5,271 research outputs found

    A time-domain veto for binary inspirals search

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    We describe a test to distinguish between actual gravitational waves from binary inspiral and false noise triggers. The test operates in the time domain, and considers the time evolution of the correlator and its statistical distribution. It should distinguish true versus noisy events with the same signal-to-noise ratio and chi-square frequency distribution. A similar test has been applied to S1 LIGO data

    Adaptive spectral identification techniques in presence of undetected non linearities

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    The standard procedure for detection of gravitational wave coalescing binaries signals is based on Wiener filtering with an appropriate bank of template filters. This is the optimal procedure in the hypothesis of addictive Gaussian and stationary noise. We study the possibility of improving the detection efficiency with a class of adaptive spectral identification techniques, analyzing their effect in presence of non stationarities and undetected non linearities in the noiseComment: 4 pages, 2 figures, uses ws-procs9x6.cls Proceedings of "Non linear physics: theory and experiment. II", Gallipoli (Lecce), 200

    DiBELLA: Distributed long read to long read alignment

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    We present a parallel algorithm and scalable implementation for genome analysis, specifically the problem of finding overlaps and alignments for data from "third generation" long read sequencers [29]. While long sequences of DNA offer enormous advantages for biological analysis and insight, current long read sequencing instruments have high error rates and therefore require different approaches to analysis than their short read counterparts. Our work focuses on an efficient distributed-memory parallelization of an accurate single-node algorithm for overlapping and aligning long reads. We achieve scalability of this irregular algorithm by addressing the competing issues of increasing parallelism, minimizing communication, constraining the memory footprint, and ensuring good load balance. The resulting application, diBELLA, is the first distributed memory overlapper and aligner specifically designed for long reads and parallel scalability. We describe and present analyses for high level design trade-offs and conduct an extensive empirical analysis that compares performance characteristics across state-of-the-art HPC systems as well as a commercial cloud architectures, highlighting the advantages of state-of-the-art network technologies

    Landslide susceptibility assessment in the Peloritani Mts. (Sicily, Italy) and clues for tectonic control of relief processes

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    Abstract. Many destructive shallow landslides hit villages in the Peloritani Mountains area (Sicily, Italy) on 1 October 2009 after heavy rainfall. The collection of several types of spatial data, together with a landslide inventory, allows the assessment of the landslide susceptibility by applying a statistical technique. The susceptibility model was validated by performing an analysis in a test area using independent landslide information, the results being able to correctly predict more than 70% of the landslides. Furthermore, the susceptibility analysis allowed the identification of which combinations of classes, within the different factors, have greater relevance in slope instability, and afterwards associating the most unstable combinations (with a short–medium term incidence) with the endogenic processes acting in the area (huge regional uplift, fault activity). Geological and tectonic history are believed to be key to interpreting morphological processes and landscape evolution. Recent tectonic activity was found to be a very important controlling factor in landscape evolution. A geomorphological model of cyclical relief evolution is proposed in which endogenic processes are directly linked to superficial processes. The results are relevant both to risk reduction and the understanding of active geological dynamics

    A Critical Comparison of Alternative Risk Priority Numbers in Failure Modes, Effects, and Criticality Analysis

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    A Geometric Processing Workflow for Transforming Reality-Based 3D Models in Volumetric Meshes Suitable for FEA

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    Conservation of Cultural Heritage is a key issue and structural changes and damages can influence the mechanical behaviour of artefacts and buildings. The use of Finite Elements Methods (FEM) for mechanical analysis is largely used in modelling stress behaviour. The typical workflow involves the use of CAD 3D models made by Non-Uniform Rational B-splines (NURBS) surfaces, representing the ideal shape of the object to be simulated. Nowadays, 3D documentation of CH has been widely developed through reality-based approaches, but the models are not suitable for a direct use in FEA: the mesh has in fact to be converted to volumetric, and the density has to be reduced since the computational complexity of a FEA grows exponentially with the number of nodes

    3D DIGITIZATION OF MUSEUM CONTENT WITHIN THE 3DICONS PROJECT

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    The main purpose of the European Project "3DIcons" is to digitize masterpieces of Cultural Heritage and provide the related 3D models and metadata to Europeana, an Internet portal that acts as an interface to millions of books, paintings, films, museum objects and archival records that have been digitised throughout Europe. The purpose of this paper is to define a complete pipeline which covers all technical and logistic aspects for creating 3D models in a Museum environment with no established digitization laboratory, from the 3D data acquisition to the creation of models that has to be searchable on the Internet through Europeana. The research group of Politecnico di Milano is dealing with the 3D modelling of the Archaeological Museum of Milan and most of its valuable content. In this paper an optimized 3D modelling pipeline is shown, that takes into account all the potential problems occurring during the survey and the related data processing. Most of the 3D digitization activity have been made exploiting the Structure From Motion (SfM) technique, handling all the acquisition (e.g. objects enlightenment, camera-object relative positioning, object shape and material, etc.) and processing problems (e.g. difficulties in the alignment step, model scaling, mesh optimization, etc.), but without neglecting the metric rigor of the results. This optimized process has been applied on a significant number of items, showing how this technique can allow large scale 3D digitization projects with relatively limited efforts

    Low-latency analysis pipeline for compact binary coalescences in the advanced gravitational wave detector era

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    The multi-band template analysis (MBTA) pipeline is a low-latency coincident analysis pipeline for the detection of gravitational waves (GWs) from compact binary coalescences. MBTA runs with a low computational cost, and can identify candidate GW events online with a sub-minute latency. The low computational running cost of MBTA also makes it useful for data quality studies. Events detected by MBTA online can be used to alert astronomical partners for electromagnetic follow-up. We outline the current status of MBTA and give details of recent pipeline upgrades and validation tests that were performed in preparation for the first advanced detector observing period. The MBTA pipeline is ready for the outset of the advanced detector era and the exciting prospects it will bring.Comment: 18 pages, 10 figure
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