Exact Inference Techniques for the Analysis of Bayesian Attack Graphs

Attack graphs are a powerful tool for security risk assessment by analysing network vulnerabilities and the paths attackers can use to compromise network resources. The uncertainty about the attacker's behaviour makes Bayesian networks suitable to model attack graphs to perform static and dynamic analysis. Previous approaches have focused on the formalization of attack graphs into a Bayesian model rather than proposing mechanisms for their analysis. In this paper we propose to use efficient algorithms to make exact inference in Bayesian attack graphs, enabling the static and dynamic network risk assessments. To support the validity of our approach we have performed an extensive experimental evaluation on synthetic Bayesian attack graphs with different topologies, showing the computational advantages in terms of time and memory use of the proposed techniques when compared to existing approaches.Comment: 14 pages, 15 figure

Bioethics: health ethics new way

The authors make a synthesis of this new discipline, the bioethics, showing its origins, the changes carried out in the social, political and technological scenario that preceded it, the facts and institutions that have contributed to its consolidation, the first publications and the institutionalisation. They cite factors that, according to Rothman, were definitive to the decline of Hipocratic ethics which accompanied the ascension of bioethics.Os autores fazem uma síntese desta nova disciplina, a bioética, mostrando suas origens, as transformações ocorridas no cenário social, político e tecnológico que a precederam, os fatos e instituições que contribuíram para sua consolidação, as primeiras publicações e sua institucionalização. Citam os fatores que, segundo Rothman, foram decisivos para o declínio da ética hipocrática que acompanhou a ascensão da bioética

Stochastic Chemical Reaction Networks for Robustly Approximating Arbitrary Probability Distributions

We show that discrete distributions on the d-dimensional non-negative integer lattice can be approximated arbitrarily well via the marginals of stationary distributions for various classes of stochastic chemical reaction networks. We begin by providing a class of detailed balanced networks and prove that they can approximate any discrete distribution to any desired accuracy. However, these detailed balanced constructions rely on the ability to initialize a system precisely, and are therefore susceptible to perturbations in the initial conditions. We therefore provide another construction based on the ability to approximate point mass distributions and prove that this construction is capable of approximating arbitrary discrete distributions for any choice of initial condition. In particular, the developed models are ergodic, so their limit distributions are robust to a finite number of perturbations over time in the counts of molecules

Role of the reversible electrochemical deprotonation of phosphate species in anaerobic biocorrosion of steels

Sulphate reducing bacteria are known to play a major role in anaerobic microbiological influenced corrosion of steels, but mechanisms behind their influence are still source of debates as certain phenomena remain unexplained. Some experiments have shown that hydrogen consumption by SRB or hydrogenase increased the corrosion rate of mild steel. This was observed only in the presence of phosphate species. Here the cathodic behaviour of phosphate species on steel was studied to elucidate the role of phosphate in anaerobic corrosion of steel. Results showed: a linear correlation between reduction waves in linear voltammetry and phosphate concentration at a constant pH value; that phosphate ions induced considerable anaerobic corrosion of mild steel, which was sensitive to hydrogen concentration in the solution; and that the corrosion potential of stainless steel in presence of phosphate was shifted to more negative values as molecular hydrogen was added to the atmosphere in the reaction vessel. Phosphate species, and possibly other weak acids present in biofilms, are suggested to play an important role in the anaerobic corrosion of steels via a reversible mechanism of electrochemical deprotonation that may be accelerated by hydrogen removal

City Focus: A web-based interactive 2D and 3D GIS application to find the best place in a city, using open data and open source software

City Focus is a webbased interactive 2D and 3D GIS application to find the best place in a city to live as well as to pass shorter staying. The user can select among different criteria and decide their importance by assigning weights to each of them. The application provides thematic maps displaying insights on the places which better fit the user’s preferences. The resulting map is computed through map algebra by means of Web Coverage Processing Service WCPS provided by RASDAMAN Database Management System. Data visualization is mainly based on NASA Web WorldWind opensource virtual globe. The app exploits exclusively open data as well as Free and Open Source Software (FOSS) for its implementation by enabling continuous improvements while minimizing development costs

Role of speech audiometry of pilots with hearing loss in evaluating their eligibility to obtain a civil aviation medical certificate (CMA): a case report

A avaliação auditiva dos pilotos é realizada anualmente para a obtenção do certificado médico aeronáutico (CMA). Muitos pilotos apresentam perda auditiva, principalmente decorrente da exposição ao ruído e da presbiacusia. Os critérios audiométricos para obtenção do CMA são preconizados pelo Regulamento Brasileiro de Aviação Civil (RBAC), e quando os limiares não são alcançados, é proposto um teste para avaliar se o piloto pode ouvir a voz do examinador em intensidade normal em um ambiente silencioso a 2 metros e de costas para este. No entanto, esse teste não avalia a capacidade de entendimento do piloto. Objetivos: Discutir e propor a utilização da logoaudiometria como teste de escolha nas avaliações dos pilotos civis que não preencherem os requisitos auditivos mínimos na audiometria tonal conforme preconizado pelo RBAC. Relato de caso: Foi avaliado o caso de um piloto que não preencheu os critérios audiométricos preconizados pelo RBAC. Este foi então submetido ao teste de escutar a voz do examinador a 2 metros e de costas para este, com resultado inconclusivo, sendo encaminhado para a realização de logoaudiometria, com resultado alterado. Discussão: A avaliação adequada da audição do piloto civil é de suma importância para não o colocar em risco e nem aos demais tripulantes. Quando o piloto não preenche os critérios audiométricos na audiometria tonal, é proposto que seja realizado um teste a 2 metros do examinador e de costas para este. No entanto, esse teste não avalia a capacidade de entendimento do que é falado. O teste também não estabelece com exatidão como deve ser avaliada a resposta do piloto e o que deve ser falado. Dessa forma é proposta a audiometria vocal com discriminação auditiva (logoaudiometria) como teste de escolha para avaliação dos pilotos que não preenchem os critérios audiométricos do RBAC. Esse teste é de fácil reprodutibilidade, pode ser realizado no mesmo local da audiometria, com palavras foneticamente equilibradas já estabelecidas no português. Conclusão: Na avaliação dos pilotos com perda auditiva na audiometria tonal maior do que a preconizada pelo RBAC é imperativa a utilização de um teste que avalie a capacidade de compreensão das palavras e que seja de fácil reprodução. O teste de mais fácil reprodução, que avalia a discriminação auditiva, é a logoaudiometria, que poderia ser utilizada quando o periciando apresentar perda auditiva na audiometria tonal.Hearing assessment of pilots is performed annually to obtain the aeronautical medical certificate (CMA). Many pilots have hearing loss, mainly caused by exposure to noise and presbycusis. Audiometric criteria for obtaining CMA is advocated by the Brazilian Civil Aviation Regulation (RBAC), and when they do not reach the thresholds, a test is given to assess if the pilot can hear the voice of the examiner at normal intensity in a quiet room at 2 meters and facing in the opposite direction of the sound source. However this test does not evaluate the ability of discrimination of the pilot. Objectives: To discuss and propose the use of speech audiometry as the test of choice in the evaluation of civil pilots who did not fulfill the minimum requirements in the tone audiometry as recommended by RBAC. Case report: a case was evaluated of a pilot who did not fulfill the audiometric criteria recommended by RBAC. He was then asked to listen to the voice of the examiner at 2 meters distance when facing backwards, whereupon the results were inconclusive, and he was then sent to undergo speech audiometry, which gave abnormal results. Discussion: A proper evaluation of hearing of the civil pilot is highly important in order not to put his or his crew’s life at risk. When the pilot does not fulfill the criteria of pure tone audiometry, it is proposed that a hearing test be performed at 2 meters distance from the examiner and while facing backwards. However this test does not evaluate the ability of discrimination of what is spoken. The test does not establish exactly how the response of the pilot should be evaluated and what should be spoken. Thus, it is proposed the speech audiometry with auditory discrimination (speech discrimination) be the test of choice for evaluation of the pilots who do not meet the audiometric criteria of RBAC. This test is easily reproducible and can be performed at the same location as audiometry, and uses phonetically balanced words already established in Portuguese. Conclusion: In the evaluation of pilots with hearing loss in the tone audiometry greater than that advocated by RBAC, it is very important to use a test that assesses the ability to discriminate words and is easily reproducible. The easiest test to reproduce, which assesses auditory discrimination, is speech audiometry and it should be used whenever a pilot has a hearing loss

Historical moment of a specialty

Os autores fazem um breve relato histórico da Medicina Legal ressaltando que é, como especialidade médica, uma das mais antigas e que vive um momento de grande relevância histórica: a fusão de duas sociedadesmédicas que disputavam o direito de emitir certificado de área de atuação para os médicos que a exercem. Os pontos principais dessa disputa são destacados, incluindo a alteração do nome da especialidade que passou a ser Medicina Legal e Perícia Médica, não se tratando de nova especialidade, apenas uma pequena mudança de denominação da antiga.  This article presents a brief history of Forensic Medicine in Brazil and emphasizes the current relevantmoment the specialty is facing: fusion of two medical societies which disputed the right to issue specialty certification for forensic medical doctors working in the area. The main dispute points are discussed, including the change in denomination of the specialty with the addition of Perícia Médica to the original name (Medicina Legal).  

Traffic medicine

Medicina de Tráfego é o ramo da ciência médica que trata da manutenção do bem estar físico, psíquico e social do ser humano que se desloca, qualquer que seja o meio que propicie a sua mobilidade. Estuda as causas do acidente de tráfego a fim de preveni-lo ou mitigar suas consequências, além de contribuir com subsídios técnicos para a elaboração do ordenamento legal e modificação do comportamento do usuário do sistema de circulação viária. [...

Design, operation, modeling and grid integration of power-to-gas bioelectrochemical systems

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