Supporting Real-Time Communication in CSMA-Based Networks : the VTP-CSMA Virtual Token Passing Approach

Tese de doutoramento. Engenharia Electrotécnica e de Computadores. Faculdade de Engenharia. Universidade do Porto. 200

Uma implementação do método de elementos finitos em geometrias não-convexas

Dissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico.Neste trabalho é utilizado o Método dos Elementos Finitos para a implementação de um código computacional capaz de resolver problemas elípticos, com ênfase na equação de Poisson. A formulação adotada abrange domínios convexos ou não-convexos, sujeitos a qualquer combinação de condições de contorno de Neumann e de Dirichlet e com qualquer configuração para as propriedades físicas e para carregamento

A Quality-of-Service (QoS) based approach for the communication support in network-based control systems: an on-going project

Due to the increased availability of low cost network technology, the implementation ofNetwork-based Control Systems (NCS) is becoming widely accepted. Current NCS areusually supported by small-dedicated communication networks (known as fieldbusnetworks) operating in access-controlled mediums, which are able to guarantee thedelivery of control data within known and bounded delays.It is however foreseeable that, access-uncontrolled networks (such as packet-basednetworks) will play an important role in future NCS. In this paper, we present an ongoingproject, proposing the use of a QoS architecture to implement NCS built uponshared networks with uncontrolled access, i.e., considering communication environmentssubject to unknown disturbances.Within this project, several QoS architectures for packet-based networks are looked atcarefully, such as the IntServ and the DiffServ architectures and the Multi-ProtocolLabel Switching (MPLS) and the Constraint Based Routing strategies. Such multipleQoS architectures will be evaluated through the use of an experimental platform enablingthe implementation and evaluation of network-based control systems

Mecanismos de Comunicação de Tempo Real para Redes IEEE 802.11

Um número significativo de trabalhos de pesquisa está sendo efetuado no desenvolvimento de redes sem fios de alto desempenho. Esta tendência é uma conseqüência da crescente utilização de comunicações sem fios em ambientes de escritório e doméstico. Então, é provável que num futuro próximo, a ampla disponibilidade de soluções de redes sem fios irá também gerar um padrão de facto para comunicação sem fios na Automação, onde o conjunto de protocolos normalizados IEEE 802.11 e IEEE 802.15.4 são os principais candidatos

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Análise dos fatores que influenciam o desempenho de um modelo de previsão de demanda de energia

The forecast of energy demand is one of the essential variables for the operation, planning, and estimation of tariffs for electric energy networks. There is currently a significant investment in modernizing the seven domains of an Intelligent Electric Grid (Smart-Grids). The operation of these various domains requires greater precision in forecasting demand for use and energy generation. Several techniques have been applied for this purpose, the most promising being machine learning, which in recent years sss received special attention. The focus of this work is to analyze a univariate demand forecasting method that employs deep artificial neural networks. The load time series history is used as input, added to the seasonality representation to predict the future load values of the electrical system. It will be shown that several factors influence the answer, and one of them is the choice of the way to decompose the problem and, therefore, the applied model.A previsão de demanda de energia é uma das variáveis mais importante para a operação, planejamento e estimativa de tarifas das redes de energia elétrica. Há um grande investimento atual na modernização dos sete domínios que compõem uma Rede Elétrica Inteligente (Smart-Grids) e a operação desses diversos domínios requer maior precisão nas previsões de demanda de uso e de geração de energia. Várias técnicas têm sido aplicadas para este fim, sendo que as mais promissoras são as de aprendizagem de máquina, que nos últimos anos  têm recebido especial atenção. O foco deste trabalho é analisar um método univariável de previsão de demanda que emprega redes neurais artificiais profundas. O histórico da série temporal da carga é usado como entrada, agregado à representação das sazonalidades para prever os valores futuros da carga do sistema elétrico. Será mostrado que vários fatores influem na resposta e um deles é a escolha da forma de decomposição do problema e portanto do modelo aplicado

How do social-economic differences in urban areas affect tuberculosis mortality in a city in the tri-border region of Brazil, Paraguay and Argentina

Abstract Background The World Health Organization (WHO) launched the “End TB Strategy”, which aims to reduce tuberculosis (TB) mortality by 95% by 2035, Brazil has made a commitment to this, however, one challenge is achieving the goal in the border region, where the TB situation is more critical. The proposal was to analyse the spatial mortality due to TB and its socio-economic determinants in the general population, around the border areas of Brazil, Paraguay and Argentina, as well as the temporal trend in this region. Method This ecological study considered the cases of TB deaths of residents of Foz do Iguaçu (BR), with its units of analysis being the census sectors. The standardized mortality rate was calculated for each area. Socioeconomic variables data were obtained from the 2010 Demographic Census of the Brazilian Institute of Geography and Statistics (IBGE). The scan statistic was applied to calculate the spatial relative risk (RR), considering a 95% confidence interval (CI). Spatial dependence was analysed using the Global Bivariate Moran I and Local Bivariate Moran I (LISA) to test the relationship between the socioeconomic conditions of the urban areas and mortality from TB. Analysis of the temporal trend was also performed using the Prais-Winsten test. Results A total of 74 cases of TB death were identified, of which 53 (71.6%) were male and 51 (68.9%) people of white skin colour. The mortality rate ranged from 0.28 to 22.75 cases per 100,000 inhabitants. A spatial relative risk area was identified, RR = 5.07 (95% CI 1.79–14.30). Mortality was associated with: proportion of people of brown skin colour (I: 0.0440, p = 0.033), income (low income I: − 0.0611, p = 0.002; high income I: − 0.0449, p = 0.026) and density of residents (3 and 4 residents, I: 0.0537, p = 0.007; 10 or more residents, I: − 0.0390, p = 0.035). There was an increase in the mortality rate in people of brown skin colour (6.1%; 95% CI = 0.029, 0.093). Conclusion Death due to TB was associated with income, race resident density and social conditions. Although the TB mortality rate is stationary in the general population, it is increasing among people of brown skin colour