10081 research outputs found
Sort by
Networks: A study in Analysis and Design
Get PDFIn this dissertation, we will look at two fundamental aspects of Networks: Network Analysis and Network Design. In part A, we look at Network Analysis area of the dissertation which involves finding the densest subgraph in each graph. The densest subgraph extraction problem is fundamentally a non-linear optimization problem. Nevertheless, it can be solved in polynomial time by an exact algorithm based on the iterative solution of a series of max-flow sub-problems. To approach graphs with millions of vertices and edges, one must resort to heuristic algorithms. We provide an efficient implementation of a greedy heuristic from the literature that is extremely fast and has some nice theoretical properties. An extensive computational analysis shows that the proposed heuristic algorithm proved very effective on many test instances, often providing either the optimal solution or near-optimal solution within short computing times. In part-B, we discuss Network design, which is a cornerstone of mathematical optimization, is about defining the main characteristics of a network satisfying requirements on connectivity, capacity, and level-of-service. In multi-commodity network design, one is required to design a network minimizing the installation cost of its arcs and the operational cost to serve a set of point-to-point connections. This prototypical problem was recently enriched by additional constraints imposing that each origin-destination of a connection is served by a single path satisfying one or more level-of-service requirements, thus defining the Network Design with Service Requirements. These constraints are crucial, e.g., in telecommunications and computer networks, in order to ensure reliable and low-latency communication. We provide a new formulation for the problem, where variables are associated with paths satisfying the end-to-end service requirements. A fast algorithm for enumerating all the exponentially-many feasible paths and, when this is not viable, a column generation scheme that is embedded into a branch-and-cut-and-price algorithm is provided
Modelling UV response of biomolecules: from electronic structure to ab-initio dynamics.
Get PDFThe interaction of organic chromophores with light initiates ultrafast processes in the timescale of femtoseconds. An atomistic understanding of the mechanism driving such photoinduced reactions opens up the door to exploit them for our benefit. This thesis studies the interactions of ultraviolet light with the DNA/RNA molecules and the amino-acid tryptophan. Using some of the most accurate electronic structure methods and sophisticated environmental modelling, the works documented herein enable quantitative comparisons with cutting-edge experimental data. The relaxation pathways undertaken by the excited molecule are revealed through static and dynamical investigations of the excited-state potential energy surface. The profound role played by the dynamic response of the environment to guide the excitation in these timescales is addressed thoroughly
Assessing the state of Nephrops norvegicus and management measures in the Central Adriatic Sea
Get PDFNephrops norvegicus is a sedentary bottom-dwelling crustacean that represents one of the main commercial species exploited in the Adriatic Sea (Central Mediterranean). An evaluation of the status of this important resource is thus extremely important in order to manage it in a sustainable way. The evaluation of N. norvegicus is complicated by several issues, mainly: (i) the complex biology and behaviour of the species itself, (ii) the presence of subpopulations with different biological traits within the same stock unit. Relevant concentration of N.norvegicus occurs within the Pomo/Jabuka Pits area which is characterised by peculiar oceanographic and geophysical conditions. This area represented for a long time an important fishing ground shared by Italian and Croatian fleets and recently a Fishery Restricted Area (FRA) was established there. The aim of the present study is to perform for the first time an evaluation of the status of the N.norvegicus subpopulation inhabiting the Pomo/Jabuka Pits also accounting for the possible effects on it of the management measures. To achieve this, the principal fisheryindependent and fishery-dependent dataset available for the study area were firstly analysed and then treated. Data collected by the CNR-IRBIM of Ancona through both indirect (“UWTV”) and direct (trawling) methods were refined by means of a revision of the time series and related biases, and a modelling approach accounting for environmental and fishery effects, respectively. Commercial data for both Italy and Croatia were treated in order to obtain landings and length distributions for the Pomo area only; an historical reconstruction of data starting from 1970 was carried out for both countries. The obtained information was used as input for a Bayesian length-based stock assessment model developed through the CASAL software; the flexibility of this model is recommended for N.norvegicus and similar species allowing to deal with sex- and fleet-based integrated assessment metho
The relatedness multiplication of the unrelated ones. An ethnography of parenting and filiation expectations around the legal category of "unaccompanied foreign minor" in Italy.
Get PDFSulla spinta dell’approvazione della legge italiana 47/2017 “Disposizioni in materia di misure di protezione dei minori stranieri non accompagnati”, questo lavoro è teso ad affrontare le complesse aspettative genitoriali e parentali sviluppatesi intorno al processo di categorizzazione MSNA di cui questa legge è diventata approdo giuridico. Le controverse aspettative di accompagnamento legatesi alla denominazione di “non accompagnato”, prese come aspetto scontato e assiomatico in molta parte della letteratura scientifica che utilizza l’acronimo, sono state qui intese come un nodo ambiguo e questionabile. Attraverso una ricerca e una metodologia antropologico-etnografica queste rappresentazioni contradditorie sono esplorate a partire da un “crocevia di campi” da queste interessati in un territorio amministrativo dell’Italia Settentrionale variamente frequentato tra 2018 e 2021. Insieme ad ambienti, metodi e sfide della ricerca locale, una prima sezione situa storicamente e contestualmente la categoria MSNA come fenomeno in sé piuttosto che come efficace espressione descrittiva di soggetti. Le due sezioni successive, dedicate rispettivamente alla neo-realtà di tutela volontaria e a quella di una comunità socio-educativa/di tipo familiare rivolta a persone di minore età, interrogano invece questi ambienti come spazi e tempi di elaborazione prima e negoziazione poi di rappresentazioni e pratiche relazionali e parentali molteplici.Impelled by the approval of Italian Law 47/2017 “Provisions on protection measures for unaccompanied foreign minors”, this work aims to address the complex parental and kinship expectations that have developed around the “MSNA” (UFM, English acronym) categorisation process ‒ to which this law is the latest juridical landmark. Here, I have understood as ambiguous and questionable the controversial “accompaniment expectations” that have often gone along with the term “unaccompanied” and have been taken for granted in much of the scientific literature resorting to this acronym.
Through anthropological-ethnographic research and methodology, these incongruous representations are explored from the “crossroads of fields” that affect them in an administrative territory of Northern Italy, variously frequented between 2018 and 2021. Together with the presentation of local research environments, methods, and challenges, the first section historically and contextually situates the MSNA category as a phenomenon itself rather than an effective subjects’ description. The next two sections are devoted to the exploration, respectively, of the neo-reality of volunteer guardianship, and of a more traditional socio-educational/family-type facility designed for minors’ reception. These latest parts interrogate these environments as spaces and times of negotiation about multiple kinship representations and practice
Spatial based approach to fisheries management. An application to bottom trawling in the strait of Sicily
Get PDFAt the beginning of my thesis project, considering that some stocks are in overfishing status due to both high fishing effort and high level of juveniles in the catch, my main purpose was to understand how to contribute to improving the state of the fishery resources of the Mediterranean Sea.
To mitigate the overfishing, the General Fisheries Commission for the Mediterranean (GFCM) adopted several Fishery Restricted Areas, which are geographically defined areas where some specific fishing activities are temporarily or permanently banned or restricted in order to reduce the exploitation patterns and conservation of specific stocks as well as of habitats and deep-sea ecosystems, including the Essential Fish Habitats (EFH) and the Vulnerable Marine Ecosystems (VME).
Considering that GFCM established 3 Fisheries Restricted Areas (FRAs) in the Strait of Sicily (SoS) in 2016 aimed at protecting the nursery areas of the deep-water rose shrimp (DPS, Parapenaeus longirostris – Lucas, 1846) and the European hake (HKE, Merluccius merluccius – Linnaeus, 1758) to reduce the exploitation pattern of undersized species, in my thesis project I devoted myself to evaluate the effect of the FRAs on the status stock and the fishery performance using a spatial bio-economic model
Perceval between epos and romance: genesis, reception and textual traditions. With critical edition of the Livre d'Helias et Perceval
Get PDFLa tesi si propone di descrivere le diverse fasi storiche attraverso le quali si è evoluta la struttura narrativa del personaggio di Perceval nei primi due secoli della sua genesi nella letteratura romanza ed europea. Il personaggio ha avuto un notevole successo dal Medioevo di Chrétien of Troyes fino all'età moderna e contemporanea. Lo studio filologico dell'evoluzione del personaggio all'interno della galassia testuale e delle forme della sua tradizione permette di delineare un quadro composito, in cui è possibile rintracciare la genesi e lo sviluppo di importanti fenomeni storico-letterari, destinati a influenzare la letteratura europea e occidentale nel lungo periodo. Una seconda parte è invece dedicata allo studio della struttura letteraria e narrativa del personaggio rintracciabile all'interno della lettura delle differenti opere che tramandano le versioni della storia di Perceval. Infine, la ricerca si concentra su un caso di studio in grado di illuminare la persistenza delle strutture sopra individuate: le Prophecies de Merlin, romanzo arturiano della seconda metà del XIII secolo, sono infatti espressione delle modalità in cui la storia della vita di Perceval viene messa in scena in testi che non si concentrano direttamente sulla sua biografia. All'interno della tradizione delle Prophecies de Merlin, il profeta del regno arturiano di cui sono raccolte numerose profezie, il caso del Livre d'Helias et Perceval è emblematico. Il Livre d'Helias et Perceval delle Prophecies de Merlin, accompagnato da uno studio filologico che comprende un'edizione critica, uno studio completo della tradizione e un'analisi linguistica, si propone quindi come caso di studio ideale per analizzare la fortuna e l'evoluzione del personaggio di Perceval nel Medioevo romanzesco ed europeo.This thesis aims to describe the different historical stages through which the narrative structure of the character of Perceval evolved during the first two centuries of its genesis in Romance and European literature. The character had a significant success from the Middle Ages (Chrétien de Troyes) up to the modern and contemporary age. The philological study about the evolution of the character within the textual galaxy and the forms of his tradition allows us to outline a composite picture, in which it is possible to trace the genesis and development of important historical-literary phenomena, destined to influence European and Western literature in the long term. A second part is instead dedicated to the study of the literary and narrative structure of the character that can be traced within the reading of the different works that hand down the versions of the story of Perceval. Finally, the research will focus on a case study capable of illuminating the persistence of the structures identified above: the Prophecies de Merlin, an arthurian romance from the second half of the 13th century, are in fact an expression of one of the many ways in which Perceval’s life story is staged in texts that do not directly focus on his biography. Within the tradition of the Prophecies de Merlin, the prophet of the Arthurian kingdom whose numerous prophecies are collected, the case of the Livre d’Helias et Perceval is emblematic. The Livre d’Helias et Perceval from the Prophecies de Merlin, accompanied by a philological study that includes a critical edition, a complete study of the tradition and linguistic analysis, is thus proposed as an ideal case study for ana-lysing the fortune and evolution of the character of Perceval in the Romance and European Middle Ages
Smart tracking of composite parts: feasibility study and effect on mechanical behaviour
Get PDFThis research proposes a solution for integrating RFID - Radio Frequency Identification technology within a structure based on CFRPs - Carbon Fiber Reinforced Polymers. Therefore, the main objective is to use technology to monitor and track composite components during manufacturing and service life.
The study can be divided into two macro-areas. The first portion of the research evaluates the impact of the composite materials used on transmitting the electromagnetic signal to and from the tag. RFID technology communicates through radio frequencies to to track and trace items associated with the tags. In the first instance, a feasibility study was carried out to assess using commercially available tags. Then, after evaluating different solutions, it was decided to incorporate the tags into coupons during production.
The second portion of the research is focused on evaluating the impact on the composite material's resistance to tag embedding. It starts with designing tensile test specimens through the FEM model with different housing configurations. Subsequently, the best configuration was tested in the facilities of the
In the Faculty of Aerospace Engineering at TU Delft, particularly in the Structure & Materials Laboratory, two tests were conducted: the first one based on ASTM D3039/D3039 - 14 - Standard Test Method for Tensile Properties of Polymer Matrix Composite Materials, the second one dividing the path to failure into failure intervals in a load-unload-reload.
Both tests were accompanied by instruments such as DIC, AE, C-Scan and Optical Microscopes.
The expected result of the inclusion of RFID tags in composite components is that it brings added value to the parts with which it is associated without affecting too much its mechanical properties. This comes first from the automatic identification of RFID during the production cycle and its useful life. As a result, improvements were made in the design of production facilities
Training competencies in managing Open Innovation processes. A case study.
No full textPer comprende più a fondo il problema che le aziende affrontare per formare le persone in grado di gestire processi di innovazione, in particolare di Open Innovation (OI), è stato realizzato nel 2021 uno studio di caso multiplo di un percorso di educazione non formale all’OI realizzato dalla società consortile ART-ER e rivolto ai dottorandi degli atenei emiliano-romagnoli. Nella seconda fase di tale percorso formativo, per rispondere alle sfide di OI lanciate dalle aziende, sono stati costituiti 4 tavoli di lavoro. A ciascun tavolo di lavoro hanno preso parte 3/4 dottorandi, due referenti aziendali, un consulente e un operatore di ART-ER. Il campione complessivo era costituito da 14 dottorandi; 8 referenti aziendali di quattro aziende; 4 membri di una società di consulenza e 4 operatori della società consortile ART-ER.
Il seguente interrogativo di ricerca ha guidato l’indagine: l’interazione tra i soggetti coinvolti in ciascun tavolo di lavoro – considerato un singolo caso - si configura come una Comunità di Pratica in grado di favorire lo sviluppo di apprendimenti individuali funzionali a gestire i processi di OI attivati nelle imprese?
I dati sono stati raccolti attraverso una ricerca documentale a tavolino, focus group, interviste semistrutturate e un questionario semistrutturato online. L’analisi dei dati è stata effettuata mediante un’analisi qualitativa del contenuto in più fasi con l’ausilio del software MAXQDA.
I risultati dimostrano che in tre casi su quattro, i tavoli di lavoro si sono configurati come una Comunità di Pratica. In questi tre tavoli inoltre è emerso lo sviluppo di alcune aree di competenza funzionali alla gestione dei processi di OI. Nella conclusione sono state presentate alcune proposte per la riprogettazione delle future edizioni del percorso formativo.To better understand the problem companies face in training people capable of managing innovation processes, in particular Open Innovation (OI), in 2021, a multiple case study of a non-formal training course – organized by the ART-ER consortium and aimed at doctoral students of Emilia-Romagna universities – was carried out.
In the second phase of this training course, four working groups were set up to respond to OI challenges launched by companies. Three/four PhD students, two company representatives, a consultant and an ART-ER operator took part in each work table. The overall sample consisted of 14 PhD students, eight company representatives from four companies, four consultancy company members, and four ART-ER consortium company operators.
The following research question guided the investigation: has the interaction between the subjects involved in each work table - considered a single case - configured as a Community of Practice capable of favouring the development of individual learning functional to managing the processes of OI activated in companies?
The data was collected through desk research, focus groups, semi-structured interviews and a semi-structured online questionnaire. The data analysis was carried out through a qualitative analysis of the content in several stages with the help of the MAXQDA software.
The results show that the working groups were configured as a Community of Practice in three out of four cases. In these three tables, the development of some areas of competence functional to the management of OI processes also emerged. In conclusion, some proposals for redesigning future editions of the training course were presented
The EU’s foreign policy towards the Western Balkans during the Juncker Commission. The cases of Bosnia Herzegovina and Serbia.
Get PDFIn February 2018, four years after the President of the Commission Jean Claude Juncker explicitly deprioritised the enlargement dossier, the European Commission relaunched the enlargement strategy to the region of the Western
Balkans. This occurred despite the persistent polarisation around the topic among the EU Member States and the still-present struggles, when not outright regression, of some of the countries in pursuing the demanded reforms.
This thesis carries out a multilevel foreign policy analysis of EU foreign policy toward the region of the Western Balkans during the period of the Juncker Commission, through the cases of Bosnia Herzegovina and Serbia.
Drawing from Actorness theory (Bretherton and Vogler 2006), combined with perspectives from new institutional leadership (Smeets and Beach 2020), and new intergovernmentalism (Moravcsik 2018; Bickerton et al. 2015), this study seeks to explain the relaunch of enlargement by examining three dimensions: the international context and the role of non-EU actors such as China, Russia, and Turkey; the EU context, through the interaction of the significant EU Member States and Institutions; finally, the local context, through the analysis of the changes in the local perception of the EU and the considered non-EU actors.
This study posits two interconnected points: first, that the changes in the international context, specifically the increased presence of non-EU actors such as China, Russia, and Turkey in the region, acted as triggering factors for the relaunch of the strategy. In addition, it argues that this relaunch was successful due to the peculiar combination of Germany’s interests and leadership within the Council, coupled with the Commission’s priorities
Hybrid Artificial Intelligence to Extract Patterns and Rules from Argumentative and Legal Texts
Get PDFThis Thesis is composed of a collection of works written in the period 2019-2022, whose aim is to find methodologies of Artificial Intelligence (AI) and Machine Learning to detect and classify patterns and rules in argumentative and legal texts.
We define our approach “hybrid”, since we aimed at designing hybrid combinations of symbolic and sub-symbolic AI, involving both “top-down” structured knowledge and “bottom-up” data-driven knowledge.
A first group of works is dedicated to the classification of argumentative patterns. Following the Waltonian model of argument and the related theory of Argumentation Schemes, these works focused on the detection of argumentative support and opposition, showing that argumentative evidences can be classified at fine-grained levels without resorting to highly engineered features.
To show this, our methods involved not only traditional approaches such as TFIDF, but also some novel methods based on Tree Kernel algorithms.
After the encouraging results of this first phase, we explored the use of a some emerging methodologies promoted by actors like Google, which have deeply changed NLP since 2018-19 — i.e., Transfer Learning and language models. These new methodologies markedly improved our previous results, providing us with best-performing NLP tools.
Using Transfer Learning, we also performed a Sequence Labelling task to recognize the exact span of argumentative components (i.e., claims and premises), thus connecting portions of natural language to portions of arguments (i.e., to the logical-inferential dimension).
The last part of our work was finally dedicated to the employment of Transfer Learning methods for the detection of rules and deontic modalities.
In this case, we explored a hybrid approach which combines structured knowledge coming from two LegalXML formats (i.e., Akoma Ntoso and LegalRuleML) with sub-symbolic knowledge coming from pre-trained (and then fine-tuned) neural architectures