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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
601

Powering of endoscopic cutting tools for minimally invasive procedures

Chen, Kehui 11 June 2013 (has links)
" Sample cutting is an important minimally invasive medical procedure. Currently there are several types of medical devices used to cut a distal biological sample, for example, a video endoscope and TurboHawk Plaque Excision Systems. Directional Atherectomy (DA) with the TurboHawk Plaque Excision Systems is a catheter-based, minimally invasive treatment method for peripheral arterial disease (PAD). During a procedure, a catheter is directed toward an area of plaque buildup to remove the plaque from the body, restoring blood flow (Covidien, 2013). Endoscopy is an important procedure used in the medical field to study and diagnose different parts of a body without the need to undergo a major surgery. The major devices are a video endoscope with a flexible or rigid insertion tube and endoscopic therapy devices. Arrays of the devices, through the instrument channel in the insertion tube of endoscopes, to perform a variety of functions are offered. The biological sample cut is one of the important endoscopic therapies. Both of Directional Atherectomy and endoscopy procedures require a power transmission from the proximal tip of device to the distal end, where the cutter is located, for cutting a sample. However, the working length is up to meters, and the diameter of the devices is in millimeter scale in the minimally invasive surgery. Thus enough power transmitting to the distal end of the device for the biological sample cutting is crucial. This research presents the effort toward the investigation of the potential power mechanisms from the proximal tip to the cutter at the distal end of the device for rapid rotational cutting motion to improve the cutting efficiency and accuracy. In this thesis, the potential powering mechanisms including fluid, electrical, and torque coils are investigated. Since the transmission power is used for a rotational cutting action, and the cutting geometry has influence on the cutting power, thus this research also focuses on the analysis of the cutting geometry for the rotational sample cutting. The Hertz contact theory and von Mises yield criterion are used to find the influence of tool geometry on the material removing process, as well as Abaqus, a commercial FEM software, is used for the finite element analysis. Fiber-reinforced composite structures are the main characteristic of the representative biological sample, and their mechanical behavior is strongly influenced by the concentration and structural arrangement of constitute such as collagen and elastin. Researches show that the biological sample, for example, a soft biological sample, has hyperelastic properties and behave anisotropically, and there are a few publications about the plastic properties and cutting mechanics. Thus a linear elastic and linear plastic material model is defined for the finite element analysis of material removal. The analytical results and finite element results both show that as the tool rake angle increases or the tool angle decreases, the magnitude of cutting force decreases. A preliminary representative sample cutting experiment was conducted, and standard cutters with different cutting geometries were tested in order to find the characteristic of the biological sample cutting and the influence of tool geometry on the required cutting power. The experiments reveal the same conclusions as the analytical and finite element results. "
602

Suscetibilidade de comunidades campestres à invasão por plantas exóticas invasoras

Bolioli, Anaclara Guido January 2016 (has links)
O objetivo geral desta tese foi examinar diferentes 1 questões associadas ao 2 processo de invasão de plantas para investigar os mecanismos, impactos e 3 medidas de recuperação da comunidade vegetal, abordando diferentes estratégias 4 metodológicas que incluem estudos observacionais, experimentos de remoção e 5 uma revisão metodológica. Os resultados do Capítulo 1 mostraram como as 6 relações entre condições climáticas e estrutura da paisagem podem determinar o 7 grau de invasão de plantas na escala regional. Observou-se que os padrões de 8 invasão dos campos sulinos estão principalmente relacionados com maior 9 densidade de estradas, menor cobertura de campo nativo e com o aumento do 10 déficit hídrico. Além disso, constatou-se que a gramínea Eragrostis plana é a 11 planta invasora mais abundante dos campos sulinos. No entanto, os resultados do 12 experimento do Capítulo 2 mostraram que sua invasão não pode ser explicada 13 pela riqueza de espécies ou composição dos grupos funcionais de plantas da 14 comunidade residente. A invasão de E. plana foi principalmente associada ao 15 distúrbio causado pela remoção de biomassa na comunidade. Neste sentido, as 16 comunidades campestres poderiam ser resistentes à invasão de E. plana até que 17 algum distúrbio aumente sua vulnerabilidade. Por outro lado, através da 18 comparação entre comunidades invadidas, removidas e não-invadidas, os 19 resultados do experimento do Capítulo 3 contribuíram no entendimento do 20 impacto real da invasão de E. plana, em termos de redução da riqueza e cobertura 21 de plantas nativas na comunidade. No entanto, embora os métodos de remoção 22 utilizados reduziram a cobertura da invasora, não foram suficientes para conseguir 23 sua erradicação local. Além disso, após três anos de remoção de E. plana, as comunidades se tornaram distintas às invadidas mas não 1 foram semelhantes às 2 comunidades não invadias, o qual poderia indicar que outras medidas de 3 restauração são ainda necessárias. Embora os experimentos de remoção de 4 espécies sejam úteis para investigar questões associadas ao processo de 5 invasão, existem limitações importantes a considerar, como foi evidenciado nos 6 Capítulos 2 e 3. Neste sentido, oferecemos a revisão bibliográfica sistemática do 7 Capítulo 4, onde se discute o potencial dos métodos de remoção utilizados para 8 estudar a resistência e a recuperação da comunidade à invasão, apontando 9 algumas limitações. Como resultado, o Capítulo 4 mostrou que a maioria dos 10 trabalhos não propõem controles adequados nos experimentos, o que pode dar 11 lugar a confundimento de efeitos. Desta forma, foram desenvolvidas algumas 12 sugestões para serem consideradas nos experimentos de remoção de espécies, 13 com o objetivo de continuar avançando nesta temática. As informações geradas 14 nesta tese podem contribuir para o entendimento do processo de invasão de 15 plantas nos ecossistemas campestres, com vistas ao manejo, à conservação e à 16 restauração das comunidades invadidas, adquirindo um senso crítico no 17 planejamento de desenhos experimentas. / The general aim of this thesis was to investigate different 1 issues associated 2 with plant invasion process to understand the mechanisms, impacts and 3 community recovery, by employing different methodological strategies such as 4 observational studies, removal experiments and a literature review. The results 5 from Chapter 1 showed how the interactions between climate and landscape 6 structure can determine the level of invasion of South Brazilian grasslands, 7 highlighting that invasion is mainly related to high road density, less native 8 grassland cover and increased aridity. Furthermore, it was confirmed that 9 Eragrostis plana is the most important invasive species in the South Brazilian 10 grasslands. However, the results from the experiment of Chapter 2 showed that its 11 invasion could not be explained by the species richness or functional group 12 composition in the community. Eragrostis plana invasion was associated with the 13 disturbance effect caused by the amount of removed biomass. Thus, grassland 14 communities may be resistant to E. plana invasion until some disturbance 15 increases their vulnerability. Moreover, by comparing invaded, removed and non16 invaded communities, the experimental results of Chapter 3 highlighted the 17 ecological impact of E. plana invasion, in terms of richness reduction and native 18 species cover. However, although removals methods reduced the cover of the 19 invasive species, they were not enough to locally extinct it. Moreover, after three 20 years of the invasive removal, communities became different from invaded ones 21 but not resembling non-invaded references, which suggest that community 22 recovery may require restoration strategies. Although removal experiments have 23 been useful to investigate certain issues associated with invasion process, there are important limitations to consider, as was shown in Chapter 1 2 and 3. For this 2 purpose, our systematic review presented in Chapter 4 discussed the potential of 3 removal methods for assessing community resistance and recovery from invasion. 4 There, we showed that most of the studies did not use adequate controls in 5 removal experiments, which can lead to confounding effects. Thus, we developed 6 suggestions to be considered in experimental designs to advance the 7 methodological technique of removals. The information generated in this thesis can 8 contribute to the understanding of plant invasion process in South Brazilian 9 grasslands and, consequently, aid to management, conservation and restoration of 10 invaded communities by acquiring a critical sense in experimental designs.
603

Att närvara eller inte närvara : närståendes erfarenheter av närvaro på sjukhus vid akut omhändertagande

Ankarling, Eva, Heimonen, Marja-Leena January 2010 (has links)
Frågan om närståendes närvaro i akutrummet har varit aktuell sedan 80-talet. Denna fråga aktualiserades i samband med ett par händelser på Foote Hospital i Michigan, USA. Trots att det snart gått tre decennier är forskningen näst intill obefintlig inom området. Ibland har livräddande åtgärder påbörjats utanför sjukhuset och det kan ha varit den närstående som påbörjat återupplivningen. Trots detta blir närstående oftast hänvisade till ett angränsande rum när patienten anländer till sjukhuset. Det finns internationella riktlinjer för Family Presence During Resuscitation (FPDR) men dessa används inte generellt på sjukhuset. Detta innebär osäkerhet hos vårdpersonalen när dessa situationer uppkommer. Bland personalen råder det delade meningar om det är till fördel eller nackdel för närstående att vara närvarande på akutrummet. Av denna anledning ville vi belysa de närståendes perspektiv i samband med akut omhändertagande. Vad är mest fördelaktigt för dem för att de ska kunna bearbeta situationen och gå vidare i livet. Vårt syfte var att beskriva befintlig forskning över närståendes erfarenheter av närvaro på sjukhus vid akut omhändertagande. Som metod använde vi oss av en litteraturstudie. I resultatet framkom att de närstående som fått möjligheten att närvara på akutrummet vid akut omhändertagande med stöd av personal var nöjda med beslutet att ha närvarit. De ansåg också att det var deras rättighet och skyldighet gentemot patienten. Den befarade oron att närstående skulle störa och kritiskt granska personalen i sitt arbete visade sig vara obefogad. Närstående upplevde istället att personalen hade gjort allt som stod i deras makt för att rädda patientens liv. De få närstående som närvarit utan stöd hade däremot en annan upplevelse av händelsen och ångrade att de hade närvarit. / Program: Fristående kurs
604

The effects of tidal restriction, Phragmites australis invasion, and precipitation change on salt marsh greenhouse gas emissions

Emery, Hollie 11 December 2018 (has links)
Salt marshes provide a range of ecosystem services and yet are subjected to anthropogenic impacts that alter the biogeochemical processes underlying these services. In particular, human activities may modify salt marsh greenhouse gas (carbon dioxide, methane, nitrous oxide) emissions by changing plant and microbial communities, hydrological regime, and sediment chemistry. Quantifying the effects of human impacts on greenhouse gas emissions is important for complete carbon budgets, and for effective management of salt marshes and the ecosystem services they provide. In Chapters 1 and 2, I investigate the effects of hydrology and plant invasion on greenhouse gas emissions. First, I show how the restriction and restoration history of four salt marshes influence methane flux in unpredictable ways. Despite comparable salinity, methane emissions from one partially restored marsh were 25 times higher than unimpacted reference sites 13+ years after restoration, but emissions from other restored sites were equal or lower. Next, I show that greenhouse gas emissions associated with invasive Phragmites australis are not different from those associated with native Spartina alterniflora. These Chapters demonstrate the de-coupling of greenhouse gas emissions, and carbon sequestration more generally, from ecosystem degradation and restoration. In Chapters 3 and 4, I quantify greenhouse gas fluxes and microbial community structure under precipitation changes that may occur with global climate change. In a field experiment, doubled rainfall and drought had significant transient impacts on porewater salinity following storms, and on the community structure of plants (doubled rainfall) or microbes (drought), yet greenhouse gas fluxes and other biogeochemical processes were not affected. The absence of biogeochemical change indicates functional redundancy and resistance or resilience exist in the microbial community, suggesting marshes may continue providing services as precipitation changes. In a lab experiment, rewetting intact cores to simulate tidal inundation or rainstorms produced a nitrous oxide pulse 10-20x the baseline flux rates, without changing the microbial community. A model of rewetting event frequency suggests that pulsed emissions may be responsible for the majority of marsh nitrous oxide emission. Precipitation change may increase coastal nitrous oxide emission if it causes more or stronger storms, and thus more rewetting events.
605

Ecological politics and practices in introduced species management

Crowley, Sarah Louise January 2017 (has links)
The surveillance and control of introduced species has become an increasingly important, yet often controversial, form of environmental management. I investigate why and how introduced species management is initiated; whether, why and how it is contested; and what relations and outcomes emerge ‘in practice’. I examine how introduced species management is being done in the United Kingdom through detailed social scientific analyses of the processes, practices, and disputes involved in a series of management case studies. First, I demonstrate how some established approaches to the design and delivery of management initiatives can render them conflict-prone, ineffective and potentially unjust. Then, examining a disputesurrounding a state-initiated eradication of monk parakeets (Myiopsitta monachus), I show why and how ‘parakeet protectors’ opposed the initiative. I identify the significance of divergent evaluations of the risks posed by introduced wildlife; personal and community attachments between people and parakeets; and campaigners’ dissatisfaction with central government’s approach to the issue. By following the story of an unauthorised (re)introduction of Eurasian beavers (Castor fiber) to England, I show how adiverse collective has, at least temporarily, been united and empowered by a shared understanding of beavers as ‘belonging’ in the UK. I consider how nonhuman citizenship is socio-politically negotiated, and how the beavers have become enrolled in a ‘wild experiment’. Finally, through a multi- sited study of grey squirrel (Sciuruscarolinensis) control initiatives, I find important variations in management practitioners’ approaches to killing squirrels, and identify several ‘modes of killing’ that comprise different primary motivations, moral principles, ultimate aims, and practical methods. I identify multiple ways in which people respond and relate to introduced wildlife, and demonstrate how this multiplicity produces both socio-political tensions and accords. Furthermore, throughout this thesis I make a series of propositions for re-configuring the management of introduced species in ways that explicitly incorporate inclusive, constructive, and context-appropriate socio-political deliberations into its design and implementation.
606

The comparative demography of invasive plants

Jelbert, K. January 2018 (has links)
Biodiversity, ecosystems, industry and human health are threatened by invasive plant species. The costs of mitigating damages run into billions of pounds per annum. Fundamental to the control of invasive plant species is an ability to predict which species will become invasive. Yet identification of predictive differences between invasive and non-invasive species has proven difficult to pinpoint. In this thesis I identify several weaknesses within published literature, and using field experiments and meta-analyses we address these to find consistent predictors of invasiveness amongst plants. Specifically, I recognize that predictors of invasiveness can be identified by studying plant species in the native range because species may undergo phenotypic and demographic changes following naturalization (Chapters 2 – 5). I also recognize the importance of comparing globally invasive and non-invasive species, and the importance of accounting for phylogenetic relationships so as not to inflate or conceal differences (Chapters 2 – 4). Finally, I investigate whether particular analyses are more appropriate for investigating life history and demographic differences (Chapter 5). This thesis comprises an introductory chapter (Chapter 1), four data chapters (Chapters 2 - 5) and a general discussion (Chapter 6). Chapters 2 and 3 compare life history traits of plant species known to be invasive elsewhere, with their exported but non-invasive sympatric relatives in the native range. Chapter 4 utilizes Population Projection Matrices held within the COMPADRE Plant Matrix Database, to compare demographic projections of stable and transient dynamics of invasive and non-invasive plants; and Chapter 5 compares ten metrics, derived from Population Projection Matrices, of seven invasive species between the native and invaded range to determine if there are demographic or life history differences that facilitate invasion, and to identify those analyses that are most likely to reveal such differences. I find reproductive capacity to be a predictor of invasiveness, and that analyses of transient dynamics are more likely than analyses of projected stable dynamics to reveal demographic or life history differences between invasive and non-invasive species or populations of plants. I discuss these findings in the context of invasive risk assessment protocols and highlight future research opportunities.
607

Bushmeat hunting, retaliatory killing, habitat degradation and exotic species as threats to Fosa (Cryptoprocta ferox) conservation

Merson, Samuel David January 2017 (has links)
Large carnivores are in global decline, chiefly resultant of anthropogenic persecution, habitat reduction and disturbance. Fosas represent Madagascar's largest carnivore, occupying much of the island's forest. This thesis examines the threats of bushmeat hunting, retaliatory killing, habitat alteration and exotic species using sociological and remote-sensing methodologies. Habitat degradation was not associated with reduced fosa occupancy, indicating some resilience within large, contiguous forests. However, competition with exotic species (cats, dogs) was associated with reduced fosa occupancy and potential temporal shifts towards greater nocturnality. Poor households were more likely to consume protected species. Conversely, wealthier households consumed more fish and eel. This pattern is reflected in Malagasy reported taste preference to consume domesticated animals and certain legally hunted wild species. Protected areas were not associated with reduced protected species consumption. Fosas' predation was a major cause of rural poultry mortality. Predation was more likely to occur in deciduous forests, in the dry season, during the evening. Fosa predation, and lower education was associated with negative Malagasy attitudes. Wealthy households, and those that had experienced fosa predation were most likely to retaliatory kill a fosa. Strategies to safeguard fosas' long-term persistence should seek to improve domestic husbandry, build robust coops with the use of watchdogs, promote education, and reduce exotic species abundance.
608

Estrutura da comunidade macrobentônica intertidal em praias invadidas pelo bivalve Isognomon bicolor (C.B. Adams, 1845) (Mollusca: Pteriidae) no Nordeste brasileiro

Queiroz, Romilda Narciza Mendonça de 27 February 2015 (has links)
Submitted by Jean Medeiros (jeanletras@uepb.edu.br) on 2016-02-29T13:38:50Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) / Approved for entry into archive by Secta BC (secta.csu.bc@uepb.edu.br) on 2016-04-12T17:18:00Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) / Made available in DSpace on 2016-04-12T17:18:00Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Romilda Narciza Mendonça de Queiroz.pdf: 1184612 bytes, checksum: c662ab49132bf777a48debcd6101143e (MD5) Previous issue date: 2015-02-27 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The invasive bivalve Isognomon bicolor is native to the Caribbean Sea and today is among the key invasive marine species in coastal habitats of the Brazilian coast. Before this problem, this study aims to characterize the structure of the macrobenthic community on beaches in the presence Isognomon bicolor and assess whether their presence may be influencing or being influenced by the distribution and density of native species. The study was conducted in the rocky beaches of Carapibus and Jacumã, Paraíba state (NE Brazil). On Carapibus beach were recorded the highest densities of the invasive I. bicolor (300 ind/m 2 ) and native benthic species (11,372.22 ind/m²). Density of I. bicolor was highest in the mesolittoral zone (347.68 ind/m²) in the rainy season (158.56 ind/m²). However, there was no difference in benthic communities of these beaches between the dry and rainy periods (p = 0.054), but beaches (p = 0.001) and mesolittoral zones (p = 0.005) were significantly different. In characterizing the distribution and zoning of the benthic community, it was observed that in the upper mesolittoral zone these two beaches, the dominant species was the bivalve Brachidontes exustus and the microgastropod Echinolittorina lineolata, and the barnacle Chthamalus sp. In the lower mesolitoral zone, B. exustus, Chthamalus sp., and I. bicolor were the main differentiating factors of the observed zonation. It was also a positive correlation between the density of I. bicolor and some native species. With the results obtained, it can be concluded that certain benthic macroinvetebrates, structural characteristics and benthic cover of the studied beaches are influencing the density and distribution of I. bicolor. / A invasão por espécies exóticas tem causado um grande impacto sobre os ecossistemas, além de prejuízos econômicos, sociais e à saúde humana. Espécie exótica invasora é aquela que foi introduzida a partir de outro ambiente, se estabeleceu, e constitui uma ameaça a biodiversidade nativa, aos recursos naturais ou a saúde humana. O bivalve Isognomon bicolor é uma espécie originária do Caribe e desde seu primeiro registro em 1994, esta espécie tem se expandido e hoje está entre as principais espécies marinhas invasoras que tem causado impactos nas comunidades entremarés na costa brasileira. Mudanças no padrão de distribuição, na disponibilidade de alimento e no tamanho ou estrutura dos substratos e refúgios tem sido ocasionadas pelo I. bicolor. Provavelmente I. bicolor foi introduzido de maneira involuntária na costa do Rio de Janeiro (Sudeste do Brasil) via incrustações em plataformas de petróleo ou nos cascos de navios, e atualmente ele tem sido registrado do litoral do Nordeste até o Sul do país. Para que uma invasão seja bem sucedida, o invasor deve possuir estratégias eficientes para a ocupação do ambiente e tolerância aos fatores abióticos. No caso do I. bicolor, sabe-se que a influência da hidrodinâmica local, temperatura, estrutura do substrato e associação com espécies nativas podem favorecer o estabelecimento deste invasor. Apesar disso, o conhecimento sobre a ecologia e distribuição espaço-temporal do I. bicolor ainda é escasso, principalmente para a região Nordeste do país, que possui características e condições ambientais diferentes dos locais onde ele tem sido estudado. Há muitos questionamentos que ainda precisam ser esclarecidos acerca dos impactos causados por esta espécie e dos fatores que permitem sua expansão relativamente rápida pelos ambientes costeiros no Brasil. Neste contexto, este estudo tem como objetivo principal caracterizar a estrutura da comunidade macrobentônica em praias com a presença do bivalve invasor Isognomon bicolor e avaliar se sua presença pode estar influenciando ou sendo influenciada pela distribuição e densidade das espécies nativas. Os dados fornecidos poderão nortear a elaboração de medidas de controle desta espécie invasora.
609

Rastreamento não invasivo para diabetes tipo 2 / The type 2 diabetes screening

Ribeiro, Áurea Celeste da Costa 07 August 2015 (has links)
Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-12T18:38:51Z No. of bitstreams: 1 AureaRibeiro.pdf: 891843 bytes, checksum: d5cc513c7bcc492d7dce1b74bc679b9f (MD5) / Made available in DSpace on 2017-06-12T18:38:51Z (GMT). No. of bitstreams: 1 AureaRibeiro.pdf: 891843 bytes, checksum: d5cc513c7bcc492d7dce1b74bc679b9f (MD5) Previous issue date: 2015-08-07 / The type 2 diabetes screening has become an important resource due to the increase in this disease in the modern world, it is estimated that there are 385 millions of diabetics in worldwide and that 46% of this number are unaware of their condition. This complicates their treatment and many patients at diagnosis already present any complications due to lack this in the early stages of diabetes. Researchers have discussed the e ectiveness of type 2 diabetes screening, for example: The Brazil made a screening in 2001 and it was considered an unnecessary cost of almost 40 million. The tracking of type 2 diabetes has become an important resource due to the large increase in this disease in the modern world, it is estimated that there are 385 million diabetics worldwide and that 46% of this number are unaware of their condition. This complicates their treatment and many patients the diagnosis already present any complications due to lack this in the early stages of diabetes. There were discussions about the effectiveness of screening for type 2 diabetes, in Brazil for example, the last scan was considered unnecessary cost of almost 40 million. Simplest and most effective methods of screening are studied, such as the US and China that use some non-invasive methods to calculate the risk of diabetes. This study proposes a non-invasive screening method based on eficient coding technique to extract features of a Brazilian database (HIPERDIA) to form a new concise representation thereof, with the decrease of redundancy. The main hypothesis worked at this stage was the pursuit of independent components, which possibly it were present at the formation of the disease. Thus, the original data were decomposed by the independent component analysis method. In the classification stage to ensure discrimination between classes was used the method of support vector machines for one class. Tests were done to check the performance of the classifier after the feature extraction phase, and showed that it increases the performance of support vector machine to one class in making the discrimination between diabetics and non-diabetics. Results were reached (100%) with the combination of certain characteristics, and the method shows promise in obtaining a non invasive type 2 diabetes screening. Other tests were done to determine the influence of each non invasive marker in the final result and the generality of the method using other databases, as t of the Pima Indians and African Americans data sets. Then, reducing the number of features used to train the method and testing whether all possible combinations among the remaining, removing one by one, a total of 12,910 possibilities. It was observed the characteristics or markers that most affected the final outcome were age and characteristics related to body fat. Testing the generality of the method in other databases found that the method works best with balanced data set. / O rastreamento do diabetes tipo 2 tornou-se um recurso importante devido ao grande aumento desta doença no mundo moderno, estima-se que haja 385 milhões de diabéticos no mundo e que 46% deste número desconhece sua condição. Isto dificulta seu tratamento e muitos pacientes no diagnóstico já apresentam alguma complicação devido a falta deste nos estágios iniciais da diabetes. Haviam discussões sobre a efetividade do rastreamento para diabetes tipo 2, no Brasil por exemplo, o último rastreamento teve um custo considerado desnecessário, de quase 40 milhões de reais. Métodos mais simples e eficazes de rastreio são estudados, como nos EUA e China que utilizam alguns métodos não invasivos para calcular o risco de diabetes. Este estudo propõe um método de rastreamento não invasivo baseado na técnica de codificação e ciente para extrair características de uma base de dados brasileira(HIPERDIA) para formar uma nova representação concisa destes, com a diminuição de redundância. A principal hipótese trabalhada nesta fase foi a busca das componentes independentes, que possivelmente estiveram presentes na formação da doença. Desta forma, os dados originais foram decompostos pelo método de análise de componentes independentes. Na fase de classificação para assegurar a discriminação entre as classes utilizou-se o método de maquinas de vetores de suporte para uma classe. Testes foram feitos para verificar o desempenho do classificador após à fase de extração de características, e mostraram que ela aumenta o desempenho da máquina de vetor de suporte para uma classe em fazer a discriminação entre diabéticos e não diabéticos. Alcançou-se resultados de (100%)com a combinação de certas características, e o método demonstra a promessa em obter-se um rastreamento de diabetes não invasivo confiável. Outros testes foram feitos para verificar a influência de cada marcador não invasivo no resultado final e a generalidade do método utilizando outras bases de dados, como a base de índios Pima e de americanos de origem africana. Diminuindo o número de características utilizadas para treinar o método e testando-se todas as possibilidades de combinações entre as restantes, retirando-se uma a uma, com um total de 12.910 possibilidades. Observou-se as características que mais afetavam no resultado final foram idade e as características relacionadas com a gordura corporal. Testando-se a generalidade do método em outras bases de dados verificou-se que o método trabalha melhor com bases balanceadas.
610

Aplicação da inspeção não intrusiva em equipamentos do sistema de dessulfurização de gás natural da plataforma de Pampo

Sampaio, Marcus Vinicius Cruz January 2009 (has links)
Este trabalho apresenta os resultados da aplicação da metodologia de inspeção não intrusiva (INI) em equipamentos do sistema de dessulfurização de gás numa plataforma petrolífera, com o auxílio da inspeção baseada em risco utilizando a norma API RP 581. A inspeção não intrusiva é aplicada tendo como fundamentos as guias de inspeção, como a DNV-RP-G103, que reúne informações de como executar e justificar o seu uso, a fim de garantir a segurança das instalações, eliminando a necessidade de uma parada do equipamento para a realização da inspeção. Contudo nem todos os equipamentos puderam ser inspecionados por esta metodologia, devido a limitações operacionais e/ou construtivas. O trabalho conclui que a inspeção não intrusiva pode ser aplicada à inspeção de equipamentos sem prejuízo ao mapa de risco do equipamento ou da unidade, e naqueles onde não é possível à utilização somente da metodologia, a mesma poderá ser aplicada em conjunto com a inspeção convencional fornecendo informações importantes sobre o estado do equipamento, melhorando assim a confiabilidade do planejamento da parada de manutenção e uma redução dos custos envolvidos. / This paper presents the results of applying the methodology of non-intrusive inspection (INI) in electrical system flue gas desulphurization an oil rig, with the help of riskbased inspection using the API RP 581. The non-intrusive inspection is implemented with the guides as the foundations of inspection, such as DNV-RP-G103, which gathers information on how to make and justify its use, to ensure the safety of installations, eliminating the need for a parade equipment to perform the inspection. However not all equipment could be inspected by this method, due to operational limitations and / or constructive. The paper concludes that the non-intrusive inspection can be applied to inspection of equipment subject to the risk map of the equipment or unit, and those where it is not possible to use only the methodology, it may be applied along with conventional inspection providing important information on the status of the equipment, thereby improving the reliability of planning maintenance shutdown and lower costs.

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