789 research outputs found
Problematiche di integrazione di flussi documentali con il Sistema Informativo. Il caso dell'Agenzia Laore della Regione Sardegna
La tesi presenta il lavoro di tirocinio svolto presso l’Agenzia Regionale Laore a partire dal 2010.
Con l’Agenzia è stato condiviso un progetto formativo che è coinciso in un momento di importante innovazione tecnologico-organizzativa all’interno dell’Agenzia, e in questo il mio contributo ha riguardato la tematica della protocollazione, gestione documentale, posta elettronica certificata e della firma digitale.
Nel Capitolo 1 è descritta la situazione di partenza, approfondito nel paragrafo 1.3 in cui ` descritta la mappatura dei processi principali. Da questa prima parte sono emersi gli obiettivi di massima di una possibile soluzione, illustrata nel capitolo 2.
Il cap. 3 descrive la pianificazione di massima per la realizzazione del progetto.
Successivamente è stato analizzato il caso specifico dell’Ufficio dell’Autorità di Controllo. Lo studio, esposto nel cap. 4, si ` concentrato sulla formalizzazione delle specifiche tecniche riguardanti un sistema informativo ad-hoc per gestire l’emergenza riguardante l’aumento massivo di richieste
L’attivit` di analisi ha fatto emergere inoltre una possibile soluzione generalizzabile a tutto l’Ente capace di superare il problema dell’incomunicabilità dei database dei vari sistemi, noto come problema dei ‘silos’. La soluzione è presentata nel cap. 5.
Le appendici illustrano i termini utilizzati (App. A), la soluzione progettata con diagrammi UML (App. B) e un esempio di mplementazione (App.C)
Evaporation and information puzzle for 2D nonsingular asymptotically flat black holes
We investigate the thermodynamics and the classical and semiclassical
dynamics of two-dimensional (), asymptotically flat, nonsingular
dilatonic black holes. They are characterized by a de Sitter core, allowing for
the smearing of the classical singularity, and by the presence of two horizons
with a related extremal configuration. For concreteness, we focus on a
version of the Hayward black hole. We find a second order
thermodynamic phase transition, separating large unstable black holes from
stable configurations close to extremality. We first describe the black-hole
evaporation process using a quasistatic approximation and we show that it ends
in the extremal configuration in an infinite amount of time. We go beyond the
quasistatic approximation by numerically integrating the field equations for
dilaton gravity coupled to massless scalar fields, describing
the radiation. We find that the inclusion of large backreaction effects () allows for an end-point extremal configuration after a finite evaporation
time. Finally, we evaluate the entanglement entropy (EE) of the radiation in
the quasistatic approximation and construct the relative Page curve. We find
that the EE initially grows, reaches a maximum and then goes down towards zero,
in agreement with previous results in the literature. Despite the breakdown of
the semiclassical approximation prevents the description of the evaporation
process near extremality, we have a clear indication that the end point of the
evaporation is a regular, extremal state with vanishing EE of the radiation.
This means that the nonunitary evolution, which commonly characterizes the
evaporation of singular black holes, could be traced back to the presence of
the singularity.Comment: 41 pages, 14 figures, references added, qualitative comparison with
the island proposal added in Sect. 8, physical results unchanged, corresponds
to the version accepted in JHE
Effective models of non-singular quantum black holes
We investigate how the resolution of the singularity problem for the
Schwarzschild BH could be related to the presence of quantum gravity effects at
horizon scales. Motivated by the analogy with the cosmological Schwarzschild-dS
solution, we construct a class of non-singular, static, asymptotically-flat BH
solutions with a dS core, sourced by an anisotropic fluid, which encodes the
quantum corrections. The latter are parametrized by a single length-scale
, which has a dual interpretation as an effective "quantum hair" and as
the length-scale resolving the classical singularity. Depending on the value of
, these solutions can have two horizons, be extremal (when the two
horizons merge) or be horizonless exotic stars. We also investigate the
thermodynamic behavior of our BH solutions and propose a generalization of the
area law in order to account for their entropy. We find a second-order phase
transition near extremality, when is of order of the classical
Schwarzschild radius . BHs with are
thermodynamically preferred with respect to those with ,
supporting the relevance of quantum corrections at horizon scales. We also find
that the extremal configuration is a zero-temperature, zero-entropy state with
its near-horizon geometry factorizing as AdS S, signalizing the
possible relevance of these models for the information paradox. We show that
the presence of quantum corrections with have observable
phenomenological signatures in the photon orbits and in the QNMs spectrum. In
particular, in the near-extremal regime, the imaginary part of the spectrum
scales with the temperature as , while it goes
to zero linearly in the near-horizon limit. Our general findings are confirmed
by revisiting two already-known models, namely the Hayward and gaussian-core
BHs.Comment: 36 pages, 7 figure
Binaural Spatialization for 3D immersive audio communication in a virtual world
Realistic 3D audio can greatly enhance the sense of presence in
a virtual environment. We introduce a framework for capturing,
transmitting and rendering of 3D audio in presence of other
bandwidth savvy streams in a 3D Tele-immersion based virtual
environment. This framework presents an efficient implementation
for 3D Binaural Spatialization based on the positions of current
objects in the scene, including animated avatars and on the fly
reconstructed humans. We present a general overview of the
framework, how audio is integrated in the system and how it can
exploit the positions of the objects and room geometry to render
realistic reverberations using head related transfer functions.
The network streaming modules used to achieve lip-synchronization,
high-quality audio frame reception, and accurate localization for
binaural rendering are also presented. We highlight how large
computational and networking challenges can be addressed efficiently.
This represents a first step in adequate networking support for Binaural
3D Audio, useful for telepresence. The subsystem is successfully
integrated with a larger 3D immersive system, with state of art capturing
and rendering modules for visual data
La Gallura in epoca medievale: 1. Storia politico-istituzionale della Gallura medievale
Analisi politico-istituzionale della Gallura in epoca medievale fino alla pace di Sanluri del 1388, quando la sua storia si stemperò in quella più ampia del regnum Sardiniae et Corsicae
Scalar stars and lumps with (A)dS core
We explore the possibility of embedding regular compact objects with (anti)
de Sitter ((A)dS) core as solutions of Einstein's gravity minimally coupled to
a real scalar field. We consider, among others, solutions interpolating between
an inner, potential-dominated core and an outer, kinetic-term-dominated region.
Owing to their analogy with slow-roll inflation, we term them gravitational
vacuum inflative stars, or gravistars for short. We systematically discuss
approximate solutions of the theory describing either the core or the
asymptotically-flat region at spatial infinity. We extend nonexistence theorems
for smooth interpolating solutions, previously proved for black holes, to
compact objects without event horizons. This allows us to construct different
classes of exact (either smooth or non-smooth) singularity-free solutions of
the theory. We first find a smooth solution interpolating between an AdS
spacetime in the core and an asymptotically-flat spacetime (a Schwarzschild
solution with a subleading deformation). We proceed by constructing
non-smooth solutions describing gravistars. Finally, we derive a smooth scalar
lump solution interpolating between in the core and a Nariai
spacetime at spatial infinity.Comment: 26 pages, 5 figures, 1 appendi
Atmospheric Newtonian noise modeling for third-generation gravitational wave detectors
The sensitivity and the frequency bandwidth of third-generation
gravitational-wave (GW) detectors are such that the Newtonian noise (NN)
signals produced by atmospheric turbulence could become relevant. We build
models for atmospheric NN that take into account finite correlation times and
inhomogeneity along the vertical direction, and are therefore accurate enough
to represent a reliable reference tool for evaluating this kind of noise. We
compute the NN spectral density from our models and compare it with the
expected sensitivity curve of the Einstein Telescope (ET) with the xylophone
design. The noise signal decays exponentially for small values of the frequency
and the detector's depth, followed by a power-law for large values of the
parameters. We find that, when the detector is built at the earth's surface,
the NN contribution in the low-frequency band is above the ET sensitivity curve
for strong wind. Building the detector underground is sufficient to push the
noise signal under the ET sensitivity curve, but the decrement is close to
marginal for strong wind. In light of the slow decay with depth of the NN,
building the detector underground could be only partially effective as passive
noise mitigation.Comment: 17 pages, 8 figure
La Gallura in epoca medievale: 3. L'insediamento umano
Questo contributo si chiude con degli accenni sull'insediamento umano e ciò pone come
primo problema quello di chiarire cosa si intenda precisamente per Gallura in questa sede,
anche perché le nette linee di demarcazione che caratterizzavano il periodo giudicale,
durante il quale i confini galluresi con gli altri giudicati dovevano essere considerati quelli
di uno stato con un altro stato, in periodo catalano-aragonese possedevano una valenza
differente, più legata a concetti geografico-amministrativi (per quanto i limiti amministrativi
ricalcassero presumibilmente i vecchi confini giudicali), e in misura minore culturali.
E però bisogna aggiungere che già alla fine del XIII, gli stravolgimenti causati dal passaggio
del giudicato di Gallura al possesso del Comune di Pisa portarono all'amputazione di
ampie aree del giudicato a favore di famiglie signorili
Influence of different stabilizing operations and storage time on the composition of essential oil of thyme (Thymus officinalis L.) and rosemary (Rosmarinus officinalis L.)
Abstract The effect of different stabilizing techniques on the composition of essential oil of rosemary (Rosmarinus officinalis L.) and thyme (Thymus officinalis L.) during one year of storage is reported. The study was aimed to know what is the stabilizing technique to keep at the best the original essential oil composition. The fresh samples were collected and treated as follows: air-dried in a laboratory scale pilot dryer, frozen in a forced-air freezer and freeze-dried in a laboratory freeze-dryer. The fresh sample served as control. The treated samples were packaged with appropriate packaging material and stored at 20 °C or −20 °C for 12 months. All the samples were hydrodistilled every three months and the oils composition was obtained by means of gas chromatography/mass spectrometry (GC/MS). Quantification of known compounds was done with the use of an internal standard. Freezing best maintained the composition of rosemary and thyme essential oil. Appropriate packaging of air-dried and freeze-dried herbs resulted in negligible quality loss up to one year of storage. The frozen and stored thyme samples showed the best retention of thymol, the most important compound, as well as of γ-terpinene and carvacrol
A framework for realistic 3D tele-immersion
Meeting, socializing and conversing online with a group of people using teleconferencing systems is still quite differ- ent from the experience of meeting face to face. We are abruptly aware that we are online and that the people we are engaging with are not in close proximity. Analogous to how talking on the telephone does not replicate the experi- ence of talking in person. Several causes for these differences have been identified and we propose inspiring and innova- tive solutions to these hurdles in attempt to provide a more realistic, believable and engaging online conversational expe- rience. We present the distributed and scalable framework REVERIE that provides a balanced mix of these solutions. Applications build on top of the REVERIE framework will be able to provide interactive, immersive, photo-realistic ex- periences to a multitude of users that for them will feel much more similar to having face to face meetings than the expe- rience offered by conventional teleconferencing systems
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