75 research outputs found

    Brokerage for Quality Assurance and Optimisation of Cloud Services: An Analysis of Key Requirements

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    As the number of cloud service providers grows and the requirements of cloud service consumers become more complex, the latter will come to depend more and more on the intermediation services of cloud service brokers. Continuous quality assurance and optimisation of services is becoming a mission-critical objective that many consumers will find difficult to address without help from cloud service intermediaries. The Broker@Cloud project envisages a software framework that will make it easier for cloud service intermediaries to address this need, and this paper provides an analysis of key requirements for this framework. We discuss the methodology that we followed to capture these requirements, which involved defining a conceptual service lifecycle model, carrying out a series of Design Thinking workshops, and formalising requirements based on an agile requirements information model. Then, we present the key requirements identified through this process in the form of summarised results

    Polarizing Double Negation Translations

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    Double-negation translations are used to encode and decode classical proofs in intuitionistic logic. We show that, in the cut-free fragment, we can simplify the translations and introduce fewer negations. To achieve this, we consider the polarization of the formul{\ae}{} and adapt those translation to the different connectives and quantifiers. We show that the embedding results still hold, using a customized version of the focused classical sequent calculus. We also prove the latter equivalent to more usual versions of the sequent calculus. This polarization process allows lighter embeddings, and sheds some light on the relationship between intuitionistic and classical connectives

    Effect of the elastic modulus of the matrix on magnetostrictive strain in composites

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    The effect of the matrix material on the magnetostriction of composites containing highly magnetostrictive particles has been studied. Experimental results showed that the elastic modulus of the matrix is an important factor determining the bulk magnetostriction of the composite. For a series of composites with the same volume fraction of magnetostrictive particles but different matrix materials, the bulk magnetostriction was found to increase systematically with decreasing elastic modulus of the matrix. A modeltheory for the magnetostriction of such composites has been developed, based on two limiting assumptions: uniform strain or uniform stress inside the composite. The theory was then used to predict the magnetostriction of the entire material from the volume fractions of the components, their elastic moduli and magnetostrictions. These predictions were in agreement with the experimental results. It is concluded that to obtain a high magnetostriction and adequate mechanical properties of a composite, the elastic moduli of the magnetostrictive phase and the matrix should be as close as possible in value

    Les grilles pour le développement médical

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    PCSV, présenté par V. Breton, à paraître dans les Comptes-Rendu de la ConférenceLe développement récent des sciences et technologies de l'information et de la communication permet aujourd'hui la création de véritables infrastructures pour le calcul et le stockage de données hétérogènes à l'échelle régionale, nationale et internationale. Ces infrastructures, appelées grilles informatiques, permettront bientôt d'utiliser les ressources informatiques mutualisées avec autant de facilité que nous utilisons aujourd'hui l'électricité. L'utilisation des grilles afin d'accélérer la découverte de médicaments est une voie très prometteuse pour l'avenir. Par cette approche in silico, le nombre de molécules ainsi que la vitesse de test peuvent être grandement augmentés induisant un coût moindre de développement de médicaments. Du 11 Juillet au 31 Août 2005, l'expérience WISDOM (Wide In Silico Docking On Malaria) a permis de tester rien moins qu'un million de ligands (médicaments potentiels) pour le traitement du paludisme: 1700 ordinateurs à travers le monde ont ainsi été associés à cette démarche permettant de réaliser en un mois ce qui aurait nécessité 80 ans sur un ordinateur classique. L'analyse des résultats est en cours. Par cette approche, on peut souhaiter également que les maladies orphelines puissent bénéficier d'un intérêt nouveau de la part des industries pharmaceutiques, à travers notamment la baisse du coût de développement d'un médicament, principal obstacle actuellement à leur mobilisation

    An mCARE Study on Patterns of Risk and Resilience for Children with ASD in Bangladesh

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    Community-wide lockdowns in response to COVID-19 influenced many families, but the developmental cascade for children with autism spectrum disorder (ASD) may be especially detrimental. Our objective was to evaluate behavioral patterns of risk and resilience for children with ASD across parent-report assessments before (from November 2019 to February 2020), during (March 2020 to May 2020), and after (June 2020 to November 2020) an extended COVID-19 lockdown. In 2020, our study Mobile-based care for children with ASD using remote experience sampling method (mCARE) was inactive data collection before COVID-19 emerged as a health crisis in Bangladesh. Here we deployed “Cohort Studies”, where we had in total 300 children with ASD (150 test group and 150 control group) to collect behavioral data. Our data collection continued through an extended COVID-19 lockdown and captured parent reports of 30 different behavioral parameters (e.g., self-injurious behaviors, aggression, sleep problems, daily living skills, and communication) across 150 children with ASD (test group). Based on the children’s condition, 4–6 behavioral parameters were assessed through the study. A total of 56,290 behavioral data points was collected (an average of 152.19 per week) from parent cell phones using the mCARE platform. Children and their families were exposed to an extended COVID-19 lockdown. The main outcomes used for this study were generated from parent reports child behaviors within the mCARE platform. Behaviors included of child social skills, communication use, problematic behaviors, sensory sensitivities, daily living, and play. COVID-19 lockdowns for children with autism and their families are not universally negative but supports in the areas of “Problematic Behavior” could serve to mitigate future risk

    Characterising strongly normalising intuitionistic sequent terms

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    This paper gives a characterisation, via intersection types, of the strongly normalising terms of an intuitionistic sequent calculus (where LJ easily embeds). The soundness of the typing system is reduced to that of a well known typing system with intersection types for the ordinary lambda-calculus. The completeness of the typing system is obtained from subject expansion at root position. This paper's sequent term calculus integrates smoothly the lambda-terms with generalised application or explicit substitution. Strong normalisability of these terms as sequent terms characterises their typeability in certain "natural'' typing systems with intersection types. The latter are in the natural deduction format, like systems previously studied by Matthes and Lengrand et al., except that they do not contain any extra, exceptional rules for typing generalised applications or substitution

    A Note on the Ordinal Analysis of RCA0+WO(σ)

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    We fill an apparent gap in the literature by giving a short and self-contained proof that the ordinal of the theory RCA0+WO(σ) is σω , for any ordinal σ satisfying ω⋅σ=σ (e.g., ωω , ωωω , ε0 ). Theories of the form RCA0+WO(σ) are of interest in Proof Theory and Reverse Mathematics because of their connections to a number of well-investigated combinatorial principles related to various subsystems of arithmetic

    Structural brain changes in patients with post-COVID fatigue: a prospective observational study

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    BACKGROUND: Post-COVID syndrome is a severe long-term complication of COVID-19. Although fatigue and cognitive complaints are the most prominent symptoms, it is unclear whether they have structural correlates in the brain. We therefore explored the clinical characteristics of post-COVID fatigue, describe associated structural imaging changes, and determine what influences fatigue severity. METHODS: We prospectively recruited 50 patients from neurological post-COVID outpatient clinics (age 18-69 years, 39f/8m) and matched non-COVID healthy controls between April 15 and December 31, 2021. Assessments included diffusion and volumetric MR imaging, neuropsychiatric, and cognitive testing. At 7.5 months (median, IQR 6.5-9.2) after the acute SARS-CoV-2 infection, moderate or severe fatigue was identified in 47/50 patients with post-COVID syndrome who were included in the analyses. As a clinical control group, we included 47 matched multiple sclerosis patients with fatigue. FINDINGS: Our diffusion imaging analyses revealed aberrant fractional anisotropy of the thalamus. Diffusion markers correlated with fatigue severity, such as physical fatigue, fatigue-related impairment in everyday life (Bell score) and daytime sleepiness. Moreover, we observed shape deformations and decreased volumes of the left thalamus, putamen, and pallidum. These overlapped with the more extensive subcortical changes in MS and were associated with impaired short-term memory. While fatigue severity was not related to COVID-19 disease courses (6/47 hospitalised, 2/47 with ICU treatment), post-acute sleep quality and depressiveness emerged as associated factors and were accompanied by increased levels of anxiety and daytime sleepiness. INTERPRETATION: Characteristic structural imaging changes of the thalamus and basal ganglia underlie the persistent fatigue experienced by patients with post-COVID syndrome. Evidence for pathological changes to these subcortical motor and cognitive hubs provides a key to the understanding of post-COVID fatigue and related neuropsychiatric complications. FUNDING: Deutsche Forschungsgemeinschaft (DFG) and German Ministry of Education and Research (BMBF)
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