1,720,998 research outputs found

    REALISTIC INTERACTION FOR MAINTAINABILITY TESTS IN VIRTUAL REALITY

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    The present work deals with the development of a simulation environment for maintainability tests in virtual reality. During Virtual Maintenance tests, the realism of both visualization and interaction greatly improves the acceptance of the experience by the user, and rises the reliability of these evaluations. Looking at the improvement of the visual realism, real time shadows play a very important role whenever spatial relationship among scene objects have to be perceived. On the other hand, the key to make interactions more realistic is to correctly model the physical behaviours of bodies in the virtual environment. In this work is given an industrial application experience of a virtual reality system designed with the illustrated key features. Such system results from the integration of an open-source software and a real-time simulation engine of rigid body dynamics. Furthermore the implementation of a hardware shadow mapping algorithm, makes the use of real-time shadows feasible even with complex assemblies

    Interazione realistica per verifiche di manutenibilità in realtà virtuale

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    Condurre verifiche di manutenibilità in realtà virtuale consente di portare nel progetto, o in re-design migliorativi, la capacità dell’uomo di curarne successivamente gli interventi manutentivi. Un ambiente di realtà virtuale destinato a valutazioni soggettive deve offrire alla persona la capacità di interagire manualmente in maniera diretta e realistica con l’ambiente. Fattori chiave in direzione dell’aumento del realismo vengono individuati nell’impiego delle ombre calcolate in tempo reale, per quello visivo, e nella modellazione del comportamento fisico degli oggetti per rendere realistica l’interazione. Nel presente lavoro viene illustrata l’esperienza di sviluppo e di impiego applicativo in ambito industriale di un sistema di realtà virtuale che integra strumenti open-source per implementare tali funzionalità e sperimentarle in interazione manuale diretta per verifiche di manutenibilità. Nel caso applicativo presentato il sistema viene impiegato, in congiunzione a dispositivi di realtà virtuale immersiva per verificare la possibilità di installare (montare e collegare) un sottosistema del velivolo executive Piaggio Aero Industries P180 Avanti, operazione particolarmente critica a causa degli spazi angusti, dei vincoli strutturali e per la forma e le dimensioni dei componenti

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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