973 resultados para Certification authorities


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The provision of security in mobile ad hoc networks is of paramount importance due to their wireless nature. However, when conducting research into security protocols for ad hoc networks it is necessary to consider these in the context of the overall system. For example, communicational delay associated with the underlying MAC layer needs to be taken into account. Nodes in mobile ad hoc networks must strictly obey the rules of the underlying MAC when transmitting security-related messages while still maintaining a certain quality of service. In this paper a novel authentication protocol, RASCAAL, is described and its performance is analysed by investigating both the communicational-related effects of the underlying IEEE 802.11 MAC and the computational-related effects of the cryptographic algorithms employed. To the best of the authors' knowledge, RASCAAL is the first authentication protocol which proposes the concept of dynamically formed short-lived random clusters with no prior knowledge of the cluster head. The performance analysis demonstrates that the communication losses outweigh the computation losses with respect to energy and delay. MAC-related communicational effects account for 99% of the total delay and total energy consumption incurred by the RASCAAL protocol. The results also show that a saving in communicational energy of up to 12.5% can be achieved by changing the status of the wireless nodes during the course of operation. Copyright (C) 2009 G. A. Safdar and M. P. O'Neill (nee McLoone).

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We report the results of a study based on revealed and stated preference data on choice of Prosecco wines in retail stores close to the origin of production in Northern Italy. Emphasis is placed on ability to reconcile the utility structure of stated preference data with that underlying revealed preference data. We extend the analysis to cover nonattendance of key attributes, such as price and certification of origin, while controlling for the large range of brand effects.

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Illegal, Unreported and Unregulated fishing has had a major role in the overexploitation of global fish populations. In response, international regulations have been imposed and many fisheries have been 'eco-certified' by consumer organizations, but methods for independent control of catch certificates and eco-labels are urgently needed. Here we show that, by using gene-associated single nucleotide polymorphisms, individual marine fish can be assigned back to population of origin with unprecedented high levels of precision. By applying high differentiation single nucleotide polymorphism assays, in four commercial marine fish, on a pan-European scale, we find 93-100% of individuals could be correctly assigned to origin in policy-driven case studies. We show how case-targeted single nucleotide polymorphism assays can be created and forensically validated, using a centrally maintained and publicly available database. Our results demonstrate how application of gene-associated markers will likely revolutionize origin assignment and become highly valuable tools for fighting illegal fishing and mislabelling worldwide.

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A presente dissertação constitui-se num estudo desenvolvido na área da educação de adultos, tendo como questão central: qual a oferta educativa e formativa certificada dirigida à população adulta do concelho de Vendas Novas, no período de 2000 a 2010? Procurámos dar resposta a esta questão, reflectindo sobre os conceitos relativos à Educação e Aprendizagem ao Longo da Vida e traçando uma breve retrospectiva das políticas educativas que nortearam este sector da educação. Atendendo à natureza do objecto em estudo, seguiu-se uma metodologia qualitativa, tendo a recolha de dados recaído sobre documentos oficiais produzidos por instâncias locais e regionais. Para a sua análise e interpretação, recorreu-se à técnica de análise de conteúdo, com o objectivo de destacar o seu conteúdo, quer evidente, quer latente. Os resultados emanados deste estudo permitiram-nos concluir efectivamente que as ofertas formativas colocadas ao dispor da população do concelho de Vendas Novas, durante a década de 2000 – 2010, foram muito diversificadas e procuraram, não só dar resposta às necessidades de formação/qualificação diagnosticadas, mas também dar cumprimento às orientações políticas nacionais e internacionais, em matéria de educação de adultos; ABSTRACT:This dissertation is the result of a study carries out in the area of adult education, having as central concern the mapping of the certified educational and training offer for adults in the county of Vendas Novas, in the period between 2000 and 2010. We tried to answer this question, reflecting on the concepts relating to education and lifelong learning and plotting a brief review of educational policies that guided this sector of education. Due to the nature of the subject under study, was followed a qualitative methodology, and data collection has relied on official documents produced by local and regional authorities. For the analysis and interpretation of data, we used the technique of content analysis, in order to highlight its content, either obvious or latent. The results emanating from this study allowed us to conclude that the provision of educational and training offer made available to the population of the county of Vendas Novas, during the decade 2000 - 2010, was very diverse and sought to address not only the training / qualification needs diagnosed, but also to comply with the national and international guidelines, in the field of adult education.

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The certification program is centered on a three-day workshop that includes detailed instruction and a 16-chapter manual/reference guide. The manual/reference guide offers a comprehensive overview of both old and new recycling issues faced by programs including composting, electronics and funding. It also provides detailed information on the requirements of county programs as outlined in the S.C. Solid Waste Policy and Management Act of 1991.