Search

Images acquired by RGB cameras on Unmanned Aerial Vehicles (UAVs) can be particularly useful to detect crowd in urban areas when restrictive conditions are imposed for the sake of public safety or health , such as during the Covid 19 pandemic. Together with acquired images, opportune pattern recognition techniques have to be considered to extract useful information. In this framework, features capturing the semantic rich information encompassed in VHR images have to be computed. In particular, Deep Neural Networks (DNN) have been recently proved to be able to extract useful features from data [1]. Moreover, in a transfer learning approach, a DNN pre-trained on a data set can be used to extract opportune features, named deep-features, from another data set, belonging to a different applicative domain [1], [2]. Here, a transfer learning technique is presented to produce change maps, detecting how people gathering increases, from VHR images. It is based on deep-features computed by using some pre-trained convolutional layers of AlexNet. The proposed methodology has been tested on a data set composed of several synthetic VHR images, that simulate crowd collecting in a park, as they can be acquired by RGB camera on a UAV flying at 10 meters height from the ground. The experimental results show that the proposed technique is able to efficiently detect change due to new people incoming in the scene or people that get away, with a low computational cost and in a near-real time operative mode.

Consonanze, V. 20 (2019): La librettologia, crocevia interdisciplinare. Problemi e prospettive, a cura di Ilaria Bonomi, Edoardo Buroni, Emilio Sala (Consonanze 20)

The hot gas in clusters of galaxies creates a distinctive spectral distortion in the cosmic microwave background (CMB) via the Sunyaev-Zel'dovich (SZ) effect. The spectral signature of the SZ can be used to measure the CMB temperature at cluster redshift ($T_{\rm CMB}(z)$) and to constrain the monopole of the y-type spectral distortion of the CMB spectrum. In this work, we start showing the measurements of $T_{\rm CMB}(z)$ for a sample extracted from the Second Catalog of galaxy clusters produced by Planck (PSZ2) and containing 75 clusters selected from CHEX-MATE. Then we show the forecasts for future CMB experiments about the constraints on the monopole of the y-type spectral distortion of the CMB spectrum via the spectrum of the SZE., To appear in the Proceedings of the International Conference entitled "mm Universe @ NIKA2", Rome (Italy), June 2021, EPJ Web of conferences

Questo documento contiene una breve descrizione dello stato dell'arte delle piattaforme e della relativa sensoristica per sistemi aerei a pilotaggio remoto (APR) nell'ambito dell'uso civile e del monitoraggio del territorio. Non essendo praticabile ed anche di scarso interesse la stesura di un elenco esaustivo dei prodotti commerciali - continuamente in evoluzione - si è preferito indicare i più recenti lavori in letteratura che rappresentano una rassegna dell'uso dei sistemi APR in vari ambiti scientifici ed applicativi, e le caratteristiche da considerare in diversi domini. Oltre a questo, si è delineato un sommario della corrente normativa che regola il settore e delle classificazioni delle varie piattaforme, normalmente adottate in letteratura. Infine, vengono presentate caratteristiche dei sensori di riferimento che saranno considerati nel progetto, con esempi di applicazioni degli stessi in domini coerenti con quelli dei task previsti.

La rilevazione dei cambiamenti ambientali da dati telerilevati è ampiamente usata in molti contesti applicativi, sia per effettuare un controllo periodico e sistematico del territorio (variazione dell'estensione abitativa, monitoraggio delle zone vegetate, etc.) sia per la gestione ed il controllo di situazioni di emergenza dovute al verificarsi di disastri naturali, quali frane, alluvioni, incendi [1]. Per catturare qualsiasi cambiamento ambientale, è indispensabile considerare immagini multi-temporali della stessa area geografica [2]. L'obiettivo dell'attività 3.2 è stato quello di progettare e realizzare una metodologia, matematicamente e statisticamente ben fondata, in grado di fondere immagini multi-temporali relative alla stessa area geografica con l'obiettivo di rilevare in modo automatico i cambiamenti a terra.

Questo documento contiene una breve descrizione dello stato dell'arte delle piattaforme e della relativa sensoristica per sistemi aerei a pilotaggio remoto (APR) nell'ambito dell'uso civile e del monitoraggio del territorio. Non essendo praticabile ed anche di scarso interesse la stesura di un elenco esaustivo dei prodotti commerciali - continuamente in evoluzione - si è preferito indicare i più recenti lavori in letteratura che rappresentano una rassegna dell'uso dei sistemi APR in vari ambiti scientifici ed applicativi, e le caratteristiche da considerare in diversi domini. Oltre a questo, si è delineato un sommario della corrente normativa che regola il settore e delle classificazioni delle varie piattaforme, normalmente adottate in letteratura. Infine, vengono presentate caratteristiche dei sensori di riferimento che saranno considerati nel progetto, con esempi di applicazioni degli stessi in domini coerenti con quelli dei task previsti.

Due to their extraordinary properties, Carbon Fiber Reinforced Polymers (CFRPs) are used in a growing number of fields (automotive, military, aircraft, aerospace, wind turbines, sport, civil infrastructure and leisure). Since the matrix in CFRPs is polymer-based, these composites have poor resistance to fire; additionally, when exposed to high temperatures, they can burn or lose their thermo-mechanical stability. Moreover, the recent huge and continuous development of CFRPs opened the question related to their disposal and total dependence on fossil resources. This thesis focussed on epoxy-based CFRPs. In more detail, commercial epoxy resins have been modified and replaced with bio-based alternatives, and short recycled carbon fibers composites have been produced. Two new bentonite-based organoclays were prepared with low cost reactants and mild reactions conditions and used to modify the flame behaviour of a commercial epoxy resin. The epoxy-modified resin flame behaviour was evaluated by cone-calorimeter and some significant improvements with just a 3 %wt loading level of organoclay were obtained. Furthermore, the possibility to recover and reuse carbon fibers by pyrolysis of CFRPs waste was studied: a validation of the recycling conditions and the treatments required to reuse recycled carbon fibers were assessed in order to obtain clean fibers and promote fiber/matrix adhesion in epoxy composites. Recycled carbon fiber were then used in a lab-scale composite manufacturing process and comparable mechanical properties for virgin and recycled short carbon fiber composites were achieved when an optimized coupled pyrolysis/oxidative process to CFRPs waste is applied. Finally, more sustainable CFRPs have been produced and characterized coupling highly bio-based epoxy systems, appropriately modified and optimized, and recycled carbon fibers. This latter work represents the first attempt aimed at replacing petroleum- BPA-based epoxy resins and high cost short virgin carbon fibers in the future CFRPs manufacturing processes.

A commercial two-components epoxy resin formulation was successfully modified by adding graphene and related materials (GRMs) and the effect of these nanofillers was assessed on their thermomechanical properties as well as on the simulation of their industrial application for the production of thick composites objects with interesting results. GMRs were added in different concentrations in order to improve thermo-mechanical properties of the nano-composite thermoset. Different dispersion methods were taken into account in order to produce stable long-lasting dispersion of the GRMs, that can withstand a commercial shelf life. Addition of the GRMs improves the glass transition temperature of the nanocomposite up to 20 °C with respect to the plain commercial formulation, and both stress and elongation at break increase up to almost 4 times the original values. Moreover, the industrial curing of some of the more promising modified resins was computer-simulated when the two-components resins are used to produce a carbon-fibre reinforced thick composite beam. Simulation results show that some of the applied GRMs helps reducing or even completely preventing the overheat phenomena that are well renown to induce significant thermal stresses negatively affecting the final object performances. These interesting effects would contribute reducing the time required for a single industrial production cycle, since no time for overheat dispersion is required, thus helping increasing the production rate.

International audience; Il presente volume include diciannove saggi sulle fonti shakepeariane nella librettistica. Strutturato in sei parti, raccoglie studi sugli adattamenti delle tragedie (Re Lear) e delle commedie (La bisbetica domata, Tanto rumore per nulla, La tempesta) e, in cinque sezioni monografiche, di Romeo e Giulietta, Amleto, Otello, Macbeth e Sogno di una notte di mezza estate. Rende pubblici i risultati della quarta fase dei seminari dedicati a «L’Opéra narrateur», Shakespeare e l’Opera (2014–2015), tenutisi nell’ambito del Laboratoire d’Études Romanes dell’Università Paris 8, in collaborazione con L’AmΩ L’Antique, le Moderne–Centre de recherche en littérature dell’Università di Nantes e con il Groupe de recherche Littérature–Musique dell’École Normale Supérieure di Parigi. Analizza il modo in cui la scena musicale ha saputo interpretare ai propri fini le azioni shakespeariane, privilegiando il nesso tra modello letterario e scrittura per il teatro in musica, senza trascurare le questioni inerenti alla messinscena, alla scenografia e alla coreografia.

In this thesis I develop a theory of political cinema. I use philosophical tools in order to build up a framework for the classification, analysis, and assessment of political cinema. I define the category of political cinema and, to do that, I also tackle the problem of what it means to be 'political'; then I analyze the relation between the value of a film as a political film and its value qua art. I move from two hypotheses: 1) the purpose of a political film can differentiate it from other kinds of films; 2) this very purpose can affect our aesthetic appraisal of political films. Hence, my aim is twofold. I aim to map the category of political cinema, and to identify analytical tools that could be used to assess the value of political films. This means that, through philosophical enquiry, I aim to construct a framework that could be of use in art-critical practice and that can help with the classification and assessment of political films. \ud I argue that a political film's epistemic value is crucial for its own assessment, as it determines the value of a film as a political film (capable of affecting the audience's system of beliefs concerning a specific, political, issue) and the value of a film qua art.\ud To proceed in my investigation, I use tools of analytic philosophy of art and cognitivist film theory, but I also import insights from cognate disciplines that can help us develop a more accurate analysis of the relation between films and the 'political'. In particular, I import tools from political science, political philosophy, epistemology, and cognitive science. Moreover, I take it that the theoretical effort needs to be tested with specific case studies, so I also use specific films as examples of the applicability and explanatory power of the theoretical framework I propose.

Modulation of arm mechanical impedance is a fundamental aspect for interaction with the external environment and its regulation is essential for stability preservation during manipulation. Even though past research on human arm movements has suggested that models of human finger impedance would benefit the study of neural control mechanisms and the design of novel hand prostheses, relatively few studies have focused on finger and hand impedance. This article touches on the two main aspects of this research topic: first it introduces a mechanical refinement of a device that can be used to effectively measure finger impedance during manipulation tasks; then, it describes a pilot study aimed at identifying the inertia of the finger and the viscous and elastic properties of finger muscles. The proposed wearable exoskeleton, which has been designed to measure finger posture and impedance modulation while leaving the palm free, is capable of applying fast displacements while monitoring the interaction forces between the human finger and the robotic links. Moreover, due to the relatively small inertia of the fingers, it allows us to meet some stringent specifications, performing relatively large displacements (~45°) before the stretch reflex intervenes (~25 ms). The results of measurements on five subjects show that inertia, damping, and stiffness can be effectively identified and that the parameters obtained are comparable with values from previous studies.

Recent studies of human arm movements have suggested that the control of stiffness may be important both for maintaining stability and for achieving differences in movement accuracy. Several studies in the robotic field demonstrated that grasp stiffness is useful for modelling and controlling manipulators but, even though it is accredited that having models of the human finger impedance would be very desirable for the control of anthropomorphous robot's hands, relatively few studies have focused on finger and hand stiffness. To allow the measurement of such entities at the finger level, an appropriate device capable of applying fast force transients while at the same time be able to monitor the finger movements is required. The work presented in this paper is a very detailed report about the design of a new hand exoskeleton system that will be used in our future works to investigate the finger stiffness range in different grasping postures and conditions.

International audience; La vera storia ci narra racchiude trentaquattro saggi di musicologi, studiosi di storia della musica, del teatro e del cinema, letterati, biografi, specialisti dei media contemporanei, direttori d’orchestra, registi e cantanti lirici. E' suddiviso in quattro sezioni: «Il tempo della narrazione», «La costruzione dell’opera», «La narrazione scenica e cinematografica», «Verdi narrato».; La vera storia ci narra recueille trente-quatre essais de musicologues, d'historiens de la musique, du théâtre et du cinéma, de littéraires, de biographes, de spécialistes des médias contemporains, de chefs d'orchestre, de metteurs en scène et de chanteurs d'opéra. Il s'articule en quatre sections : «Le temps de la narration », «La construction de l’oeuvre », «La narration scénique et cinématographique », «Verdi narré ».

It is well known that menopause is associated with an increase of cardiovascular (CV) risk factors, including changes on metabolic profile, body composition, haemdynamic loads and cardiovascular remodelling. The latter starts with an increase of arterial elastance and early concentric left ventricular remodeling, manifested by an increment of the relative wall thickness. We investigated morphological and functional effects of short-term aerobic exercise at moderate intensity without diet restriction on cardiovascular apparatus in post-menopause women. Seventy-six post-menopausal healthy sedentary postwomen (56± 4 yrs) underwent clinical history, physician and anthropometric exam, 12-lead electrocardiography. Echocardiography was used to assess LV geometry and systolic and diastolic functions. Relative diastolic wall thickness (RWT), midwall fractional shortening (MFS) and arterial elastance (AE) were calculated to evaluate the LV concentric remodeling, the intrinsic systolic function and the vascular load, respectively. Data were collected before and after 14 weeks of moderate aerobic exercise training (four time per week). After the intervention program, systolic and diastolic arterial pressure, heart rate and hip circumference were significantly decreased (P = 0,01; P = 0,00; P = 0,00; P = 0,01, respectively). Left ventricular mass/height 2.7, ejection fraction and MFS were higher (p< 0,00; P= 0,00; P =0,00), while relative wall thickness (RWT) and AE were lower (P, Italian Journal of Anatomy and Embryology, Vol 118, No 2 (Supplement) 2013

background activity but no interictal discharges suggestive of epilepsy. Neuropsychological evaluations with 2-year intervals showed progressivewordfinding difficulties, attentionand memory-deficits. He became nearly mute and apathetic and was unable to continue his work as a process-controller. The MRI was repeated 8-year after symptom-onset showing prominent atrophy of the left hemisphere (figure), consistent with the clinical diagnosis progressive non-fluent aphasia. Case-management was still lacking at referral to our memory clinic. The presence of epilepsy in the presented patient with PPA has led to a long-lasting delay in clinical diagnosis and adequate care. Patients with subtle speech difficulties usually seek medical attention on average 2-3 years after symptom-onset. Primary and secondary care physicians often do not recognise PPA-symptoms adding a further diagnostic delay. Complaints are often attributed to psychogenic factors (burnout, mood or anxiety) or to other comorbid conditions, which even led to a diagnostic delay of 8 years in our case. Conclusions: An atypical age-at-onset, slow disease progression, absence of cognitive or behavioural problems are all factors delaying referral to a memory clinic in PPA. Diagnostic delay is even more pronounced in the presence of comorbid conditions which may affect speech.

Background. The treatment of choice in steroid-resistant ITP is still controversial, due to the recent advent of new drugs (anti-CD20 and thrombopoietin mimetics) which have encouraged a generalized tendency to delay splenectomy. Consequently, the importance to define the efficacy and safety of splenectomy in the long-term is substantial. Patients and Methods. We retrospectively analyzed the data of 233 ITP patients who underwent splenectomy between 1959 and 2001, in 6 different European hematological Institutions and have now a minimum follow-up of 10 years from surgery. Results. Of the 233 patients, 206 (88%) achieved a response (87% complete). Sixty-eight out of 206 (33%) responsive patients relapsed, mostly (75%) within 4 years from first response. In 92 patients (39.5%), further treatment was required after splenectomy, which was effective in 76 cases (83%). In 138 patients (59%) response was maintained, free of any treatment, at last contact. No significant association between baseline characteristics and likelihood of stable response was found. Overall, 73 (31%) and 58 (25%) patients experienced at least one infectious or hemorrhagic complication. A stable response to splenectomy was associated with a lower rate of infectious (p=0.004) and hemorrhages (p

This paper presents the design of a direct driven under-actuated portable hand exoskeleton for rehabilitation. The design of the proposed Hand EXOskeleton SYStem (HEXOSYS) was driven by multi-objective optimisation strategy and inspiration from the human hand. The optimisation algorithm resulted in the choice of optimum link lengths of the device. The optimisation criteria are based on dexterity, isotropy and exertion of perpendicular forces on the finger digits. Furthermore, a series of experiments on the human hand using appropriate sensory instrumentation guided the selection of actuators thereby resulting in a rehabilitation device which is compatible with the human hand force capabilities. The provision of force as well as position feedback gives quantitative feedback to the therapist and would imply a more efficient rehabilitation process. The first prototype of the device has been designed and realized.

Background Forearm surface electromyography (EMG) has been in use since the Sixties to feed-forward control active hand prostheses in a more and more refined way. Recent research shows that it can be used to control even a dexterous polyarticulate hand prosthesis such as Touch Bionics's i-LIMB, as well as a multifingered, multi-degree-of-freedom mechanical hand such as the DLR II. In this paper we extend previous work and investigate the robustness of such fine control possibilities, in two ways: firstly, we conduct an analysis on data obtained from 10 healthy subjects, trying to assess the general applicability of the technique; secondly, we compare the baseline controlled condition (arm relaxed and still on a table) with a "Daily-Life Activity" (DLA) condition in which subjects walk, raise their hands and arms, sit down and stand up, etc., as an experimental proxy of what a patient is supposed to do in real life. We also propose a cross-subject model analysis, i.e., training a model on a subject and testing it on another one. The use of pre-trained models could be useful in shortening the time required by the subject/patient to become proficient in using the hand. Results A standard machine learning technique was able to achieve a real-time grip posture classification rate of about 97% in the baseline condition and 95% in the DLA condition; and an average correlation to the target of about 0.93 (0.90) while reconstructing the required force. Cross-subject analysis is encouraging although not definitive in its present state. Conclusion Performance figures obtained here are in the same order of magnitude of those obtained in previous work about healthy subjects in controlled conditions and/or amputees, which lets us claim that this technique can be used by reasonably any subject, and in DLA situations. Use of previously trained models is not fully assessed here, but more recent work indicates it is a promising way ahead.

The state-of-the-art in control of hand prosthetics is far from optimal. The main control interface is represented by surface electromyography (EMG): the activation potentials of the remnants of large muscles of the stump are used in a non-natural way to control one or, at best, two degrees-of-freedom. This has two drawbacks: first, the dexterity of the prosthesis is limited, leading to poor interaction with the environment; second, the patient undergoes a long training time. As more dexterous hand prostheses are put on the market, the need for a finer and more natural control arises. Machine learning can be employed to this end. A desired feature is that of providing a pre-trained model to the patient, so that a quicker and better interaction can be obtained. To this end we propose model adaptation with least-squares SVMs, a technique that allows the automatic tuning of the degree of adaptation. We test the effectiveness of the approach on a database of EMG signals gathered from human subjects. We show that, when pre-trained models are used, the number of training samples needed to reach a certain performance is reduced, and the overall performance is increased, compared to what would be achieved by starting from scratch.

This work aims at demonstrating, at a pilot plant scale, the potential of the pyro-gasification process to produce carbon fibers (CF) as secondary raw materials. The solid residue obtained upon pyrolysis of CFRP was characterized and oxidized, applying different process conditions to provide clean fibers. The same process was applied to virgin fibers, thus highlighting the protective action that char provides to CF during the oxidation step. The recovered fibers were used to produce new short fiber composites which, upon optimization of the mixing and curing conditions, were competitive with the performance of pristine fibers composites. Indeed, the oxidation leaves an oxygen rich surface which positively interacts with the epoxy resin, thus promoting adhesion without the requirement of an additional sizing process after the CFs recycling. These results provided sufficient validation of the recovered CF quality, thus leading to the scale up of the process to produce an integrated pyro-gasification semi—industrial plant.

Antioxidant activity of native vitamin C (ascorbic acid, AH2) is hampered by instability in solution. Selective loading of AH2 into the inner lumen of natural halloysite nanotubes (HNT) yields a composite nanoantioxidant (HNT/AH2), which was characterized and investigated for its reactivity with the persistent 1,1-diphenyl-2-picrylhydrazyl (DPPH&bull, ) radical and with transient peroxyl radicals in the inhibited autoxidation of organic substrates, both in organic solution (acetonitrile) and in buffered (pH 7.4) water in comparison with native AH2. HNT/AH2 showed excellent antioxidant performance being more effective than native ascorbic acid by 131% in acetonitrile and 290% (three-fold) in aqueous solution, under identical settings. Reaction with peroxyl radicals has a rate constant of 1.4 &times, 106 M&minus, 1 s&minus, 1 and 5.1 &times, 104 M&minus, 1, respectively, in buffered water (pH 7.4) and acetonitrile, at 30 &deg, C. Results offer physical understanding of the factors governing HNT/AH2 reactivity. Improved performance of HNT/AH2 is unprecedented among forms of stabilized ascorbic acid and its relevance is discussed on kinetic grounds.

New flame retardant organo-modified bentonites, based on nitrogen-containing compounds were synthesized via an ion exchange process starting from pristine bentonite with acidified 6-(4-butylphenyl)−1,3,5-triazine-2,4-diamine (BFTDA) and 11-amino-N-(pyridine-2yl)undecanamide (APUA). The amount of nitrogen rich organic modifier in the obtained organoclays (Bento-BFTDA and Bento-APUA) determined by TGA is around 0.4 mmol/g for both samples. With the aim to study the effect of these additives on a commercial epoxy resin, nanocomposites containing 3 and 5 wt% of the nanofillers were prepared by solventless addition to the epoxy resin formulation. For the sake of comparison similar nanocomposites with plain unmodified bentonite were produced. The nanocomposite's thermo-mechanical properties of all the produced samples were measured and they resulted slightly improved or practically unaffected. Finally, when the flame behavior was assessed in the cone-calorimeter, an encouraging decrease of 17% in the peak heat released rate (pHRR) was obtained at 3 wt% loading level with Bento-APUA. These promising results suggest that the APUA modified organoclay, prepared with low cost reactants and mild reaction conditions, might efficiently act as a flame retardant.

The present work deals with two organophilic bentonites, based on nitrogen-containing compounds: these organoclays were synthesized via an ion exchange process starting from pristine bentonite with 6-(4-butylphenyl)-1,3,5-triazine-2,4-diamine (BFTDA) and 11-amino-N-(pyridine-2yl)undecanamide (APUA) and then used for the production of epoxy-based flame retardant nanocomposites. The amount of organic modifier in the organoclays Bento-BFTDA and Bento-APUA was determined with a TGA analysis and is around 0.4mmol/g for both samples. The effect of the organoclays on a commercial epoxy resin nanocomposite’s thermo-mechanical and flammability properties was investigated. Composites containing 3wt% and 5wt% of the nanofillers were prepared by solventless addition of each organoclay to the epoxy resin, followed by further addition of the hardener component. For the sake of comparison a similar nanocomposite with the plain unmodified bentonite was produced in similar condition. The nanocomposites’s thermo-mechanical properties of all the produced samples were measured and they resulted slightly improved or practically unaffected. On the contrary, when the flame behaviour was assessed in the cone-calorimeter, an encouraging decrease of 17% in the peak heat released rate (pHRR) was obtained at 3wt% loading level with Bento-APUA. This is a promising result, assessing that the APUA modified organoclay might act as flame retardant.

Poly(m-phenylene isophtalamide) electrospun nanofibrous membranes were produced to be used as structural reinforcements for carbon fiber reinforced composites production. In order for the polymer to be electrospun, it needs however to be fully solubilized, so the addition of some salts is required to help disrupt the tight macromolecular packing based on intra- and inter-molecular hydrogen bonding. Such salts may also contribute to the electrospinnability of the overall solution, since the provide it with a higher conductivity, whatever the solvent might be. The salt haobwever stays in the final nanofibrous mat. The membranes containing the salt are also observed to be highly hygroscopic, with a water content up to 26%, in the presence of 20%wt LiCl in the nanofibrous mat. When those membranes were interleaved among prepregs to produce a laminates, the obtained composite displayed thermal properties comparable to those of a reference nanofiber-free composite, though the former showed also easier delamination. Hence the removal of the hygroscopic salt was performed, that lead to thinner membranes, whose water content matched that of the pristine polymer. The washing step induced a thinning of the layers and of the fibers diameters, though no fiber shrinking nor membrane macroscopic damages were observed. These preliminary encouraging results thus pave the way to a deeper study of the optimized condition for producing convenient poly(m-phenylene isophtalamide) electrospun nanofibrous membranes to be used for carbon fiber reinforced composites structural modification.