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From atoms to extended structures via ab-initio and multi-scale simulations
Full text linkThis thesis deals with the theoretical and computational modelling of materials by using a variety of ab-initio approaches to accurately predict the properties of realistic structures. A number of known and novel carbon-based materials are studied, exploiting the unique versatility of carbon to bind into several bonding configurations, with the aim of tailoring their electronic and mechanical characteristics. In this regard, the methods used to carry out electronic structure simulations depend on the system size: from the Dirac-Hartree-Fock approach to model molecular properties, to Density Functional Theory used for periodic solids, such as diamond and graphene-related materials composed by a few to some hundred of atoms, to Density Functional Tight Binding or plane Tight Binding to study nanowires or Beltrami pseudospheres, which are composed by some hundreds to a few millions atoms. The details of these methods are introduced in the chapters where they are used. The criterion used to present these concepts is to organize the chapters, with the exception of the last one, according to the increasing dimension of the systems. More in details, the first chapter uses the Dirac-Hartree-Fock approach to simulate atoms and molecules, such bromotrifluoromethane; the second chapter deals with periodic systems characterized by unit cells with a relatively small number of atoms, such as diamond and
graphite; the third one discusses graphene and graphene-related materials with lower density; the fourth one present a new computational and experimental model of silicon
carbide nanowires coated with silicon dioxide shell; the fifth chapter is focused on the study of sp2-hybridized carbon atoms, arranged on a Beltrami surface. The latter topic spans different research fields such as geometrical topology, physics and mechanical engineering.
Finally, the last chapter is dedicated to an on going work which deals with the Non-Adiabatic Molecular Dynamics simulation of amorphous silica samples where we couple the nuclear dynamic of the system to the electronic structure
Security Testing of Permission Re-delegation Vulnerabilities in Android Applications
No full textSmartphones play an important role in our daily lives. Once used only for communication purposes are now also used for several day-to-day activities ranging from social media and entertainment to privacy sensitive operations such as data storage, fitness tracking, mobile banking and sending/receiving business e-mails. This is achieved thanks to the several smartphone applications (apps) that are available. One of the most popular smartphone operating systems is Android. As of now, there are more than 3 million apps for Android. The Android platform facilitates reuse of apps' functionalities by allowing an app to request a task from another app installed on the same device through inter-process communication mechanism. This possibility is probably one of the reasons for the popularity of Android where an app can reuse a feature available in other apps. However, this integration also poses security risks to the privacy of the end-users if it is not implemented properly. Permission re-delegation vulnerability is a kind of privilege escalation that happens when unprivileged apps exploit this integration feature to make privileged apps perform a privileged action on their behalf.
Static analysis techniques as well as run-time protections have been proposed to detect permission re-delegation vulnerabilities. However, as acknowledged by their authors, most of these approaches are affected by many false positives and, hence, fall short of precision because, they do not discriminate between intentional task requests and actual permission re-delegation vulnerabilities.
In this thesis, we propose automatic techniques to classify potential permission re-delegation vulnerabilities detected by static analysis in real world Android apps as intentional task requests or actual vulnerabilities and to automatically generate test cases that show how the vulnerabilities can be exploited. This could be helpful for developers to easily analyze their apps and fix vulnerabilities before releasing their apps.
The proposed approaches have been experimentally validated with thousands of real world apps and have been seen to perform better than state-of-the-art tools and techniques in terms of precision
"We're not rated X for nothin', baby!" Satire and Censorship in the Translation of Underground Comix
Full text linkGli underground comix nascono negli Stati Uniti nell’ambito della Controcultura degli anni
Sessanta e Settanta, un periodo di grande rinnovamento culturale, lotte contro qualsiasi forma di autorità,
movimenti per la libertà di parola e per i diritti civili. Quella che può dirsi a tutti gli effetti una
“rivoluzione” nel mondo del fumetto accompagnò e rese possibili i grandi cambiamenti sociali legati a
temi considerati tabù come il sesso, la droga, la satira politica e religiosa. A questi artisti va dunque il
merito di aver riscoperto il respiro antagonista e il potere comunicativo del fumetto, liberandolo da
compromessi verbali e visuali visivi, e interrogandone coraggiosamente le possibilità espressive.
Nel rappresentare la realtà senza filtri e senza mai scendere a patti con i codici sociali e le autoinibizioni che questi inducono, gli underground comix si trovarono a fare i conti con il linciaggio
mediatico e con diverse forme di censura, tanto preventiva quanto punitiva. Proprio a partire da questa
considerazione, risulta interessante approfondire dal punto di vista linguistico-culturale e retoriconarrativo come questi fumetti sono arrivati in Italia prima attraverso la circolazione sotterranea delle
pubblicazioni alternative e poi consacrata nelle edizioni “mainstream” curate dalle maggiori case editrici.
Le opere di questi autori costituiscono infatti un caso di studio molto stimolante sia per le questioni
sociolinguistiche (jargon) sia per la satira e lo humor impietoso e radicale espressi attraverso una grafica
incisiva e dialoghi talora surreali e spesso oltraggiosi.
L’obiettivo di questa ricerca è dunque sviluppare un’analisi traduttologica di tale produzione e
prevede la raccolta, la disamina e il confronto delle pubblicazioni in lingua italiana di queste opere,
prestando particolare attenzione alla resa degli elementi di critica sociale e di avanguardismo che ne
caratterizzano lo stile. Presupposto del mio studio è che vi siano politiche editoriali, fattori sociali e
ideologici che motivano la scelta di modificare, mitigare o omettere alcuni contenuti ‒ dialoghi, pensieri
e immagini ‒ nel passaggio ad un’altra lingua e dunque ad un altro contesto socioculturale, nella
consapevolezza che la traduzione non è mai innocente o neutrale.
Lo studio si articola in tre sezioni. Nella prima parte, viene sviluppata un’indagine storicosociologica del panorama underground americano, dalle origini del fumetto americano e dai fattori che
hanno reso questo medium un bersaglio della censura fino alla nascita della controcultura in seno alla
quale i fumettisti underground hanno sviluppato la loro poetica. La seconda sezione prende in esame gli
strumenti utilizzati per studiare il fumetto in traduzione, sviluppando un framework di riferimento che
trae spunto dalle ricerche in campo multimodale, narratologico e semiotico. In particulare, viene
investigata la nozione di isotopia, quale interessante strumento di analisi del fumetto come testo sincretico
che si incentra sulle relazione di significazione tanto delle immagini quanto delle parole e soprattutto
dell’interazione tra codice verbale e visuale. Le isotopie forniscono dunque le istruzioni di lettura (talora
prodotte inconsciamente dall’autore) e di resa del profilo semantico di un testo sia in ambito critico che
traduttivo. Inoltre, in quanto categoria testuale che congiunge l’aspetto formale e contenutistico, sono
l’espressione più diretta dello stile dell’autore. La terza sezione presenta il corpus di fumetti in esame e
sviluppa concretamente l’analisi della produzione underground tradotta in italiano seguendo quattro filoni
tematici, tra i più controversi all’interno di questo panorama fumettistico: il sesso, la droga, la violenza
politica e la religione. Focus dell’analisi contrastiva sono le strategie traduttive, gli approcci ideologici, le
politiche editoriali e la possibile censura in traduzione
On agonism and design: dialogues between theory and practice
Full text linkDesign has the potential to disrupt the status quo, yet disruption inevitably introduces new conflicts. One of the challenges of Social Design is to navigate the social, political and material conflicts that define contemporary lives and find new ways to transform them into creative resources. In addressing that challenge this thesis investigates agonism, a multifaceted theory that explicates conflict and grounds the need for such an investigation in design activism. The political implications, practical considerations and design potentials of agonism are examined in detail, and three core principles of agonism are defined: Identities, Dialogues and Agonistic Space. These principles are elaborated through their relation to intersubjectivity as a fundamental aspect of human experience, its interactional role in identity formation and communication, and its influence on the production and performance of space. A Constructive Design Research methodology is employed that contributes to the understanding agonism through a series of research trajectories and interventions. Design strategies to enact agonism are proposed around game, play and interaction design: Identities can be investigated through Role-Playing, Dialogues can be initiated through Storytelling, and Agonistic Space can be manifested as a Third Place. These strategies are field tested to examine various communities and the conflicts within them. A game intervention Mind the Gap confronts the endemic problem of the gender gap in academic and professional communities of ICT and STEM. A research intervention takes agonistic perspectives to elucidate conflicts of European migration and participatory urban planning in a neighbourhood community in the U.K. A digital intervention applies agonism towards engaging a platform community that has no material form, in the online project of commonfare.net. These interventions experiment with creative inquiry, game and play as design speculations, sketching and constructing playful inerventions that engage participants in agonism, to enact challenges to the status quo and illuminate potential solutions to complex societal issues. The utility and outcomes of the principles and strategies are evaluated with a focus on emergent intersubjectivity through Dialogic Syntax and Critical Discourse Analyses of gameplay, narratives and design artifacts. The main contributions of this thesis are its shift from empathic perspectives to intersubjectivity in design research, and its operationalization of the theory of agonism for Social Design. Secondary contributions include the elaboration of game and play as design speculation that includes critical reflections on their real-world practices, and the artifact Mind the Gap which has evolved from prototype to a co-created, community driven experience that continues to engage people in meaningful dialogues that challenge the status quo of the gender gap
Doing it better: economic performance and social mobility of migrant entrepreneurs in Rome and Milan restaurant sector
Full text linkThis dissertation investigates the differentiation of migrants’ entrepreneurial performances in the restaurant sector. By adopting a biographical approach, this study analyses five main dimensions and their combinations in shaping performances: the context in which migrant entrepreneurs operate, the different businesses’ characteristics and strategies, migrants’ reliance on networks, their implementation of human capital, the individuals’ life trajectories, their classes of origin, and paths of upward (and eventually downward) social mobility. This study is based on 50 biographical interviews conducted in the two most important cities in Italy: Milan and Rome. In order to better understand the differentiation of performances, the sample includes entrepreneurs who reach good performances, those who manage to survive, and those who are in crisis. The findings evidence the intersection between networks, human capital, motivation, projects, and experiences of migrant entrepreneurs. These elements implement themselves, by creating a virtuous cycle, as far as successful cases are concerned. However, when these elements do not foster each other, migrant entrepreneurs tend to face many difficulties in conducting their businesses. This study also emphasises how economic performance and social mobility are not always interrelated, and some counterintuitive results emerge. On the one hand, it is underlined the importance of shelter enterprises, that do not have good business performances but can play a relevant social role in fostering upward social mobility for those entrepreneurs who come from lower classes of origin. On the other hand, good business performances are not always connected to the entrepreneurs’ upward mobility, which is often barely maintained and, in some cases, even declined
Measurement of the density profile of quantized vortices and of the equation of state in a 3D interacting Bose gas
Full text linkIn this thesis I present two different research topics investigated during the course of my PhD, regarding the analysis of spatial structures in a Bose Einstein condensate. Ultracold atomic gases offer a privileged platform for such kind of experiments, thanks to the fine control that can be achieved on the system’s parameters and to the availability of advanced imaging schemes allowing for a great measurement accuracy.
The first topic is about the shape of quantized vortices in an elongated condensate, with the goal of providing a quantitative analysis of the density structure of a quantized vortex filament hosted in a bulk 3D superfluid. We analyzed the shape of the vortex and studied its dynamics during a free expansion, or time of flight (TOF), of the hosting BEC, with the goal of making a quantitative comparison between theory and experiment for the structure of the core of a quantized vortex in three-dimensional (3D) condensates. Simultaneously imaging the sample along orthogonal directions after a long TOF allowed to map the complete 3D shape of the vortex at the end of the free flight, while the full expansion dynamics has been simulated with numerical solutions of the Gross-Pitaevskii equation. The same data analysis procedure has been applied to both the experimental images and to the density profiles computed with the simulations to ensure a faithful comparison.
We were able to detail the evolution of the vortex parameters at all times combining a simple analytic scaling-law model valid at early times, experimental data for the width and the depth of the core at long expansion times, and the numerics that were used to bridge between the two. Additionally, we could check the validity of the predictions on the scaling of vortex parameters with the size of the BEC using the experimental data to interpolate between theoretical limiting models. We concluded that quantized vortex filaments can be optically imaged with standard techniques in 3D atomic BECs, at a level of accuracy which indeed is enough to show good quantitative agreement with the predictions of the GP theory for the width, depth, and overall shape of the vortex core.
The second topic is a measurement of the equation of state of a single component BEC. The goal of this project is to verify the non-monotonic behaviour of the chemical potential of a homogeneous Bose gas of weakly interacting particles as a function of temperature, where one expects to find a maximum across the critical point of transition to the superfluid phase. This effect is believed to be a general feature of the normal-to-superfluid phase transition: it has been already experimentally demonstrated in unitary Fermi gases, and although the same is predicted to happen also in a gas of weakly interacting bosons, no experimental evidence has been reported so far. The measurement relies on the local density approximation, which allows to extract information about the thermodynamics of a homogeneous system from accurate measurements of the local properties of a trapped one. My work has focused on developing a series of imaging and data analysis techniques to measure the 3D density profile of a harmonically trapped gas, even in regimes of extreme density such as inside a Bose condensate. With a new high-dynamic-range method we were able to image the 3D density distribution of a trapped sample, leading to a low-noise measurement of the density distribution.
We confirmed the existence of the non-monotonic behaviour of the chemicial potential across, and set the basis for further measurements of the thermodynamics of the system across the transition.In this thesis I present two different research topics investigated during the course of my PhD, regarding the analysis of spatial structures in a Bose Einstein condensate. Ultracold atomic gases offer a privileged platform for such kind of experiments, thanks to the fine control that can be achieved on the system’s parameters and to the availability of advanced imaging schemes allowing for a great measurement accuracy.
The first topic is about the shape of quantized vortices in an elongated condensate, with the goal of providing a quantitative analysis of the density structure of a quantized vortex filament hosted in a bulk 3D superfluid. We analyzed the shape of the vortex and studied its dynamics during a free expansion, or time of flight (TOF), of the hosting BEC, with the goal of making a quantitative comparison between theory and experiment for the structure of the core of a quantized vortex in three-dimensional (3D) condensates.
Simultaneously imaging the sample along orthogonal directions after a long TOF allowed to map the complete 3D shape of the vortex at the end of the free flight, while the full expansion dynamics has been simulated with numerical solutions of the Gross-Pitaevskii equation. The same data analysis procedure has been applied to both the experimental images and to the density profiles computed with the simulations to ensure a faithful comparison.
We were able to detail the evolution of the vortex parameters at all times combining a simple analytic scaling-law model valid at early times, experimental data for the width and the depth of the core at long expansion times, and the numerics that were used to bridge between the two. Additionally, we could check the validity of the predictions on the scaling of vortex parameters with the size of the BEC using the experimental data to interpolate between theoretical limiting models. We concluded that quantized vortex filaments can be optically imaged with standard techniques in 3D atomic BECs, at a level of accuracy which indeed is enough to show good quantitative agreement with the predictions of the GP theory for the width, depth, and overall shape of the vortex core.
The second topic is a measurement of the equation of state of a single component BEC. The goal of this project is to verify the non-monotonic behaviour of the chemical potential of a homogeneous Bose gas of weakly interacting particles as a function of temperature, where one expects to find a maximum across the critical point of transition to the superfluid phase. This effect is believed to be a general feature of the normal-to-superfluid phase transition: it has been already experimentally demonstrated in unitary Fermi gases, and although the same is predicted to happen also in a gas of weakly interacting bosons, no experimental evidence has been reported so far. The measurement relies on the local density approximation, which allows to extract information about the thermodynamics of a homogeneous system from accurate measurements of the local properties of a trapped one. My work has focused on developing a series of imaging and data analysis techniques to measure the 3D density profile of a harmonically trapped gas, even in regimes of extreme density such as inside a Bose condensate. With a new high-dynamic-range method we were able to image the 3D density distribution of a trapped sample, leading to a low-noise measurement of the density distribution.
We confirmed the existence of the non-monotonic behaviour of the chemicial potential across, and set the basis for further measurements of the thermodynamics of the system across the transition
Multi-target Prediction Methods for Bioinformatics: Approaches for Protein Function Prediction and Candidate Discovery for Gene Regulatory Network Expansion
Full text linkBiology is experiencing a paradigm shift since the advent of next generation sequencing technologies. The retrieved data largely exceeds the capability of biologists to investigate all possibilities in the laboratories, hence predictive tools able to guide the research are now a fundamental component of their workflow. Given the central role of proteins in living organisms, in this thesis we focus on their functional analysis and the intrinsic multi-target nature of this task. To this end, we propose different predictive methods, specifically developed to exploit side knowledge among target variables and examples.
As a first contribution we face the task of protein-function prediction and more in general of hierarchical-multilabel classification (HMC). We present Ocelot a predictive pipeline for genome-wide protein characterization.
It relies on a statistical-relational-learning tool, where the knowledge on the input examples is coded by the combination of multiple kernel matrices, while relations among target variables are expressed as logical constraints.
Both, the mislabeling of examples and the infringement of logical rules are penalized by the loss function, but Ocelot do not forces hierarchical consistency. To overcome this limitation, we present AWX, a neural-networks output-layer that guarantees the formal consistency of HMC predictions.
The second contribution is VSC, a binary classifier designed to incorporate the concepts of subsampling and locality in the definition of features to be used as the input of a perceptron. A locality-based confidence measure is used to weight the contribution of maximum-margin hyper-planes built by subsampling pairs of examples of opposite class.
The rationale is that local methods can be exploited when a multi-target task is expected, but not reflected in the annotation space.
The third and last contribution are NES2RA and OneGenE, two approaches for finding candidates to expand known gene regulatory networks. NES2RA adopts variable-subsetting strategies, enabled by volunteer distributed computing, and the PC algorithm to discover candidate causal relationships within each subset of variables. Then, ranking aggregators combine the partial results into a single ranked candidate genes list. OneGenE overcomes the main limitation of NES2RA, i.e. latency, by precomputing candidate expansion lists for each transcript of an organism that are then aggregated on-demand
Sperimentare le idee di Maria Montessori: percorso di ricerca nella scuola primaria trentina.
Full text linkIn questo lavoro di tesi sono stati delineati i tratti salienti dell’approccio educativo montessoriano, evidenziandone da una parte la profonda complessità nonché attualità che lo caratterizzata e dall’altra le numerose conferme sia dalla didattica considerata innovativa, sia dalle scienze psicologiche.
È stato inoltre presentato un percorso di ricerca volto a monitorare la recente sperimentazione dell'approccio pedagogico montessoriano in alcune scuole primarie della provincia di Trento. La ricerca é stata condotta utilizzando sia strumenti di natura qualitativa (come una check list osservativa prodotta ad hoc per la ricerca), sia questionari standardizzati, con l'intento di confrontare i dati raccolti con un campione rappresentativo di una più vasta realtà scolastica
Conversational Agent for Health Coaching
No full textPoor diet and physical inactivity are two of the biggest healthcare challenges we are facing, and are related to individuals lifestyle. In fact, a poor lifestyle is strongly correlated to chronic diseases, the leading causes for morbidity and mortality. Adhering to a healthy diet and following an active lifestyle are thus necessary to promote the overall health. However, maintaining a healthy diet and physically active lifestyle is hard. This is due to poor health literacy, lack of awareness, motivation and effective
intervention support. Recent years have seen a blast of mHealth apps for health promotion, targeting in particular dietary behavior change. However, reviews showed
difficulties in effective adoption and use of these applications in long-term health promotion. Contemporary approaches have focused on tracking user condition and
few have analyzed aspects of user interaction with the system. To promote individuals health, users can benefit from some form of tailored guidance or coaching. That said, to ensure adequate users support, personalized care with
a human agent in the loop can enhance the care delivery. Due to the increasing demand for continuous care by users and the shortage of caregiver resources, current health services are inefficient relative to user support and decreasing caregivers workload. Digital health devices can act as a key player in providing interactive health activities
(via mobile and telemedicine systems), enhancing self-monitoring (through wearable tracker) and tailored coaching (using either automated or manual coaching systems).
However, they’re ineffective in providing continuous health services and creating a balance between users support and caregivers workload. In addition, even with the
technology existence, there is low motivation to maintain a healthy diet or exercise routines. Individuals use messaging applications as part of their regular daily routines. We
harness the power of messaging chatbot systems to provide behavior change interventions for healthy lifestyle promotion. We particularly introduce the role of chatbot in task automation and adhering users to a health plan. Thus, in this thesis we present the concept of "Conversational User Interface in Health Coaching Interventions" that consists of a just-in-time health services to users and caregivers. We discuss ways to integrate the chatbot to assist caregivers with their tasks and support
users with their condition. We get users to cue themselves to action by attaching the chatbot with users’ daily messaging routines. The service will eliminate the
technology barrier and impairment for the users i.e., elderly. The chatbot accesses reliable user compliance data, sets adherence reminders by condition, and reports
daily individuals adherence. The chatbot alerts the coach through a web application in critical cases. The approach facilitates adherence to health interventions by
investigating a human-virtual agent mediated coaching approach on user motivation to adhere to the health promotion plan. The approach was validated with different experimentation phases. Using multiple research methods, this dissertation has made several contributions to the understanding of user motivation and the role of a semi-automated system with a human and virtual agent in tracking individuals with poor lifestyle. We will discuss the main
contributions and experimentation results throughout the thesis
Struttura e funzione del nuovo giudizio in Cassazione
Full text linkIl presente lavoro esamina struttura e funzione del giudizio avanti la Suprema Corte di Cassazione: in particolare l’attenzione è rivolta all’influsso esercitato dai numerosi interventi legislativi emanati nell’ultimo decennio per tentare di porre rimedio ai problemi che ormai da lungo tempo affliggono la Corte in termini di carico di lavoro, durata del processo, persuasività ed autorevolezza della sua giurisprudenza. A questi fini, dopo una breve illustrazione circa lo scopo dell’indagine, nel primo capitolo sono analizzate, anche sotto l’aspetto statistico, le problematiche inerenti alle sopravvenienze ed alle pendenze dei ricorsi, alla durata del giudizio ed ai contrasti giurisprudenziali interni alla stessa Cassazione, per poi prendere in considerazione le diverse soluzioni prospettate recentemente dal legislatore.
Nel secondo capitolo tali riforme sono esaminate con specifico riferimento alla loro incidenza sulla struttura del giudizio di legiitmità, inclusi i criteri di redazione degli atti introduttivi. Esse da un lato hanno tentato di introdurre requisiti più stringenti in ordine alla formulazione del ricorso, sia in termini di inammissibilità sia incidendo sulla deducibilità del vizio di motivazione, dall’altro hanno modificato il procedimento vero e proprio col fine di stabilire modalità più snelle di definizione dei giudizi, prima istituendo un’apposita Sezione “spoglio” caratterizzata dal rito camerale e poi estendendo quest’ultimo a tutti i processi privi di rilievo nomofilattico. Caratteristica precipua di tale disamina è un costante raffronto con la disciplina del procedimento avanti le Sezioni Penali della Cassazione, ponendo in luce il forte debito che le riforme del rito civile portano verso quest’ultima.
Nel terzo capitolo l’indagine si sposta sulle funzioni attribuite dall’art.65 ord.giud. alla Corte di Cassazione, cioè l’esatta osservanza della legge e la sua uniforme interpretazione, onde comprendere se anch’esse siano state incise dalle riforme. Si evidenzia in particolare come il senso attribuito al termine “nomofilachia” si sia evoluto nel tempo e sia attualmente diverso da quello ideato in origine da Calamandrei. Analizzando le funzioni summenzionate si tenta di comprendere come possano essere interpretate oggi, a settantacinque anni dalla loro introduzione. Alla luce di ciò si evidenzia come i recenti interventi legislativi, pur optando per una nuova concezione della nomofilachia, non siano riusciti a perseguirla in modo coerente ed unitario