1731 research outputs found
Sort by
Verbs as nouns: empirical investigations on event-denoting nominalizations
No full textIn this thesis, I study the differences in form and interpretation presented by event-denoting nominalizations. Frequently, languages have more than one type of event nominalization, such as deverbal nouns derived by means of suffixes (Italian mutamento / mutazione, ‘change’, ‘mutation’, or English assignment, explosion) and their corresponding verbal nouns, e.g. infinitives (il mutare, ‘the changing’) or gerunds (exploding). These are usually perceived as alternatives, since their semantic difference is not clearly understood by neither native speakers nor linguists. The aim of this work is to understand the rationale that leads us to choose one form instead of the other and to define the linguistic features involved. The hypothesis underlying the whole thesis is that different forms are never true synonyms and, thus, present some differences in use, distribution or meaning.
In a first study, I explore the role of the base verb in the nominalization selection. I investigate if the various nominalizations are formed from different types of base verbs and which characteristics define their domain of application. By means of statistical modeling, I highlight how the transitivity of the base verb partially determines which nominalization is preferred. Moreover, I show that NIs are not used to make up for the lack of a corresponding EDN, refuting previous claims. Then, I move forward analyzing the cases in which both forms are derived from the same base and I try to understand if they differ in meaning. In the second study presented, I use collocation analysis to observe their semantic dissimilarities. With focus on a single syntactic pattern, I find out that nominal infinitives and deverbal nouns inherit only part of the base verb senses. The former usually prefer metaphorical and abstract senses, whereas the latter select more concrete and literal ones.
Lastly, I use distributional semantic models to observe quantitatively the semantic shift of the two processes. I confirm the hypothesis that nominal infinitives are more transparent and more semantically regular than deverbal nouns, given their inflectional nature.
The studies presented have been conducted on Italian and German; however, the findings are relevant for the general treatment of nominalizations and may be replicated for further languages. Overall, my work shows how quantitative analyses of corpus data can help us investigate problems that are hardly addressed by linguists introspection. Moreover, it includes in the study of nominalizations nominal infinitives, non-finite verbal forms which, contrary to English gerunds, have not received the attention they deserve
Applications of Intelligent Manufacturing and of Numerical/Analytical Modeling Techniques to Milling Processes
No full textMilling is one of the most important and common processes widely used in manufacturing industry, which is a very competitive environment. For this reason, manufacturing companies are facing many different challenges. The offering of a variety of high quality products, the restriction of production time and costs, the increase of productivity, and the need for flexibility of production are the goals that manufacturers have to consider and achieve in order to succeed in their field. These aspects relate to the process study, optimization and control, and in recent years many attempts to find possible solutions and techniques to manage these steps in a proper way have been done. The first solution that a lot of enterprises were motivated to research and utilize relates to the application of the finite element modeling (FEM) techniques to study manufacturing processes or to highlight behaviour of products, for example of cutting tools, during the design phase. The second technique deals with the manufacturing process control, and is aimed at the increasing of automation level of modern production systems by evolving them towards the paradigm of Intelligent Manufacturing. The present work is focused on the study and evaluation of the effectiveness of both techniques.
The first part of the research presented in this thesis is dedicated to the study of the application of Intelligent Manufacturing Systems to milling processes. In particular, in the Chapter 1 it is discussed the improvement of the artificial operator called Evaluation and Perception Controller (EPC) built by the Mechatronics group of the University of Trento within the national project Michelangelo in 2013. In this thesis it is proposed to improve the performance characteristics of the EPC system in terms of the process quality, described by the surface roughness value. In particular, it is proposed to associate the surface roughness term to the scallop height value, and to include a model that describes the mechanism of scallop height formation into the Optimal Control Problem formulation.
Chapter 2 of this work is related to the application of FEM techniques to study milling processes. In particular, in this section the influence of CAD cutting tool models (STEP and STL) on 3D FEM AdvantEdge prediction accuracy in terms of the average and maximum cutting forces, and deformed chip thickness and curvature radius values are studied. In addition, this part of the thesis includes also the discussion of the problems related to the application of 2D FEM modeling techniques to study the influence of cutting tools geometries on the feed and tangential cutting forces that act in three-dimensional cutting processes.
Chapter 3 of this thesis is dedicated to the development of a model suitable for prediction of cutting forces that act in non-tilted and tilted side down-milling processes performed with end mills. The development of this model has two purposes. First of all, it can be included into the EPC controller, thus extending the field of the possible applications of this system. The second purpose relates to the fact that in case the side down-milling process simulations are performed by using cutting forces coefficients identified based on 2D FEM cutting forces data, the proposed model allows to overcome the mismatches between real processes and 2D FEM, and to simulate two cutting forces, feed and normal, arising in three-dimensional processes
Calvino nella letteratura mondiale: la ricezione in Cina e in Giappone
No full textL'obiettivo della mia tesi é quello di osservare e di studiare lo sviluppo e la fortuna delle opere di Italo Calvino in Oriente; in particolare, in Cina e in Giappone
Gastrointestinal condition, nutritional aspects and gut microbiota in Autism Spectrum Disorders: a new perspective for research and intervention
No full textIn the last two decades several studies have been trying to explore a possible role for gut microbiota in Autism Spectrum Disorders (ASD), supported by the high incidence of gastrointestinal disorders among ASD children and by the now well recognized existence of the brain-gut-microbiota axis (the complex system of bidirectional interactions between central nervous system, gastrointestinal tract and microorganisms inhabiting the gut). Nevertheless, results about alterations in gut microbiota composition and/or activity in ASD are to date strongly contrasting.
A possible explanation could be that these studies tend to treat ASD as a unique pathology, whereas it includes different cognitive-behavioural phenotypes. Moreover, they do not consider factors which are important for children’s gut flora development, such as type of delivery, nutritional history (e.g. formula milk during lactation) and medical history (e.g. antibiotics intake) as well as factors that may affect the present composition of microbiota, such as the current diet (e.g. the strong food selectivity that often occurs in ASD children) and the presence of gastrointestinal disorders. In this study, I developed an interview to parents to assess whether there are differences related to the above mentioned aspects between ASD children and typically developing children and among ASD themselves, considering differences in cognitive level and severity of autistic traits. I also explored the use of special diets such as gluten-, lactose and casein free diets, the reasons for their adoption and the possible benefits for the child.
Moreover, I decided to include in this interview also a section dedicated to parental difficulties in managing mealtime in order to collect information useful to plan future interventions. I found differences between ASD- and typical children in the incidence of gastrointestinal disorders and food selectivity. Especially, some children initially eat everything and then switch to a more and more restricted diet. This could be considered an early symptom of the pathology. I also found an association between gastrointestinal disorders and severity of autistic traits.
Furthermore, I collected faecal samples from ASD families (two parents, an ASD child and a typically developing sibling) and analysed them with metaproteomics and bioinformatics techniques in order to assess microbiota activity and evaluate it in light of ASD phenotype, nutritional habits, gastrointestinal disorders and genetic proximity. Demonstrating the existence of a different microbiota composition in ASD or at least in a subgroup could allow to identify a biomarker of a possible development of ASD and to design preventive interventions, even through probiotics intake. Moreover, it could help to better understand the molecular mechanism underlying this pathology
How Learning and Motivational Shifts Determine the Incentive Salience of Reward Cues: a Human Behavioral Perspective
No full textReward cues acquire distinctive incentive properties from their association with motivationally significant outcomes. These incentive properties are manifest in an augmented salience that provides reward cues with the capacity to attract attention, also in contexts where pursuing the reward is not relevant. I will first examine the unresolved debate concerning the learning parameters that define the cue-reward association and eventually modulate attention. Specifically, whether the cue attentional salience is governed by reward expectancy or uncertainty. I will then study another incentive property of reward cues, that is the ability to strengthen the performance of a separately learned instrumental action exerted to obtain an outcome, a phenomenon known as Pavlovian-Instrumental transfer (PIT). Since the motivational value of reward is altered when reward is devalued, an interesting question is whether the incentive properties of reward cues change accordingly, both in the attentional and in the operant domain. Therefore, I will investigate the effects of motivational shifts on the incentive properties of reward cues, by means of reward devaluation. In the context of the ability of a cue attentional salience to update in accordance with the altered outcome value, I will further analyze the influence of incentive learning (i.e. the possibility to re-associate the cue with the devalued outcome). The procedures adopted through the experiments share two main phases: a learning phase in which human thirsty participants learned cue-beverage reward associations involving different contingencies, and a test phase in which no reward was delivered. During the learning phase, participants accumulated the beverage reward that acted as an incentive, since it was not consumed through this phase. This allowed a controlled devaluation procedure by consummatory satiation (i.e. a motivational shift) that was administered at different moments during the experiments depending of the hypothesis at test. Results showed that the cues that better predicted the reward during learning were the stimuli preferentially attended at test, and the stimuli that invigorated more the instrumental action for the outcome. These incentive attributes persisted despite reward devaluation: the attentional bias and the PIT effect emerged unaltered after participants quenched their thirst. Reward cues persisted in capturing attention after reward devaluation even when participants were given the chance for incentive learning by means of an additional learning phase. Taken together, the evidence that emerged indicates that the incentive properties of reward cues, once acquired, can surprisingly and irrationally outlast reward devaluation and can resist incentive learning, suggesting that some incentive properties of the cue can become independent from those of the reward. These results may provide important implications for the understanding of the psychological mechanisms underlying different types of addiction
Ontological foundations for feature-based product modelling
Get PDFThe work presented in the thesis strives from the need of providing ontological foundations for product knowledge management; in particular, it provides an ontological characterisation of engineering features on the grounds of foundational theories of ontology engineering.
Inasmuch as feature-based models are employed for disparate application tasks, on the one side we develop a high-level understanding of features by distinguishing the domain entities that are modelled in their terms. In this manner, we aim at an ontology that is not strictly committed to specific application requirements but it is broadly applicable to product knowledge representation. On the other hand, we focus on the representation of (some aspects of) the physical layouts of material products. The notion of form feature plays a relevant role in this context and attention will be paid in the different ways in which it can be understood and represented according to engineering conceptualisations
Responsabilità civile e gestione del rischio assicurativo
No full textIl lavoro analizza le modalità di delimitazione temporale del rischio elaborate a fronte dell’emersione post-industriale di sempre più numerose fattispecie di danno segnate da un notevole scarto temporale tra la produzione e la manifestazione del pregiudizio nella sfera giuridica del danneggiato, in aperto contrasto con la necessità, sottesa alla tecnica assicurativa, di poter calcolare il premio con precisione, avuto riguardo alla frequenza e magnitudo della sinistrosità in copertura. Il tentativo è di individuare le origini, la struttura e i profili funzionali della tecnica di gestione del rischio che il mercato assicurativo ha elaborato al fine di superare tali ciriticità, ovvero le polizze on claims made basis. Esse rappresentano, infatti, sul piano della prassi, l’unica opzione contrattuale disponibile per la clientela che intende garantire copertura alla responsabilità civile derivante da attività potenzialmente foriere di provocare sinistri a carattere lungolatente (segnatamente, responsabilità da malpratice professionale, da prodotto difettoso, da inquinamento ambientale). La metodologia impiegata è di carattere comparativo. Per tale via, l’indagine - previa ricognizione dei reciproci nessi tra responsabilità civile e assicurazione, di cui, in ultima analisi, il tema in oggetto rappresenta la più recente epifania - spiega le ragioni di circolazione del modello elaborato negli ordinamenti di common law e affronta, in chiave critica, gli ostacoli di ordine concettuale che ne hanno impedito un pieno riconoscimento nel nostro ordinamento giuridico.
In questa prospettiva, viene criticamente vagliata la pronuncia delle Corte di Cassazione a sezioni unite del 6 maggio scorso, nonché il recente provvedimento del Governo che ha introdotto una disciplina regolamentare per le polizze professionali contro la responsabilità civile degli avvocati (D.M. 22 settembre 2016), onde saggiare gli effetti che - nel breve medio-periodo - ne potranno verosimilmente scaturire
Scultura in legno nella Lombardia dei Visconti
Get PDFLa tesi è dedicata alle testimonianze della scultura in legno della Lombardia viscontea, entro un arco cronologico compreso tra il secondo XIII secolo e la metà del XV. Gli intagli discussi sono in parte quelli che gli studi hanno portato, nel tempo, all’attenzione della critica. Un’altra parte, invece, consiste di materiale inedito o comunque misconosciuto, la cui scoperta è il frutto di un lavoro di ricerca condotto presso gli uffici catalogo delle Soprintendenze e, soprattutto, delle Diocesi lombarde. La tesi prende avvio con un capitolo in cui si affronta il problema della fortuna critica della scultura lignea lombarda del Medioevo, ripercorrendo le tappe di quella che è una storia fatta – almeno per buona parte del Novecento – di silenzi e occasioni mancate. Segue poi una breve presentazione delle più antiche opere lignee oggi note, nobili cimeli dei secoli XII e XIII che, sia pur nella loro problematicità, sanciscono gli esordi della produzione dei territori in esame. Il terzo capitolo è invece dedicato alle opere del tardo Duecento e del primo Trecento, mentre le testimonianze del secondo Trecento e del primo Quattrocento trovano posto nel quarto capitolo. All’appendice (capitolo quinto), fa quindi seguito un ampio catalogo costituito da schede comprendenti le caratteristiche conservative, storiche e stilistiche delle diverse opere trattate
Brain Decoding for Brain Mapping: Definition, Heuristic Quantification, and Improvement of Interpretability in Group MEG Decoding
No full textIn the last century, a huge multi-disciplinary scientific endeavor is devoted to answer the historical questions in understanding the brain functions. Among the statistical methods used for this purpose, brain decoding provides a tool to predict the mental state of a human subject based on the recorded brain signal. Brain decoding is widely applied in the contexts of brain-computer interfacing, medical diagnosis, and multivariate hypothesis testing on neuroimaging data. In the latest case, linear classifiers are generally employed to discriminate between experimental conditions. Then, the derived weights are visualized in the form of brain maps to further study the spatio-temporal patterns of the underlying neurophysiological activity. It is well known that the brain maps derived from weights of linear classifiers are hard to interpret because of high correlations between predictors, low signal-to-noise ratio, across-subject variability, and the high dimensionality of the neuroimaging data. Therefore, improving the interpretability of brain decoding approaches is of primary interest in many neuroimaging studies. Despite extensive studies of this type, at present, there is no formal definition for interpretability of multivariate brain maps. As a consequence, there is no quantitative measure for evaluating the interpretability of different brain decoding methods. In this thesis, as the primary contribution, we propose a theoretical definition of interpretability in linear brain decoding; we show that the interpretability of multivariate brain maps can be decomposed into their reproducibility and representativeness. As an application of the proposed definition, we exemplify a heuristic for approximating the interpretability in multivariate analysis of evoked magnetoencephalography (MEG) responses. We propose to combine the approximated interpretability and the generalization performance of the model into a new multi-objective criterion for model selection. Our results, for the simulated and real MEG data, show that optimizing the hyper-parameters of the regularized linear classifier based on the proposed criterion results in more informative multivariate brain maps. More importantly, the presented definition provides the theoretical background for quantitative evaluation of interpretability, and hence, facilitates the development of more effective brain decoding algorithms in the future. As the secondary contribution, we present an application of multi-task joint feature learning for group-level multivariate pattern recovery in single-trial MEG decoding. The proposed method allows for recovering sparse yet consistent patterns across different subjects, and therefore enhances the interpretability of the decoding model. We evaluated the performance of the multi-task joint feature learning in terms of generalization, reproducibility, and quality of pattern recovery against traditional single-subject and pooling approaches on both simulated and real MEG datasets. Our experimental results demonstrate that the multi-task joint feature learning framework is capable of recovering meaningful patterns of varying spatio-temporally distributed brain activity across individuals while still maintaining excellent generalization performance. The presented methodology facilitates the application of brain decoding for characterizing the fine-level distinctive patterns of brain activity in group-level inference on neuroimaging data
Lightwave circuits for integrated Silicon Photonics
No full textThis thesis work covers scientific and technological advancements in integrated silicon photonics circuits aimed at developing an All-On-Chip device for quantum photonics experiments. The work has been carried out within the framework of project SiQuro, where the Silicon-On-Insulator platform is chosen to integrate all the components of an optical bench necessary for a quantum experiment into a single chip. The problem of generating photon pairs have been addressed by studying second order polarisation effects in strained silicon with the aim to realize a bright photon pairs source based on Spontaneous Down Conversion. The study revealed that processes other than the Pockels effect are responsible for the non-linearity coefficients previously measured, suggesting to look for other candidate processes for the generation of photon pairs, as third order non-linear processes. To provide with the bright coherent source necessary to enable non-linear processes the integration of a hybrid III-V-silicon mode-locked laser has also been studied. During this study, technological novelties have also been developed by modelling the wedge profile obtained during the wet etching of silicon glass materials to engineer 3D structures. In parallel, the physics of whispering gallery mode resonators, both in silicon and in silicon glass materials, have been addressed. Silicon nitride Ultra High-Quality resonators have been demonstrated by using a strip-loaded configuration, while relative tuning of resonant modes has been demonstrated in an all-optical experiment exploiting the thermo-optic effect.
This work represents a step forward in the study of the physics and applications of silicon-based lightwave circuits for integrated photonics