26 resultados para Optical Reference Frame
Resumo:
Dissertation to obtain the degree of Master in Electrical and Computer Engineering
Resumo:
The Pliensbachian/Toarcian boundary (Lower Jurassic) is well represented in the Lusitanian Basin (Portugal), mainly in the Peniche area, recorded by a marl/limestone series. Calcareous nannofossil assemblages are described herein, with the aim to contribute to the Toarcian GSSP definition. Marly samples were collected 3 m below and 7 m above this boundary and analysed for calcareous nannofossils. The main nannofossils observed were Biscutum finchii, B. grande, Calcivascularis jansae, Crepidolithus crassus, C. granulatus, C. impontus, Lotharingius hauffii, L. sigillatus, L. aff. L. velatus, Schizosphaerella spp. and Tubirhabdus patulus. This assemblage indicates that the Pliensbachian/Toarcian boundary in Peniche lies in the upper part of the NJ5b Subzone. Schizosphaerella and Lotharingius dominate the assemblage. The abundant occurrence of C. jansae and the common occurrence of B. grande indicate a strong Tethyan influence.
Resumo:
Dissertação apresentada para a obtenção do Grau de Doutor em Informática
Resumo:
Dissertation presented at Faculdade de Ciências e Tecnologia of Universidade Nova de Lisboa to obtain the Master degree in Electrical Engineering and Computer Science
Resumo:
RESUMO - A preocupação com os conhecimentos, atitudes, crenças e práticas, no que concerne à utilização de radiações ionizantes para fins de diagnóstico, e a sensibilização de todos os agentes envolvidos, médicos, técnicos, físicos, utentes e responsáveis pela Saúde Publica, relativamente aos níveis de radiação emitida nos exames de Tomografia Computorizada (TC), assume particular importância no domínio da Saúde Pública, na medida em que é necessário influenciar o desenvolvimento de práticas que promovam, auditem e garantam a prestação do controlo da qualidade radiológica e dosimétrica nos serviços de Radiologia a nível Nacional. Para tal, e no âmbito da publicação de estudos já realizados ao nível da União Europeia, ―Orientações Europeias dos Critérios de Qualidade para a Tomografia Computorizada (1999) ‖, é proposto estabelecer orientações na realização de estudos que permitam, numa primeira fase, estabelecer a comparação com os resultados obtidos pelos mecanismos de Controlo da Qualidade (CQ), analisar e proceder aos ajustes (se necessário) e, numa segunda fase, implementar uma moldura sistemática de avaliação periódica dos níveis de dose de radiação por exame TC e que permita a monitorização dos dados. Nesse sentido, propõe-se a realização de um Estudo Nacional que envolva a rede hospitalar pública, privada e universitária, partindo da metodologia utilizada em estudos prévios noutros países da Europa, como seja, selecção do equipamento de TC existente na Instituição Hospitalar, onde serão reunidas informações através do preenchimento de questionários relativos ao equipamento a utilizar. Serão recolhidos dados relativos ao utente, ao equipamento e parâmetros de aquisição de imagem, que permitam identificar os níveis de referência de diagnóstico (NRD) em TC, na realidade Portuguesa. Foi efectuado um estudo piloto numa instituição EPE e os valores obtidos não são significativos, nem podem assumir valor preditivo dado o reduzido tamanho da amostra. Apesar disso, sugerem a existência de parâmetros que podem ser alterados e com isso podem fazer variar a dose de radiação utilizada. ENSP/UNL Maria de Fátima Vaz de Carvalho 5 Espera-se obter com este estudo, como foi referido, a base do estabelecimento dos NRD em TC em Portugal. ----------------- ABSTRACT - The purpose of this study, in an empirical point of view, emerges from concern with the knowledge, attitudes, beliefs and practices regarding the use of ionizing radiation for diagnostic purposes and awareness of all actors involved, medical physical, technical, and responsible public health for the development of practices that promote, audited and ensure the provision of radiological quality control and dosing in radiology service at national level. In view of the complexity and characteristics involved in relation to ionizing radiation, all assume their part in protecting the physical integrity of each user and a global perspective, to ensure the safeguarding of public health, while global and globalizing factor. To this end, and in the context of the publication of studies already carried out at European Union level, "European guidelines for quality criteria for computed tomography", it is proposed to establish guidelines in conducting studies to initially establish the comparison with the results obtained by QC and make adjustments if necessary, and subsequently implement a systematic periodic assessment frame that allows monitoring of data. Accordingly, it is proposed to conduct a national study involving the public network, private and University hospitals, that extends from the methodology used in previous studies in other countries of Europe, as is, selection of equipment of existing CT in Hospital Institution, where information will be gathered by filling out questionnaires concerning the equipment to be used. Data will be collected for the wearer, equipment and parameters of image acquisition, identifying diagnostic reference levels (NRD) in CT in Portuguese fact. A pilot study was carried out in an institution EPE and the values obtained are not significant, nor can they take predictive value given the small sample size. Despite this, suggest the existence of parameters that can be changed and this can vary the dose of radiation used It is hoped to get with this study, as mentioned, the basis of the establishment of NRD in CT in Portugal.
Resumo:
This paper approaches issues related to frame problems and nonresponse in surveys. These nonsampling errors affect the accuracy of the estimates whereas the estimators became biased and less precise. We analyse some estimation methods that deal with those problems and give an especial focus to post-stratification procedures.
Resumo:
Dissertation presented to obtain the PhD degree in Electrical and Computer Engineering - Electronics
Resumo:
Dissertation submitted in partial fulfillment of the requirements for the Degree of Master of Science in Geospatial Technologies
Resumo:
Dissertação para obtenção do grau de Mestre em Engenharia Electrotécnica e de Computadores
Resumo:
Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in Electrical and Computer Engineering of the Faculdade de Ciências e Tecnologia of Universidade Nova de Lisboa
Resumo:
Dissertação Apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Ciências da Conservação, especialização em Pintura
Resumo:
A Work Project, presented as part of the requirements for the Award of a Masters Degree in Management from the NOVA – School of Business and Economics
Resumo:
Dissertação para obtenção do Grau de Doutor em Biotecnologia
Resumo:
The paper presented herein proposes a reliability-based framework for quantifying the structural robustness considering the occurrence of a major earthquake (mainshock) and subsequent cascading hazard events, such as aftershocks that are triggered by the mainshock. These events can significantly increase the probability of failure of buildings, especially for structures that are damaged during the mainshock. The application of the proposed framework is exemplified through three numerical case studies. The case studies correspond to three SAC steel moment frame buildings of 3-, 9-, and 20- stories, which were designed to pre-Northridge codes and standards. Twodimensional nonlinear finite element models of the buildings are developed using the Open System for Earthquake Engineering Simulation framework (OpenSees), using a finite-length plastic hinge beam model and a bilinear constitutive law with deterioration, and are subjected to multiple mainshock-aftershock seismic sequences. For the three buildings analyzed herein, it is shown that the structural reliability under a single seismic event can be significantly different from that under a sequence of seismic events. The reliability-based robustness indicator used shows that the structural robustness is influenced by the extent by which a structure can distribute damage.
Resumo:
Dissertação para obtenção do Grau de Mestre em Engenharia Electrotécnica e Computadores