69 research outputs found

    A comparison of 2D and 3D Delaunay triangulations for fingerprint authentication

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    The two-dimensional (2D) Delaunay triangulation-based structure, i.e., Delaunay triangle, has been widely used in fingerprint authentication. However, we also notice the existence of three-dimensional (3D) Delaunay triangulation, which has not been extensively explored. Inspired by this, in this paper, the features of both 2D and 3D Delaunay triangulation-based structures are investigated and the findings show that a 3D Delaunay structure, e.g., Delaunay tetrahedron, can provide more feature types and a larger number of elements than a 2D Delaunay structure, which was expected to provide a higher discriminative capability. However, higher discrimination does not necessarily lead to better performance, especially in biometric applications, when biometric uncertainty is unavoidable. Experimental results show that the biometric uncertainty such as missing or spurious minutiae causes more negative influence on the 3D Delaunay triangulation than that on the 2D Delaunay triangulation in three out of four experimental data sets

    Viabilidade do emprego de ácido fluorídrico 10% para a remoção de íons paramagnéticos em amostras de solos e suas respectivas frações físicas

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    A utilização de efluentes de esgoto tratado na irrigação, ao invés de realizar a disposição deste subproduto nos cursos d'água tem sido uma alternativa antiga, popular e atrativa, com triplo propósito: tratamento complementar do efluente, fonte de água e de nutrientes ao sistema solo-planta. Entretanto, no Brasil, há falta de tradição na reciclagem de águas residuárias, particularmente, do efluente de esgoto tratado e, conseqüentemente, poucos têm sido as pesquisas relacionadas a este tema. Com a finalidade de fornecer mais informações para subsidiar as pesquisas nesta área, este trabalho visa avaliar, por meio de técnicas químicas e espectroscopias, o processo de humificação na matéria orgânica dos solos irrigados com efluente de esgoto tratado em experimentos de campo. Os cinco tratamentos estudados foram: TSI (controle) - irrigado com água potável e adição de nitrogênio via fertilizante mineral, T100, T125, T150 e T200 irrigado com efluente de esgoto tratado e adição de nitrogênio via fertilizante mineral. Os resultados obtidos mostram variações no teor de carbono e no grau de humificação, para os solos irrigados com efluente de esgoto tratado, decorrentes do aumento da atividade de decomposição da matéria orgânica, estimulada pelo aumento de água no solo.Treated sewage effluent utilization for irrigation represents an antique, popular and attractive alternative to the common disposal of effluent to watercourses and includes three main purposes: effluent complementary treatment, water and nutrient source to the soil-plant system. However, because in Brazil no experiences in wastewater recycling exists consequently few scientific studies were carried out despite the importance of the subject. The present study aimed to evaluate by chemical and spectroscopy techniques the soil organic matter from soils irrigated with treated sewage effluent. Five treatments were evaluated: TSI (control) irrigation with potable water and addition of the nitrogen as mineral fertilizer; T100, T125, T150 and T200 - irrigation with treated sewage sludge effluent and addition of the nitrogen as mineral fertilizer. The results obtained shown changes in the carbon contend and humification degree for the soils irrigated with treated sewage sludge effluent due to the increase activity of the decomposition of organic matter, stimulated by the increase of water in the soil.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    A cancelable iris- and steganography-based user authentication system for the Internet of Things

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    Remote user authentication for Internet of Things (IoT) devices is critical to IoT security, as it helps prevent unauthorized access to IoT networks. Biometrics is an appealing authentication technique due to its advantages over traditional password-based authentication. However, the protection of biometric data itself is also important, as original biometric data cannot be replaced or reissued if compromised. In this paper, we propose a cancelable iris- and steganography-based user authentication system to provide user authentication and secure the original iris data. Most of the existing cancelable iris biometric systems need a user-specific key to guide feature transformation, e.g., permutation or random projection, which is also known as key-dependent transformation. One issue associated with key-dependent transformations is that if the user-specific key is compromised, some useful information can be leaked and exploited by adversaries to restore the original iris feature data. To mitigate this risk, the proposed scheme enhances system security by integrating an effective information-hiding technique-steganography. By concealing the user-specific key, the threat of key exposure-related attacks, e.g., attacks via record multiplicity, can be defused, thus heightening the overall system security and complementing the protection offered by cancelable biometric techniques

    TOMADA DE DECISÃO E TEORIA DOS PROSPECTOS EM AMBIENTE CONTÁBIL: UMA ANÁLISE COM FOCO NO EFEITO FRAMING

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    Por conta da recente implantação no Brasil das normas internacionais de Contabilidade – IFRS, que possuem a filosofia básica da prevalência da essência sobre a forma, tornou-se mais necessário aos profissionais de Contabilidade o exercício do julgamento. Assim sendo, na busca por entender de que forma profissionais de Contabilidade estão analisando e produzindo informações, o presente estudo tem por objetivo mostrar de que forma a Teoria dos Prospectos, mas especificamente o Efeito Framing, pode interferir no processo de análise e produção de informação contábil. Para tanto, aplicou-se um questionário estruturado e não disfarçado a profissionais da área de Contabilidade, com o intuito de verificar de que forma o Efeito Framing poderia moldar uma tomada de decisão dentro do ambiente contábil. O questionário foi dividido em dois tipos (I e II), devido a necessidade de se testar a mesma pergunta nos campos dos ganhos e das perdas. Na análise dos resultados dos questionários utilizou-se a análise de frequência das alternativas de cada questão e aplicou-se testes de diferença de proporções. Dentre os resultados, pôde-se identificar a presença do Efeito Framing, visto que por meio da manipulação da forma como a informação é transmitida, constatou-se que, de maneira geral, os respondentes apresentaram uma atitude favorável ao ganho certo, ou mais provável, quando estavam no campo dos ganhos, mas no campo das perdas, apresentaram uma propensão ao risco escolhendo a opção mais arriscada. Cabe ressaltar que a maior contribuição desse estudo está em conscientizar os profissionais de Contabilidade de que seus julgamentos são passivos de desvios, por conta dos efeitos da Teoria da Racionalidade Limitada. &nbsp

    Caracterização química e espectroscópica de solos irrigados com efluente de esgoto tratado

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    A utilização de efluentes de esgoto tratado na irrigação, ao invés de realizar a disposição deste subproduto nos cursos d'água tem sido uma alternativa antiga, popular e atrativa, com triplo propósito: tratamento complementar do efluente, fonte de água e de nutrientes ao sistema solo-planta. Entretanto, no Brasil, a reciclagem de águas residuárias, particularmente, do efluente de esgoto tratado, não é uma prática comum e, conseqüentemente, trabalhos científicos relacionados a este tema são incipientes. Com a finalidade de fornecer mais informações para subsidiar as pesquisas nesta área, este trabalho visa avaliar, por meio de técnicas química e espectroscópica, o processo de humificação na matéria orgânica dos solos irrigados com efluente de esgoto tratado em experimentos de campo. Os cinco tratamentos estudados foram: TSI (controle) - irrigado com água potável e adição de nitrogênio via fertilizante mineral, T100, T125, T150 e T200 irrigado com efluente de esgoto tratado e adição de nitrogênio via fertilizante mineral. Os resultados obtidos mostram variações no teor de carbono e no grau de humificação, para os solos irrigados com efluente de esgoto tratado, decorrentes do aumento da atividade de decomposição da matéria orgânica, estimulada pelo aumento da quantidade de água no solo.FAPESPCNPqCoordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES

    Molecular characterization of Glaesserella parasuis strains isolated from North America, Europe and Asia by serotyping PCR and LS-PCR

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    Glaesserella parasuis strains were characterized by serotyping PCR, vtaA virulence marker Leader Sequence (LS)-PCR, clinical significance, and geographic region. Overall, the serovars 4, 5/12, 7, 1, and 13 were the most commonly detected. Serovars of greatest clinical relevance were systemic isolates that had a higher probability of being serovar 5/12, 13, or 7. In comparison, pulmonary isolates had a higher likelihood of being serovars 2, 4, 7, or 14. Serovars 5/12 and 13 have previously been considered disease-associated, but this study agrees with other recent studies showing that serovar 7 is indeed associated with systemic G. parasuis disease. Serovar 4 strains illustrated how isolates can have varying degrees of virulence and be obtained from pulmonary, systemic, or nasal sites. Serovars 8, 9, 15, and 10 were predominantly obtained from nasal samples, which indicates a limited clinical significance of these serovars. Additionally, most internal G. parasuis isolates were classified as virulent by LS-PCR and were disease-associated isolates, including serovars 1, 2, 4, 5/12, 7, 13, and 14. Isolates from the nasal cavity, including serovars 6, 9, 10, 11, and 15, were classified as non-virulent by LS-PCR. In conclusion, the distribution of G. parasuis serovars remains constant, with few serovars representing most of the strains isolated from affected pigs. Moreover, it was confirmed that the LS-PCR can be used for G. parasuis virulence prediction of field strains worldwide.info:eu-repo/semantics/publishedVersio

    Molecular characterization of Glaesserella parasuis strains isolated from North America, Europe and Asia by serotyping PCR and LS-PCR.

    Get PDF
    Glaesserella parasuis strains were characterized by serotyping PCR, vtaA virulence marker Leader Sequence (LS)-PCR, clinical significance, and geographic region. Overall, the serovars 4, 5/12, 7, 1, and 13 were the most commonly detected. Serovars of greatest clinical relevance were systemic isolates that had a higher probability of being serovar 5/12, 13, or 7. In comparison, pulmonary isolates had a higher likelihood of being serovars 2, 4, 7, or 14. Serovars 5/12 and 13 have previously been considered disease-associated, but this study agrees with other recent studies showing that serovar 7 is indeed associated with systemic G. parasuis disease. Serovar 4 strains illustrated how isolates can have varying degrees of virulence and be obtained from pulmonary, systemic, or nasal sites. Serovars 8, 9, 15, and 10 were predominantly obtained from nasal samples, which indicates a limited clinical significance of these serovars. Additionally, most internal G. parasuis isolates were classified as virulent by LS-PCR and were disease-associated isolates, including serovars 1, 2, 4, 5/12, 7, 13, and 14. Isolates from the nasal cavity, including serovars 6, 9, 10, 11, and 15, were classified as non-virulent by LS-PCR. In conclusion, the distribution of G. parasuis serovars remains constant, with few serovars representing most of the strains isolated from affected pigs. Moreover, it was confirmed that the LS-PCR can be used for G. parasuis virulence prediction of field strains worldwide
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