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 ($2\text{D}$), 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 $2\text{D}$ 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 $2\text{D}$ dilaton gravity coupled to $N$ massless scalar fields, describing the radiation. We find that the inclusion of large backreaction effects ($N \gg 1$) 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 $\ell$, which has a dual interpretation as an effective "quantum hair" and as the length-scale resolving the classical singularity. Depending on the value of $\ell$, 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 $\ell$ is of order of the classical Schwarzschild radius $R_{\rm S}$. BHs with $\ell\sim R_{\rm S}$ are thermodynamically preferred with respect to those with $\ell\ll R_{\rm S}$, 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$_2\times$ S$^2$, signalizing the possible relevance of these models for the information paradox. We show that the presence of quantum corrections with $\ell\sim R_{\rm S}$ 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 $c_1/\ell+c_2\ell T_\text{H}^2$, 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 $1/r^2$ deformation). We proceed by constructing non-smooth solutions describing gravistars. Finally, we derive a smooth scalar lump solution interpolating between $\text{AdS}_4$ 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