Considerações sobre Confiabilidade no Projeto de Submarinos

O projeto de submarinos com o foco em confiabilidade significa realizar o desdobramento dos requisitos de confiabilidade para atingir os padrões de desempenho e segurança requeridos. O propósito desse trabalho é estabelecer diretrizes de caráter geral para planejar e desdobrar os requisitos de confiabilidade no projeto de submarinos nucleares. Portanto, foram revistos alguns textos selecionados sobre engenharia da confiabilidade e projeto de submarinos. A motivação para realização desta pesquisa decorre da natureza complexa do submarino nuclear, a sua sofisticação tecnológica e o potencial de acidentes catastrófico. Assim, a questão da confiabilidade é fator crítico de sucesso. São abordados no texto os seguintes itens: O Ciclo de Vida do Submarino; Confiabilidade de Sistemas; O Submarino na Perspectiva de Sistema e Confiabilidade; e Confiabilidade no Projeto de Submarinos. Ressalta-se a necessidade do estabelecimento de um programa formal de confiabilidade na estrutura gerencial do projeto

OCUPAÇÃO DO SOLO E TRANSPORTES POR BONDES E TRENS NA REGIÃO METROPOLITANA DO RIO DE JANEIRO (RMRJ): DA VIABILIZAÇÃO URBANA A CRISE DO SISTEMA

  The objective of this study is to evaluate transport by trolley car and trains, as a public service which enabled land use in the metropolitan region of Rio de Janeiro (RMRJ), as well as better understand the role, evolution and importance of the public transport system in the development of centrality in the region. This study is structured on an exploratory and descriptive approach, from a research on the axes that supports a better understanding on the subject, and a desk study on the metropolitan area of RMRJ. This work shows that the tram and rail systems were relevant and enablers for urban occupation, but did not remain effi cient when demand increased and when the system gave precarious signals.O objetivo deste trabalho é o de identifi car o papel dos sistemas de transportes por bondes e trens, enquanto serviço público que viabilizou a ocupação do solo na Região Metropolitana do Rio de Janeiro (RMRJ), bem como melhor compreender o papel, evolução e a importância do sistema de transporte público no desenvolvimento das centralidades na região. Este estudo se estrutura sobre uma abordagem exploratória e descritiva, a partir de uma investigação sobre os eixos que apoiam uma melhor compreensão sobre o assunto, e de um estudo documental sobre a RMRJ. O trabalho evidenciou que os sistemas de bondes e o ferroviário, foram relevantes e viabilizadores para a ocupação urbana, porém não se mantiveram efi cientes quando a demanda se elevou e quando o sistema deu sinais de precarização

Mean clustering coefficients: the role of isolated nodes and leafs on clustering measures for small-world networks

Many networks exhibit the small-world property of the neighborhood connectivity being higher than in comparable random networks. However, the standard measure of local neighborhood clustering is typically not defined if a node has one or no neighbors. In such cases, local clustering has traditionally been set to zero and this value influenced the global clustering coefficient. Such a procedure leads to underestimation of the neighborhood clustering in sparse networks. We propose to include $\theta$ as the proportion of leafs and isolated nodes to estimate the contribution of these cases and provide a formula for estimating a clustering coefficient excluding these cases from the Watts and Strogatz (1998 Nature 393 440-2) definition of the clustering coefficient. Excluding leafs and isolated nodes leads to values which are up to 140% higher than the traditional values for the observed networks indicating that neighborhood connectivity is normally underestimated. We find that the definition of the clustering coefficient has a major effect when comparing different networks. For metabolic networks of 43 organisms, relations changed for 58% of the comparisons when a different definition was applied. We also show that the definition influences small-world features and that the classification can change from non-small-world to small-world network. We discuss the use of an alternative measure, disconnectedness D, which is less influenced by leafs and isolated nodes.Comment: final version of the manuscrip

The implementation of post-processing algorithm for ultrasonic testing of welds

The current development of systems of pulse-echo ultrasonic testing systems is conditioned by the increasing of inspection results reliability. The application of Synthetic Aperture Focusing Technique (SAFT) is one of the solutions to this problem. The implementation of the post-processing algorithms based on SAFT strongly depends on the conditions of the ultrasonic scanning. In this paper, the issues related to SAFT implementation in the case of ultrasonic inspection of welds are considered. As a result, the post-processing algorithm, which takes into account the main features of such objects inspection, is proposed. The capabilities of the suggested algorithm were verified via the computer simulations. It was determined that the suggested algorithm is able to provide accurate and precise imageries of the flaws located in the weld

Ethnography in counseling psychology research: Possibilities for application.

The emphasis placed on prolonged engagement, fieldwork, and participant observation has prevented wide-scale use of ethnography in counseling psychology. This article provides a discussion of ethnography in terms of definition, process, and potential ethical dilemmas. The authors propose that ethnographically informed methods can enhance counseling psychology research conducted with multicultural communities and provide better avenues toward a contextual understanding of diversity as it relates to professional inquiry

Beurling slow and regular variation

We give a new theory of Beurling regular variation ( Part II). This includes the previously known theory of Beurling slow variation ( Part I) to which we contribute by extending Bloom's theorem. Beurling slow variation arose in the classical theory of Karamata slow and regular variation. We show that the Beurling theory includes the Karamata theory

Análise comparativa entre ecofuncional por pediatra e ecocardiografia compreensiva por cardiologista em unidade de terapia intensiva pediátrica e neonatal

Introduction: Bedside ultrasound performed by a non-imaging specialist has proven to be a useful tool in the diagnostic evaluation and performance of invasive procedures. Several clinical situations favor manifestations of hemodynamic instability, especially in intensive care units. Nowadays, several pediatric units have used functional echocardiography (fECHO) and, often, before the examination by echocardiography performed by a cardiologista (cECHO). Objective: Compare the accuracy of echocardiography performed by a pediatrician (fECHO) and a cardiologist (cECHO) on neonatal and pediatric patients in an intensive care unit. Material and Methods: Retrospective analysis of the medical records of pediatric patients from zero days to 14 years, admitted to the intensive care unit, with a clinical indication for evaluation by comprehensive echocardiography of anatomical cardiac alterations were also evaluated through ecofunctional by a pediatrician. Results: Eight nine patients were admitted from zero days to 14 years, 55 of whom were male, and 34 were female. The respective sensitivity and specificity of fECHO and cECHO were 80% and 96.2% for the persistence of the ductus arteriosus; 88.4% and 98.4% for congenital acyanotic heart disease; 77.7% and 98.7% for congenital cyanotic heart disease; 83.3% and 98.8% for ventricular hypertrophy; 100% and 100% for pericardial effusion; 76.2% and 96.2% for persistent neonatal pulmonary hypertension. Conclusions: The results demonstrate a good accuracy of the pediatrician performing fECHO compared with a examination performed by the cardiologist, which does not reduce the importance and obligation of expert assessment. The incorporation of fECHO in the routine pediatric evaluation allows for the expansion and improvement of the pediatrician's physical examination.Introdução: A ultrassonografia à beira do leito realizada por não especialista em imagem tem mostrado ser uma ferramenta útil na avaliação diagnóstica e realização de procedimentos invasivos. Diversas situações clínicas favorecem manifestações de instabilidade hemodinâmica, principalmente, nas unidades de terapia intensiva. Neste sentido, unidades pediátricas têm utilizado ecocardiografia funcional, muitas vezes, antes do exame realizado por um ecocardiografista. Objetivo: Avaliar a acurácia da ecocardiografia realizada por pediatra comparativamente à realizada por ecocardiografista em pacientes de uma unidade neonatal e pediátrica de tratamento intensivo. Material e Métodos: Análise retrospectiva dos prontuários de pacientes pediátricos de zero dia a 14 anos, internados na unidade de terapia intensiva, com indicação clínica para avaliação da existência de alterações anatômicas por ecocardiografia compreensiva e que também foram avaliados através da ecocardiografia funcional por pediatra. Resultados: Um total de 89 casos foram analisados com admissão variando de zero dia a 14 anos, sendo 55 do sexo masculino e 34 do sexo feminino. A sensibilidade e especificidade, respectivamente, da ecocardiografia funcional pelo pediatra comparado à ecocardiografia compreensiva feita pelo cardiologista relativamente às alterações encontradas foram: 80% e 96,2% para persistência do canal arterial; 88,4% e 98,4% para cardiopatia congênita acianótica; 77,7% e 98,7% para cardiopatia congênita cianótica e/ou críticas; 83,3% e 98,8% para miocardiopatia hipertrófica; 100% e 100% para derrame pericárdico; e 76,2% e 96,2% para hipertensão pulmonar persistente neonatal. Conclusões: Os resultados demonstram boa acurácia do pediatra realizando a ecocardiografia funcional quando comparado com exame realizado pelo cardiologista (ecocardiografia compreensiva), o que não reduz a importância e obrigatoriedade da análise do especialista. A incorporação da ecocardiografia funcional na avaliação rotineira pediátrica permite expandir e melhorar o exame físico pelo pediatra

The impact of first and second language exposure on learning second language constructions

We study how the learning of argument structure constructions in a second language (L2) is affected by two basic input properties often discussed in literature – the amount of input and the time of L2 onset. To isolate the impact of the two factors on learning, we use a computational model that simulates bilingual construction learning. In the first two experiments we manipulate the sheer amount of L2 exposure, both in absolute and in relative terms (that is, in relation to the amount of L1 exposure). The results show that higher cumulative amount of L2 exposure leads to higher performance. In the third experiment we manipulate the prior amount of L1 input before the L2 onset (that is, the time of L2 onset). Given equal exposure, we find no negative effect of the later onset on learners’ performance. This has implications for theories of order of acquisition and bilingual construction learning