970 resultados para Code Division Multiple Access System
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Pervasive and distributed Internet of Things (IoT) devices demand ubiquitous coverage beyond No-man’s land. To satisfy plethora of IoT devices with resilient connectivity, Non-Terrestrial Networks (NTN) will be pivotal to assist and complement terrestrial systems. In a massiveMTC scenario over NTN, characterized by sporadic uplink data reports, all the terminals within a satellite beam shall be served during the short visibility window of the flying platform, thus generating congestion due to simultaneous access attempts of IoT devices on the same radio resource. The more terminals collide, the more average-time it takes to complete an access which is due to the decreased number of successful attempts caused by Back-off commands of legacy methods. A possible countermeasure is represented by Non-Orthogonal Multiple Access scheme, which requires the knowledge of the number of superimposed NPRACH preambles. This work addresses this problem by proposing a Neural Network (NN) algorithm to cope with the uncoordinated random access performed by a prodigious number of Narrowband-IoT devices. Our proposed method classifies the number of colliding users, and for each estimates the Time of Arrival (ToA). The performance assessment, under Line of Sight (LoS) and Non-LoS conditions in sub-urban environments with two different satellite configurations, shows significant benefits of the proposed NN algorithm with respect to traditional methods for the ToA estimation.
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In this thesis asynchronous contention resolution diversity slotted ALOHA (ACRDA) is studied and implemented on computer to simulate a typical massive IoT scenario. Chapter 1 gives a general overview of existing multiple access schemes, reporting their fundamental concepts focusing more on Coded Random Access schemes and their characteristics. In Chapter 2 the asynchronous protocol ACRDA is explained in depth analyzing all parts of the scheme. In the third Chapter the results obtained following various simulations of the asynchronous scheme are reported and their performance are analyzed.
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The 2009 pandemic influenza A (H1N1) caused significant morbidity and mortality. Acute lung injury is the hallmark of the disease, but multiple organ system dysfunction can develop and lead to death. Therefore, we sought to investigate whether there was postmortem evidence of H1N1 presence and virus-induced organ injury in autopsy specimens. Five cases in which patients died of influenza A (H1N1) virus infection were studied. The lungs of all patients showed macroscopic and microscopic findings already described for H1N1 (consolidation, edema, hemorrhage, alveolar damage, hyaline membrane, and inflammation), and H1N1 viruses were present in alveolar cells in immunochemical studies. Acute tubular necrosis was present in all cases, but there was no evidence of direct virus-induced kidney injury. Nevertheless, H1N1 viruses were found in the cytoplasm of glomerular macrophages in the kidneys of 4 patients. Therefore, our data provide strong evidence that H1N1 presence is not restricted to the lungs.
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Trabalho Final de Mestrado para obtenção do grau de Mestre em Engenharia de Redes de Comunicação e Multimédia
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The records of the first two Colombian patients with AIDS and paracoccidioidomycosis are presented. Both patients were males and had no known risk factors for HIV although in the past they had worked in the field where they could have been infected with the fungus. They exhibited the juvenile type of disease with multiple organ system involvement and symptoms of short duration. They were deeply immunodepressed as indicated by less than 100 CD4 T lymphocytes per mL; however, serologic tests revealed circulating anti-Paracoccidioides brasiliensis antibodies and in one patient the first diagnostic clue came from such tests. In one case, the mycosis preceded the AIDS diagnosis while in the other, both pathologies were discovered simultaneously. Antimycotic therapy with itraconazole was administered for over 10 months, with an initial dose of 200 mg/day followed by 100 mg/day; marked improvement of the mycotic signs and symptoms was soon noticed an there have been no signs of relapse. The patients´ improvement was also due to the combined retroviral treatment that was instituted. In spite of the rarity of the AIDS-paracoccidioidomycosis association, physicians practicing in endemic areas should consider the presence of the mycosis in immunosuppressed patients, since a prompt diagnosis and institution of combined antimycotic-anti-retroviral treatments would result in patient improvement and survival. It appears possible that the longer survival time of today's AIDS patients would give the quiescent fungus the opportunity to revive, multiply and cause overt disease.
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Inhalation injuries are currently the factor most responsible for mortality in thermally injured patients. Inhalation injuries may occur independently, but generally occur together with skin burn. Smoke inhalation affects all levels of the respiratory system and the extent of the inhalation injury depends on the duration, exposure, amount and toxicity of the fume temperature, concentration and solubility of toxic gases, the occurrence of the accident in a closed space and pre-existing diseases. Smoke inhalation also induces changes in the systemic organs with the need for more fluid for resuscitation. Systemic vasoconstriction, with an elevation in systemic vascular resistance, a fall in myocardial contractility and a great increase in lymphatic flow in soft tissue are the most important changes in systemic organs. On admission of a burn patient there is a high suspicion of inhalation injury when there are signs and symptoms such as hoarseness, strides, dyspnea, carbonaceous sputum, anxiety or disorientation, with or without face burns. The patient with these findings has partial airway obstruction and there is substantial risk complete airway obstruction occurring of secondary to the edema. Patients with suspected inhalation injury should be intubated so as to maintain airway patency and avoid a total obstruction. This group of patients frequently develop respiratory failure with the need for mechanical ventilatory support. Nosocomial infections, sepsis and multiple organ system failure may occur. Late complications of inhalation injury are tracheitis, tracheal stenosis or tracheomalacia and chronic airway disease, which is relatively rare. Early diagnosis of inhalation injury and treatment in a Burn Unit by a group of highly motivated clinicians and a good team of nurses is essential in order to decrease the morbidity and mortality related to inhalation injury.
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A crescente tendencia no acesso móvel tem sido potenciada pela tecnologia IEEE 802.11. Contudo, estas redes têm alcance rádio limitado. Para a extensão da sua cobertura é possível recorrer a redes emalhadas sem fios baseadas na tecnologia IEEE 802.11, com vantagem do ponto de vista do custo e da flexibilidade de instalação, face a soluções cabladas. Redes emalhadas sem fios constituídas por nós com apenas uma interface têm escalabilidade reduzida. A principal razão dessa limitação deve-se ao uso do mecanismo de acesso ao meio partilhado Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) em topologias multi-hop. Especificamente, o CSMA/CA não evita o problema do nó escondido levando ao aumento do número de colisões e correspondente degradação de desempenho com impacto direto no throughput e na latência. Com a redução da tecnologia rádio torna-se viável a utilização de múltiplos rádios por nó, sem com isso aumentar significativamente o custo da solução final de comunicações. A utilização de mais do que um rádio por nó de comuniações permite superar os problemas de desempenho inerentes ás redes formadas por nós com apenas um rádio. O objetivo desta tese, passa por desenvolver uma nova solução para redes emalhadas multi-cana, duar-radio, utilizando para isso novos mecanismos que complementam os mecanismos definidos no IEEE 802.11 para o estabelecimento de um Basic Service Set (BSS). A solução é baseada na solução WiFIX, um protocolo de routing para redes emalhadas de interface única e reutiliza os mecanismos já implementados nas redes IEEE 802.11 para difundir métricas que permitam à rede escalar de forma eficaz minimizando o impacto na performance. A rede multi-hop é formada por nós equipados com duas interfaces, organizados numa topologia hierárquica sobre múltiplas relações Access Point (AP) – Station (STA). Os resultados experimentais obtidos mostram a eficácia e o bom desempenho da solução proposta face à solução WiFIX original.
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A dissertação em apreço resultou da necessidade em otimizar os recursos técnicos, mas sobretudo humanos, afetos às verificações de instrumentos de medição, no âmbito do Controlo Metrológico Legal. Estas verificações, realizadas nos termos do cumprimento das competências outrora atribuídas à Direção de Serviços da Qualidade da então Direção Regional da Economia do Norte, eram operacionalizadas pela Divisão da Qualidade e Licenciamento, na altura dirigida pelo subscritor da presente tese, nomeadamente no que respeita aos ensaios efetuados, em laboratório, a manómetros analógicos. O objetivo principal do trabalho foi alcançado mediante o desenvolvimento de um automatismo, materializado pela construção de um protótipo, cuja aplicação ao comparador de pressão múltiplo, dantes em utilização, permitiria realizar a leitura da indicação de cada manómetro analógico através de técnicas de processamento de imagem, função esta tradicionalmente efetuada manualmente por um operador especializado. As metodologias de comando, controlo e medição desse automatismo foram realizadas através de um algoritmo implementado no software LabVIEW® da National Intruments, particularmente no que respeita ao referido processamento das imagens adquiridas por uma câmara de vídeo USB. A interface com o hardware foi concretizada recorrendo a um módulo de Aquisição de Dados Multifuncional (DAQ) USB-6212, do mesmo fabricante. Para o posicionamento horizontal e vertical da câmara de vídeo USB, recorreu-se a guias lineares acionadas por motores de passo, sendo que estes dispositivos foram igualmente empregues no acionamento do comparador de pressão. Por último, procedeu-se à aquisição digital da leitura do padrão, recorrendo à respetiva virtualização, bem como a uma aplicação desenvolvida neste projeto, designada appMAN, destinada à gestão global do referido automatismo, nomeadamente no que se refere ao cálculo do resultado da medição, erro e incerteza associada, e emissão dos respetivos documentos comprovativos.
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Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e de Computadores
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Dissertação para obtenção do Grau de Mestre em Engenharia Eletrotécnica e Computadores
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RESUMO - O presente estudo situa-se nas áreas gerais da Saúde Pública, dos Sistemas de Saúde e do Acesso à Prestação de Cuidados de Saúde e procura analisar o conteúdo e concretização do Direito de Acesso a Cuidados de Saúde na perspectiva de dois sistemas de saúde paradigmaticamente distintos, um sistema de acesso universal, representado pelo Serviço Nacional de Saúde português e um sistema de saúde de “não universal”, cujo paradigma é o modelo existente nos Estados Unidos da América, onde entidades gestoras de cuidados, Managed Care Organizations, são chamadas a desempenhar um papel central no acesso e prestação de cuidados de saúde. O vasto campo de investigação representado pela problemática do acesso a cuidados de saúde e a necessidade de limitar o trabalho de investigação subjazem à definição de quatro vertentes a analisar: (a) a existência ou não de uma base legal que preveja e regule o exercício do direito de acesso a cuidados de saúde; (b) o conteúdo deste direito no âmbito de cada um dos sistemas em estudo; (c) as condições de concretização do acesso a cuidados de saúde em ambos os sistemas, e, por último (d) a existência de garantias de efectivação do mesmo. Analisados os sistemas em estudo à luz das vertentes apresentadas, concluímos que a existência de um quadro normativo próprio, que explicite o conteúdo e condições de efectivação do direito, apresenta maiores garantias de concretização do exercício do Direito de Acesso a Cuidados de Saúde, entendendo-se que um sistema de acesso dependente da actuação de entidades gestoras de cuidados não beneficia o acesso a cuidados de saúde, nomeadamente por não garantir equidade no momento de procura e necessidade de cuidados. Os dados apresentados foram recolhidos através do recurso a uma metodologia qualitativa. A análise documental foi aplicada na recolha dos dados relativos à evolução e caracterização dos sistemas, bem como às condições de acesso. No âmbito do sistema de saúde de acesso universal, ou seja, o caso português, procedeu-se essencialmente à análise dos normativos aplicáveis. No que se refere ao sistema de saúde norte-americano, na ausência de base legal aplicável, recorreu-se sobretudo à análise de literatura e documentos. A participação no vi Second Biennal Seminar in Law and Bioethics1 e na 30th Annual Health Law Professors Conference2, realizados em Bóston, EUA, em Julho de 2007, permitiram uma melhor percepção da actual situação da prestação de cuidados naquele País, nomeadamente de algumas das reformas em curso, bem como um melhor entendimento das características do sistema prestador norte-americano em si mesmo. 1 Seminário organizado nos dias 30 e 31 de Maio, numa colaboração entre a Escola Nacional de Saúde Pública e o Departamento de Direito da saúde, Bioética e Direitos Humanos da Escola de Saúde Pública da Universidade de Bóston, sob o tema: “Law and ethics in rationing Access to care in a high-cost global economy”. A nossa participação deveu-se a um convite da Prof.ª Paula Lobato de Faria para colaborar na sessão sobre o sistema de saúde português. 2 Reunião realizada em Bóston nos dias 31 de Maio a 2 de Junho, sobretudo a sessão dedicada ao tema “New Models for Reform”, sobre os novos modelos de sistema de saúde em desenvolvimento nos EUA.
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Six esterase isozymes were studied during the development of Anopheles darlingi by using polyacrylamide gel electrophoresis and two different substrates, a-naphthylcelate and a-naphthylpropionate. Esterases 5 and 6'were detected in all developmental stages esterases 1 and 2 were more intensively stained if larvae, while esterases 3 and 4 were better visualized in pupae and adults. Strong differences in intensity of some of the isozymes were observed during the pupal stage.Four out of the six isozymes showed variation in the electrophoretic mobility. Esterase-2 was choosed for genetic studies, because was the best stained isozyme in the gels. Two codominant alleles {Est2*S and Est2*F) code for this polymorphic system, with the Est*S frequency equal to 0.521. Phenotypic distribution is in agreement with hardy-Weinberg expectations.
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Introduction. The Andalusian Public Health System Virtual Library (Biblioteca Virtual del Sistema Sanitario Público de Andalucía, BV-SSPA) was created in June 2006, after being determined by the II Quality Plan in the key process Guarantee the Knowledge Exchange into the Health System which was established by the Strategy IV, Knowledge Management, 2005-2008. It is a government strategy with its own budget and management with the aim of rationalizing the subscriptions into the Andalusian Health System and democratizing the health professional access to qualify scientific information, regardless of the professional workplace. Andalusia is a wide region with more than 8 million inhabitants, more than 90,000 health professionals for 41 hospitals, 1,500 primary healthcare centres, and 12 centres for non-medical attention purposes, and the Virtual Library was created to cover all this Health Services. Before the creation of the BV-SSPA every centre had its own budget and management decisions concerning scientific resources, with the creation of the BV-SSPA both management and budget were centralized. Objectives. With this work we pretend to analyze if the results after these five years have reached the expectations from an economic point of view and determine if really we can offer a benefit to the Andalusian Professional and Society in general. We will demonstrate the following: - The BV-SSPA supposed a cost reduction. It meant cost-effectiveness. - It resulted in Economics of Scale, as we have every year more resources and services investing a minor proportional amount of money. - In terms of Efficiency it implemented more services than the System had before its creation, we a lower budget. Methods. The BV-SSPA was appointed the only intermediary for contracting electronic resources destined to the Andalusian Health System. This had some consequences which should be analyzed: - Hospitals were not allowed to subscribe any resources. - Services offered for the whole System. - A remote access system was created. - Tools to give more visibility to the Public Health System were developed. - Negotiations techniques changed as the BV-SSPA is stronger than individual hospitals. Results. - The amount of 2,431 electronic reviews, 8 data bases and other scientific information resources at the disposal of the Andalusian Health System Professionals and available worldwide requiring only an internet connection. Before the BV-SSPA, 5,267 titles were subscribed by hospital and 2,967 of them were subscribed repeatedly (by two or more hospitals), this represented more than 55%. The rationalization of the subscription investment has been reached. - The establishment of several important scientific services for the whole territory of Andalusia, not only big hospitals. - The use of appropriate tools through a Web 2.0 and Social Media to be acknowledged by most National Health Professionals. Conclusions. It has been demonstrated that the BV-SSPA has become the Central Unit for purchasing, offering librarian services and a reference for users in terms of knowledge management, but from the point of view of business it has also obtained the following results: - Cost-Effectiveness: Its budget for subscriptions is lower than the hospital former one in a 30% and now more electronic resources are available. - Economics of Scale: Near 95,000 health professionals can access this Virtual Library in 2010. Before its creation Professionals for small hospital and Primary Care centres were not able to access to scientific information subscribed by big hospitals. - Efficiency Besides the central electronic purchasing, services were created for the System, without increasing the expenses: - Remote access to all the library resources independent of the user’s location. The BV-SSPA usage increased in a 147% in 2008, when it was installed. - The Document Supply Service implemented in 2009. - The Institutional Repository which contains the whole intellectual, scientific production generated by the Andalusian Public Health Professionals as a result of their healthcare, research or managing activity. - The creation of an application developed by the BV-SSPA to study the Andalusian Health System Scientific Production. - The visibility of the Andalusian Health System reached thanks to the BV-SSPA, through the numerous events in which it participates and organizes such as the 2nd. European National Digital Libraries of Health Conferences and the National Conference of Health Science Information and Documentation held in Cadiz in 2010; and its profile in social media where it can be contacted by citizens and health professionals all over the world. - Negotiation with electronic resource suppliers is much more advantageous as the BV-SSPA is stronger to deal with them thanks to its consolidated budget, its managing independence and its visibility.
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Introduction To guarantee the success of a virtual library it is essential that all users can access all the library resources independently of the user’s location. Achieving this goal in the Andalusian Public Health System has been a particularly difficult task, due to it is made up of 10 research centers and 95.000 health-care professionals. Aims Since the BV-SSPA started three years ago, one of its mayor aims has been to provide remote access to all its resources in this complex scenario, as well as facilitate the access to the virtual library to both professionals and citizens. IP access was guaranteed because health-care professionals could access everything from their workplaces thanks to the intranet, but it was restricted when they were not there. The BV-SSPA solved this problem by installing a federated authentication and authorization system called PAPI and a PAPI rewriting proxy. After three years the BV-SSPA has met a new challenge: adapting its federated access system to Metalib and SFX, specifically the access management module PDS had to be connected with the existing PAPI system. This new challenge came along with the introduction of a new metasearcher and link resolver. Material and Methods Initially there were three independent systems: • A Metalib and SFX PDS module, • A federated authentication and authorization system: PAPI. • A PAPI Rewriting Proxy. The chosen solution went through the reutilization of the existing software. To achieve this goal, a PHP connector between these applications was developed and several modules in the PDS configuration were modified. On the other hand, providing a simplified access to Metalib has been solved using Xerxes and integrating it in a Drupal website. Results Thanks to this connector the BV-SSPA was able to get all its users remotely accessing its new metasearcher without changing the way they used to validate, or without having to remember a new username and password. Futhermore, thanks to Xerxes, it is possible to use Metalib from a simple interface and without having to leave the BV-SSPA website to go its native interface.
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This is the annual performance report for the Individuals with Disabilities Education Act, Part C, which was submitted on February 2, 2010 to the United States Department of Education, Office of Special Education Programs. The report provides data on the State's Early ACCESS system and the 10 Regional Grantees' performance in 14 national indicators.