Thesis (M.S.)--School of Advanced Air and Space Studies, 2008. / "June 2008." Vita. Includes bibliographical references (p. 141-148). Also available via the Internet.

Un logiciel critique est un logiciel dont le mauvais fonctionnement peut avoir un impact important sur la sécurité ou la vie des personnes, des entreprises ou des biens.L'ingénierie logicielle pour les systèmes critiques est particulièrement difficile et combine différentes méthodes pour garantir la qualité des logiciels produits.Parmi celles-ci, les méthodes formelles peuvent être utilisées pour prouver qu'un logiciel respecte ses spécifications.Le travail décrit dans cette thèse s'inscrit dans le contexte de la validation de propriétés de sûreté de programmes critiques, et plus particulièrement des propriétés numériques de logiciels embarqués dans des systèmes de contrôle-commande.La première partie de cette thèse est consacrée aux preuves de stabilité au sens de Lyapunov.Ces preuves s'appuient sur des calculs en nombres réels, et ne sont pas valables pour décrire le comportement d'un programme exécuté sur une plateforme à arithmétique machine.Nous présentons un cadre théorique générique pour adapter les arguments des preuves de stabilité de Lyapunov aux arithmétiques machine.Un outil effectue automatiquement la traduction de la preuve en nombres réels vers une preuve en nombres a virgule flottante.La seconde partie de la thèse porte sur l'analyse des relations affines, en utilisant une interprétation abstraite basée sur l'approximation des valuations associées aux points de contrôle d'un programme par des polyèdres convexes.Nous présentons ALICe, un framework permettant de comparer différentes techniques de génération d'invariants.Il s'accompagne d'une collection de cas de tests tirés de publications sur l'analyse de programmes, et s'interface avec trois outils utilisant différents algorithmes de calcul d'invariants: Aspic, iscc et PIPS.Afin d'affiner les résultats de PIPS, deux techniques de restructuration de code sont introduites, et plusieurs améliorations sont apportées aux algorithmes de génération d'invariants et évaluées à l'aide d'ALICe. / A critical software is a software whose malfunction may result in death or serious injury to people, loss or severe damage to equipment or environmental harm.Software engineering for critical systems is particularly difficult, and combines different methods to ensure the quality of produced software.Among them, formal methods can be used to prove that a software obeys its specifications.This thesis falls within the context of the validation of safety properties for critical software, and more specifically, of numerical properties for embedded software in control-command systems.The first part of this thesis deals with Lyapunov stability proofs.These proofs rely on computations with real numbers, and do not accurately describe the behavior of a program run on a platform with machine arithmetic.We introduce a generic, theoretical framework to adapt the arguments of Lyapunov stability proofs to machine arithmetic.A tool automatically translates the proof on real numbers to a proof with floating-point numbers.The second part of the thesis focuses on linear relation analysis, using an abstract interpretation based on the approximation by convex polyhedrons of valuations associated with each control point in a program.We present ALICe, a framework to compare different invariant generation techniques.It comes with a collection of test cases taken from the program analysis literature, and interfaces with three tools, that rely on different algorithms to compute invariants: Aspic, iscc and PIPS.To refine PIPS results, two code restructuring techniques are introduced, and several improvements are made to the invariant generation algorithms and evaluated using ALICe.

Por meio de tradicionais e novos conceitos da Geopolítica, são analisadas as especiais circunstâncias que cercaram as relações entre a Argentina e os principais países do mundo desenvolvido, os EUA e parte da Europa, durante a Guerra das Malvinas, para, a partir desse mesmo ferramental conceitual, verificar como esse episódio teve seu impacto nas relações de Brasil e Argentina na América do Sul. Os principais acontecimentos políticos, táticos e logísticos desse conflito são descritos para auxiliar nessa análise feita. A partir desse ponto de inflexão na história sul-americana, utiliza-se o conceito de Medidas de Confiança Mútua (MCM) para se verificar como as Marinhas de Brasil e Argentina intensificaram suas relações dentro do novo marco geopolítico acordado entre os dois países. São descritos os sucessos dessa política de aproximação em cinco fases históricas distintas, didaticamente elaboradas: duas anteriores à própria Guerra das Malvinas, e três posteriores. Destacam-se, neste estudo, justamente, as três últimas fases. Ou seja, a terceira fase, após a Guerra das Malvinas, onde são descritos, dentre outros aspectos, os encontros estratégicos organizados pelo EMFA (Brasil) e pelo EMCFA (Argentina) no final da década de 80 do século passado; a quarta fase, ao longo da década de 90, por ter sido o período em que as principais MCM de sucesso ocorreram; e a quinta fase, já na virada do milênio, onde são discutidos os limites atuais das MCM que vêm sendo adotadas e as possíveis perspectivas futuras. A primeira e a segunda fases situam-se ainda nos períodos iniciais e intermediários da Guerra Fria, mas, por já existirem ali algumas MCM embrionárias entre as Marinhas de Brasil e Argentina, importantes para desdobramentos futuros, estas fases têm também discutidas as suas importâncias históricas. Enfatiza-se que, na primeira fase, os principais episódios ocorreram sob grande influência dos EUA, enquanto, na segunda fase, já se constatava uma ligeira autonomia regional nas medidas adotadas. / There are analyzede, by means of traditional and new concepts of geopolitics, the special circumstances that surrounded the relations between Argentina and the main developed countries, the United States and part of Europe, during the Malvinas War, in order to, based on such conceptual tool, exam, how such episode impacted the Brazil-Argentina relations on South America. The main political, tactic and logistic events are described to help with the analysis. As of this turning point in the South-American history, it is used the concept of Mutual Confidence Measures (MCM) to verify how the Brazilian and Argentinean Navies intensified their relations in the new giopolitics milestone agreed upon between both countries. There are described the successful events in such approaching policy and politics in five different phases, didactically worked out: two prior to the Malvinas War and three afterwards. This study high lights precisely the three last phases, i.e., the phases after the Malvinas War. In the third phase, there are described, among other aspects, the strategic meetings organized by the EMFA (Brazil) and the EMCFA (Argentina) at the end of the 1980s; in the forth phase, are highly emphasized the 1990s since this is the period during which most of the MCM succeeded; and, in the fifth phase, already at the turning of the millennium, the current limits of the MCM, that are being adopted, are discussed, as well as the possible perspectives for the future. The first and second phases are the ones still during the beginning and intermediate periods of the Cold War. These phases are also discussed because they already presented some embryonic MCM policies between the Brazilian and Argentinean Navies, important for the way the events unfolded later on. In the first phase, there are stressed the main episodes that took place under the influence of the US, while, in the second, one can already notice a slight regional autonomy in the measures adopted.

Por meio de tradicionais e novos conceitos da Geopolítica, são analisadas as especiais circunstâncias que cercaram as relações entre a Argentina e os principais países do mundo desenvolvido, os EUA e parte da Europa, durante a Guerra das Malvinas, para, a partir desse mesmo ferramental conceitual, verificar como esse episódio teve seu impacto nas relações de Brasil e Argentina na América do Sul. Os principais acontecimentos políticos, táticos e logísticos desse conflito são descritos para auxiliar nessa análise feita. A partir desse ponto de inflexão na história sul-americana, utiliza-se o conceito de Medidas de Confiança Mútua (MCM) para se verificar como as Marinhas de Brasil e Argentina intensificaram suas relações dentro do novo marco geopolítico acordado entre os dois países. São descritos os sucessos dessa política de aproximação em cinco fases históricas distintas, didaticamente elaboradas: duas anteriores à própria Guerra das Malvinas, e três posteriores. Destacam-se, neste estudo, justamente, as três últimas fases. Ou seja, a terceira fase, após a Guerra das Malvinas, onde são descritos, dentre outros aspectos, os encontros estratégicos organizados pelo EMFA (Brasil) e pelo EMCFA (Argentina) no final da década de 80 do século passado; a quarta fase, ao longo da década de 90, por ter sido o período em que as principais MCM de sucesso ocorreram; e a quinta fase, já na virada do milênio, onde são discutidos os limites atuais das MCM que vêm sendo adotadas e as possíveis perspectivas futuras. A primeira e a segunda fases situam-se ainda nos períodos iniciais e intermediários da Guerra Fria, mas, por já existirem ali algumas MCM embrionárias entre as Marinhas de Brasil e Argentina, importantes para desdobramentos futuros, estas fases têm também discutidas as suas importâncias históricas. Enfatiza-se que, na primeira fase, os principais episódios ocorreram sob grande influência dos EUA, enquanto, na segunda fase, já se constatava uma ligeira autonomia regional nas medidas adotadas. / There are analyzede, by means of traditional and new concepts of geopolitics, the special circumstances that surrounded the relations between Argentina and the main developed countries, the United States and part of Europe, during the Malvinas War, in order to, based on such conceptual tool, exam, how such episode impacted the Brazil-Argentina relations on South America. The main political, tactic and logistic events are described to help with the analysis. As of this turning point in the South-American history, it is used the concept of Mutual Confidence Measures (MCM) to verify how the Brazilian and Argentinean Navies intensified their relations in the new giopolitics milestone agreed upon between both countries. There are described the successful events in such approaching policy and politics in five different phases, didactically worked out: two prior to the Malvinas War and three afterwards. This study high lights precisely the three last phases, i.e., the phases after the Malvinas War. In the third phase, there are described, among other aspects, the strategic meetings organized by the EMFA (Brazil) and the EMCFA (Argentina) at the end of the 1980s; in the forth phase, are highly emphasized the 1990s since this is the period during which most of the MCM succeeded; and, in the fifth phase, already at the turning of the millennium, the current limits of the MCM, that are being adopted, are discussed, as well as the possible perspectives for the future. The first and second phases are the ones still during the beginning and intermediate periods of the Cold War. These phases are also discussed because they already presented some embryonic MCM policies between the Brazilian and Argentinean Navies, important for the way the events unfolded later on. In the first phase, there are stressed the main episodes that took place under the influence of the US, while, in the second, one can already notice a slight regional autonomy in the measures adopted.

The aim of the study was to determine the causes of IODs in the workplace and to identify possible preventative measures to reduce IODs. A literature review was conducted as part of the study, involving assessment of all related articles and books on the subject of IODs in the workplace. A qualitative research methodology was utilised to conduct the study. The main research instruments were four focus group interviews and eight individual interviews. The study concluded that employees experienced IODs in different ways, with most participants describing negative experiences such as physical pain, undue financial hardship, psychological trauma and lack of support from the employer. A minor percentage experienced IODs in a positive sense in that there is heightened safety awareness in the workplace after an IOD has occurred, and the adoption of a more cautious approach by employees when performing their duties. From a practical and organisational/managerial perspective, the adoption of effective training of security officers and adherence to organisational standard operating procedures will assist in reducing IODs in the workplace. Limitations of the study included the small sample size from the research population, perceived language barriers during the interview processes and non-participation and inputs from managers at the organisation. However, it is hoped that the study will form the basis for further research to broaden the field to include parastatal or public-service entities / Human Resource Management / M. Com. (Human Resource Management)