218 research outputs found
Machine learning for transitional and turbulent flows
No full textL'abstract è presente nell'allegato / the abstract is in the attachmen
Evaluating tourist flows in historic cities: the case of Venice
No full textVenice is one of the world's great tourist-historic urban attractions, but this has produced a number of well-documented threats to both its physical and cultural environments, as well as conflicts with the needs of its residents and commuters. This has led to demands that tourist inflows should be limited. Against this background, the authors argue that, in practice, Venice's tourist demand is both varied and complex. This is illustrated by their analysis of a ninefold classification of tourists, which highlights important differences in spatial behaviour, perceptiveness, receptiveness and spending power. On this basis, they propose that some categories of tourists shuld be actively encouraged. Finally, they conclude by emphasizing the key role of the water transport system, and the need to plan for effective separation of the access, circulation and exit of the tourist and the resident/commuting populations. -Author
A Comparison of Local and Global Strategies for Exploiting Field Inversion on Separated Flows at Low Reynolds Number
No full textThe prediction of separated flows at low Reynolds numbers is crucial for several applications in aerospace and energy fields. Reynolds-averaged Navier–Stokes (RANS) equations are widely used but their accuracy is limited in the presence of transition or separation. In this work, two different strategies for improving RANS simulations by means of field inversion are discussed. Both strategies require solving an optimization problem to identify a correction field by minimizing the error on some measurable data. The obtained correction field is exploited with two alternative strategies. The first strategy aims to the identification of a relation that allows to express the local correction field as a function of some local flow features. However, this regression can be difficult or even impossible because the relation between the assumed input variables and the local correction could not be a function. For this reason, an alternative is proposed: a U-Net model is trained on the original and corrected RANS results. In this way, it is possible to perform a prediction with the original RANS model and then correct it by means of the U-Net. The methodologies are evaluated and compared on the flow around the NACA0021 and the SD7003 airfoils
L. Muscarà, M. Cisternino, A. Ferrero, A. Iob, F. Larocca, K. Samouchos, H. Telib "Enhancing turbulence modeling with data-driven approaches: a focus on the field inversion and machine learning paradigm. "
No full textHomo viator. Un viaggio socio antropologico tra le migrazioni e la mobilità umana
No full textA ogni inizio dell’estate – con il conseguente diradarsi delle cronache politiche (al netto, ovviamente, del cambio di governo
durante l’agosto 2019) – lo sguardo di molti cittadini italiani si dirige verso Lampedusa, ma la motivazione non risiede in, pur giustificate, ambizioni balneari, quanto nel consueto sbarco dei migranti che, lungi dal concentrarsi nel solo periodo estivo, trova nella stagione vacanziera quella visibilità in altri momenti negata. Il quadro migratorio che si presenta oggi è sicuramente meno unidirezionale e più articolato, effettivamente globale. Allo stesso tempo, le cause delle migrazioni sono articolate e complesse, riconducibili a un quadro di deprivazioni, nel quale guerre (esterne e interne), persecuzioni (politiche e confessionali) e crisi di produzione (agricola o industriale) giocano un ruolo importante, ma raramente svolgono un vero e proprio monologo
La Politique des États et leur géographie... And their centres
No full textJean Gottmann*, La politique des États et leur géographie, Paris, CTHS, 2007, 261 p + XXI p., préface et bibliographie complète des travaux de Jean Gottmann par Luca Muscara. Jean Gottmann was indeed interested in political geography and in the cloisonnement du monde as he called the political fragmentation of the surface of our Planet. In this book Gottmann exposes his theory on the iconography/circulation interplay: iconography is the force at the “foundation” of political entity; circulat..
Bibliografia completa di Jean Gottmann
No full textGottmann's geographic literature spans over sixty years of activity -- between 1933 and 1994 -- and is composed of almost 400 titles, about twenty of which are books. Published mostly in French and English, his writings were translated in fourteen languages including Spanish, Portuguese, Italian, Tamil, Dutch, Turkish, Slovenian, Japanese, Polish, Yiddish, German and modern Greek. Jean Gottmann's first official bibliography -- covering his writings between 1933 and 1984 -- was published in Patten, J. (ed.), 1983 in The Expanding City, Essays in honour of Professor Jean Gottmann, London-New York Academic Press, pp. xvii-xxxv. The same bibliography is entirely reprinted, with just one addition relative to 1983, in his volume of the same year: The Coming of the Transactional City, printed in College Park by the University of Maryland's Institute for Urban Studies. A selection of his publications dedicated to urban geography between 1949 and 1987 can be found in Jean Gottmann and Robert Harper, 1990, Since Megalopolis, the Urban Writings of Jean Gottmann, Baltimore and London, The Johns Hopkins University Press, pp. 269-280. Thanks to the partial opening of the Fond Gottmann, housed at the Bibliothèque Nationale de France Département des Cartes et Plans it was possible to verify his entire bibliography on the same notebook where Gottmann kept note of his own publications. Finally, the information in this bibliograhy was compared to the one available from the indexes of those thematic volumes that are selections of previously published essays from different scientific journals. In particular Etudes sur l'Etat d'Israel (1958), Essais sur l'aménagement de l'espace habité (1966), La cité invincible (1983) e Since Megalopolis (1990). We would like to thank Jean-Yves Sarazin, curator of the Fond Gottmann at the Bibliothéque Nationale de France in Paris, for his kind re-reading of the complete bibliography. We would also like to invite the reader that may be informed of recent and/or posthumous publications of Jean Gottmann - not included in this list - to contact the author
Les mots justes de Jean Gottmann
No full text"Je crois que la pensée humaine a subi vers le milieu du siècle (entre 1945 et 1960) une inflexion notable due aux effet des chocs successifs de la bombe d´Hiroshima, du Sputnik, des radios de poche et de la première vague d´ordinateurs. L´humanité fut amenée à reconsidérer ses propres capacités envers l´Univers et envers elle-même. Elle s´est mise à réviser bien des méthodes et des concepts ; chacun s´est posé la question de son rôle dans le monde physique d´une part et dans le monde, très d..
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