5,825 research outputs found

    Security Attributes Based Digital Rights Management

    Get PDF
    Most real-life systems delegate responsibilities to different authorities. We apply this model to a digital rights management system, to achieve flexible security. In our model a hierarchy of authorities issues certificates that are linked by cryptographic means. This linkage establishes a chain of control, identity-attribute-rights, and allows flexible rights control over content. Typical security objectives, such as identification, authentication, authorization and access control can be realised. Content keys are personalised to detect illegal super distribution. We describe a working prototype, which we develop using standard techniques, such as standard certificates, XML and Java. We present experimental results to evaluate the scalability of the system. A formal analysis demonstrates that our design is able to detect a form of illegal super distribution

    3D physical modeling of tsunamis generated by submerged landslides at a conical island. The role of initial acceleration

    Get PDF
    This paper presents a new set of 3D experiments aimed to gain insight on the role of the initial acceleration upon the generation process of tsunamis by submerged landslides that may occur at the flanks of conical islands. The experiments have been carried out in a large wave tank by varying the initial acceleration of the landslide model. A novel system, relying on the use of a computer controlled stepped motor, has been employed to control the motion of the landslide model. The experiments have been carried out in a parametric way by changing the initial acceleration of the landslide, aiming to reproduce different triggering mechanisms. Preliminary experimental findings confirmed the crucial role of the initial acceleration of the submerged landslide in generating tsunamis

    The Brera Multi-scale Wavelet Chandra Survey. I. Serendipitous source catalogue

    Full text link
    We present the BMW-Chandra source catalogue drawn from essentially all Chandra ACIS-I pointed observations with an exposure time in excess of 10ks public as of March 2003 (136 observations). Using the wavelet detection algorithm developed by Lazzati et al. (1999) and Campana et al. (1999), which can characterise both point-like and extended sources, we identified 21325 sources. Among them, 16758 are serendipitous, i.e. not associated with the targets of the pointings, and do not require a non-automated analysis. This makes our catalogue the largest compilation of Chandra sources to date. The 0.5--10 keV absorption corrected fluxes of these sources range from ~3E-16 to 9E-12 erg cm^-2 s^-1 with a median of 7E-15 erg cm^-2 s^-1. The catalogue consists of count rates and relative errors in three energy bands (total, 0.5-7keV; soft, 0.5-2keV; and hard, 2-7keV), and source positions relative to the highest signal-to-noise detection among the three bands. The wavelet algorithm also provides an estimate of the extension of the source. We include information drawn from the headers of the original files, as well, and extracted source counts in four additional energy bands, SB1 (0.5-1keV), SB2 (1-2keV), HB1 (2-4keV), and HB2 (4-7keV). We computed the sky coverage for the full catalogue and for a subset at high Galactic latitude (|b|> 20deg). The complete catalogue provides a sky coverage in the soft band (0.5-2keV, S/N =3) of ~8 deg^2 at a limiting flux of 1E-13 erg cm^-2 s^-1, and ~2 deg^2 at a limiting flux of ~1E-15 erg cm^-2 s^-1.Comment: Accepted by A&A, Higher res. Figs 4 and 5 at http://www.ifc.inaf.it/~romano/BMC/Docs/aapaper/9601f4.eps http://www.ifc.inaf.it/~romano/BMC/Docs/aapaper/9601f5.eps, Catalog Web pages: http://www.brera.inaf.it/BMC/bmc_home.html http://www.ifc.inaf.it/~romano/BMC/bmc_home.html (Mirror

    DILATION TREATMENT OF BENIGN STRICTURED OF COLOCOLONIC ANASTOMOSES

    Get PDF
    SCOPO DI QUESTO ARTICOLO E' DI METTERE IN LUCE LA COMPLIANCE, I BENEFICI ED IL MIGLIORAMENTO DELLA QUALITA' DELLA VITA, NEI SOGGETTI AFFETTI DA STENOSI BENIGNA POST-ANASTOMOTICA COLO-COLICA E COLO-RETTALE E TRATTATI CON DILATAZIONE ENDOSCOPICA DEL TRATTO STENOTICO. LA DILATAZION PER VIA ENDOSCOPICA RISULTA ESSERE SICURA E DI SEMPLICE ESECUZIONE E PERMETTE DI OTTENERE RISULTATI SODDISFACENTI ANCHE PER PERIODI PROLUNGATI. I CRITERI STANDARD PER UNA EFFICACE DILATAZIONE VARIANO TRA 1 10 E 13 MM

    POSTURE AND POSTUROLOGY, ANATOMICAL AND PHYSIOLOGICAL PROFILES: OVERVIEW AND CURRENT STATE OF ART

    Get PDF
    Background and aim of work: posture is the position of the body in the space, and is controlled by a set of anatomical structures. The maintenance and the control of posture are a set of interactions between muscle-skeletal, visual, vestibular, and skin system. Lately there are numerous studies that correlate the muscle-skeletal and the maintenance of posture. In particular, the correction of defects and obstruction of temporomandibular disorders, seem to have an impoact on posture. The aim of this work is to collect information in literature on posture and the influence of the stomatognatich system on postural system. Methods: Comparison of the literature on posture and posturology by consulting books and scientific sites. results: the results obtained from the comparison of the of the literature on posture and posturology by consulting books and scientific sites. Some studies support the correlation between stomatognatich system and posture, while others such a correlation. Conclusions: further studies are necessary to be able to confirm one or the other argument. (www.actabiomedica.it

    Measuring and explaining the diversity of voices and viewpoints in the news

    Get PDF
    News media can be considered to fulfil their democratic role as a “marketplace of ideas” only if they present a diverse content that gives space to a wider range of ideas and viewpoints. But how can content diversity be assessed? And what determines actor and viewpoint diversity in the first place? By employing measurements of actor and viewpoint diversity at the article and newspaper level, this study provides a complete overview on the content diversity of immigration news, and it investigates factors that have an impact on content diversity of immigration newspaper articles in Belgium, Germany, Italy and the United Kingdom (2013-2014). The results of a multilevel analysis indicate that both the articles’ size and the elite character of a newspaper play a key role in enhancing news’ multiperspectivalness. Also, the findings show that these two measurements of content diversity are different yet related to each other

    Argentum-quarz solution in the treatment of anorectal fistulas: Is it possible a conservative approach?

    Get PDF
    Patients suffering from chronic intestinal diseases (Crohn's disease, Ulcerative Colitis, Indeterminate Colitis) are prone to the development of pyogenic complications. These complications are most commonly in the form of perianal or intraabdominal abscesses and/or fistulas. The treatment of these complications are managed differently but, after an initial treatment based on medical or minimally invasive management, the solution of the pathological condition is always achieved by a surgical procedure. In the last few years prospective studies have proposed an alternative conservative therapeutic approach based on application of fibrin glue in the healing of patients with fistulas-in-ano. In this paper we suggest and discuss the therapeutic potential of silver and quarz in the conservative treatment of anorectal fistulas pointing out their role in modulating particular steps of the pathogenetic process which characterizes this pathological condition

    The Gaia-ESO Survey: dynamics of ionized and neutral gas in the Lagoon nebula (M8)

    Get PDF
    We present a spectroscopic study of the dynamics of the ionized and neutral gas throughout the Lagoon nebula (M8), using VLT/FLAMES data from the Gaia-ESO Survey. We explore the connections between the nebular gas and the stellar population of the associated star cluster NGC6530. We characterize through spectral fitting emission lines of H-alpha, [N II] and [S II] doublets, [O III], and absorption lines of sodium D doublet, using data from the FLAMES/Giraffe and UVES spectrographs, on more than 1000 sightlines towards the entire face of the Lagoon nebula. Gas temperatures are derived from line-width comparisons, densities from the [S II] doublet ratio, and ionization parameter from H-alpha/[N II] ratio. Although doubly-peaked emission profiles are rarely found, line asymmetries often imply multiple velocity components along the line of sight. This is especially true for the sodium absorption, and for the [O III] lines. Spatial maps for density and ionization are derived, and compared to other known properties of the nebula and of its massive stars 9 Sgr, Herschel 36 and HD 165052 which are confirmed to provide most of the ionizing flux. The detailed velocity fields across the nebula show several expanding shells, related to the cluster NGC6530, the O stars 9 Sgr and Herschel 36, and the massive protostar M8East-IR. The origins of kinematical expansion and ionization of the NGC6530 shell appear to be different. We are able to put constrains on the line-of-sight (relative or absolute) distances between some of these objects and the molecular cloud. The large obscuring band running through the middle of the nebula is being compressed by both sides, which might explain its enhanced density. We also find an unexplained large-scale velocity gradient across the entire nebula. At larger distances, the transition from ionized to neutral gas is studied using the sodium lines.Comment: 26 pages, 31 figures, accepted on Astronomy and Astrophysics journa
    corecore