739 research outputs found

    A Kolmogorov theorem for nearly-integrable Poisson systems with asymptotically decaying time-dependent perturbation

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    The aim of this paper is to prove the Kolmogorov theorem of persistence of Diophantine flows for nearly-integrable Poisson systems associated to a real analytic Hamiltonian with aperiodic time dependence, provided that the perturbation is asymptotically vanishing. The paper is an extension of an analogous result by the same authors for canonical Hamiltonian systems; the flexibility of the Lie series method developed by A. Giorgilli et al., is profitably used in the present generalisation.Comment: 10 page

    European Perceptions of Autonomous and Robotized Cars

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    This article explores users\u2019 attitudes, perceptions, views, and emotions toward car automation and robotization, two processes increasingly affecting society in different ways\u2013\u2013namely, the rise of autonomous and robotized cars (and vehicles in general) and the increasing level of robotization of current cars. To address these questions, we investigated the feeling of trust and comfort toward driverless cars among Europeans using two Eurobarometer surveys. Making use of two representative samples of the European population, we aimed to explore citizens\u2019 attitudes and opinions about automation and digitization. The two surveys involved, respectively, 27,801 and 27,901 participants from all EU-28 countries. Furthermore, we investigated, in Northern Italy, the perception of robotization of cars and other technologies of everyday use, as well as the attitudes and opinions of children and preteens (n = 740), and adolescents (n = 801)\u2014 relevant social groups not covered in the Eurobarometer surveys

    Gluten free rice cookies with resistant starch ingredients from modified waxy rice starches : nutritional aspects and textural characteristics

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    Experimental gluten-free (GF) rice cookies were formulated with 100% rice flour (CTR) or by substituting 50% of rice flour with native waxy rice starch (WRS) or with three different resistant starch (RS) ingredients obtained from debranched, annealed or acid and heat-moisture treated WRS (RSa, RSb and RSc, respectively). Chemical composition, in vitro starch digestibility and physical and textural characteristics were carried out. Among cookies, RSa-cookies had the highest total dietary fibre content, the lowest rapidly digestible starch and the highest RS contents. All the three RS preparations have proved effective in increasing the proportion that tested as RS with respect to native WRS. However, the estimated RS loss for each applied RS ingredients caused by the baking process followed the order of RSa < RSc < RSb. Last, the lowest vitro glycaemic index value was measured for RSa-cookies. Among cookies, differences in colour and hardness were reported. The partial replacement of commercial rice flour with RSa could contribute to formulate GF cookies with higher dietary fibre content and likely slowly digestible starch properties more than equivalent amounts of RSb and RSc

    European perceptions of autonomous and robotized cars

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    open3noThis article explores users’ attitudes, perceptions, views, and emotions toward car automation and robotization, two processes increasingly affecting society in different ways––namely, the rise of autonomous and robotized cars (and vehicles in general) and the increasing level of robotization of current cars. To address these questions, we investigated the feeling of trust and comfort toward driverless cars among Europeans using two Eurobarometer surveys. Making use of two representative samples of the European population, we aimed to explore citizens’ attitudes and opinions about automation and digitization. The two surveys involved, respectively, 27,801 and 27,901 participants from all EU-28 countries. Furthermore, we investigated, in Northern Italy, the perception of robotization of cars and other technologies of everyday use, as well as the attitudes and opinions of children and preteens (n = 740), and adolescents (n = 801)— relevant social groups not covered in the Eurobarometer surveys.openFortunati, L., Lugano, G., Manganelli, A.M.Fortunati, L.; Lugano, G.; Manganelli, A. M

    Persistence of Diophantine flows for quadratic nearly-integrable Hamiltonians under slowly decaying aperiodic time dependence

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    The aim of this paper is to prove a Kolmogorov-type result for a nearly-integrable Hamiltonian, quadratic in the actions, with an aperiodic time dependence. The existence of a torus with a prefixed Diophantine frequency is shown in the forced system, provided that the perturbation is real-analytic and (exponentially) decaying with time. The advantage consists of the possibility to choose an arbitrarily small decaying coefficient, consistently with the perturbation size.Comment: Several corrections in the proof with respect to the previous version. Main statement unchange

    Integrability and strong normal forms for non-autonomous systems in a neighbourhood of an equilibrium

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    The paper deals with the problem of existence of a convergent "strong" normal form in the neighbourhood of an equilibrium, for a finite dimensional system of differential equations with analytic and time-dependent non-linear term. The problem can be solved either under some non-resonance hypotheses on the spectrum of the linear part or if the non-linear term is assumed to be (slowly) decaying in time. This paper "completes" a pioneering work of Pustil'nikov in which, despite under weaker non-resonance hypotheses, the nonlinearity is required to be asymptotically autonomous. The result is obtained as a consequence of the existence of a strong normal form for a suitable class of real-analytic Hamiltonians with non-autonomous perturbations.Comment: 10 page

    Intracranial dermoid cysts: variations of radiological and clinical features

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    Background: Intracranial dermoid cysts are uncommon, and their clinical features as well as surgical management differ from patient to patient. Dermoids are generally benign lesions, but may cause spontaneous complications such as meningitis and/or hydrocephalus due to rupture and epileptic seizures depending on their location. Little has been reported about characteristic imaging findings with resulting therapeutic considerations, and only a few reports exist about associated hydrocephalus. Imaging modalities have changed and can facilitate differential diagnosis and follow-up if applied correctly. In this paper, we attempt to contribute our clinical experience with the management of dermoid cysts. Patients and methods: The charts of five men and two women with intracranial dermoid cysts were retrospectively reviewed. The patients were treated between September 1993 and September 2006. Selected patients are presented in detail. Results: Tumour location, size and radiographic characteristics varied in each patient. Clinical presentations comprised focal neurological deficits as well as epileptic seizures, persistent headache, mental changes and psycho-organic syndromes. One patient underwent delayed ventriculo-peritoneal shunting after ruptured fatty particles caused obstructive hydrocephalus. Despite dermoid rupture into the subarachnoid space, three patients never developed hydrocephalus. Diffuse vascular supra-tentorial lesions were seen in one patient as a result of aseptic meningitis. Diffusion-weighted imaging (DWI) hyperintensity in dermoids is related to decrease of water proton diffusion and should be used for both the diagnosis and follow-up of this lesion. Conclusion: Although dermoid cysts are known to be benign entities per se, their rupture can cause a wide range of symptoms including aseptic meningitis and/or hydrocephalus. This may be due to intraventricular obstruction and/or paraventricular compression. While rupture does not necessarily bring about hydrocephalus, radical removal of the tumour and close monitoring of ventricular size is required. Although not widely recognised as such, DWI is considered to be a useful imaging modality in the diagnosis and follow-up of dermoid

    Do People Perceive Alexa as Gendered? A Cross-Cultural Study of People’s Perceptions, Expectations, and Desires of Alexa

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    Mainly, the scholarly debate on Alexa has focused on sexist/anti-woman gender representations in the everyday life of many families, on a cluster of themes such as privacy, insecurity, and trust, and on the world of education and health. This paper takes another stance and explores via online survey methodology how university student respondents in two countries (the United States, n = 333; and Italy, n = 322) perceive Alexa's image and gender, what they expect from this voice-based assistant, and how they would like Alexa to be. Results of a free association exercise showed that Alexa's image was scarcely embodied or explicitly gendered. Rather, Alexa was associated with a distinct category of being-the VBA, virtual assistant, or digital helper-with which one talks, and which possesses praiseworthy technical and social traits. Expectations of Alexa and desires regarding Alexa's ideal performance are presented and compared across the two country samples
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