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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.
41

Desempenho de empresas brasileiras de aviação civil: uma análise das relações entre indicadores financeiros e não financeiros

Silva, João Marcelo dos Santos 23 May 2016 (has links)
Submitted by Silvana Teresinha Dornelles Studzinski (sstudzinski) on 2016-07-14T13:44:22Z No. of bitstreams: 1 João Marcelo dos Santos Silva_.pdf: 1621235 bytes, checksum: 6093d587a32c1490524b5320d31297bb (MD5) / Made available in DSpace on 2016-07-14T13:44:22Z (GMT). No. of bitstreams: 1 João Marcelo dos Santos Silva_.pdf: 1621235 bytes, checksum: 6093d587a32c1490524b5320d31297bb (MD5) Previous issue date: 2016-05-23 / Nenhuma / Esta dissertação busca analisar a relação existente na avaliação de desempenho medida por meio de indicadores não financeiros e indicadores financeiros de empresas do setor aéreo brasileiro. A pesquisa realizada é do tipo aplicada, com abordagem quantitativa com análise documental. Para atender aos objetivos, foram realizadas a correlação de Pearson e a regressão dinâmica. A pesquisa teve como amostra as empresas TAM, GOL e AZUL que juntas atenderam mais de 90% do mercado doméstico de aviação civil em 2013. O período pesquisado é de 2002 até 2013 para TAM e GOL. A AZUL, fundada em 2008, teve os dados pesquisados do ano de sua fundação até 2013. A coleta de dados foi realizada nos sites da ANAC e da CVM. Os resultados das correlações sugerem haver uma relação entre os indicadores não financeiros com a imobilização e o endividamento da GOL. Porém, há uma relação negativa de todos os indicadores não financeiros com os indicadores de margem e rentabilidade para TAM e GOL, ao contrário do que foi encontrado para a AZUL. Os resultados da regressão dinâmica mostram que não foi possível explicar a relação entre os indicadores não financeiros com os indicadores de rentabilidade. Contudo, foi encontrada relação com baixo poder de explicação de todos os indicadores não financeiros com os indicadores de participação de capital de terceiros da TAM e GOL e de endividamento bancário para esta última companhia. Portanto, o desempenho operacional (não financeiro) das companhias aéreas brasileiras TAM e GOL cresceu substancialmente no período pesquisado, mas não foi suficiente para melhorar o desempenho dos indicadores de rentabilidade e, além disso, ampliou o endividamento das empresas. Alguns dos fatores que contribuíram para o baixo desempenho da rentabilidade são: as variações cambiais do dólar americano em relação à moeda brasileira, os custos elevados com combustíveis, a diminuição das receitas por ASK maior que as reduções dos custos operacionais e a elevação de despesas financeiras. Além disso, há a dificuldade em repassar o aumento de custos no preço de comercialização dos bilhetes. / This research seeks to analyze the relationship in the performance evaluation measured by non-financial indicators and financial indicators of companies in the Brazilian airline industry. The survey is the kind applied with a quantitative approach with document analysis. To meet the objectives, we conducted Pearson's correlation and dynamic regression. The research’s sample are the TAM, GOL and AZUL companies that together treated more than 90% of the domestic civil aviation market in 2013. The studied period is from 2002 to 2013 for TAM and GOL. Founded in 2008, AZUL had researched the data of the year of its foundation until 2013. Data collection was carried out on the sites of ANAC and the CVM. The results of the correlations suggest the existence of a relationship between non-financial indicators with the immobilization and the indebtedness of GOL. But there is a negative relationship of all non-financial indicators with margin and profitability indicators for TAM and GOL, contrary to what was found for AZUL. The results of dynamic regression show that it was not possible to explain the relationship between the non-financial indicators with profitability indicators. However, it was found a relationship with low explanatory power of all non-financial indicators with non-capital participation indicators of TAM and GOL and bank debt to the latter company. Therefore, the (non-financial) operating performance of the Brazilian airlines TAM and GOL grew substantially in the period surveyed, but it was not enough to improve the performance of profitability indicators and additionally increased the indebtedness of companies. Some of the factors that contributed to the poor performance of profitability are: the exchange variation of the US dollar against the Brazilian currency, high fuel costs, the decrease in revenues per ASK greater than the reductions in operating costs, and higher financial expenses. Furthermore, there is a difficulty in passing the cost increase to the sales price of the tickets.
42

Kapacitets- och känslighetsanalys av bagagehanteringssystem på Arlanda flygplats / Capacity and sensitivity analysis of luggage handling system at Stockholm-Arlanda airport

Bernandersson, Martin January 2005 (has links)
<p>Detta är en kapacitets- och känslighetsanalys av bagagehanteringssystem vid Arlanda flygplats. Studien är ett examensarbete för civilingenjörsutbildningen Kommunikations- och Transportsystem vid Linköpings universitet och är utförd på uppdrag av Luftfartsverket, LFV Teknik under 2004 och 2005. </p><p>Studien har gjorts med datorstödd simulering som analysverktyg. Studien har gjorts genom att en simuleringsmodell av det studerade systemet har byggts i simuleringsprogrammet Arena. Denna modell har matats med trafikunderlag från en normalvecka under 2004. Utifrån denna modell och utifrån förväntade trafikökningar har sedan ett antal kapacitets- och känslighetsanalysscenarier formulerats och dessa har sedan simulerats och resultaten har tolkats och analyserats samt jämförts med resultaten från grundmodellen. </p><p>Kapacitetsanalysen visar att anläggningen är väl rustad för att ta emot den annalkande trafikökning som förväntas under de närmaste åren, eftersom den ökade trafiken inte innebär några signifikanta problem genom ökat antal väskor som inte hinner med sina flighter. Det som dock kan vara en begränsande faktor är att fickallokeringssystemet inte är effektivt och det sänker anläggningens verkliga kapacitet. För att kunna nyttja anläggningen maximalt bör fickallokeringssystemet ses över. </p><p>Känslighetsanalysen visar att systemet är mycket sårbart för störningar, särskilt om kommunikationen med BSM-centralen går ner eller om en Röntgen Level 2-maskin går sönder. Sådana händelser resulterar i att anläggningens kapacitet minskar kraftigt och i vissa fall klarar anläggningen inte av att hantera dagens trafikmängd. En handlingsplan för hur dessa störningar och konsekvenserna av dem ska minimeras bör införas snarast. </p> / <p>This is a capacity and sensitivity analysis of a baggage handling system at Stockholm-Arlanda airport. The study is a Master's Thesis in Communication and Transport Systems Engineering at the University of Linköping. The study was done on behalf of the Swedish Civil Aviation Administration. The analysis tool that was used is simulation. </p><p>In the study, a simulation model of the baggage handling system was implemented in the simulation program Arena. A base scenario containing the traffic program from one week in 2004 was created and used as a reference scenario. A total of 8 different scenarios were created to form the capacity and sensitivity analyses. </p><p>The capacity analysis showed that the baggage handling system will be able to handle the forecasted increases in traffic over the next few years with relative ease. The X-ray machines are currently not working at anywhere near full capacity. However, the system is currently not being used in an efficient way. The pocket allocation method is far from optimal because flights that use more than one pocket are allocated adjacent pockets only which can be very inefficient. This method needs to be revised for the system to work efficiently. </p><p>The sensitivity analysis showed that the system is very vulnerable if certain things happen. In particular if the communication link with the Baggage Source Message-central in London is lost there will be big problems because all luggage will go to the Manual Encoding Station (MES). The MES will then be very digested and it will take a considerably larger amount of time for the baggage to pass through the system. Problems will also occur if one of the two Level 2 X-ray-machines break down. The remaining machine cannot handle all the baggage by itself, especially not if there are flights to the USA about to depart since baggage heading for the USA must be run through X-ray Level 2. It is strongly recommended that handling plans are formed to minimise the effects of such events.</p>
43

Kapacitets- och känslighetsanalys av bagagehanteringssystem på Arlanda flygplats / Capacity and sensitivity analysis of luggage handling system at Stockholm-Arlanda airport

Bernandersson, Martin January 2005 (has links)
Detta är en kapacitets- och känslighetsanalys av bagagehanteringssystem vid Arlanda flygplats. Studien är ett examensarbete för civilingenjörsutbildningen Kommunikations- och Transportsystem vid Linköpings universitet och är utförd på uppdrag av Luftfartsverket, LFV Teknik under 2004 och 2005. Studien har gjorts med datorstödd simulering som analysverktyg. Studien har gjorts genom att en simuleringsmodell av det studerade systemet har byggts i simuleringsprogrammet Arena. Denna modell har matats med trafikunderlag från en normalvecka under 2004. Utifrån denna modell och utifrån förväntade trafikökningar har sedan ett antal kapacitets- och känslighetsanalysscenarier formulerats och dessa har sedan simulerats och resultaten har tolkats och analyserats samt jämförts med resultaten från grundmodellen. Kapacitetsanalysen visar att anläggningen är väl rustad för att ta emot den annalkande trafikökning som förväntas under de närmaste åren, eftersom den ökade trafiken inte innebär några signifikanta problem genom ökat antal väskor som inte hinner med sina flighter. Det som dock kan vara en begränsande faktor är att fickallokeringssystemet inte är effektivt och det sänker anläggningens verkliga kapacitet. För att kunna nyttja anläggningen maximalt bör fickallokeringssystemet ses över. Känslighetsanalysen visar att systemet är mycket sårbart för störningar, särskilt om kommunikationen med BSM-centralen går ner eller om en Röntgen Level 2-maskin går sönder. Sådana händelser resulterar i att anläggningens kapacitet minskar kraftigt och i vissa fall klarar anläggningen inte av att hantera dagens trafikmängd. En handlingsplan för hur dessa störningar och konsekvenserna av dem ska minimeras bör införas snarast. / This is a capacity and sensitivity analysis of a baggage handling system at Stockholm-Arlanda airport. The study is a Master's Thesis in Communication and Transport Systems Engineering at the University of Linköping. The study was done on behalf of the Swedish Civil Aviation Administration. The analysis tool that was used is simulation. In the study, a simulation model of the baggage handling system was implemented in the simulation program Arena. A base scenario containing the traffic program from one week in 2004 was created and used as a reference scenario. A total of 8 different scenarios were created to form the capacity and sensitivity analyses. The capacity analysis showed that the baggage handling system will be able to handle the forecasted increases in traffic over the next few years with relative ease. The X-ray machines are currently not working at anywhere near full capacity. However, the system is currently not being used in an efficient way. The pocket allocation method is far from optimal because flights that use more than one pocket are allocated adjacent pockets only which can be very inefficient. This method needs to be revised for the system to work efficiently. The sensitivity analysis showed that the system is very vulnerable if certain things happen. In particular if the communication link with the Baggage Source Message-central in London is lost there will be big problems because all luggage will go to the Manual Encoding Station (MES). The MES will then be very digested and it will take a considerably larger amount of time for the baggage to pass through the system. Problems will also occur if one of the two Level 2 X-ray-machines break down. The remaining machine cannot handle all the baggage by itself, especially not if there are flights to the USA about to depart since baggage heading for the USA must be run through X-ray Level 2. It is strongly recommended that handling plans are formed to minimise the effects of such events.
44

Analysis of the restructuring of the Russian defence industry (by the example of aviation industry and knaapo) and the creation of United Aviation Construction Corporation

Kuzmina, Maryana January 2007 (has links)
Made available in DSpace on 2009-11-18T19:00:50Z (GMT). No. of bitstreams: 1 Maryana-Kuzmina.pdf: 444000 bytes, checksum: 32161672bcd7120007547cd7d391f7ce (MD5) Previous issue date: 2007 / The present study is focused on the analysis of the three main governmental measures occurred in 2000-2006 in Russian defense industry: the creation of the holding structures, the establishing of the state monopoly in arms export, and creation of the United Aviation Construction Corporation (Ob¿edinennaya Aviastroitel¿naya Corporatziya), which was initiated by the President and Government of Russian Federation in 2006. The last project assumes the consolidation and joining of all producers of civil and military aviation into one united corporation in order to save the technological and productive potential of the sector after serious crisis in 1990-s. On the other hand, this project can be considered as one of the measures to establish state control and hierarchy in the defense industry. The current project tries to analyze the necessity and the possible impacts of restructuring processes. In order to perform such analysis, I need to observe the evolution of the sector, which involves the description of the restructuring and reforming of the industry since the disintegration of the Soviet Union. The current situation in aviation sector was shaped by number of reforms performed by Government of Russian Federation, which I describe in phases: conversion, privatization, decentralization, followed by evident desire of the state to establish control over some companies. Later on, I am trying to understand the reasons lying behind all reforms of 2000-2006 and the integration of the industry. I also try to predict which impacts on the companies it will have. The last part presents the main conclusions of the paper.
45

Feasibility of a Direct Sampling Dual-Frequency SDR Galileo Receiver for Civil Aviation / Faisabilité d’un récepteur Galileo SDR bi-fréquence à échantillonnage direct pour l’Aviation Civile

Blais, Antoine 25 September 2014 (has links)
Cette thèse étudie l'intérêt des architectures SDR à échantillonnage direct pour des récepteurs Galileo dans le contexte particulier de l'Aviation Civile, caractérisé notamment par une exigence de robustesse à des interférences bien spécifiées, principalement les interférences causées par les signaux DME ou CW. Le concept de Software Defined Radio traduit la migration toujours plus grande, au sein des récepteurs, des procédés de démodulation d'une technologie analogique à du traitement numérique, donc de façon logicielle. La quasi généralisation de ce choix de conception dans les architectures nouvelles nous a conduit à le considérer comme acquis dans notre travail. La méthode d'échantillonnage direct, ou Direct Sampling, quant à elle consiste à numériser les signaux le plus près possible de l'antenne, typiquement derrière le LNA et les filtres RF associés. Cette technique s'affranchit donc de toute conversion en fréquence intermédiaire, utilisant autant que possible le principe de l'échantillonnage passe-bande afin de minimiser la fréquence d'échantillonnage et en conséquence les coûts calculatoires ultérieurs. De plus cette thèse s'est proposée de pousser jusqu'au bout la simplification analogique en renonçant également à l'utilisation de l'AGC analogique qui équipe les récepteurs de conception traditionnelle. Seuls des amplificateurs à gain fixe précéderont l'ADC. Ce mémoire rend compte des travaux menés pour déterminer si ces choix peuvent s'appliquer aux récepteurs Galileo multifréquences (signaux E5a et E1) destinés à l'Aviation Civile. La structure du document reflète la démarche qui a été la notre durant cette thèse et qui a consisté à partir de l'antenne pour, d'étape en étape, aboutir au signal numérique traité par la partie SDR. Après une introduction détaillant le problème posé et le contexte dans lequel il s'inscrit, le deuxième chapitre étudie les exigences de robustesse aux interférences auquel doit se soumettre un récepteur de navigation par satellites destiné à l'Aviation Civile. Il s'agit de la base qui conditionne toute la démarche à suivre. Le troisième chapitre est consacré au calcul des fréquences d'échantillonnage. Deux architectures d'échantillonnage sont proposées. La première met en oeuvre un échantillonnage cohérent des deux bandes E5a et E1 tandis que la seconde implémente un échantillonnage séparé. Dans les deux cas, la nécessité de filtres RF supplémentaires précédant l'échantillonnage est mise en évidence. L'atténuation minimale que doivent apporter ces filtres est spécifiée. Ces spécifications sont suffisamment dures pour qu'il ait été jugé indispensable d'effectuer une étude de faisabilité. C'est l'objet du chapitre quatre où une approche expérimentale à base d'un composant disponible sur étagère a été menée. La problématique de la gigue de l'horloge d'échantillonnage, incontournable ici eu égard à la haute fréquence des signaux à numériser, est étudiée dans le chapitre cinq. Des résultats de simulation sont présentés et un dimensionnement de la qualité de l'horloge d'échantillonnage est proposé. Dans le chapitre six, la quantification, second volet de la numérisation, est détaillée. Il s'agit très précisément du calcul du nombre minimum de bits de quantification que doit exhiber l'ADC pour représenter toute la dynamique, non seulement du signal utile mais aussi des interférences potentielles. Au vu des débits de données conséquents mis en évidence dans les chapitres trois et six, le chapitre sept évalue la possibilité de réduire la dynamique de codage du signal à l'aide de fonctions de compression. Le dernier chapitre est focalisé sur la séparation numérique des bandes E5a et E1 dans l'architecture à échantillonnage cohérent introduite au chapitre deux. Ici aussi l'atténuation minimale que doivent apporter les filtres requis est spécifiée. / This thesis studies the relevance of DS SDR architectures applied to Galileo receivers in the specific context of Civil Aviation, characterized in particular by strict requirements of robustness to interference, in particular, interference caused by DME or CW signals. The Software Defined Radio concept renders the major tendency, inside the receiver, to move the demodulation part from an analog technology to digital signal processing, that is software. The choice of this kind of design is nearly generalized in new receiver architectures so it was considered the case in this work. The Direct Sampling method consists in digitizing the signal as close as possible to the antenna, typically after the LNA and the associated RF bandpass filter. So this technique does not use any conversion to an intermediate frequency, using as much as possible the bandpass sampling principle in order to minimize the sampling frequency and consequently the downstream computational costs. What is more, this thesis aiming at the greatest simplification of the analog part of the receiver, the decision was made to suppress the analog AGC which equips the receivers of classical architecture. Only fixed gained amplifiers should precede the ADC. This document exposes the work done to determine if these choices can apply to a multifrequency (E5a and E1 signals) Galileo receiver intended for a Civil Aviation use. The structure of the document reflects the approach used during this thesis. It progresses step by step from the antenna down to the digital signal, to be processed then by the SDR part. After an introduction detailing the problem to study and its context, the second chapter investigates the Civil Aviation requirements of robustness to interference a satellite navigation receiver must comply with. It is the basis which completely conditions the design process. The third chapter is devoted to the determination of the sampling frequency. Two sampling architectures are proposed: the first implements coherent sampling of the two E5a and E1 bands while the second uses separate sampling. In both cases the necessity to use extra RF filters is shown. The minimum attenuation to be provided by these filters is also specified. These requirements are strong enough to justify a feasibility investigation. It is the subject of chapter four where an experimental study, based on a SAW filter chip available on the shelf, is related. The issue of the sampling clock jitter, of concern with the Direct Sampling technique because of the high frequency of the signal to digitize, is investigated in chapter five. Some simulation results are presented and a dimensioning of the quality of the sampling clock is proposed. In chapter six, quantization, a byproduct of digitization, is detailed. Precisely it is the calculation of the number of bits the ADC must have to digitally represent the whole dynamic of, not only the useful signal, but also of the potential interference. Considering the high binary throughput highlighted in chapters three and six, chapter seven evaluates the possibility to reduce the coding dynamic of the digital signal at the output of the ADC by means of compression functions. The last chapter is focused on the digital separation of the two E5a and E1 bands in the coherent sampling architecture presented in chapter two. Here also specifications of minimum attenuation are given. Lastly the conclusions synthesize the contributions of this thesis and proposes ideas for future work to enrich them and more generally the subject of DS-SDR Galileo receivers for Civil Aviation.
46

Posouzení bezpečnostních opatření k ochraně civilního letectví před protiprávními činy na mezinárodních letištích v České republice se zaměřením na letiště v Českých Budějovicích / Assessment of safeguards to protect civil aviation against acts of unlawful interference at internatial airports especially focused on České Budějovice airport.

URBAN, Jiří January 2012 (has links)
This diploma thesis provides a basic description and an indication of technical and legislative issues that are closely related to the safety of civil aviation. Well known accidents related to illegal acts are also described in this paper. The aim of this paper is to assess the current personnel?s state and knowledge relating to civil aviation security at international airports, focusing on the airport in České Budějovice. Two hypotheses are presented H ? 1 and H ? 2, which are evaluated using statistical survey and to perform structural analysis of security at international airports in the Czech Republic and structural analysis of security system of LKCS and then compare them, or possibly suggest additional measures that would increase security at the airport. This paper evaluates the level of knowledge on the basis of a questionnaire survey of personnel of České Budějovice airport and Prague - Ruzyně Airport on civil aviation security issues concerning illegal acts and compares this level of knowledge by application of statistical survey. Structural analysis of the security system and legislation used in international civil aviation in the Czech Republic and also analysis of security system according to the applicable legislation at the international nonpublic airport in České Budějovice are performed. These analyses are compared and evaluated. The analysis of results and the confirmation or refutation of hypotheses H ? 1 and H ? 2 are presented in the discussion including suggestion of precautions that could improve the security at the České Budějovice airport.
47

Rota de colisão: a cultura da Varig Grande e a aviação civil brasileira em meio à globalização / Route of collision: the culture of "Big Varig" and the brazilian civil aviation during globalization

Sandra Regina de Oliveira 22 July 2009 (has links)
Esta dissertação de História tem por objetivo demonstrar a estreita relação existente entre a crise da VARIG e a mudança de paradigma do governo brasileiro com relação à aviação civil e, conseqüentemente, com relação às empresas nacionais de aviação, a partir da década de 1980, através da adoção dos preceitos neoliberais que marcaram a desregulamentação da aviação civil no mercado doméstico norte-americano. Desta forma, a partir do momento que o Estado brasileiro passou oficialmente a adotar políticas para o mercado da aviação, cujas diretrizes foram traçadas nos Estados Unidos da América, foi possível associar o estudo da história da aviação n acional à história da política governamental no que tange às suas relações com a política internacional, levando-nos a traçar um paralelo entre a política externa brasileira e a política externa dos EUA, tal a grande influência deste país no desenvolvimento da aviação civil no Brasil, principalmente após a Segunda Guerra Mundial, até as mudanças neoliberais das últimas décadas. Pôde-se, assim, observar em que grau a política externa norte-americana conseguiu influenciar a evolução da aviação no Brasil, em função da maior ou menor autonomia dos diversos governos brasileiros a esta política específica. Para demonstrar a relação existente entre a crise da VARIG e esta mudança de paradigma, foi necessário estudar os aspectos relacionais externos da empresa, o quanto o lema VARIG Grande se atrelava à política econômica de um BRASIL Grande, concebido durante o chamado Milagre Brasileiro, isto é, o quanto sua política empresarial esteve associada à política nacional- desenvolvimentista do Estado, que ao entrar em crise desestabilizou a histórica estratégia da VARIG, principalmente após a década de 1990, quando os espaços de interlocução entre a burocracia estatal e as empresas privadas se reduziram ao extremo. No caso da VARIG, foi preciso também analisar os seus aspectos relacionais internos, construídos ao longo de seus mais de oitenta anos de história, com práticas institucionais bastante próximas às das em presas estatais. Na conclusão, será demonstrada a co-responsabilidade do Estado na formação, no crescimento, no início da crise e na intensificação do processo de queda da empresa , através de atuações determinantes, em momentos diferentes da história do país.
48

Rota de colisão: a cultura da Varig Grande e a aviação civil brasileira em meio à globalização / Route of collision: the culture of "Big Varig" and the brazilian civil aviation during globalization

Sandra Regina de Oliveira 22 July 2009 (has links)
Esta dissertação de História tem por objetivo demonstrar a estreita relação existente entre a crise da VARIG e a mudança de paradigma do governo brasileiro com relação à aviação civil e, conseqüentemente, com relação às empresas nacionais de aviação, a partir da década de 1980, através da adoção dos preceitos neoliberais que marcaram a desregulamentação da aviação civil no mercado doméstico norte-americano. Desta forma, a partir do momento que o Estado brasileiro passou oficialmente a adotar políticas para o mercado da aviação, cujas diretrizes foram traçadas nos Estados Unidos da América, foi possível associar o estudo da história da aviação n acional à história da política governamental no que tange às suas relações com a política internacional, levando-nos a traçar um paralelo entre a política externa brasileira e a política externa dos EUA, tal a grande influência deste país no desenvolvimento da aviação civil no Brasil, principalmente após a Segunda Guerra Mundial, até as mudanças neoliberais das últimas décadas. Pôde-se, assim, observar em que grau a política externa norte-americana conseguiu influenciar a evolução da aviação no Brasil, em função da maior ou menor autonomia dos diversos governos brasileiros a esta política específica. Para demonstrar a relação existente entre a crise da VARIG e esta mudança de paradigma, foi necessário estudar os aspectos relacionais externos da empresa, o quanto o lema VARIG Grande se atrelava à política econômica de um BRASIL Grande, concebido durante o chamado Milagre Brasileiro, isto é, o quanto sua política empresarial esteve associada à política nacional- desenvolvimentista do Estado, que ao entrar em crise desestabilizou a histórica estratégia da VARIG, principalmente após a década de 1990, quando os espaços de interlocução entre a burocracia estatal e as empresas privadas se reduziram ao extremo. No caso da VARIG, foi preciso também analisar os seus aspectos relacionais internos, construídos ao longo de seus mais de oitenta anos de história, com práticas institucionais bastante próximas às das em presas estatais. Na conclusão, será demonstrada a co-responsabilidade do Estado na formação, no crescimento, no início da crise e na intensificação do processo de queda da empresa , através de atuações determinantes, em momentos diferentes da história do país.
49

Varför är det säkrare att flyga än att få sjukvård? : En jämförande studie av säkerhetsutveckling inom hälso- och sjukvård respektive civilflyg

Hallberg, Anders January 2008 (has links)
Syftet med denna jämförande studie är att söka förklaringsfaktorer till varför hälso- och sjukvård respektive civilflyg har utvecklats olika i säkerhetstänkande. Frågeställningen är huruvida de statliga tillsynsmyndigheternas förutsättningar och arbetssätt har betydelse för säkerhetskulturen i respektive tillsynsverksamhet. Till förutsättningarna hör författningarna - skiljer sig dessa åt? Myndigheternas arbetssätt, dvs. tillsynens utformning – vilken betydelse har den? Resultaten visar att säkerhetsrelaterade författningar inom civilflyget är tydligare jämfört med hälso- och sjukvården. Inom civilflyget anges tydligt hur säkerhetsarbetet ska organiseras, till skillnad mot hälso- och sjukvården. Tillsynsmyndigheternas arbetssätt påverkas av skillnader i författningarnas utformning. Luftfartsstyrelsen kan påverka de flygsäkerhetsrelaterade resurserna vid en flygplats. Socialstyrelsen har små möjligheter att påverka sjukvårdens bemanning. Genom civilflygets föreskrifter har man uppnått strikt följsamhet mot upprättade rutiner. Miljön för avvikelserapportering är icke-bestraffande. Felhandlingar förebyggs genom övningar och repetitionsutbildningar. Socialstyrelsen saknar bemyndigande i utbildningsfrågan. Tillståndsplikten inom civilflyget har sannolikt främjat säkerhetsutvecklingen, så även det internationella samarbetet. Slutsatsen är att utformningen av författningarna har betydelse för tillsynsmyndigheternas möjligheter att påverka säkerhetsutvecklingen inom respektive tillsynsområde. Bristen på tydlighet i författningarna kan förlångsamma sjukvårdens utveckling mot ökande patientsäkerhet. / The aim of this comparative study is to find explanations to why healthcare and civil aviation have developed differently regarding safety culture. The question at issue is: Which significance do prerequisities and work procedures of governmental supervisory authorities have for the development of safety culture in the two areas of supervision, respectively. Among prerequisities are the constitutions – do they differ? Among work procedures are the design of the supervision – which role does it play? Results show that constitutions relating to safety issues in civil aviation are more distinct as compared to health care. In civil aviation, it is clearly stated how the security work should be organized, in contrast to health care. The work procedures of supervisory authorities are affected by differences in the wording of constitutions. The Swedish Civil Aviation Authority is able to influence the staffing of an airport. The National Board of Health and Welfare has only minor possibilities to influence the staffing within health care. By application of the regulations of civil aviation, strict compliance to established local routines has been achieved. The environment for reporting of adverse events is blame-free. Human errors are prevented by drills and recurrent educations. The National Board of Health and Welfare has no authority in educational issues. The licence duty of civil aviation has probably facilitated the development of safety culture. The same holds true for the international collaboration within civil aviation. The conclusion is that the wording of constitutions is important for the ability of supervisory authorities to influence the development of safety culture within the two investigated fields of supervision, respectively. The lack of clarity in the wording of constitutions and regulations within health care might slow down the development of safety culture.
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Détection robuste et précoce des pannes oscillatoires dans les systèmes de commandes de vol

Simon, Pascal 07 December 2011 (has links)
Le travail de recherche effectué dans cette thèse a été réalisé dans le cadre d'une convention CIFRE entre le laboratoire IMS de l'université Bordeaux 1 et la société Airbus Operations S.A.S. Cette thèse traite de la détection robuste et précoce des pannes oscillatoires de faible amplitude dans les systèmes de commandes de vol électriques. Une panne oscillatoire est une oscillation anormale d'une surface de contrôle due à un dysfonctionnement dans la chaîne d'asservissement de la servocommande d'une gouverne. Les pannes oscillatoires ont une influence sur la structure, l'aéroélasticité et la pilotabilité de l'avion, lorsqu'ils sont situés dans la bande passante de l'actionneur. La capacité à détecter ces pannes est très importante car elles ont un impact sur la conception structurale de l'avion. Au plan méthodologique, nous nous sommes focalisés sur l'estimation adaptative des paramètres et de l'état à base d'une technique de filtrage non linéaire local. Le mécanisme de filtrage opère sur un modèle non linaire de la chaine de contrôle-commande de l’actionneur hydraulique en amont des surfaces de contrôle. L'algorithme d'estimation est basé sur une interpolation polynomiale d'opérateurs linéaire, et offre l'avantage d'une implémentation relativement aisée. Un problème crucial et sous-jacent est la détermination des hyper-paramètres de réglage de cet algorithme. Nous avons proposé une démarche hors-ligne dédiée, en intégrant un critère de sensibilité vis-à-vis des pannes que nous devons détecter. La technique proposée a été implémentée et testée: les résultats expérimentaux obtenus sur banc essai et sur un simulateur A380 ont clairement mis en évidence l'apport de la nouvelle approche en termes de performances, tout en gardant le même niveau de robustesse. / The research work done in this PhD has been caried out in the frame of an industrial convention (CIFRE) between the IMS laboratory and Airbus Operations S.A.S. The thesis deals with robust and early detection of oscillatory failures (OFC: Oscillatory Failure Case) in the Electrical Flight Control System. An oscillatory failure is an abnormal oscillation of a control surface due to component malfunction in control surface servoloops. OFCs have an influence on structural loads, aeroelasticity and controllability when located within the actuator bandwidth. The ability to detect these failures is very important because they have an impact on the structural design of the aircraft. Usual monitoring techniques cannot always guarantee to remain within an envelope with acceptable robustness. In this work, we develop a model based strategy to detect such failures with small amplitude at a very early stage. The monitoring strategy is based on dedicated non linear local filtering for on-line joint parameter/state estimation, allowing for model parameter variations during A/C flight. This strategy is associated with the same decision making rules as currently used for in-service Airbus A380. We propose a method for adjusting the tuning parameters so that various design goals and trades-off can be easily formulated and managed. The performance of the proposed fault detection scheme is measured by its detection delay, its propensity to issue false alarms and whether it permits a failure to go undetected. The proposed technique has been implemented and tested with success on Airbus test facilities including an A380 flight simulator.

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