3,795 research outputs found

    Point-free Ultrametric Spaces and the Category of Fuzzy Subsets

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    Some attempts to establish a link between point-free geometry and the categorical approach to fuzzy set theory is exposed. In fact, it is possible to find functors between the category of fuzzy sets as defined by Höhle in [4] and a category whose objects are the pointless ultrametric spaces

    Didattica del ragionamento: un esempio di deduzione logica in ambiente Mathematica

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    Si mostra come, in un ambiente adeguato per il calcolo simbolico, si possano introdurre elementi di programmazione logica, “traducendo” una teoria in un insieme di definizioni di funzioni. Dal punto di vista didattico, tale riduzione della programmazione logica a programmazione funzionale risulta utile per l’ampliamento dell’uso di strumenti informatici all’ambito della logica matematica. Inoltre, un ulteriore obiettivo è quello di facilitare, attraverso tali strumenti, lo sviluppo di competenze non solo nell’ambito del calcolo numerico-algebrico ma anche in quello dell’ informazione di tipo assertivo-logico. Il nostro punto di vista è che nella sperimentazione didattica sia possibile riferirsi alla logica non solo per quanto riguarda il calcolo proposizionale ma anche al suo aspetto deduttivo. E’ necessario evidenziare come il metodo assiomatico sia presente nella vita di tutti i giorni. Nozioni come quelle di “sistema di assiomi” e di “teorema” devono essere interpretate in termini di informazione disponibile, (in generale non completa) circa situazioni della vita reale, e di conseguenze che si possono ricavare a partire da tale informazione

    Editorial. Still searching for the origin of migraine. From comorbidities to chronicization

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    Migraine is amultifactorial disorder with huge ramifications in the central nervous system. Despite the enormous progress made in recent years in understanding the pathophysiological mechanisms underlying this painful condition, little is known about the factors behind the evolution from the episodic to the chronic form of migrain

    Grasp Stability Prediction for a Dexterous Robotic Hand Combining Depth Vision and Haptic Bayesian Exploration.

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    Grasp stability prediction of unknown objects is crucial to enable autonomous robotic manipulation in an unstructured environment. Even if prior information about the object is available, real-time local exploration might be necessary to mitigate object modelling inaccuracies. This paper presents an approach to predict safe grasps of unknown objects using depth vision and a dexterous robot hand equipped with tactile feedback. Our approach does not assume any prior knowledge about the objects. First, an object pose estimation is obtained from RGB-D sensing; then, the object is explored haptically to maximise a given grasp metric. We compare two probabilistic methods (i.e. standard and unscented Bayesian Optimisation) against random exploration (i.e. uniform grid search). Our experimental results demonstrate that these probabilistic methods can provide confident predictions after a limited number of exploratory observations, and that unscented Bayesian Optimisation can find safer grasps, taking into account the uncertainty in robot sensing and grasp execution

    School climate as predictor of teachers’ competences to recognize the educational needs of adopted children in Italy

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    The current study examines the association between different components of school climate (teacher-principal and teacher-parent relationships, parents’ involvement in school activities, connection between school and the local services) and teachers’ competences and knowledge regarding the adoption experience. Participants were 573 teachers (95.7% women; mean age= 47.06, SD= 8.66, ranging between 25 and 65) residing in three Italian regions characterized by rates of international adoptions that are higher than the national average. The association between school climate and teachers’ knowledge and competences on adoption was evaluated via independent multiple logistic regression analyses. Findings show that three of the components of school climate under examination are associated to teachers’ knowledge and competences regarding the adoption experience. Thus, interventions aimed at improving school climate hold promise for promoting teachers’ capacity to handle the challenges of the adoption process

    Assessing safety functionalities in the design and validation of driving automation

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    This paper aims to contribute to the comprehensive and systematic safety assessment of Automated Driving Systems (ADSs) by identifying unknown hazardous areas of operation. The current methodologies employed in this domain typically involve estimating the distributions of situational variables based on human-centered field test, crash databases, or expert knowledge of critical values. However, due to the lack of a-priori knowledge regarding the influential factors, their critical ranges, and their distributions, these approaches may not be entirely suitable for the assessment of emerging automated driving technologies. To deal with this challenging problem, here we propose a testing methodology incorporating realistic yet unobserved driving conditions, distinguished by numerous situational variables, so to encompass unknown unsafe conditions comprehensively. Our methodology utilizes stochastic simulation and uncertainty modeling techniques to account for the variability of realistic driving conditions and their impact on ADSs' performances. By doing so, we aim to identify unsafe operational regions and triggering conditions that can lead to hazardous behaviors, thus improving the development and safety of automated driving functions. For our purposes, the Latin Hypercube Sampling technique and the recently proposed PAWN density-based sensitivity analysis method are employed. We apply this methodology for the first time in the specific field of ADSs design and validation, using an exemplificative use case. We discuss and compare the results obtained from our approach with those obtained from a traditional approach

    Tree-ring–based summer mean temperature variations in the Adamello–Presanella Group (Italian Central Alps), 1610–2008 AD

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    Abstract. Climate records from remote mountain sites and for century-long periods are usually lacking for most continents and also for the European Alps. However, detailed reconstructions of climate parameters for pre-instrumental periods in mountain areas, suffering of glacial retreat caused by recent global warming, are needed in the view of a better comprehension of the environmental dynamics. We present here the first annually-resolved reconstruction of summer (JJA) mean temperature for the Adamello–Presanella Group (Central European Alps), one of the most glaciated mountain groups of the Italian Central Alps. The reconstruction has been based on four larch tree-ring width chronologies derived from living trees sampled in four valleys surrounding the Group. The reconstruction spans from 1610 to 2008 and the statistical verification of the reconstruction demonstrates the positive skill of the tree-ring dataset in tracking summer temperature variability also in the recent period

    Three-Dimensional Limit Analysis of the Vicoforte Elliptical Dome

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    Limit Analysis provides a conceptually simple and robust method to estimate the safety of structures and has been long applied to the analysis of the ultimate collapse state of two-dimensional masonry structures or structural elements. In revolving symmetric domes, the three-dimensional problem can be reduced to the two-dimensional case under appropriate hypotheses. The Vicoforte dome is the largest elliptical dome in the world, and its complex geometry makes this kind of analysis not straightforward. Starting from some basic assumptions, a method for analyzing the three-dimensional elliptical geometry and understand the behavior at collapse of the drum-dome system using limit analysis is proposed. The three dimensional collapse mechanism is found and the system behavior including the presence of tension rings at different levels is interpreted. The results are compared against a nonlinear finite element model
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