17,287 research outputs found

    On Various Negative Translations

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    Several proof translations of classical mathematics into intuitionistic mathematics have been proposed in the literature over the past century. These are normally referred to as negative translations or double-negation translations. Among those, the most commonly cited are translations due to Kolmogorov, Godel, Gentzen, Kuroda and Krivine (in chronological order). In this paper we propose a framework for explaining how these different translations are related to each other. More precisely, we define a notion of a (modular) simplification starting from Kolmogorov translation, which leads to a partial order between different negative translations. In this derived ordering, Kuroda and Krivine are minimal elements. Two new minimal translations are introduced, with Godel and Gentzen translations sitting in between Kolmogorov and one of these new translations.Comment: In Proceedings CL&C 2010, arXiv:1101.520

    Security Policy Consistency

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    With the advent of wide security platforms able to express simultaneously all the policies comprising an organization's global security policy, the problem of inconsistencies within security policies become harder and more relevant. We have defined a tool based on the CHR language which is able to detect several types of inconsistencies within and between security policies and other specifications, namely workflow specifications. Although the problem of security conflicts has been addressed by several authors, to our knowledge none has addressed the general problem of security inconsistencies, on its several definitions and target specifications.Comment: To appear in the first CL2000 workshop on Rule-Based Constraint Reasoning and Programmin

    THE ENTROPIC ANALYSIS OF ELECTORAL RESULTS: THE CASE OF EUROPEAN COUNTRIES

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    Entropy is a measure of information and uncertainty which has been used recently in different areas, besides of its original utilization in physics. Finance, microeconomics, macroeconomics, utility functions or even psychology are approached areas, using analogies between the areas physics and nature, creating a new research area: Econophysics (see, for example, Ausloos et al, 1999 or Bouchaud, 2002). This paper intends to explore the utilization of entropy through politics and election results, an area just slightly explored (Gill, 2005). It generalizes interpretation of entropy, considering it a measure of dissatisfaction and disillusion of populations in relation to politics. Some phenomena like the increase of abstention in a country, consequence of the dissatisfaction of population and of their alienation in relation to politics could be detected and analysed. This discontentment could result, for example, in the appearance of new political parties, with more division of votes and increasing entropy (result of the discontentment and uncertainty by electors). Absolute majorities, while imply less dispersion of votes, are synonym of more confidence in a given party, making a reduction of entropy. Electoral results could also be influenced by particular phenomena, like those terrorist attacks made in vespers of the two last elections in Spain, with consequences on the affluence to the polls by electors, and influencing levels of entropy. Elections' dates could also influence results: for example, elections on summer season suffer from more abstention. Elections' results could also be connected with aspects like safety feeling of citizens, with unpopular socio-economic policies taken by government or even with the economic performance of a country. One of the purposes of this paper is to find these types of phenomena and try to relate them with the concept of entropy. Another objective is to analyse the reality in different European countries.Entropy, electoral results, satisfaction and dissatisfaction of population

    Análise das propriedades psicométricas da versão portuguesa de um instrumento de avaliação de e-Literacia em Saúde

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    Contexto: As fontes de informação eletrónica assumem um papel primordial nos contextos de informação em saúde, tornando-se fontes privilegiadas para toda a população, sobretudo adolescentes. Objetivos: Validar a eHealth Literacy Scale para a população portuguesa; conhecer os níveis de e-literacia eletrónica nos adolescentes, bem como a sua relação com variáveis sociodemográficas. Metodologia: Foi realizado um estudo quantitativo, descritivocorrelacional, retrospetivo e transversal, utilizando uma amostra não probabilística de 1215 adolescentes. Resultados: A escala apresenta bons valores de consistência interna, bem como correlação entre todos os itens, maioritariamente moderada e estatisticamente muito significativa. Foram encontradas diferenças nalguns itens entre rapazes e raparigas. Adolescentes em anos de escolaridade mais avançados reconheceram não saber onde encontrar recursos sobre saúde na internet, em relação aos que frequentam níveis de escolaridade inferior. Conclusão: Os adolescentes da amostra apresentam bons níveis de e-literacia em saúde. Incluir o desenvolvimento desta literacia nos programas de saúde escolar, permitirá aos jovens adquirir as competências necessárias para uma boa tomada de decisão e promover a saúde no futuro.info:eu-repo/semantics/publishedVersio

    Pay as You Go: A Generic Crypto Tolling Architecture

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    The imminent pervasive adoption of vehicular communication, based on dedicated short-range technology (ETSI ITS G5 or IEEE WAVE), 5G, or both, will foster a richer service ecosystem for vehicular applications. The appearance of new cryptography based solutions envisaging digital identity and currency exchange are set to stem new approaches for existing and future challenges. This paper presents a novel tolling architecture that harnesses the availability of 5G C-V2X connectivity for open road tolling using smartphones, IOTA as the digital currency and Hyperledger Indy for identity validation. An experimental feasibility analysis is used to validate the proposed architecture for secure, private and convenient electronic toll payment
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