202 research outputs found

    Fluid Model Checking of Timed Properties

    Get PDF
    We address the problem of verifying timed properties of Markovian models of large populations of interacting agents, modelled as finite state automata. In particular, we focus on time-bounded properties of (random) individual agents specified by Deterministic Timed Automata (DTA) endowed with a single clock. Exploiting ideas from fluid approximation, we estimate the satisfaction probability of the DTA properties by reducing it to the computation of the transient probability of a subclass of Time-Inhomogeneous Markov Renewal Processes with exponentially and deterministically-timed transitions, and a small state space. For this subclass of models, we show how to derive a set of Delay Differential Equations (DDE), whose numerical solution provides a fast and accurate estimate of the satisfaction probability. In the paper, we also prove the asymptotic convergence of the approach, and exemplify the method on a simple epidemic spreading model. Finally, we also show how to construct a system of DDEs to efficiently approximate the average number of agents that satisfy the DTA specification

    LA CARTELLA CLINICA ELETTRONICA

    Get PDF
    Questo lavoro offre una descrizione a più livelli della Cartella Clinica Elettronica (CCE), una fotografia della gestione attuale delle informazioni cliniche in ambito Riabilitativo (ospedaliero e territoriale) delle Aziende pubbliche della Regione Toscana. Analizza, nello specifico settore di riabilitazione territoriale dell'età evolutiva della Unità Operativa di Riabilitazione Funzionale dell'A.U.S.L. 12 Viareggio , le criticità riscontrate nei confronti della documentazione riabilitativa cartacea (Cartella Riabilitativa) e le aspetative risolutive attese da un sistema elettronico. Offre una panoramica sulla Cartella Clinica (cartacea), la sua storia ed evoluzione, i riferimenti normativo-legislativi e le caratteristiche. Descrive il contesto di sviluppo della Cartella Clinica Elettronica, gli aspetti normativi e legislativi, le caratteristiche, i requisiti ed i vantaggi per operatori, cittadini ed amministrazioni, rispetto allo strumento tradizionale. Descrive inoltre brevemente la questione dell'approccio dell'operatore sanitario allo strumento elettronico, ad oggi molto differenziabile tra le varie generazioni di operatori sanitari

    The use of coated micropowders to reduce radiation heat transfer in foam insulation

    Get PDF
    Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Architecture, 1991.Includes bibliographical references (leaves 126-129).Polyurethane foam is the most effective insulation currently available for buildings. Chlorofluorocarbon (CFC) blowing agents, which have low thermal conductivities, contribute highly to the effectiveness of this insulation. However, CFC blowing agents are being phased out because they are depleting the earth's protective ozone layer. Alternate blowing agents, with higher thermal conductivities, will compromise the insulating value of the foam insulation. To counteract this effect, the author has sought to improve the effectiveness of foam insulation by increasing its extinction coefficient. In this work, theoretical analysis and experimental measurements have been used to study and increase the extinction coefficient of polyurethane foam insulation. Radiative heat transfer, which accounts for approximately 25% of the total heat transfer through foams, is inversely proportionate to the extinction coefficient. Foam cell walls presently have a transmissivity of about 80% to infrared radiation. The extinction coefficient of foams can be improved by decreasing the cell sizes or by increasing the absorptivity of the foam cell walls. The approach of this work has been to increase the cell wall opacity through the addition of opaque micropowders. Conduction through the solid polymer is of the same magnitude as the radiative transfer, also accounting for approximately 25% of the heat transfer of the foam. To maintain the low thermal conductivity of the polymer, the micropowders added to reduce radiative transfer through the foam must not change its characteristic conductivity. Polymer micropowders with thermally opaque coatings of graphite have been developed in this work using core micropowders with diameters between 8 and 30 [mu]m. Theory predicts that the smaller the particle size, the larger the resulting improvement in extinction coefficient. The coatings required for opacity are less than 0.1 [mu]m thick, composing less than 7% of the overall volume of the powder. The extinction coefficients of the coated micropowders have been experimentally derived and agree well with analytical predictions. These coated micropowders have been added to foams with the goal of increasing their extinction coefficients. The resulting foams indeed demonstrate improved extinction coefficients when compared to a powderless control foam. This improvement results both from reduction in cell size and increased cell wall opacity. The resulting effective conductivities of the foams have been decreased by as much as 6% through the addition of these relatively large micropowders. These results correlate well with predicted values and indicate that the addition of smaller particles will result in even more improvement.by Arlene Lanciani Marge.M.S

    A multiscale approach for precipitation verification applied to the FORALPS case studies

    No full text
    International audienceMultiscale methods, such as the power spectrum, are suitable diagnostic tools for studying the second order statistics of a gridded field. For instance, in the case of Numerical Weather Prediction models, a drop in the power spectrum for a given scale indicates the inability of the model to reproduce the variance of the phenomenon below the correspondent spatial scale. Hence, these statistics provide an insight into the real resolution of a gridded field and must be accurately known for interpolation and downscaling purposes. In this work, belonging to the EU INTERREG IIIB Alpine Space FORALPS project, the power spectra of the precipitation fields for two intense rain events, which occurred over the north-eastern alpine region, have been studied in detail. A drop in the power spectrum at the shortest scales (about 30 km) has been found, as well as a strong matching between the precipitation spectrum and the spectrum of the orography. Furthermore, it has also been shown how the spectra help understand the behavior of the skill scores traditionally used in Quantitative Precipitation Forecast verification, as these are sensitive to the amount of small scale detail present in the fields

    Precisiones sobre la luz en el Pantheon de Roma

    Get PDF
    [EN] Adriano’s Pantheon is one of the most celebrated works in the history of architecture. Many questions have captivated its visitors, but it is the light that has captured most of the attention: after stripping the building of its symbolic load, the manifestation of its interior light seems to be the only purpose of this immense “space-light” that has fascinated architects, art historians, painters and photographers throughout time. It seems difficult to add anything new, but being fully aware of this, the author of this article hopes to point out some of the different aspects of light in the Pantheon that he considers haven’t been developed enough: the reason behind the solar and urban orientation of the temple regarding the north-south axis; the reconstruction of the light and shadow sequence that must have occurred in the original access to the interior of the temple; the interpretation of the ocular beam of light as an immaterial reminiscence of the false central support of the Etruscan domes, turned into a subtle column that without ever reaching the vertical position, falls in different ways on the surfaces that create the interior.[ES] El Pantheon de Adriano es una de las obras más celebradas de la historia de la arquitectura. Han sido muchas las cuestiones que han cautivado a cuantos han entrado en él, pero es la luz la que ha acaparado el mayor protagonismo: una vez despojado el edificio de su originaria carga simbólica, la manifestación de su luz interior parece ser el único fin de este inmenso espacio-luz que tanto ha fascinado a arquitectos, historiadores del arte, pintores y fotógrafos. Parece difícil poder aportar nada nuevo. Consciente de ello, el autor del presente artículo sólo pretende apuntar algunas cuestiones sobre distintos aspectos de la luz en el Pantheon que considera que no han sido aún suficientemente desarrolladas: el por qué de la orientación solar y urbana del templo con respecto al eje norte-sur; la reconstrucción de la secuencia de luz y sombra que debió de darse en el recorrido original de acceso al interior del templo; la interpretación del haz de luz ocular como reminiscencia inmaterial del soporte central de las falsas cúpulas etruscas, convertida en una columna de materia sutil que, sin alcanzar nunca la vertical, incide de manera variada sobre los paramentos que conforman el interior.Linares De La Torre, O. (2015). Further observations on the light in the Pantheon in Rome. VLC arquitectura. Research Journal. 2(1):33-55. doi:http://dx.doi.org/10.4995/vlc.2015.3376.SWORD335521Deleuze, G. El pliegue. Leibniz y el barroco. Barcelona: Paidós, 1898Giedion, S. El Presente eterno: los comienzos de la arquitectura. Madrid: Alianza, 1981Hatecoeur, L. Mystique et Architecture: Symbolisme du cercle et de la coupole. Paris: A. et J. Picard et Cie, 1954Lanciani, R. Forma Urbis Romae, Quasar, Roma, 1990Macdonald, W. L. The Pantheon: design, meaning and progeny. Cambridge: Harvard University Press, 1976Miguel Arbonés, E. La Luz en la configuración del espacio. Tesis doctoral, Universidad Politécnica de Madrid, 2006Montero Fernández, F.J. El Panteón: Imagen, Tiempo y Espacio. Proyecto y Patrimonio. Sevilla: Universidad de Sevilla, 2004Stamper, J. W. The Architecture of Roman temples: the republic to the middle empire. Cambridge: Cambridge University Press, 200

    Archaeoseismology: Methodological issues and procedure

    Get PDF
    Archaeoseismic research contributes important data on past earthquakes. A limitation of the usefulness of archaeoseismology is due to the lack of continuous discussion about the methodology. The methodological issues are particularly important because archaeoseismological investigations of past earthquakes make use of a large variety of methods. Typical in situ investigations include: (1) reconstruction of the local archaeological stratigraphy aimed at defining the correct position and chronology of a destruction layer, presumably related to an earthquake; (2) analysis of the deformations potentially due to seismic shaking or secondary earthquake effects, detectable on walls; (3) analysis of the depositional characteristics of the collapsed material; (4) investigations of the local geology and geomorphology to define possible natural cause(s) of the destruction; (5) investigations of the local factors affecting the ground motion amplifications; and (6) estimation of the dynamic excitation, which affected the site under investigation. Subsequently, a 'territorial' approach testing evidence of synchronous destruction in a certain region may delineate the extent of the area struck by the earthquake. The most reliable results of an archaeoseismological investigation are obtained by application of modern geoarchaeological practice (archaeological stratigraphy plus geological–geomorphological data), with the addition of a geophysical-engineering quantitative approach and (if available) historical information. This gives a basic dataset necessary to perform quantitative analyses which, in turn, corroborate the archaeoseismic hypothesis. Since archaeoseismological investigations can reveal the possible natural causes of destruction at a site, they contribute to the wider field of environmental archaeology, that seeks to define the history of the relationship between humans and the environment. Finally, through the improvement of the knowledge on the past seismicity, these studies can contribute to the regional estimation of seismic hazard

    The Cult Statues of the Pantheon

    Get PDF
    This article reconsiders the possible statuary of the Pantheon in Rome, both in its original Augustan form and in its later phases. It argues that the so-called ‘Algiers Relief’ has wrongly been connected with the Temple of Mars Ultor and is in fact evidence of the association of the Divus Julius with Mars and Venus in the Pantheon of Agrippa, a juxtaposition which reflects the direction of Augustan ideology in the 20s b.c. and the building's celestial purpose. This triple statue group became the focus of the later Pantheon, and its importance is highlighted by the hierarchized system of architectural ornament of the present building

    Role for Circadian Clock Genes in Seasonal Timing: Testing the Bunning Hypothesis

    Get PDF
    A major question in chronobiology focuses around the “Bünning hypothesis” which implicates the circadian clock in photoperiodic (day-length) measurement and is supported in some systems (e.g. plants) but disputed in others. Here, we used the seasonally-regulated thermotolerance of Drosophila melanogaster to test the role of various clock genes in day-length measurement. In Drosophila, freezing temperatures induce reversible chill coma, a narcosis-like state. We have corroborated previous observations that wild-type flies developing under short photoperiods (winter-like) exhibit significantly shorter chill-coma recovery times (CCRt) than flies that were raised under long (summer-like) photoperiods. Here, we show that arrhythmic mutant strains, per01, tim01 and ClkJrk, as well as variants that speed up or slow down the circadian period, disrupt the photoperiodic component of CCRt. Our results support an underlying circadian function mediating seasonal daylength measurement and indicate that clock genes are tightly involved in photo- and thermo-periodic measurements

    Entre consumos suntuários e comuns: a posse de objetos exóticos entre alguns habitantes do Porto (séculos XVI – XVII)

    Get PDF
    O estudo da documentação referente aos doadores da Misericórdia do Porto entre os séculos XVI e XVII, através dos objetos exóticos patentes nos respectivos testamentos e inven- tários – estes últimos provenientes de uma área que se estende de Macau ao Brasil –, permite discernir uma panóplia de objetos que mudaram a cultura material dos portuenses em contato com os territórios da expansão portuguesa. Um levantamento sistemático permitiu já rastrear, até o ano de 1699, 257 doadores, dos quais se apresentarão aqui apenas alguns, referentes a benfeitores que, não obstante possuírem bens móveis nesse âmbito, não são dados como tendo estado nos territórios de expansão transoceânica. Argumentar-se-á que essa circulação de objetos não foi exclusiva das elites nobiliárquicas, nem dos grandes centros urbanos, pelo que a sua difusão atingiu maiores proporções do que aquelas que a historiografia tem admitido até agora. A cidade em observação neste estudo – o Porto dos séculos XVI e XVII – estava longe de ser das maiores da Europa nesse período, quer em dimensão territorial, quer em efetivos populacionais, embora se situasse numa região de demografia pujante, que canalizou os seus excedentes desde cedo para a emigração interna e externa – o Entre Douro e Minho. Como teremos ocasião de verificar, fidalgos e nobres possuíam bens exóticos, mas estes encontravam-se também entre mercadores e até artesãos mais desafogados. Por outro lado, nem todos os objetos provenientes dos espaços da expansão transoceânica devem ser conotados com bens de luxo.The study of the sources referring to the donors of the Misericórdia of the city of Porto during the sixteenth and seventeenth centuries has revealed the presence of numerous exotic objects in their last wills and inventories. A survey has traced 257 donors until 1699, some of them having died in an area that extends from Macao to Brazil. Only a small number of cases shall be presented here, pertaining to benefactors who, in spite of owning objects of transoceanic origin, seem to have remained in mainland Portugal. It shall be argued that the circulation of objects has not been exclusive either to the elites of the nobility or to the large urban centres, their diffusion having been on a larger scale than what has been admitted until now. The city under scrutiny in this study – Porto during the sixteenth and seventeenth centuries – was not one of the bigger cities in this period, either in what respects to size or population, although it was located in an area of flourishing demography, that channelled its surplus population early on to internal and external emigration. Fidalgos and noblemen owned exotic goods, but these were to be found among merchants and even well-to-do artisans. On the other hand, not all objects originating from the areas of transoceanic expansion should be considered as luxury goods.info:eu-repo/semantics/publishedVersio
    corecore