Predição em modelos de tempo de falha acelerado com efeito aleatório para avaliação de riscos de falha em poços petrolíferos

We considered prediction techniques based on models of accelerated failure time with random e ects for correlated survival data. Besides the bayesian approach through empirical Bayes estimator, we also discussed about the use of a classical predictor, the Empirical Best Linear Unbiased Predictor (EBLUP). In order to illustrate the use of these predictors, we considered applications on a real data set coming from the oil industry. More speci - cally, the data set involves the mean time between failure of petroleum-well equipments of the Bacia Potiguar. The goal of this study is to predict the risk/probability of failure in order to help a preventive maintenance program. The results show that both methods are suitable to predict future failures, providing good decisions in relation to employment and economy of resources for preventive maintenance.

Modelo de tempo de falha acelerado com fração de cura : uma abordagem unificada

In this work we study the accelerated failure-time generalized Gamma regression models with a unified approach. The models attempt to estimate simultaneously the effects of covariates on the acceleration/deceleration of the timing of a given event and the surviving fraction. The method is implemented in the free statistical software R. Finally the model is applied to a real dataset referring to the time until the return of the disease in patients diagnosed with breast cancer

Função Afifim: Teoria e aplicações

In this work we present a proposal to contribute to the teaching and learning of affine function in the first year of high school having as prerequisite mathematical knowledge of basic education. The proposal focuses on some properties, special cases and applications of affine functions in order to show the importance of the demonstrations while awaken student interest by showing how this function is important to solve everyday problems

PEWS-RT, um sistema de tempo de execução para a linguagem PEWS

Web services are loosely coupled applications that use XML documents as a way of integrating distinct systems on the internet. Such documents are used by in standards such as SOAP, WSDL and UDDI which establish, respectively, integrated patterns for the representation of messages, description, and publication of services, thus facilitating the interoperability between heterogeneous systems. Often one single service does not meet the users needs, therefore new systems can be designed from the composition of two or more services. This which is the design goal behind the of the Service Oriented Architecture. Parallel to this scenario, we have the PEWS (Predicate Path-Expressions for Web Services) language, which speci es behavioural speci cations of composite web service interfaces.. The development of the PEWS language is divided into two parts: front-end and back-end. From a PEWS program, the front-end performs the lexical analysis, syntactic and semantic compositions and nally generate XML code. The function of the back-end is to execute the composition PEWS. This master's dissertation work aims to: (i) reformulate the proposed architecture for the runtime system of the language, (ii) Implement the back-end for PEWS by using .NET Framework tools to execute PEWS programs using the Windows Work ow Foundation

O carnaval de Natal/RN: espaço dos "índios" no tempo de folia

A cidade de Natal/RN apresenta-se como palco para múltiplas manifestações culturais, entre as quais se encontram as tribos de índios carnavalescas. O presente estudo procurará compreender a produção do carnaval destas agremiações enquanto uma manifestação de lazer e trabalho. Pautado numa visão pluralista, percebemos que os vários usos do espaço implicam em territorialidades que envolvem as dimensões política, econômica e simbólica, intermediadas pela cultura. Sob a análise proposta, pretendemos desvendar as dinâmicas espaciais e os vários agentes sociais que engendram relações de poder, trabalho e sociabilidades, mostrando neste mundo carnavalesco seus aspectos culturais e suas práticas sociais, guardando, em seu cerne, o caráter popular e ordinário do cotidiano. A pesquisa mostra que, para além da racionalidade hegemônica, existem outras racionalidades, manifestadas em microterritorialidades, que acionam mecanismos e táticas cotidianas, valorizando-se o fenômeno do estar-junto, existentes no interior dos centros urbanos, nos bairros e nas ruas