351 research outputs found

    Genetically evolved dynamic control for quadruped walking

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    The aim of this dissertation is to show that dynamic control of quadruped locomotion is achievable through the use of genetically evolved central pattern generators. This strategy is tested both in simulation and on a walking robot. The design of the walker has been chosen to be statically unstable, so that during motion less than three supporting feet may be in contact with the ground. The control strategy adopted is capable of propelling the artificial walker at a forward locomotion speed of ~1.5 Km/h on rugged terrain and provides for stability of motion. The learning of walking, based on simulated genetic evolution, is carried out in simulation to speed up the process and reduce the amount of damage to the hardware of the walking robot. For this reason a general-purpose fast dynamic simulator has been developed, able to efficiently compute the forward dynamics of tree-like robotic mechanisms. An optimization process to select stable walking patterns is implemented through a purposely designed genetic algorithm, which implements stochastic mutation and cross-over operators. The algorithm has been tailored to address the high cost of evaluation of the optimization function, as well as the characteristics of the parameter space chosen to represent controllers. Experiments carried out on different conditions give clear indications on the potential of the approach adopted. A proof of concept is achieved, that stable dynamic walking can be obtained through a search process which identifies attractors in the dynamics of the motor-control system of an artificial walker

    The European Ombudsman as an Insurmountable Roadblock?

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    Pandemic crisis and democratic regression – Italy and Brazil

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    L’articolo, impiegando in particolare i risultati dei report annuali predisposti da alcuni tra i più autorevoli istituti e network internazionali che misurano lo stato della democrazia nel mondo, prende in considerazione gli effetti della pandemia da Covid-19 su Italia e Brasile, al fine di verificare se le misure adottate per fronteggiare il virus abbiano effettivamente determinato una regressione democratica nei due Stati, che per la loro storia costituzionale esprimono un diverso consolidamento di un sistema democratico.Utilizando principalmente os resultados dos relatórios anuais elaborados por alguns dos mais importantes institutos e redes que medem o estado da democracia no mundo, o artigo considera os efeitos da pandemia de covid-19 na Itália e no Brasil, a fim de verificar se as medidas adotadas para o enfrentamento do vírus levaram, na verdade, a um retrocesso democrático nos dois Estados, que, por seu histórico constitucional, expressam uma forma diferente de consolidação de um sistema democrático.Using in particular the results of the annual reports prepared by some of the most important institutes and networks that measure the state of democracy in the world, the article considers the effects of the Covid-19 pandemic on Italy and Brazil, in order to verify whether the measures adopted to deal with the virus have actually led to a democratic regression in the two States, which, due to their constitutional history, express a different way of consolidation of a democratic system

    A markov-model-based framework for supporting real-time generation of synthetic memory references effectively and efficiently

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    Driven by several real-life case studies and in-lab developments, synthetic memory reference generation has a long tradition in computer science research. The goal is that of reproducing the running of an arbitrary program, whose generated traces can later be used for simulations and experiments. In this paper we investigate this research context and provide principles and algorithms of a Markov-Model-based framework for supporting real-time generation of synthetic memory references effectively and efficiently. Specifically, our approach is based on a novel Machine Learning algorithm we called Hierarchical Hidden/ non Hidden Markov Model (HHnHMM). Experimental results conclude this paper

    Prevalence of Salmonellae, Listeriae, and Yersiniae in the Slaughterhouse Environment and on Work Surfaces, Equipment, and Workers

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    In 1995 and 1996 a nine-month study was carried out in 11 pig abattoirs located in the Molise region (Italy) to evaluate the degree of contamination of- the slaughterhouse environment, work surfaces, equipment, and personnel by Salmonella spp., Listeria spp., and Yersinia spp. A total of 219 samples were taken over three replications including slaughtering floor and wall, hooks, work-tables, chopping blocks, knives, cleavers, dehairing devices, hands of personnel, clothing, hand-wash basins, and cold room handles, floor, wall, and hooks. Overall, six abattoirs (54.5%) had one or more positive sites, while only 14 of the 219 sites (6.4%) tested were positive for any of considered microorganisms. Salmonella spp. were isolated from 1 of 9 cleavers (11.1 %), 1 of 16 worktables (6.25%), and 1 of 18 slaughtering floors (5.6%). Yersinia enterocolitica was found on 3 slaughtering floors (16.7%) and on 2 worktables (12.5%). Yersinia kristensenii was detected on 2 slaughtering floor swabs (11.1 %). Listeria monocytogenes was isolated from 2 of 20 cold room floor swabs (13.3%) and from 1 of 14 hand-wash basins (7.1%). Other species of Listeria were detected on slaughtering wall and floor swabs and on chopping blocks. Our study indicates that slaughtering floors, cold room floors, and worktables are important sites in abattoirs that may possibly harbor pathogens like Salmonella spp., Yersinia enterocolitica , and Listeria monocytogenes , and that cleaning and sanitizing of the slaughterhouse environment and equipment need a greater emphasis

    Presentazione

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    Il contributo presenta i contributi della sezione monografica dedicata al centenario della Costituzione del Liechtenstei

    Moral dilemmas in self-driving cars

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    Abstract: Autonomous driving systems promise important changes for future of transport, primarily through the reduction of road accidents. However, ethical concerns, in particular, two central issues, will be key to their successful development. First, situations of risk that involve inevitable harm to passengers and/or bystanders, in which some individuals must be sacrificed for the benefit of others. Secondly, and identification responsible parties and liabilities in the event of an accident. Our work addresses the first of these ethical problems. We are interested in investigating how humans respond to critical situations and what reactions they consider to be morally right or at least preferable to others. Our experimental approach relies on the trolley dilemma and knowledge gained from previous research on this. More specifically, our main purpose was to test the difference between what human drivers actually decide to do in an emergency situations whilst driving a realistic simulator and the moral choices they make when they pause to consider what they would do in the same situation and to better understand why these choices may differs.Keywords: Self-driving Cars; Trolley Problem; Moral Choices; Moral Responsibility; Virtual Reality Dilemmi morali nelle automobili a guida autonomaRiassunto: I sistemi di guida autonomi promettono importanti cambiamenti per il futuro dei trasporti, principalmente attraverso la riduzione degli incidenti stradali. Tuttavia, vi sono preoccupazioni etiche, in particolare due questioni centrali, fondamentali per il loro sviluppo. In primo luogo, le situazioni di rischio che comportano inevitabili danni ai passeggeri e/o ai pedoni, ovvero situazioni in cui alcune persone devono essere sacrificate a beneficio di altri. In secondo luogo, l’identificazione delle parti responsabili in caso di incidente. Il nostro lavoro affronta il primo di questi problemi etici. Siamo interessati a studiare come gli umani rispondono a situazioni critiche e quali reazioni considerano moralmente giuste o almeno preferibili. Il nostro approccio sperimentale si basa sul trolley problem e sulle conoscenze acquisite da precedenti ricerche su questo ambito. Più specificamente, il nostro scopo principale è quello di testare la differenza tra ciò che i conducenti umani decidono effettivamente di fare in una situazione di emergenza, mentre guidano un simulatore realistico, e le scelte morali che compiono se posti nella stessa situazione e hanno la possibilità di decidere senza limiti di tempo. Lo scopo è inoltre comprendere come e perché queste scelte possono differire.Parole chiave: Automobili a guida autonoma; Trolley problem; Scelte morali; Responsabilità morale, Realtà virtual

    Autoimmune Hepatitis and Celiac Disease: Case Report Showing an Entero-Hepatic Link

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    Celiac disease is an autoimmune disorder primarily targeting the small bowel, although extraintestinal extensions have been reported. The autoimmune processes can affect the liver with manifestations such as primary biliary cirrhosis and autoimmune hepatitis. We describe a 61-year-old woman with celiac disease and an increased levels of aminotransferases. The persistence of increased levels of aminotransferases after 1 year of gluten-free diet and the positivity for an anti-nuclear and anti-double-strand DNA antibodies led to a misdiagnosis of systemic lupus erythematosus-related hepatitis. Based on these findings the patient was placed on steroids, which after a few months were stopped because of the onset of diabetes mellitus. Soon after steroid withdrawal, the patient had a marked increase in aminotransferases and γ-globulins, and a liver biopsy revealed chronic active hepatitis. A course of three months of steroids and azathioprine normalized both biochemical and clinical parameters. Currently the patient is symptom-free and doing well. In conclusion, a hypertransaminasemia persisting after a gluten-free diet should be interpreted as a sign of coexisting autoimmune liver disease. Any autoantibody positivity (in this case to ANA and anti-dsDNA) should be carefully considered in order to avoid misdiagnosis delaying appropriate clinical management
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