MRO and Fleet Reliability Implementation and Improvements

With the constant development in the aviation area, it is the search for a greater availability of the aircraft as well as the reduction of costs related to the maintenance that are leading operators and maintenance centers to implement reliability programs. In general, excluding test operations and other specific operations, civil aviation is designed in order to carry transport flights with passengers, mail or specific cargo. While military aviation is designed to carry out aerial combat operations, logistical transport support, surveillance or reconnaissance flights, among others special operations. Thus, civil aviation is aimed for repetitive and systematic air transport and military aviation for punctual and particular operations. The success of the use of Reliability Programs in civil aviation increases the reliability of the aircrafts related to maintenance costs and availability. This success has, step by step, seduced the interest in military aviation. Due to the type of maintenance (MRO) that OGMA is responsible for and in parallel decision with the Operator (costumer), it was agreed to implement a Reliability Program, as a continuous improvement project, with the goal of increasing the reliability of rotable components as well as of the self military cargo aircrafts of the fleet. By this, this MSc Thesis is focused on the validation, implementation and application of an Aircraft Reliability Program, calculation of reliability metrics, generation of alerts, root cause search and failure modes, implementation of a failure mode and analysis related to design and processes as well as corrective actions and their monitoring. Issues such as maintenance data, metrics calculation, alert levels analysis, root causes investigation, corrective actions implementation and monitoring processes are addressed.É com o constante desenvolvimento na área da aviação que se procura uma maior disponibilidade das aeronaves, bem como a diminuição de custos relacionados com a manutenção, que estão a levar operadoras e centros de manutenção a inserir programas de fiabilidade. De uma forma geral, excluindo operações de teste e outras mais específicas, a aviação civil está implementada por forma a realizar voos de transporte, com passageiros, correio ou cargas específicas. Por outro lado, a aviação militar está desenhada para realizar operações de combate aéreo, suporte de transporte logístico, voos de vigilância ou reconhecimento, entre outros de carácter operacional especial. Assim sendo, a aviação civil está direcionada para transporte aéreo repetitivo e sistemático e a aviação militar para operações pontuais e particulares. O sucesso do uso de Programas de Fiabilidade na aviação civil faz aumentar a fiabilidade das aeronaves relativamente ao rendimento dos custos de manutenção das aeronaves, bem como a disponibilidade das mesmas. Este sucesso tem cativado, a pouco e pouco, o interesse por parte da aviação militar. Devido ao tipo de manutenção (MRO) que a OGMA é responsável, e em paralela decisão com o Operador (cliente), foi acordado a implementação de um Programa de Fiabilidade, como projeto de melhoria contínua inicial, com vista em aumentar a fiabilidade de componentes rotáveis e das próprias aeronaves de uma frota militar de carga. Desta forma, esta dissertação de mestrado foca-se na validação, implementação e aplicação de um Programa de Fiabilidade de Aeronaves, cálculo de métricas de fiabilidade, geração de alertas, implementação de análises de modos de falha e efeitos direcionados para processos e desenho/projeto de componentes, pesquisa de causas raiz e modos de falha, implementação de ações corretivas e sua monitorização. São abordados temas como dados de manutenção usados, o cálculo de métricas de fiabilidade, a análise de níveis de alerta, a investigação de causas raiz, a implementação de ações corretivas e sua monitorização

Perturbations created from the baseline in tennis: a test of barker’s behaviour setting theory

The purpose of this study was to characterise perturbations created from the baseline in men's tennis following Barker's ecological psychology approach. In selected rallies of expert level tennis matches we identified the shot responsible for this perturbation and characterised it using a sequential approach based on the positioning of the players in the court, the technical actions used by both players, and the displacements that each player forced on the opponent. Results reveal specific patterns of player behaviour and types of displacement in response to the opponent. Moreover, we found significant variability of the technical actions and action zones expressed during the perturbation processes. These results suggest that perturbation behaviours are constrained by the 'behaviour setting', which allows individuality during the search for effective solutions to achieve a specific goal. This test of Barker's behaviour setting theory in sport offers a principled guidance for coaches embed psychology into task design for practice sessions.info:eu-repo/semantics/publishedVersio

SPICE implementation of a finite element method based model for bipolar power semiconductors

This paper describes the methodology associated with the practical implementation, in SPICE circuit simulator, of a Finite Element Method (FEM) based model developed for Bipolar Power Semiconductor (BPS) simulation. The methodology is based on a modular approach that associates each zone of the semiconductor to a subcircuit implemented into SPICE simulator. Modeling a semiconductor is based in the union of the set of subcircuit modules necessary to the different zones. Calculus of instantaneous distribution of lightly doped zones carriers (ambipolar diffusion equation (ADE) solution in space/time) is made with a group of subcircuit modules, analogue to FEM elements. The paper shows how each module is implemented and how easily elements with different sizes, topologies or physical properties are made. Remaining semiconductor zones (highly doped emitters narrow base and MOS zones) are modeled with subcircuits using classical approaches. Voltage drops are modeled with subcircuits implementing a Boltzmann approach for junctions and a Poisson approach for depletion zones. Description for obtaining each associated SPICE subcircuit is made. Global solution is approached by serial addition of these modules (each one directly related to one element of the domain). The paper concludes with simulations showing hole/electron distribution, in time/space, in low-doped zones of PIN Diodes, BJTs and IGBTs, as well as, corresponding dynamic commutation waveforms for current and voltage

REX: general-purpose CNL with code generation support

Controlled natural languages (CNLs) have been proposed to address some of the issues of natural language when it is used to express requirements. CNLs, however, are based on formal grammar, which can easily become complex, hard to read, and especially hard to write, and the implementation of support tools can also demand a significant effort. Moreover, unanticipated constructions cannot be handled or have to be handled in unexpected and cumbersome ways. In this article, we present REX, a CNL with a simple grammar that is, thus, easy to understand and easy to support, but still general purpose. To accomplish this, instead of trying to support every conceivable construction and imposing a language on the users, through a small but comprehensive set of rules and through patterns, users specify their own language and how natural it is. Another of the benefits of CNLs is the possibility to automate the transformation of a text or specification into something useful, thereby reducing manual labor and transformation errors. In this article, we also present the support tools that were used to transform a REX text into code and a complete application. It is also shown that this CNL and its support tools can be easily adapted to suit different needs

A framework for dependability evaluation of PROFIBUS networks

Fieldbus networks have been assuming a high acceptance in the industrial environment, replacing the old centralized control architectures. Due to time critical nature of the tasks involved in these environments, the fulfillment of dependability attributes is usually required. Therefore the dependability is an important parameter on system design, which should be evaluated. Several factors can affect system dependability. The environmental ones are the most common and due to the particularity of the industrial environment this susceptibility is increased. In this paper it is proposed a framework based on fault injection techniques, supported by a hardware platform which emulates a fault set, representative of industrial environment scenarios, intending to disturb data communications on a PROFIBUS network. From these fault injection experiments, relevant data is gathered and a further analysis is carried out to evaluate dependability attributes

Saint Jérôme de Júlio Bressane : la traduction comme chemin critique

En 1999, le cinéaste brésilien Júlio Bressane fait le lancement de Saint Jérôme qui a été tourné dans le sertão de Paraíba. Ce film sera analysé ici à partir des séries culturelles, en pensant leprocessus de « transcréation » (CAMPOS 1992) au cinéma. L'article poursuit le débat à travers deux éléments : les textures picturales en rapport avec la photographie et les gestes du protagoniste. Peinture, littérature et musique contribuent à étayer la discussion sur la traduction au cinéma, dans une quête « de propriétés sonores et visuelles » (Ibidem, p. 35), et ce, pour renvoyer au « signe Jérôme » (BRESSANE 2001: 19). Les mouvements de caméra sur le corps de l'acteur et la profondeur de champ traduisent cette personnification de la culture qui se confond avec le paysage.In 1999, Brazilian movie director Júlio Bressane launched Saint Jerome which was shot in Paraíba's sertão, at the North-East of Brazil. The film is examined here in its pictorial series as a "transcreation" process (CAMPOS 1992) to cinema. The discussion brings up two elements: pictorial textures placed by photography, and gestures of the protagonist. Paintings, literature and cinema interact to provide "sound and image properties" (Ibidem, p. 35) related to the "Jerome sign" (BRESSANE 2001: 19). Camera movements slide over the actor's body, alternating with depth of field to translate this great character of culture which blends with the landscape

Automatic speech recognition for European Portuguese

Dissertação de mestrado em Informatics EngineeringThe process of Automatic Speech Recognition (ASR) opens doors to a vast amount of possible improvements in customer experience. The use of this type of technology has increased significantly in recent years, this change being the result of the recent evolution in ASR systems. The opportunities to use ASR are vast, covering several areas, such as medical, industrial, business, among others. We must emphasize the use of these voice recognition systems in telecommunications companies, namely, in the automation of consumer assistance operators, allowing the service to be routed to specialized operators automatically through the detection of matters to be dealt with through recognition of the spoken utterances. In recent years, we have seen big technological breakthrough in ASR, achieving unprecedented accuracy results that are comparable to humans. We are also seeing a move from what is known as the Traditional approach of ASR systems, based on Hidden Markov Models (HMM), to the newer End-to-End ASR systems that obtain benefits from the use of deep neural networks (DNNs), large amounts of data and process parallelization. The literature review showed us that the focus of this previous work was almost exclusively for the English and Chinese languages, with little effort being made in the development of other languages, as it is the case with Portuguese. In the research carried out, we did not find a model for the European Portuguese (EP) dialect that is freely available for general use. Focused on this problem, this work describes the development of a End-to-End ASR system for EP. To achieve this goal, a set of procedures was followed that allowed us to present the concepts, characteristics and all the steps inherent to the construction of these types of systems. Furthermore, since the transcribed speech needed to accomplish our goal is very limited for EP, we also describe the process of collecting and formatting data from a variety of different sources, most of them freely available to the public. To further try and improve our results, a variety of different data augmentation techniques were implemented and tested. The obtained models are based on a PyTorch implementation of the Deep Speech 2 model. Our best model achieved an Word Error Rate (WER) of 40.5%, in our main test corpus, achieving slightly better results to those obtained by commercial systems on the same data. Around 150 hours of transcribed EP was collected, so that it can be used to train other ASR systems or models in different areas of investigation. We gathered a series of interesting results on the use of different batch size values as well as the improvements provided by the use of a large variety of data augmentation techniques. Nevertheless, the ASR theme is vast and there is still a variety of different methods and interesting concepts that we could research in order to seek an improvement of the achieved results.O processo de Reconhecimento Automático de Fala (ASR) abre portas para uma grande quantidade de melhorias possíveis na experiência do cliente. A utilização deste tipo de tecnologia tem aumentado significativamente nos últimos anos, sendo esta alteração o resultado da evolução recente dos sistemas ASR. As oportunidades de utilização do ASR são vastas, abrangendo diversas áreas, como médica, industrial, empresarial, entre outras. É de realçar que a utilização destes sistemas de reconhecimento de voz nas empresas de telecomunicações, nomeadamente, na automatização dos operadores de atendimento ao consumidor, permite o encaminhamento automático do serviço para operadores especializados através da detecção de assuntos a tratar através do reconhecimento de voz. Nos últimos anos, vimos um grande avanço tecnológico em ASR, alcançando resultados de precisão sem precedentes que são comparáveis aos atingidos por humanos. Por outro lado, vemos também uma mudança do que é conhecido como a abordagem tradicional, baseados em modelos de Markov ocultos (HMM), para sistemas mais recentes ponta-a-ponta que reúnem benefícios do uso de redes neurais profundas, em grandes quantidades de dados e da paralelização de processos. A revisão da literatura efetuada mostra que o foco do trabalho anterior foi quase que exclusivamente para as línguas inglesa e chinesa, com pouco esforço no desenvolvimento de outras línguas, como é o caso do português. Na pesquisa realizada, não encontramos um modelo para o dialeto português europeu (PE) que se encontre disponível gratuitamente para uso geral. Focado neste problema, este trabalho descreve o desenvolvimento de um sistema de ASR ponta-a-ponta para o PE. Para atingir este objetivo, foi seguido um conjunto de procedimentos que nos permitiram apresentar os conceitos, características e todas as etapas inerentes à construção destes tipos de sistemas. Além disso, como a fala transcrita necessária para cumprir o nosso objetivo é muito limitada para PE, também descrevemos o processo de coleta e formatação desses dados em uma variedade de fontes diferentes, a maioria delas disponíveis gratuitamente ao público. Para tentar melhorar os nossos resultados, uma variedade de diferentes técnicas de aumento de dados foram implementadas e testadas. Os modelos obtidos são baseados numa implementação PyTorch do modelo Deep Speech 2. O nosso melhor modelo obteve uma taxa de erro de palavras (WER) de 40,5% no nosso corpus de teste principal, obtendo resultados ligeiramente melhores do que aqueles obtidos por sistemas comerciais sobre os mesmos dados. Foram coletadas cerca de 150 horas de PE transcritas, que podem ser utilizadas para treinar outros sistemas ou modelos de ASR em diferentes áreas de investigação. Reunimos uma série de resultados interessantes sobre o uso de diferentes valores de batch size, bem como as melhorias fornecidas pelo uso de uma grande variedade de técnicas de data augmentation. O tema ASR é vasto e ainda existe uma grande variedade de métodos diferentes e conceitos interessantes que podemos investigar para melhorar os resultados alcançados

Envelhecimento e os desafios à investigação e intervenção : processos de infoexclusão e infointervenção

O envelhecimento tem sido encarado como um desafio constituindo-se como objeto de estudo e de intervenção de entidades supra nacionais, nacionais e locais e das mais variadas áreas do saber. Tendo em conta a diversidade de saberes pretendemos com este texto compreender o envelhecimento, as políticas, a investigação e a intervenção social com destaque para a infoexclusão e a infointervenção. Como sabemos o contexto de crise económica e financeira e a retração das políticas públicas e sociais aumenta as desigualdades e coloca em causa o bem-estar das pessoas idosas. Somos desafiados por isso a questionar, de um ponto de vista crítico, as estratégias adotadas para dar resposta ao grupo de pessoas idosas destacando os processos de infoexclusão e formas de infointervenção.Este trabalho é financiado por Fundos Nacionais através da FCT - Fundação para a Ciência e Tecnologia, no âmbito do projeto UID/CPO/00713/2013