136 research outputs found
Efficient SMT-Based Analysis of Failure Propagation
No full textThe process of developing civil aircraft and their related systems includes multiple phases of Preliminary Safety Assessment (PSA). An objective of PSA is to link the classification of failure conditions and effects (produced in the functional hazard analysis phases) to appropriate safety requirements for elements in the aircraft architecture. A complete and correct preliminary safety assessment phase avoids potentially costly revisions to the design late in the design process. Hence, automated ways to support PSA are an important challenge in modern aircraft design. A modern approach to conducting PSAs is via the use of abstract propagation models, that are basically hyper-graphs where arcs model the dependency among components, e.g. how the degradation of one component may lead to the degraded or failed operation of another. Such models are used for computing failure propagations: the fault of a component may have multiple ramifications within the system, causing the malfunction of several interconnected components. A central aspect of this problem is that of identifying the minimal fault combinations, also referred to as minimal cut sets, that cause overall failures.
In this paper we propose an expressive framework to model failure propagation, catering for multiple levels of degradation as well as cyclic and nondeterministic dependencies. We define a formal sequential semantics, and present an efficient SMT-based method for the analysis of failure propagation, able to enumerate cut sets that are minimal with respect to the order between levels of degradation. In contrast with the state of the art, the proposed approach is provably more expressive, and dramatically outperforms other systems when a comparison is possible
Melhoria do processo de atendimento ao cliente: um estudo de caso
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de Produção.Com o objetivo de conhecer, descrever e avaliar o processo de atendimento às correspondências encaminhadas à empresa pesquisada, este estudo teve o propósito de apresentar um novo modelo de atendimento ao cliente e foi desenvolvido com base na análise de dados obtidos por meio de questionários aplicados via correspondência eletrônica aos funcionários da empresa, de nível administrativo. A partir dos resultados foi possível identificar os fatores críticos do processo em questão e determinar as estratégias de aprimoramento para o atendimento das necessidades formais dos clientes. Este estudo destacou, em especial, a formação de grupos de trabalho "Donos do Processo", cuja estrutura tem como objetivo a orientação, a execução e o acompanhamento do processo em questão. Ele evidencia ainda a automação da ferramenta de registro, tornando-a mais interativa, controladora e dinâmica, e caracteriza o envolvimento e o apoio de todos os níveis hierárquicos da organização, desde a concepção do projeto, até a sua efetiva implementação. A fundamentação teórica centrou-se no gerenciamento de processos, nos conceitos de atendimento ao cliente, na gestão da qualidade e na cultura do comprometimento humano. Com base nos conhecimentos adquiridos e na proposta pela qual fundamenta-se esta pesquisa, buscou-se, por último, a constatação dos conceitos abordados, que resultou na compreensão do modelo adotado. Ressalta ainda as influências internas e governamentais, estabelecendo ações para a busca do comprometimento dos integrantes da organização, visando o alcance e manutenção das metas estabelecidas. Esta pesquisa aborda fundamentalmente a importância da aplicação da metodologia de gerenciamento de processos como modelo para a gestão dos resultados de performance e de melhoria do processo de atendimento ao cliente. Aiming to know, to describe and to evaluate the process of service to the correspondences directed to the researched company, this study had the goal to present a new model of service to the customer and was developed based on the analysis of data achieved through questionnaires applied by eletronic correspondence to the employees of the company. From the results it was possible to identify the critical factors of the process in question, and to determine the strategies of improvement for the service of the formal necessities of the customers. These study outstands in special, the formation of work groups "Owners of the Process", whose structure has as objective the leading, accomplishment and the follow up of the process in question. The study still outstands the automation of the "registering tool", making it more interactive, controller and dynamics, evolvement and the support of all the hierarchic levels of the organization, the conception of the project, until its effective implementation. The theoretical presupposing was based in the management of processes, in the concepts of service to the customer, in the management of the quality, and the culture of the human commitment. Based on the knowledge achieved and in the proposal for which this research is based, it was aimed finally, the confirmation of the approached concepts, that resulted in the understanding of the adopted model. It still out stands the internal and governmental influences, establishing actions for the search of the commitment of the members of the organization, aiming at the reach and maintenance of the established goals. This research basically approaches the importance of the use of the methodology of management of process as a model for the management of the results of performance and improvement of the process of service to the customer
Formal Design and Safety Analysis of AIR6110 Wheel Brake System
No full textSAE Aerospace Information Report 6110, “Contiguous Aircraft/System Development Process Example,” follows the development of a complex wheel brake system (WBS) using processes in the industry standards Arp4754A, “Guidelines for Development of Civil Aircraft and Systems,” and Arp4761, “Guidelines and Methods for Conducting the Safety Assessment Process on Civil Airborne Systems and Equipment.”
Air6110 employs informal methods to examine several WBS architectures which meet the same requirements with different degrees of reliability.
In this case study, we analyze the Air6110 with formal methods. First, WBS architectures in Air6110 formerly using informal steps are recreated in a formal manner. Second, methods to automatically analyze and compare the behaviors of various architectures with additional, complementary information not included in the Air6110 are presented. Third, we provide an assessment of distinct formal methods ranging from contract-based design, to model checking, to model based safety analysi
The illegal parrot trade in the neo-tropics: the relationship between poaching and illicit pet markets
No full textDue to the global illegal parrot trade in conjunction with habitat loss, parrots are among the most threatened bird species in the world. Despite laws against parrot poaching throughout the neo-tropics, the lack of enforcement in the wild and in city pet markets enables poachers, itinerant fences (i.e. middlemen), and sellers to continue in the illegal wildlife trade while parrot populations further decline. Recent publications, which take account of parrot poaching variation in Mexico, Bolivia, and Peru, have enabled criminologists to attempt to explain why some parrot species tend to be poached more often than others. Using two recent studies that look at illicit pet markets in 7 cities within Peru and Bolivia (Gastanaga et al., 2010; Herrera and Hennessey, 2008), this dissertation will analyze why some parrot species end up on any of the seven illicit pet markets (N=50) and why some species were never found on any illicit pet market despite their close proximity to one (N=17). Using the CRAVED model (Clarke, 1999) and the Choice-Structuring Properties (Clarke and Cornish, 1987) concept to examine the illegal parrot trade, this study finds that illicit parrot markets are not homogenous in nature. Using GIS data on where parrot ranges are relative to the illicit markets they appear on, this study reveals there are three types of illicit parrot markets: local, regional, and feeder markets. Local markets will mostly be comprised of highly local species, whereas regional markets will obtain species from very far off distances via itinerant fences. Feeder markets on the other hand, are mostly responsible for creating a large internal parrot trade within countries such as Peru and Bolivia. They supply not only local demand, but also supply other cities with parrots. This study also finds support for opportunity-based factors such as availability and abundance in relation to poaching risk. This is now the third study to substantiate these concepts as the most important factors related to poaching. Other CRAVED factors such as enjoyability and removability were not found to be significantly related to poaching, despite previous findings in Bolivia and Mexico showing otherwise.Ph. D.Includes bibliographical referencesIncludes vitaby Stephen Ferreira Pire
Improvement of software verification processes by combining formal methods with Model Driven Engineering
No full textLors d’un développement logiciel, et plus particulièrement d’un développement d’applications embarquées avioniques, les activités de vérification représentent un coût élevé. Une des pistes prometteuses pour la réduction de ces coûts est l’utilisation de méthodes formelles. Ces méthodes s’appuient sur des fondements mathématiques et permettent d’effectuer des tâches de vérification à forte valeur ajoutée au cours du développement. Les méthodes formelles sont déjà utilisées dans l’industrie. Cependant, leur difficulté d’appréhension et la nécessité d’expertise pour leur mise en pratique sont un frein à leur utilisation massive. Parallèlement au problème des coûts liés à la vérification logicielle, vient se greffer la complexification des logiciels et du contexte de développement. L’Ingénierie Dirigée par les Modèles (IDM) permet de faire face à ces difficultés en proposant des modèles, ainsi que des activités pour en tirer profit.Le but des travaux présentés dans cette thèse est d’établir un lien entre les méthodes formelles et l’IDM afin de proposer à des utilisateurs non experts une approche de vérification formelle et automatique de programmes susceptible d’améliorer les processus de vérification actuels. Nous proposons de générer automatiquement sur le code source des annotations correspondant aux propriétés comportementales attendues du logiciel, et ce, à partir de son modèle de conception. Ces annotations peuvent ensuite être vérifiées par des outils de preuve déductive, afin de s’assurer que le comportement du code est conforme au modèle. Cette thèse CIFRE s’inscrit dans le cadre industriel d’Atos. Il est donc nécessaire de prendre en compte le contexte technique qui s’y rattache. Ainsi, nous utilisons le standard UML pour la modélisation,le langage C pour l’implémentation et l’outil Frama-C pour la preuve du code. Nous tenons également compte des contraintes du domaine du logiciel avionique dans lequel Atos est impliqué et notamment les contraintes liées à la certification.Les contributions de cette thèse sont la définition d’un sous-ensemble des machines à états UML dédié à la conception comportementale de logiciel avionique et conforme aux pratiques industrielles existantes, la définition d’un patron d’implémentation C, la définition de patrons de génération des propriétés comportementales sur le code à partir du modèle et enfin l’implémentation de l’approche dans un prototype compatible avec l’environnement de travail des utilisateurs potentiels en lien avec Atos. L’approche proposée est finalement évaluée par rapport à l’objectif de départ, par rapport aux attentes de la communauté du génie logiciel et par rapport aux travaux connexes.During software development, and more specifically embedded avionics applications development, verification is very expensive. A promising lead to reduce its costs is the use of formal methods. Formal methods are mathematical techniques which allow performing rigorous and high-valued verification tasks during software development. They are already applied in industry. However, the high level of expertise required for their use is a major obstacle for their massive use. In addition to the verification costs issue, today software and their development are subject to an increase in complexity. Model Driven Engineering (MDE) allows dealing with these difficulties by offering models, and tasks to capitalize on these models all along the development lifecycle. The goal of this PhD thesis is to establish a link between formal methods and MDE in order to propose to non-expert users a formal and automatic software verification approach which helps to improve software verification processes. We propose to automatically generate annotations, corresponding to the expected behavioural properties of the software, from the design model to the source code. Then, these annotations can be verified using deductive proof tools in order to ensure that the behaviour of the code conforms to the design model. This PhD thesis takes place in the industrial context of Atos. So, it is necessary to take into account its technical specificities. We use UML for the design modeling, the C language for the software implementation and the Frama-C tool for the proof of this implementation. We also take into account the constraints of the avionics field in which Atos intervenes, and specifically the certification constraints. The contributions of this PhD thesis are the definition of a subset of UML state machine dedicated to the behavioural design of embedded avionics software and in line with current industrial practices, the definition of a C implementation pattern, the definition of generation patterns for the behavioural properties from the design model to the source code and the implementation of the whole approach in a prototype in accordance with the working environment of the potential users associated with Atos. The proposed approach is then assessed with respect to the starting goal of the thesis, to the expectation of the software engineering community and to related work
Formal Software Verification at Model and at Source Code Levels
No full textInternational audienceIn a software development lifecycle, it is often more than half of the development time that is dedicated to verification activities. Formal methods offer new possibilities for verification. In the specification phase, simulation or model-checking allow users to detect errors in models. In the implementation phase, analysis techniques, like static analysis, make the verification tasks more exhaustive and more automatic. In this context, we propose to take advantage of these methods to improve embedded software development processes based on the V-model
La beauté : « une promesse qui ne peut être tenue » ? Étude comparative des esthétiques de Blaise Pascal et de Charles Baudelaire
No full textEven if two centuries separate them, Pascal and Baudelaire draw from the same fund of Jansenist tradition, sharing a common imaginary and a similar anthroplogical conception. Both experience nostalgia for the Fall. One might think that their aesthetics are based on symmetrical principles. However, since Baudelaire considers himself cursed and predestined to evil, any exit from the top of the metaphysical disaster is impossible for him. Unable to bring himself to contemplate again the Pascalian model of true beauty which finds its ultimate foundation in the divine understanding, Baudelaire erects the "false beauties" stigmatized by the author of Pensées in True beauty. And then, the poetic Art begins to assume the functions of religion given that he and he alone has the power to assure the salvation of the cursed poet.Même si deux siècles les séparent, Pascal et Baudelaire puisent dans le même fonds de tradition janséniste, partageant un imaginaire commun et une conception anthropologique similaire. Tous deux éprouvent la nostalgie de la Chute. On pourrait donc croire que leurs esthétiques se fondent sur des principes symétriques. Toutefois, étant donné que Baudelaire s'estime maudit et prédestiné au mal, toute sortie par le haut du désastre métaphysique lui est impossible. Ne pouvant se résoudre à contempler de nouveau le modèle pascalien de vraie beauté qui se trouve dans l'entendement divin, Baudelaire érige les « fausses beautés » stigmatisées par l'auteur des Pensées en Vraie beauté. C'est alors que l'Art poétique se met à assurer les fonctions de la religion puisque lui et lui seul a le pouvoir d'assurer le salut du poète maudit
A Laranja Mecânica no Brasil: análise das traduções e recepção da obra e de Anthony Burgess no país
No full textDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Comunicação e Expressão, Programa de Pós-Graduação em Estudos da Tradução, Florianópolis, 2020.Este trabalho apresenta a tradução comentada ao português brasileiro do entremez intitulado ?La destreza?, obra satírica do escritor espanhol Francisco de Quevedo y Villegas (1580-1645). Foi utilizado como texto fonte para a tradução a edição de Eugenio Asensio, que reúne um amplo e primordial estudo acerca do gênero entremez em seu livro Itinerario del entremés ? desde Lope de Rueda a Quiñones de Benavente con cinco entremeses de D. Francisco de Quevedo, publicado no ano de 1971. O processo tradutório é realizado sobretudo sob a perspectiva da equivalência natural, proposta por estudiosos como Pym (2017) e Britto (2012), e da transcriação, tendo como base Haroldo de Campos (2015) ? ainda que os dois últimos possuam posturas divergentes em relação a teorias da tradução. Faço ainda, ao longo dos capítulos deste trabalho, um estudo acerca dos elementos que permeiam Quevedo e seu entremez ?La destreza?, isto é, o gênero teatral, o Século de Ouro, as relações sociais que o autor manteve ao longo de sua vida, outros gêneros literários pelos quais caminhou e a importância dos demais escritores áureos. Para tais pesquisas, foram consultados os trabalhos de renomados estudiosos de Quevedo, tais como Asensio (1971), Fernández (2009), Sabor de Cortázar (2010), Arellano (2012), entre muitos outros. Esta pesquisa se faz importante devido à aproximação entre culturas distintas favorecida pelo ato tradutório. Um gênero literário tão prestigiado em terras espanholas como o teatro é passível de ser transportado ao Brasil e ainda manter a comicidade característica do entremez, assim como favorecer o conhecimento acerca da história e do contexto do período áureo espanhol.Resumen: Este trabajo presenta la traducción anotada al portugués brasileño del entremés ?La destreza?, obra satírica del escritor español Francisco de Quevedo y Villegas (1580-1645). Fue utilizado como texto fuente para la traducción la edición de Eugenio Asensio, que reúne un amplio y primordial estudio acerca del género entremés en su libro Itinerario del entremés ? desde Lope de Rueda a Quiñones de Benavente con cinco entremeses de D. Francisco de Quevedo, publicado en el año de 1971. El proceso de traducción es realizado fundamentalmente bajo la perspectiva de la equivalencia natural, propuesta por estudiosos como Pym (2017) y Britto (2012), y de la transcriação, con base en Haroldo de Campos (2015) ? aunque los dos últimos estudiosos tengan visiones diferentes en relación a teorías de la traducción. Hago aún, a lo largo de los capítulos de este trabajo, un estudio acerca de los elementos que cercan Quevedo y su entremés ?La destreza?, es decir, el género teatral, el Siglo de Oro, las relaciones sociales que el autor mantuvo a lo largo de su vida, otros géneros literarios que escribió y la importancia de los demás escritores áureos. Para tales investigaciones, fueron consultados los trabajos de renombrados estudiosos de Quevedo, tales como Asensio (1971), Fernández (2009), Sabor de Cortázar (2010), Arellano (2012), entre muchos otros. Esta investigación es importante por la aproximación entre culturas distintas favorecida por el acto de la traducción. Un género literario tan prestigiado en España como el teatro puede ser trasportado a Brasil y mantener la comicidad característica del entremés, bien como favorecer el conocimiento acerca de la historia y del contexto del período áureo español
Considering the Aeronautics Cyber-Security Standards for Multi-Core Platforms
No full textNew complex functions are emerging for avionic systems. These new functions ask for high performance computing, which mean the need to embed new type of hardware such as hybrid architectures integrating multi or many-core processors. However, these processors are often Commercial Off-The-Shelf and suffer a lack of documentation and predictability. In the all-connected trend of today digital world, these issues can lead to new security vulnerabilities exploitable by malicious people. In the context of the PHYLOG 2 research project aiming at defining a certification framework for multi-core platforms, we study the aeronautics standards ED-202A/DO-326A and ED-203A/DO-356A about airworthiness security. The objective is to take into account these standards at the level of the multicore processors in order to ensure the compliance of security assessment and development for certification. We present our review and understanding of the standards and their projection at the level of multi-core platforms. In addition, we describe our application on a use case and report our feedback
Trying to Elicit and Assign Goals to the Right Actors
No full textInternational audienceAt the beginning of a project, an organisation may define very abstract goals. These high-level goals describe organisation characteristics that all projects must fulfil. Due to the very generic and abstract nature of these goals, it is sometimes not easy to break them down into more concrete goals and to decide who should be responsible for what. For many years, goal modelling approaches have proposed frameworks for eliciting and defining stakeholders' goals in an organisation. In the context of an aeronautical company, we conducted an application on a case of study of a goal modelling method. From high-level goals, we have supported business experts in eliciting more concrete goals, assigning them to the right actors and identifying possible organisational needs. For this, we started from an existing method that we have adapted to fit our purposes
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