able to provide multi-services based on multi-actors and multi and interchangeable energy carriers. In recent years, the Municipality of Torino represents an experimental scenario, in which practical experiences in the below-areas have taken place through a number of projects: 1. energy efficiency in building; 2. smart energy grids management and smart metering; 3. biowaste-to-energy: mixed urban/industrial waste management with enhanced energy recovery from biogas. This work provides an overview and update on the most interesting initiatives of smart energy management in the urban context of Torino, with an analysis and quantification of the advantages gained in terms of energy and environmental efficiency

    CAR T cells targeting tumor endothelial marker CLEC14A inhibit tumor growth

    Get PDF
    Engineering T cells to express chimeric antigen receptors (CARs) specific for antigens on hematological cancers has yielded remarkable clinical responses, but with solid tumors, benefit has been more limited. This may reflect lack of suitable target antigens, immune evasion mechanisms in malignant cells, and/or lack of T cell infiltration into tumors. An alternative approach, to circumvent these problems, is targeting the tumor vasculature rather than the malignant cells directly. CLEC14A is a glycoprotein selectively overexpressed on the vasculature of many solid human cancers and is, therefore, of considerable interest as a target antigen. Here, we generated CARs from 2 CLEC14A-specific antibodies and expressed them in T cells. In vitro studies demonstrated that, when exposed to their target antigen, these engineered T cells proliferate, release IFN-Îł, and mediate cytotoxicity. Infusing CAR engineered T cells into healthy mice showed no signs of toxicity, yet these T cells targeted tumor tissue and significantly inhibited tumor growth in 3 mouse models of cancer (Rip-Tag2, mPDAC, and Lewis lung carcinoma). Reduced tumor burden also correlated with significant loss of CLEC14A expression and reduced vascular density within malignant tissues. These data suggest the tumor vasculature can be safely and effectively targeted with CLEC14A-specific CAR T cells, offering a potent and widely applicable therapy for cancer

    In situ commissioning of the ATLAS electromagnetic calorimeter with cosmic muons

    Get PDF
    In 2006, ATLAS entered the {\it in situ} commissioning phase. The primary goal of this phase is to verify the detector operation and performance with cosmic muons. Using a dedicated cosmic muon trigger from the hadronic Tile calorimeter, a sample of approximately 120 000120\,000 events was collected in several modules of the barrel electromagnetic (EM) calorimeter between August 2006 and March 2007. As cosmic events are generally non-projective and arrive asynchronously with respect to the trigger clock, methods to improve the standard signal reconstruction for this situation are presented. Various selection criteria for projective muons and clustering algorithms have been tested, leading to preliminary results on calorimeter uniformity in η\eta and timing performance

    Position resolution and particle identification with the ATLAS EM calorimeter

    Full text link
    In the years between 2000 and 2002 several pre-series and series modules of the ATLAS EM barrel and end-cap calorimeter were exposed to electron, photon and pion beams. The performance of the calorimeter with respect to its finely segmented first sampling has been studied. The polar angle resolution has been found to be in the range 50-60 mrad/sqrt(E (GeV)). The neutral pion rejection has been measured to be about 3.5 for 90% photon selection efficiency at pT=50 GeV/c. Electron-pion separation studies have indicated that a pion fake rate of (0.07-0.5)% can be achieved while maintaining 90% electron identification efficiency for energies up to 40 GeV.Comment: 32 pages, 22 figures, to be published in NIM

    Energy Linearity and Resolution of the ATLAS Electromagnetic Barrel Calorimeter in an Electron Test-Beam

    Get PDF
    A module of the ATLAS electromagnetic barrel liquid argon calorimeter was exposed to the CERN electron test-beam at the H8 beam line upgraded for precision momentum measurement. The available energies of the electron beam ranged from 10 to 245 GeV. The electron beam impinged at one point corresponding to a pseudo-rapidity of eta=0.687 and an azimuthal angle of phi=0.28 in the ATLAS coordinate system. A detailed study of several effects biasing the electron energy measurement allowed an energy reconstruction procedure to be developed that ensures a good linearity and a good resolution. Use is made of detailed Monte Carlo simulations based on Geant which describe the longitudinal and transverse shower profiles as well as the energy distributions. For electron energies between 15 GeV and 180 GeV the deviation of the measured incident electron energy over the beam energy is within 0.1%. The systematic uncertainty of the measurement is about 0.1% at low energies and negligible at high energies. The energy resolution is found to be about 10% sqrt(E) for the sampling term and about 0.2% for the local constant term
    • …
    corecore