Dissertations / Theses: 'Formal control models'

1

Sieunarine, Clint Vaalmicki. "Evolving access control : formal models and analysis." Thesis, University of Oxford, 2011. http://ora.ox.ac.uk/objects/uuid:46dde528-207c-4e86-a282-20e73a5de10c.

Full text

Abstract:

Any model of access control has two fundamental aims: to ensure that resources are protected from inappropriate access and to ensure that access by authorised users is appropriate. Traditionally, approaches to access control have fallen into one of two categories: discretionary access control (DAC) or mandatory access control (MAC). More recently, role-based access control (RBAC) has offered the potential for a more manageable and flexible alternative. Typically, though, whichever model is adopted, any changes in the access control policy will have to be brought about via the intervention of a trusted administrator. In an ever-more connected world, with a drive towards autonomic computing, it is inevitable that a need for systems that support automatic policy updates in response to changes in the environment or user actions will emerge. Indeed, data management guidelines and legislation are often written at such a high level of abstraction that there is almost an implicit assumption that policies should react to contextual changes. Furthermore, as access control policies become more complicated, there is a clear need to express and reason about such entities at a higher level of abstraction for any meaningful analysis to be tractable, especially when consideration of complex state is involved. This thesis describes research conducted in formalising an approach to access control, termed evolving access control (EAC), that can support the automatic evolution of policies based on observed changes in the environment as dictated by high-level requirements embodied in a metapolicy. The contribution of this research is a formal, conceptual model of EAC which supports the construction, analysis and deployment of metapolicies and policies. The formal EAC model provides a framework to construct and describe metapolicies and to reason about how they manage the evolution of policies. Additionally, the model is used to analyse metapolicies for desirable properties, and to verify that policies adhere to the high-level requirements of the metapolicy. Furthermore, the model also allows the translation of verified policies to machine-readable representations, which can then be deployed in a system that supports fine-grained, dynamic access control.

APA, Harvard, Vancouver, ISO, and other styles

2

Ahlman, Karin. "Improving formal analysis of computerised rail traffic control systems using domain models." Thesis, Uppsala universitet, Institutionen för informationsteknologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-283398.

Full text

Abstract:

During the formal analysis of a computerized railway control system, it may be difficult to understand if a found counterexample to a requirement is a scenario which can happen in the real world or not. By putting sensible constraints on the inputs to the system, i.e. by defining a domain model for the system, some impossible scenarios are excluded from the formal analysis, which means that the formal analysis is simplified. This thesis presents a domain model for railway control systems, expressing constraints on how trains can behave in a railway network. The railway network is abstracted into a simple graph structure and the model is described in a temporal predicate logic using operators for the initial (I) and the next (X) value. The model is carefully defined in order not to introduce any unrealistic behavior.

APA, Harvard, Vancouver, ISO, and other styles

3

Muhammad, W. "Assistance à l'Abstraction de Composants Virtuels pour la Vérification Rapide de Systèmes Numériques." Phd thesis, Université de Nice Sophia-Antipolis, 2008. http://tel.archives-ouvertes.fr/tel-00454617.

Full text

Abstract:

De nos jours la conception des IP (IP: Intellectual Property) peut bénéficier de nouvelles techniques de vérification symbolique: abstraction de donnée et analyse statique formelle. Nous pensons qu'il est nécessaire de séparer clairement le Contrôle des Données avant toute vérification automatique. Nous avons proposé une définition du contrôle qui repose sur l'idée intuitive qu'il a un impact sur le séquencement de données. Autour de cette idée, le travail a consisté à s'appuyer sur la sémantique des opérateurs booléens et proposer une extension qui exprime cette notion deséquencement. Ceci nous a mené à la conclusion que la séparation parfaite du contrôle et des données est illusoire car les calculs dépendent trop de la représentation syntaxique. Pour atteindre notre objectif, nous nous sommes alors basés sur la connaissance fournie par le concepteur: séparation a priori des entrées contrôle et des entrées données. De cela, nous avons proposé un algorithme de slicing pour partitionner le modèle. Une abstraction fut alors obtenue dans le cas où le contrôle est bien indépendant des données. Pour accélérer les simulations, nous avons remplacé le traitement de données, défini au niveau bit par un modèle d'exécution fonctionnel, tout en gardant inchangé la partie contrôle. Ce modèle intègre des aspects temporels qui permet de se greffer sur des outils de model checking. Nous introduisons la notion de significativité support des données intentionnelles dans les modèles IP. La significativité est utilisée pour représenter des dépendances de données booléennes en vue de vérifier formellement et statiquement les lots de données. Nous proposons plusieurs approximations qui mettent en oeuvre cette nouvelle notion.

APA, Harvard, Vancouver, ISO, and other styles

4

MOREIRA, Anne Lorayne Gerônimo Silva Augusto. "Modelagem e veriﬁcação automática de um protocolo de controle de fluxo adaptativo usando traços de execução." Universidade Federal de Campina Grande, 2016. http://dspace.sti.ufcg.edu.br:8080/jspui/handle/riufcg/768.

Full text

Abstract:

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-05-22T14:55:43Z No. of bitstreams: 1 ANNE LORAYNE GERÕNIMO SILVA AUGUSTO MOREIRA - DISSERTAÇÃO (PPGCC) 2016.pdf: 843001 bytes, checksum: 3c03d468b4f80d420da1bad90adf7ca0 (MD5)
Made available in DSpace on 2018-05-22T14:55:43Z (GMT). No. of bitstreams: 1 ANNE LORAYNE GERÕNIMO SILVA AUGUSTO MOREIRA - DISSERTAÇÃO (PPGCC) 2016.pdf: 843001 bytes, checksum: 3c03d468b4f80d420da1bad90adf7ca0 (MD5) Previous issue date: 2016
Capes
O desenvolvimento de sistemas embarcados possibilitou uma forte expansão no número de aplicações dependentes de dispositivos programáveis em áreas tão distintas como automobilística, sistemas ﬁnanceiros e sistemas médicos. Uma eventual falha em algum desses sistemas pode provocar diferentes graus de danos e prejuízos e, por isso, exige-se um alto grau de conﬁabilidade em seu funcionamento. O aumento da complexidade dos novos sistemas computacionais e a pressão econômica e busca de novos mercados, concorrem para a busca da redução nos prazos de entrega dos dispositivos programáveis e de seus softwares e sistemas embarcados. Este trabalho apresenta um estudo de caso para a utilização de um método de veriﬁcação formal de software aplicado a um sistema computacional de controle de ﬂuxo adaptativo para Gateways Bluetooth Low-Energy utilizados em sistemas de monitoramento remoto de pacientes. Os resultados obtidos neste trabalho conﬁrmam a viabilidade da aplicação do método na veriﬁcação formal do software proposto.
The embedded system development had a positive impact on the expansion of applications dependent on programmable devices inside many areas such as automotive industry, ﬁnancial services, and medical systems. A failure in any of these systems can cause losses and damages on many levels. Therefore, embedded systems require a high level of reliability while operating. The increasing complexity of these new computational systems, the cost-effective pressure, and the new market demand, contribute to reduce the delivery deadlines of the programmable devices, their softwares, and embedded systems. This research presents a case study in which we evaluated the usage of a formal veriﬁcation method applied to a computational controlling system, with adaptive ﬂow, for Gateway Bluetooth Low Energy used in patient monitoring systems. The results obtained in this study conﬁrm the application feasibility of the formal veriﬁcation method of the proposed software.

APA, Harvard, Vancouver, ISO, and other styles

5

Duplouy, Yann. "Applying Formal Methods to Autonomous Vehicle Control." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLN048/document.

Full text

Abstract:

Cette thèse s'inscrit dans le cadre de la conception de véhicules autonomes, et plus spécifiquement de la vérification de contrôleurs de tels véhicules. Nos contributions à la résolution de ce problème sont les suivantes : (1) fournir une syntaxe et une sémantique pour un modèle de systèmes hybrides, (2) étendre les fonctionnalités du model checker statistique Cosmos à ce modèle et (3) valider empiriquement la pertinence de notre approche sur des cas d'étude typiques du véhicule autonome.Nous avons choisi de combiner le modèle des réseaux de Petri stochastiques de haut niveau (qui était le formalisme d'entrée de Cosmos) avec le formalisme d'entrée de Simulink afin d'atteindre un pouvoir d'expression suffisant. En effet Simulink est très largement utilisé dans le domaine automobile et de nombreux contrôleurs sont spécifiés avec cet outil. Or Simulink n'a pas de sémantique formellement définie. Ceci nous a conduit à concevoir une telle sémantique en deux temps : tout d'abord en introduisant une sémantique dite exacte mais qui n'est pas opérationnelle puis en la complétant par une sémantique approchée intégrant le facteur d'approximation recherché.Afin de combiner le modèle à événements discrets des réseaux de Petri et le modèle continu spécifié en Simulink, nous avons proposé au niveau syntaxique une interfacereposant sur de nouveaux types de transitions et au niveau sémantique une extension de la boucle de simulation. L'évaluation de ce nouveau formalisme a été entièrement implémentée dans Cosmos.Grace à ce nouveau formalisme, nous avons développé et étudié les deux cas d'étude suivants : d'une part une circulation dense sur une section d'autoroute et d'autre part l'insertion du véhicule dans une voie rapide. L'analyse des modélisations correspondantes a démontré la pertinence de notre approche
This thesis takes place in the context of autonomous vehicle design, and concerns more specifically the verification of controllers of such vehicles. Our contributions are the following: (1) give a syntax and a semantics for a hybrid system model, (2) extend the capacities of the model-checker Cosmos to that kind of models, and (3) empirically confirm the relevance of our approach on typical case studies handling autonomous vehicles.We chose to combine high-level stochastic Petri nets (which is the input formalism of Cosmos) with the input formalism of Simulink, to obtain an adequate expressive power. Indeed, Simulink is largely used in the automotive industry and numerous controllers have been specified using this tool. However, there is no formal semantics for Simulink, which lead us to define such a semantics in two steps:first, we propose an exact (but not operational) semantics, then we complete it by an approximate semantics that includes the targeted approximation level.In order to combine the discrete event model of Petri nets and the continous model specified in Simulink, we define a syntactic interface that relies on new transition types; its semantics consists of an extension of the simulation loop. The evaluation of this new formalism has been entirely implemented into Cosmos.Using this new formalism, we have designed and studied the two following case studies: on one hand, a heavy traffic on a motorway segment, and on the other hand the insertion of a vehicle into a motorway. Our approach has been validated by the analysis of the corresponding models

APA, Harvard, Vancouver, ISO, and other styles

6

Moeti, Sekhonyana. "Formal analysis of state estimation for nonlinear model predictive control." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/20065.

Full text

Abstract:

The main goal of this study is to carry out a closed-loop performance analysis of state estimation methods when implemented in the formulation of nonlinear model predictive control. The analysis is facilitated by two nonlinear optimal state estimation methods: augmented state EKF (ASEKF) and augmented state UKF (ASUKF) for comparison purposes. Each state estimation method is coupled to the same NMPC controller to form state estimation-based NMPC controllers, that is, to form the ASEKF-NMPC and ASUKFNMPC controllers. The resulting NMPC controllers are applied for position control of the magnetic levitation system to validate their closed-loop performances. The ASEKFNMPC and ASUKF-NMPC controllers are further applied for the angular position control of the inverted pendulum mounted on a cart system for comparative analysis. The controlled system is perturbed with different error sources: output step disturbance and 5%parametric plant-model mismatch. Output step disturbance is introduced to the system to disturb the pendulum from its upright position while the 5% mismatch is applied to the parameters of the model of the controlled system throughout the simulation. To facilitate fair analysis, Pareto front ranking method is chosen as an evaluation method whereby the cost functions are defined according to the author's preferences. The cost functions served as performance markers for analyzing performance of ASEKF and ASUKF in NMPC formulation in multidimensional space. The tunable parameters of the ASEKFNMPC and ASUKF-NMPC controllers are chosen to be the decision variables of the evaluation problem. The state estimation methods are evaluated in terms of estimation accuracy, system's response time, peak overshoot and control performance. The Level Diagrams tool is used for good visualization of the Pareto fronts to evaluate which estimator performs better in the closed-loop. Finally, the points on the Level Diagrams which provide a performance closest to the desired are selected and tested through simulation runs on the inverted pendulum on a moving cart system.

APA, Harvard, Vancouver, ISO, and other styles

7

Benson, Glenn Stuart. "A formal protection model of security in distributed systems." Diss., Georgia Institute of Technology, 1989. http://hdl.handle.net/1853/12238.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Ianagui, André Seiji Sandes. "Modelagem e controle de atuador antagônico de liga de memória de forma." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-15072013-164506/.

Full text

Abstract:

Este trabalho apresenta a modelagem, identificação de parâmetros e projeto do sistema de controle de um atuador rotacional antagônico com refrigeração forçada baseado em fios de liga de memória de forma, tendo em vista a aplicação em manipuladores robóticos. O modelo é baseado na abordagem de transformação de fases por subcamadas, que leva em conta a alta não linearidade que ocorre devido à dinâmica de transformação de fases do fio de memória de forma (especialmente a alta histerese envolvida). Um algoritmo de otimização por meio de Programação Quadrática Sequencial é então usado para se estimar os parâmetros do modelo de difícil obtenção exata, como as temperaturas de transição de fase dos fios de liga de memória de forma e o coeficiente de convecção. A função objetivo adotada é o erro entre a posição medida experimentalmente e a posição obtida por meio de modelagem e simulação. Parte-se de valores de parâmetros iniciais de tabela para a aplicação do algoritmo. Os resultados são em seguida comparados e avaliados com experimentos independentes em malha aberta, com o modelo apresentando boa correlação com a planta para uma excitação de até 2,0 Hz. Por fim, um sistema de controle não linear por modos deslizantes baseado no modelo é desenvolvido e simulado utilizando o modelo estimado, tanto em modo de controle de torque como em controle de posição. Aplica-se um controlador com camada limite e linearização utilizando a realimentação dos estados e o modelo estimado. Este tipo de controlador é robusto a eventuais diferenças entre o modelo e o sistema real. O controlador é então utilizado num modelo sistema de experimental, a partir do qual são obtidos resultados de desempenho dinâmico e exatidão do atuador controlado ao mesmo tempo em que são feitas comparações com os resultados das simulações. Por fim, demonstra-se que os objetivos iniciais do trabalho são atingidos, ao se realizar satisfatoriamente o controle de posição e de torque com robustez, exatidão e desempenho dinâmico adequados à aplicação prevista.
This work presents the modeling, grey-box parameter estimation and control design of a force-cooled antagonistic shape memory alloy (SMA) rotational actuator, having in mind the application in robotic manipulators. The model is based on a sub-layer phase transformation approach, taking account the large non-linearities that rise from the phase-transformation dynamics (in special, the highly hysteretic dynamics). An optimization Quadratic Sequential Programming Algorithm is used to for estimate estimating the model parameters, which are hard to obtain accurately, like the such as phase transition temperatures of the shape memory alloy wires and the convection coefficient. The objective function adopted is the error between the experimentally measured position and the position obtained by means of modeling and simulation. Initial parameters for the algorithm application are taken from factory tables\' datasheets. The results are then compared and evaluated with independent open loop experiments. At last, a model based nonlinear shape memory alloy SMA control scheme is designed and simulated using the estimated model, in torque and position control modes. The control scheme applied uses limit layer and feedback linearization using based on the estimated model. This control scheme is robust to eventual mismatch between modeling and the real system. The controller is then used in an experimental model, from which results of dynamic behavior and accuracy of the controlled actuator are obtained and compared with the simulated results. At last, it is showed that the initial objectives of this work are achieved, by satisfactorily performing position and torque control with robustness, accuracy and dynamic performances adequate to the application targeted.

APA, Harvard, Vancouver, ISO, and other styles

9

Brown, Douglas Graeme. "Formal network behaviour analysis using model checking." Thesis, Queensland University of Technology, 2016. https://eprints.qut.edu.au/93693/1/Douglas_Brown_Thesis.pdf.

Full text

Abstract:

In this research we modelled computer network devices to ensure their communication behaviours meet various network standards. By modelling devices as finite-state machines and examining their properties in a range of configurations, we discovered a flaw in a common network protocol and produced a technique to improve organisations' network security against data theft.

APA, Harvard, Vancouver, ISO, and other styles

10

Cohen, Raphaël P. "Formal Verification and Validation of Convex Optimization Algorithms For model Predictive Control." Thesis, Toulouse, ISAE, 2018. http://www.theses.fr/2018ESAE0030/document.

Full text

Abstract:

L’efficacité des méthodes d’optimisation modernes, associée à l’augmentation des ressources informatiques, a conduit à la possibilité d’utiliser ces algorithmes d’optimisation en temps réel agissant dans des rôles critiques. Cependant, cela ne peut se produire sans porter une certaine attention à la validité de ces algorithmes. Ce doctorat traite de la vérification formelle des algorithmes d'optimisation convexe lors qu'ils sont utilisés pour la guidance de systèmes dynamiques. En outre, nous démontrons comment les preuves théoriques des algorithmes d'optimisation en temps réel peuvent être utilisées pour décrire les propriétés fonctionnelles au niveau du code, les rendant ainsi accessibles à la communauté des méthodes formelles
The efficiency of modern optimization methods, coupled with increasing computational resources, has led to the possibility of real-time optimization algorithms acting in safety critical roles. However, this cannot happen without addressing proper attention to the soundness of these algorithms. This PhD thesis discusses the formal verification of convex optimization algorithms with a particular emphasis on receding-horizon controllers. Additionally, we demonstrate how theoretical proofs of real-time optimization algorithms can be used to describe functional properties at the code level, thereby making it accessible for the formal methods community

APA, Harvard, Vancouver, ISO, and other styles

11

Chaves, Lennon Corrêa, and 92-99155-6510. "Formal verification applied to attitude control software of unmanned aerial vehicles." Universidade Federal do Amazonas, 2018. https://tede.ufam.edu.br/handle/tede/6368.

Full text

Abstract:

Submitted by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-05-10T17:55:53Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_lennon_chaves.pdf: 2813829 bytes, checksum: 48c3fbefe451491c81bbf9ddb680a318 (MD5)
Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2018-05-10T17:56:13Z (GMT) No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_lennon_chaves.pdf: 2813829 bytes, checksum: 48c3fbefe451491c81bbf9ddb680a318 (MD5)
Made available in DSpace on 2018-05-10T17:56:14Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) dissertacao_lennon_chaves.pdf: 2813829 bytes, checksum: 48c3fbefe451491c81bbf9ddb680a318 (MD5) Previous issue date: 2018-02-02
During the last decades, model checking techniques have been applied to improve overall system reliability, in unmanned aerial vehicle (UAV) approaches. Nonetheless, there is little effort focused on applying those methods to the control-system domain, especially when it comes to the investigation of low-level implementation errors, which are related to digital controllers and hardware compatibility. The present study addresses the mentioned problems and proposes the application of a bounded model checking tool, named as Digital System Verifier (DSVerifier), to the verification of digital-system implementation issues, in order to investigate problems that emerge in digital controllers designed for UAV attitude systems. A verification methodology to search for implementation errors related to finite word-length effects ( e.g., arithmetic overflows and limit cycles), in UAV attitude controllers, is presented, along with its evaluation, which aims to ensure correct-by-design systems. Experimental results show that failures in UAV attitude control software used in aerial surveillance, which are hardly found by simulation and testing tools, can be easily identified by DSVerifier.
Durante as últimas décadas, técnicas de verificação de modelos tem sido utilizadas para melhorar a confiabilidade de sistemas, no que diz respeito a veículos aéreos não-tripulados (VANTs). Contudo, existem poucos esforços focados em aplicar esses métodos ao controle de sistemas, especialmente os relativos à investigação de erros de implementação de baixo nível, os quais estão relacionados a controladores digitais e compatibilidade de hardware. O presente trabalho aborda os problemas mencionados e propõe a aplicação de uma ferramenta de verificação limitada de modelos, conhecida como Digital System Verifier (DSVerifier) ou Verificador de Sistemas Digitais, à verificação de implementação de sistemas digiais, com o objetivo de investigar problemas em controladores digitais projetados para sistemas de atitude em VANTs. Apresenta-se uma metodologia de verificação para procurar por erros de implementação relacionados a efeitos de tamanho de palavra finita (i.e, estouros aritméticos e ciclos-limites), em controladores de atitude de VANTs, juntamente com sua avaliação, o que visa garantir a corretude desses sistemas. Resultados experimentais mostram que falhas encontradas em software de controle de atitude de VANTs usados em vigilância aérea, as quais são dificilmente encontradas pro simulação e ferramentas de teste, podem ser facilmente identificadas pelo DSVerifier.

APA, Harvard, Vancouver, ISO, and other styles

12

Chen, Zhe. "The control system in formal language theory and the model monitoring approach for reliability and safety." Thesis, Toulouse, INSA, 2010. http://www.theses.fr/2010ISAT0014/document.

Full text

Abstract:

Cette thèse contribue à l’étude de la fiabilité et de la sécurité-innocuité des systèmes informatisés, modélisés par des systèmes à événements discrets. Les principales contributions concernent la théorie des Systèmes de Contrôle (notés C Systems) et l’approche par Monitoring des modèles.Dans la première partie de la thèse, nous étudions la théorie des Systèmes de Contrôle qui combine et étend de façon significative, les systèmes de réécriture de la théorie des langages et le contrôle supervisé. Un système de contrôle est une structure générique qui contient deux composants : le composant contrôlé et le composant contrôlant qui restreint le comportement du composant contrôlé. Les deux composants sont exprimés en utilisant le même formalisme comme des automates ou des grammaires. Nous considérons différentes classes de systèmes de contrôle basés sur différents formalismes comme, par exemple, les automates, les grammaires, ainsi que leurs versions infinies et concurrentes. Ensuite, une application de cette théorie est présentée. Les systèmes de contrôle basés sur les automates de Büchi sont utilisés pour vérifier par model-checking, des propriétés définissant la correction sur des traces d’exécution spécifiées par une assertion de type nevertrace.Dans la seconde partie de la thèse, nous investiguons l’approche de monitoring des modèles dont la théorie des systèmes de contrôle constitue les fondations formelles. Le principe pivot de cette approche est la «spécification de propriétés comme contrôleur». En d’autres termes, pour un système, les exigences fonctionnelles, d’une part, et des propriétés, d’autre part, sont modélisées et implantées séparément, les propriétés spécifiées contrôlant le comportement issu des exigences fonctionnelles. De cette approche découle ainsi deux techniques alternatives, respectivement nommées monitoring de modèle et génération de modèle. Cette approche peut être utilisée de diverses manières pour améliorer la fiabilité et la sécurité-innocuité de divers types de systèmes. Nous présentons quelques applications qui montrent l’intérêt pratique de cette contribution théorique. Tout d’abord, cette approche aide à prendre en compte les évolutions des spécifications des propriétés. En second lieu, elle fournit une base théorique à la sécurité fonctionnelle, popularisée par la norme IEC 61508. En troisième lieu, l’approche peut être utilisée pour formaliser et vérifier l’application de guides de bonnes pratiques ou des règles de modélisation appliquées par exemple pour des modèles UML.Ces résultats constituent les bases pour des études futures de dispositifs plus perfectionnés, et fournissent une nouvelle voie pour s’assurer de la fiabilité et de la sécurité-innocuité des systèmes
This thesis contributes to the study of reliability and safety of computer and software systems which are modeled as discrete event systems. The major contributions include the theory of Control Systems (C Systems) and the model monitoring approach.In the first part of the thesis, we study the theory of control systems which combines and significantly extends regulated rewriting in formal languages theory and supervisory control. The control system is a generic framework, and contains two components: the controlled component and the controlling component that restricts the behavior of the controlled component. The two components are expressed using the same formalism, e.g., automata or grammars. We consider various classes of control systems based on different formalisms, for example, automaton control systems, grammar control systems, and their infinite versions and concurrent variants. After that, an application of the theory is presented. The Büchi automata based control system is used to model and check correctness properties on execution traces specified by nevertrace claims.In the second part of the thesis, we investigate the model monitoring approach whose theoretical foundation is the theory of control systems. The key principle of the approach is “property specifications as controllers”. In other words, the functional requirements and property specification of a system are separately modeled and implemented, and the latter one controls the behavior of the former one. The model monitoring approach contains two alternative techniques, namely model monitoring and model generating. The approach can be applied in several ways to improve reliability and safety of various classes of systems. We present some typical applications to show its strong power. First, the approach provides better support for the change and evolution of property specifications. Second, it provides the theoretical foundation of safety-related systems in the standard IEC 61508 for ensuring the functional validity. Third, it is used to formalize and check guidelines and consistency rules of UML.These results lay out the foundations for further study of more advanced control mechanisms, and provide a new way for ensuring reliability and safety

APA, Harvard, Vancouver, ISO, and other styles

13

Wang, Timothy. "Credible autocoding of control software." Diss., Georgia Institute of Technology, 2015. http://hdl.handle.net/1853/53954.

Full text

Abstract:

Formal methods is a discipline of using a collection of mathematical techniques and formalisms to model and analyze software systems. Motivated by the new formal methods-based certification recommendations for safety-critical embedded software and the significant increase in the cost of verification and validation (V\&V), this research is about creating a software development process for control systems that can provide mathematical guarantees of high-level functional properties on the code. The process, dubbed credible autocoding, leverages control theory in the automatic generation of control software documented with proofs of their stability and performance. The main output of this research is an automated, credible autocoding prototype that transforms the Simulink model of the controller into C code documented with a code-level proof of the stability of the controller. The code-level proof, expressed using a formal specification language, are embedded into the code as annotations. The annotations guarantee that the auto-generated code conforms to the input model to the extent that key properties are satisfied. They also provide sufficient information to enable an independent, automatic, formal verification of the auto-generated controller software.

APA, Harvard, Vancouver, ISO, and other styles

14

JESUS, JUNIOR Joabe Bezerra de. "Design e validação formal de sistemas de controle de voo fly-by-wire." Universidade Federal de Pernambuco, 2009. https://repositorio.ufpe.br/handle/123456789/2282.

Full text

Abstract:

Made available in DSpace on 2014-06-12T15:56:13Z (GMT). No. of bitstreams: 2 arquivo2770_1.pdf: 3435334 bytes, checksum: c4ebc011cd6476e268421539acd59c8c (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2009
Associação para Promoção da Excelência do Software Brasileiro
O gerenciamento e o projeto de sistemas de engenharia complexos é um desafio interessante. A engenharia de sistemas é um campo interdisciplinar da engenharia focado na melhoria da qualidade de projetos de sistemas. Ela encoraja o uso de métodos e ferramentas como simulação, otimização, análise de confiabilidade e análise estatística para aumentar o conhecimento do sistema, frequentemente representado como um conjunto de modelos. Uma enorme variedade de sistemas dinâmicos precisa ser controlada e pode ser modelada usando os princípios da Teoria de Controle, a base da disciplina de engenharia de controle. Em particular, a engenharia de controle objetiva criar leis de controle para o sistema, que são modeladas usando diagramas de bloco (também chamados de diagramas de leis de controle) e validadas/verificadas usando simulação. Entretanto, a maior parte das validações de leis de controle realizadas na indústria é feita usando ferramentas de simulação como o Simulink, e simulações não cobrem todos os comportamentos do modelo. Além disso, não é fácil modelar uma arquitetura complexa na qual redundância e monitoramento são comumente usados para se obter segurança. Neste trabalho, nós apresentamos três principais contribuições: (1) um conjunto de regras de tradução de modelos Simulink para a algebra de processos CSP (Communicating Sequential Processes), incluindo uma infraestrutura para suportar vários blocos discretos de Simulink; (2) uma estratégia para validar a integração de uma proposta de arquitetura com as leis de controle; e (3) a validação de um sistema de controle de voo dos profundores de um avião produzido pela Embraer. Os resultados mostram que a estratégia pode ser aplicada a modelos complexos através do uso das técnicas formais de abstração de dados e verificação de modelos. Ademais, a estratégia proposta aprimora o processo de desenvolvimento padrão (modelo V) seguido pela indústria por encontrar potenciais defeitos em fases de especificação do projeto, reduzindo tempo de desenvolvimento e custos

APA, Harvard, Vancouver, ISO, and other styles

15

Cardoso, Felipe Rafael Motta. "Um modelo de controle formal para o gerenciamento de riscos de projeto de software." Instituto Tecnológico de Aeronáutica, 2012. http://www.bd.bibl.ita.br/tde_busca/arquivo.php?codArquivo=2053.

Full text

Abstract:

Este trabalho de pesquisa propõe o projeto e desenvolvimento de um Modelo de Controle Formal (MCF) que propicie gerenciar riscos de projeto de software. Visa prover ao Gestor de Projetos, um mecanismo para identificar e controlar riscos que possam impactar negativamente nos objetivos do projeto, facilitando a tomada de decisão. O MCF desenvolvido contempla as Práticas Específicas (Specific Practices - SPs) do Modelo Integrado de Maturidade e de Capacidade para Desenvolvimento (Capability Maturity Model Integration for Development - CMMI-DEV) que abordam riscos de projeto de software. Foram identificados nove processos para representar os elementos contidos no MCF. Os processos definidos foram modelados utilizando uma Rede de Petri Colorida (Coloured Petri Net - CPN) e representaram a visão sistêmica deste trabalho de pesquisa. A ferramenta matemática e gráfica adotada permitiu um rastreamento minucioso e não ambíguo de cada etapa do sistema modelado. Elaborou-se um Instrumento de Inspeção que reuniu os elementos principais dos processos definidos no MCF, atuando como a visão semântica da Gestão de Riscos. O Instrumento de Inspeção foi mapeado para um protótipo de ferramenta denominada Risk Management Environment (RIMAE), tendo em vista os aspectos relacionados ao armazenamento, consulta, e interface com a organização no qual o estudo de caso foi realizado. O MCF foi aplicado em um projeto real, denominado Sistema de Navegação em Ambiente Linux (SINAL). Entre outras vantagens observadas neste trabalho de pesquisa, o uso do MCF fornece conhecimento pró-ativo e uma visão holística dos riscos para todos stakeholders envolvidos.

APA, Harvard, Vancouver, ISO, and other styles

16

Ferrarezi, Rodrigo César. "Framework para modelagem e verificação formal de programas de controle de sistemas instrumentados de segurança." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/3/3152/tde-31122015-112539/.

Full text

Abstract:

Devido à alta complexidade dos Sistemas Produtivos, o projeto de sistemas de controle adequados às exigências normativas vinculadas aos processos industriais que são executados, e seu impacto no ser humano e no ambiente demandam a necessidade do desenvolvimento de soluções de controle que sejam seguras e estáveis no sentido de não causar interrupções no processo produtivo e danos ao ser humano e ao meio. Uma abordagem para o desenvolvimento de sistemas que contemplem estes requisitos baseia-se no conceito de Sistemas Instrumentados de Segurança e na aplicação das normas IEC 61508 e IEC 61511. Entretanto, assim como o desenvolvimento de qualquer software, os programas de controle de SIS também estão sujeitos a erros de especificação e projeto, mesmo quando o desenvolvimento é feito conforme os critérios normatizados. Além dos erros de projeto, também deve ser levado em consideração que as camadas de prevenção e mitigação especificadas nas normas podem ser desenvolvidas separadamente e dessa forma podem ocorrer comportamentos não previstos ou indesejáveis quando da operação conjunta delas. Uma das formas para uma melhoria na confiabilidade desses programas e que também é um requerimento pertinente ao ciclo de desenvolvimento de um SIS - de acordo com as normas de segurança IEC 61508 e IEC 61511 - é a aplicação de técnicas de verificação formal dos modelos desses programas de controle bem como o uso de um ambiente unificado para modelagem desses sistemas de controle, onde suas interações possam ser mais bem compreendidas. Atualmente, umas das técnicas mais proeminentes para a verificação de sistemas é o Model Checking, que realiza uma busca exaustiva no espaço de estados de um sistema dirigido por eventos, verificando as propriedades especificadas a partir de proposições estabelecidas em lógica temporal. Para esse trabalho é utilizada a lógica TCTL devido a sua capacidade de expressar propriedades em domínio temporal denso. Como ferramenta computacional será usado o ambiente GHENeSys, que propicia um ambiente unificado para modelagem, simulação e verificação dos sistemas por conjugar os benefícios de rede de Petri para modelagem e as técnicas de Model Checking para verificação de modelos.
Due to the high complexity of the actual Productive Systems, the design of suitable control systems according to the applicable industrial standards, and the possible negative impacts on the human being, on the environment and on equipment, the development of control solutions that are be both secure and stable as some systems have to operate nonstop is much demanded. One approach for the development systems with such requirements is the use of Safety Instrumented Systems complying with the standards IEC 61508 and IEC 61511. However, as on the development of any kind of software, SIS control programs are also prone to specification and design errors, even when the control programs are developed according to the applicable standards. Besides design errors, must be taken into consideration the fact that the SIS prevention and mitigation layers, as prescribed on the standards, can be developed individually and thus presenting unanticipated or undesirable behaviors when operating together. One way to improve the reliability of these control programs, which is also required by the safety standards IEC 61508 and IEC 61511 as part of the SIS development cycle, is the application of formal verification techniques on the control software models. Another way is to use a unified approach for modeling these control systems, and thus having the opportunity to understand their interactions better. Currently, one of the most prominent techniques for the verification of systems is the Model Checking. Such technique performs an exhaustive search in the space state of an event driven system, verifying the properties specified as established propositions in temporal logic. On this work, the TCTL logic is used due its ability to express properties in the dense time domain. As computational tool will be used GHENeSys environment, as it provides a unified environment for modeling, simulating and the verification of systems, which enjoys the benefits of modelling through Petri Nets and Model Checking techniques for formal verification.

APA, Harvard, Vancouver, ISO, and other styles

17

SOUZA, Janderson Silva de. "Módulo de resolução de conflitos de forma semiautomática em modelo Or-BAC." Universidade Federal de Pernambuco, 2017. https://repositorio.ufpe.br/handle/123456789/27687.

Full text

Abstract:

Submitted by Pedro Barros (pedro.silvabarros@ufpe.br) on 2018-10-05T19:43:53Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Janderson Silva de Souza.pdf: 4857522 bytes, checksum: d5bf546fb0cfb97dd15d1aaf748b6789 (MD5)
Approved for entry into archive by Alice Araujo (alice.caraujo@ufpe.br) on 2018-11-22T18:26:23Z (GMT) No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Janderson Silva de Souza.pdf: 4857522 bytes, checksum: d5bf546fb0cfb97dd15d1aaf748b6789 (MD5)
Made available in DSpace on 2018-11-22T18:26:23Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) DISSERTAÇÃO Janderson Silva de Souza.pdf: 4857522 bytes, checksum: d5bf546fb0cfb97dd15d1aaf748b6789 (MD5) Previous issue date: 2017-06-13
SETEC
A especificação de diretivas de segurança em um Modelo de Controle de Acesso que inclui permissões e proibições algumas vezes pode ocasionar conflitos. Isso corresponde a uma situação em que um sujeito tem a permissão e proibição (ambos) para executar uma determinada ação e um determinado objeto. Esse tipo de problema pode afetar profundamente a estabilidade do modelo, pois suas exigências de segurança são primordiais para o bom funcionamento dos sistemas que dependem dele. Como principal contribuição, este trabalho faz uma abordagem comparativa entre alguns modelos existentes e suas tratativas e propõe um método de resolução desses conflitos de uma forma semiautomática, no entanto, poderá ocorrer situações em que será necessária a intervenção do administrador para uma tomada de decisão mais complexa. O Organization Based Access Control (Or-BAC) foi selecionado por se tratar de um modelo base para outros modelos derivados. Este modelo é dotado de mecanismo de herança, o que permite que regras redundantes e potenciais conflitos sejam tratados em tempo polinomial. Além disso, o modelo possui uma ferramenta de apoio para simulação de aplicação de regras chamada MotOrBAC, o qual fornece as interfaces necessárias para a implementação do módulo de resolução de conflitos.
Specifying security policies in an Access Control Model that includes permissions and prohibitions may have conflicts. This corresponds to a situation in which a subject has the both permission and prohibition to execute a certain action and a certain object. This type of problem can profoundly affect the stability of the model because its security requirements are paramount for the proper functioning of the systems that depend on it. As a main contribution, this thesis makes a comparative approach between some existing models and their dealings also proposes a method of solving these conflicts in a semiautomatic way, however, there may be situations in which the intervention of the administrator will be necessary for a more complex decision making. The Or-BAC was selected because it is a base model for other derived models. This model is endowed with an inheritance mechanism, which allows redundant rules and potential conflicts to be treated in polynomial time. In addition, the model has a support tool for simulation of rule application called MotOrBAC, which provides the necessary interfaces for the implementation of the conflict resolution module.

APA, Harvard, Vancouver, ISO, and other styles

18

Faria, Cássio Thomé de [UNESP]. "Controle da variação do arqueamento de um aerofólio utilizando atuadores de memória de forma." Universidade Estadual Paulista (UNESP), 2010. http://hdl.handle.net/11449/94509.

Full text

Abstract:

Made available in DSpace on 2014-06-11T19:27:13Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-27Bitstream added on 2014-06-13T19:55:32Z : No. of bitstreams: 1 faria_ct_me_ilha.pdf: 2001879 bytes, checksum: 8c06397bc7d8057b53383eaa08ea1d01 (MD5)
Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O projeto de aeronaves convencionais, em geral, apresentam uma série de dificuldades de se realizar de maneira eficiente um amplo número de missões, uma vez que para atender esses requisitos estas aeronaves deveriam ser capazes de realizar grandes alterações em sua geometria. Surge então um novo conceito de projeto de aeronaves, as chamadas aeronaves adaptativas, as quais são capazes de alterar sua geometria, de modo a adaptar a aeronave a um dado tipo de missão. Este novo conceito se tornou ainda mais atrativo com os avanços tecnológicos promovidos pelo estudo de novos materiais, os chamados materiais inteligentes, que apresentam alta densidade de energia, vantagem que leva a uma redução de peso nos mecanismos atuados desta maneira. Este trabalho apresenta um novo modelo adaptativa, utilizando fios atuadores de ligas de memória de forma para realizar uma rotação relativa entre duas seções de um aerofólio, este mecanismo possibilitaria a variação da linha de arqueamento de uma seção aeronáutica. Neste trabalho uma modelagem matemática para se descrever o comportamento deste sistema é apresentada, bem como um modelo aerodinâmico para se verificar o comportamento do sistema em funcionamento. Um controlador do tipo nebuloso é ainda projetado para se controlar a forma do perfil, e ensaios experimentais são conduzidos para se verificar a modelagem termo-mecânica apresentada.
Conventional airplane design, in general, has a large difficulty to attend in an efficient way several mission requirements, once that to attend these requirements the airplane has to perform great shape changes in its structure. Motivated by this problem a new concept in airplane design arise, one called morphing airplanes, which are air vehicles capable of changing its shape to adapt it self to a defined mission. This new concept became even more attractive with the development of active smart material, which can be a high power density actuator, reducing the weight of such morphing mechanism. This work proposes a novel model for morphing wings, using a pair of shape memory alloy wires to create a rotation between two wing sections, this mechanism allows the airfoil to change its camber line. A mathematical model is derived to describe the thermo-mechanical structure behavior, and also an aerodynamic model is investigated. A fuzzy controller is designed to control the system shape, and some experimental tests are used to verify the thermo-mechanical modeling proposed.

APA, Harvard, Vancouver, ISO, and other styles

19

Sprock, Timothy A. "A metamodel of operational control for discrete event logistics systems." Diss., Georgia Institute of Technology, 2016. http://hdl.handle.net/1853/54946.

Full text

Abstract:

Discrete Event Logistics Systems (DELS) are a class of dynamic systems that are defined by the transformation of discrete flows through a network of interconnected subsystems. The DELS domain includes systems such as supply chains, manufacturing systems, transportation networks, warehouses, and health care delivery systems. Advancements in computer integrated manufacturing and intelligent devices have spurred a revolution in manufacturing. These smart manufacturing systems utilize technical interoperability and plant-wide integration at the device-level to drive production agility and efficiency. Extending these successes to enterprise-wide integration and decision-making will require the definitions of control and device to be extended and supported at the operations management and the business planning levels as well. In the future, smart operational control mechanisms must not only integrate real-time data from system operations, but also formulate and solve a wide variety of optimization analyses quickly and efficiently and then translate the results into executable commands. However in contemporary DELS practice, these optimization analyses, and analyses in general, are often purpose-built to answer specific questions, with an implicit system model and many possible analysis implementations depending on the question, the instance data, and the solver. Also because of the semantic gap between operations research analysis models such as job-shop scheduling algorithms and IT-based models such as MES, there is little integration between control analysis methods and control execution tools. Automated and cost-effective access to multiple analyses from a single conceptual model of the target system would broaden the usage and implementation of analysis-based decision support and system optimization. The fundamental contribution of this dissertation is concerned with interoperability and bridging the gap between operations research analysis models and practical applications of the results. This dissertation closes this gap by constructing a standard domain-specific language, standard problem definitions, and a standard analysis methodology to answer the control questions and execute the prescribed control actions. The domain specific language meets a broader requirement for facilitating interoperability for DELS, including system integration, plug-and-play analysis methods and tools, and system design methodologies. The domain-specific language formalizes a recurring product, process, resource, and facility description of the DELS domain. It provides a common language to discuss our systems, including the questions that we want to ask about our systems, the problems that we need to solve in order to answer those questions, and the mechanisms to deploy the solution. A canonical set of control questions defines the comprehensive functional specification of all the decision-making mechanisms that a controller needs to be able to provide; i.e. a model of analysis models or a metamodel of operational control. These questions refine the interoperability mechanism between system and analysis models by mapping classes of control analysis models to implementation and execution mechanisms in the system model. A standard representation of each class of control problems is only a partial solution to fully addressing operational control. The final contribution of this dissertation constructs a round-trip analysis methodology that completes the bridge between operations research analysis models and deployable control mechanisms. This contribution formalizes an analysis pathway, from formulating an analysis model to executing a control action, that is grounded in a more fundamental insight into how analysis methods are executed to support operational control decision-making.

APA, Harvard, Vancouver, ISO, and other styles

20

Schlesinger, Sebastian [Verfasser], Sabine [Akademischer Betreuer] Glesner, Sabine [Gutachter] Glesner, Holger [Gutachter] Giese, and Ina [Gutachter] Schäfer. "Formal verification of model refactorings for hybrid control systems / Sebastian Schlesinger ; Gutachter: Sabine Glesner, Holger Giese, Ina Schäfer ; Betreuer: Sabine Glesner." Berlin : Technische Universität Berlin, 2018. http://d-nb.info/1170228321/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Hodges, Glenn A. "Designing a common interchange format for unit data using the Command and Control information exchange data model (C2IEDM) and XSLT." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2004. http://library.nps.navy.mil/uhtbin/hyperion/04Sep%5FHodges.pdf.

Full text

Abstract:

Thesis (M.S. in Modeling Virtual Environments and Simulation (MOVES))--Naval Postgraduate School, Sept. 2004.
Thesis advisor(s): Curtis Blais, Don Brutzman. Includes bibliographical references (p. 95-98). Also available online.

APA, Harvard, Vancouver, ISO, and other styles

22

Faria, Cássio Thomé de. "Controle da variação do arqueamento de um aerofólio utilizando atuadores de memória de forma /." Ilha Solteira : [s.n.], 2010. http://hdl.handle.net/11449/94509.

Full text

Abstract:

Resumo: O projeto de aeronaves convencionais, em geral, apresentam uma série de dificuldades de se realizar de maneira eficiente um amplo número de missões, uma vez que para atender esses requisitos estas aeronaves deveriam ser capazes de realizar grandes alterações em sua geometria. Surge então um novo conceito de projeto de aeronaves, as chamadas aeronaves adaptativas, as quais são capazes de alterar sua geometria, de modo a adaptar a aeronave a um dado tipo de missão. Este novo conceito se tornou ainda mais atrativo com os avanços tecnológicos promovidos pelo estudo de novos materiais, os chamados materiais inteligentes, que apresentam alta densidade de energia, vantagem que leva a uma redução de peso nos mecanismos atuados desta maneira. Este trabalho apresenta um novo modelo adaptativa, utilizando fios atuadores de ligas de memória de forma para realizar uma rotação relativa entre duas seções de um aerofólio, este mecanismo possibilitaria a variação da linha de arqueamento de uma seção aeronáutica. Neste trabalho uma modelagem matemática para se descrever o comportamento deste sistema é apresentada, bem como um modelo aerodinâmico para se verificar o comportamento do sistema em funcionamento. Um controlador do tipo nebuloso é ainda projetado para se controlar a forma do perfil, e ensaios experimentais são conduzidos para se verificar a modelagem termo-mecânica apresentada.
Abstract: Conventional airplane design, in general, has a large difficulty to attend in an efficient way several mission requirements, once that to attend these requirements the airplane has to perform great shape changes in its structure. Motivated by this problem a new concept in airplane design arise, one called morphing airplanes, which are air vehicles capable of changing its shape to adapt it self to a defined mission. This new concept became even more attractive with the development of active smart material, which can be a high power density actuator, reducing the weight of such morphing mechanism. This work proposes a novel model for morphing wings, using a pair of shape memory alloy wires to create a rotation between two wing sections, this mechanism allows the airfoil to change its camber line. A mathematical model is derived to describe the thermo-mechanical structure behavior, and also an aerodynamic model is investigated. A fuzzy controller is designed to control the system shape, and some experimental tests are used to verify the thermo-mechanical modeling proposed.
Orientador: Vicente Lopes Junior
Coorientador: Carlos de Marqui Junior
Banca: Gustavo Luiz Chagas Manhães de Abreu
Banca: Álvaro Martins Abdalla
Mestre

APA, Harvard, Vancouver, ISO, and other styles

23

Semião, Luís António Pereira. "Utilização de ligas com memória de forma no controlo de vibrações em estruturas inteligentes de Engenharia Civil." Master's thesis, FCT - UNL, 2010. http://hdl.handle.net/10362/4187.

Full text

Abstract:

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Engenharia Civil - Estruturas e Geotecnia
As ligas com memória de forma possuem duas propriedades singulares: a memória de forma e a superelasticidade. A memória de forma, é a capacidade do material recuperar a sua forma original através de uma variação de temperatura. A segunda propriedade destas ligas, e na qual esta dissertação se focará, é a superelasticidade. A superelasticidade é a propriedade termo-mecânica do material que permite a recuperação da forma inicial ao ser cessado o carregamento a que este está sujeito, permitindo recuperar de deformações elásticas na ordem dos 8%, bastante superiores aos materiais regularmente utilizados na construção de edifícios, juntando o facto de nos ciclos de carga e descarga o material dissipar energia. Esta propriedade é extremamente atractiva para o controlo de vibrações sísmicas nos edifícios. Esta dissertação tem como objectivo o estudo da utilização de ligas com memória de forma (Shape memory alloys) no controlo de vibrações em estruturas inteligentes de engenharia civil através de modulações matemáticas e computacionais que permitem simular o comportamento do material. Foram estudados 2 modelos constitutivos para o comportamento das ligas com memória de forma:Tanaka e Auricchio. Estes modelos foram analisados recorrendo ao programa Matlab onde foram efectuados simulações num oscilador de um grau de liberdade que provaram que ambos são realistas. Os modelos apresentam como principal diferença a gestão da mudança de fases. O modelo de Auricchio relaciona na suas equações constitutivas a tensão, a deformação e a fracção de fase martensitica, enquanto que o modelo de Tanaka junta o factor temperatura, tornando este último modelo mais completo e realista. Como conclusão verificou-se que no intervalo de frequências 0.01Hz e 4Hz a dissipação se manteve constante. No último capítulo com o recurso ao programa Ansys e com base no modelo constitutivo de Auricchio foi analisada uma estrutura em pórtico onde foi avaliado o comportamento desta a uma acção sísmica. Como conclusões verificou-se que apesar de a estrutura com recurso a tirantes SMA apresentar valores de deslocamento máximo superiores à estrutura com tirantes de aço, o amortecimento efectuava-se de forma mais célere.

APA, Harvard, Vancouver, ISO, and other styles

24

Bosch, Leslie Ann. "Financial Identity Formation: The Role of Perceived Parental SES, Parental Financial Communication, Formal Education, Work Experience, Attitudes, Subjective Norms, and Perceived Behavioral Control." Diss., The University of Arizona, 2013. http://hdl.handle.net/10150/293357.

Full text

Abstract:

Young adulthood is a crucial period for identity development, and an unclear sense of identity has been associated with deleterious psychological and social outcomes (Kroger & Marcia, 2011). Young adults have also identified self-sufficiency, including financial independence, as an essential aspect associated with attaining adulthood (Arnett, 2000). However, current realities such as global economic uncertainty and a shift toward greater personal responsibility for financial security may threaten the successful attainment of these essential goals (Furstenberg, Rumbaut, & Settersten, 2005). Hence, I explored identity formation (Erikson, 1950, 1968) in the domain of finance. Four socialization factors (perceived parental SES, parental financial communication, formal financial education, and high school work experience) and three beliefs (attitudes, subjective norms, and perceived behavioral control) were used to predict financial identity (achievement, foreclosure, moratorium, and diffusion) in a sample of college students (N = 2,098) who were surveyed at two time points approximately 2.5 years apart. Four models were tested using structural equation modeling (SEM). First, using crossectional data, I tested the extent to which socialization factors and financial beliefs predicted financial identity. I found support for 79% of the hypothesized associations between the variables. Second, using crossectional data, I examined the degree to which financial beliefs mediated the association between socialization factors and financial identity. Findings indicated that financial beliefs partially mediated the association between parental financial communication and financial identity. Third, using longitudinal data, Time 1 (T1) socialization factors and T1 beliefs were used to predict Time 2 (T2) financial identity. As expected, T1 financial identity was the most robust predictor of T2 financial identity. After controlling for T1 financial identity, T1 variables were most predictive of changes in T2 foreclosure: Increases in foreclosure were predicted by perceived parental SES, parental communication, formal education, and subjective norms. Finally, T1 financial beliefs were allowed to mediate the association between T1 socialization factors and T2 financial identity. I found no evidence of mediation using longitudinal data. Findings from this study suggest that identity formation within the financial domain is consistent with identity formation in other recognized identity domains.

APA, Harvard, Vancouver, ISO, and other styles

25

Arantes, Gilz Paulo Ricardo. "Embedded and validated control algorithms for the spacecraft rendezvous." Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30155/document.

Full text

Abstract:

L'autonomie est l'une des préoccupations majeures lors du développement de missions spatiales que l'objectif soit scientifique (exploration interplanétaire, observations, etc) ou commercial (service en orbite). Pour le rendez-vous spatial, cette autonomie dépend de la capacité embarquée de contrôle du mouvement relatif entre deux véhicules spatiaux. Dans le contexte du service aux satellites (dépannage, remplissage additionnel d'ergols, correction d'orbite, désorbitation en fin de vie, etc), la faisabilité de telles missions est aussi fortement liée à la capacité des algorithmes de guidage et contrôle à prendre en compte l'ensemble des contraintes opérationnelles (par exemple, saturation des propulseurs ou restrictions sur le positionnement relatif entre les véhicules) tout en maximisant la durée de vie du véhicule (minimisation de la consommation d'ergols). La littérature montre que ce problème a été étudié intensément depuis le début des années 2000. Les algorithmes proposés ne sont pas tout à fait satisfaisants. Quelques approches, par exemple, dégradent les contraintes afin de pouvoir fonder l'algorithme de contrôle sur un problème d'optimisation efficace. D'autres méthodes, si elles prennent en compte l'ensemble du problème, se montrent trop lourdes pour être embarquées sur de véritables calculateurs existants dans les vaisseaux spatiaux. Le principal objectif de cette thèse est le développement de nouveaux algorithmes efficaces et validés pour le guidage et le contrôle impulsif des engins spatiaux dans le contexte des phases dites de "hovering" du rendez-vous orbital, i.e. les étapes dans lesquelles un vaisseau secondaire doit maintenir sa position à l'intérieur d'une zone délimitée de l'espace relativement à un autre vaisseau principal. La première contribution présentée dans ce manuscrit utilise une nouvelle formulation mathématique des contraintes d'espace pour le mouvement relatif entre vaisseaux spatiaux pour la conception d'algorithmes de contrôle ayant un traitement calculatoire plus efficace comparativement aux approches traditionnelles. La deuxième et principale contribution est une stratégie de contrôle prédictif qui assure la convergence des trajectoires relatives vers la zone de "hovering", même en présence de perturbations ou de saturation des actionneurs. [...]
Autonomy is one of the major concerns during the planning of a space mission, whether its objective is scientific (interplanetary exploration, observations, etc.) or commercial (service in orbit). For space rendezvous, this autonomy depends on the on-board capacity of controlling the relative movement between two spacecraft. In the context of satellite servicing (troubleshooting, propellant refueling, orbit correction, end-of-life deorbit, etc.), the feasibility of such missions is also strongly linked to the ability of the guidance and control algorithms to account for all operational constraints (for example, thruster saturation or restrictions on the relative positioning between the vehicles) while maximizing the life of the vehicle (minimizing propellant consumption). The literature shows that this problem has been intensively studied since the early 2000s. However, the proposed algorithms are not entirely satisfactory. Some approaches, for example, degrade the constraints in order to be able to base the control algorithm on an efficient optimization problem. Other methods accounting for the whole set of constraints of the problem are too cumbersome to be embedded on real computers existing in the spaceships. The main object of this thesis is the development of new efficient and validated algorithms for the impulsive guidance and control of spacecraft in the context of the so-called "hovering" phases of the orbital rendezvous, i.e. the stages in which a secondary vessel must maintain its position within a bounded area of space relatively to another main vessel. The first contribution presented in this manuscript uses a new mathematical formulation of the space constraints for the relative motion between spacecraft for the design of control algorithms with more efficient computational processing compared to traditional approaches. The second and main contribution is a predictive control strategy that has been formally demonstrated to ensure the convergence of relative trajectories towards the "hovering" zone, even in the presence of disturbances or saturation of the actuators.[...]

APA, Harvard, Vancouver, ISO, and other styles

26

Santos, Felipe Crestani dos. "Metodologia de análise de sistemas de proteção com controle distribuído através da ferramenta de modelagem e verificação formal estatística." Universidade Estadual do Oeste do Paraná, 2017. http://tede.unioeste.br/handle/tede/3398.

Full text

Abstract:

Submitted by Miriam Lucas (miriam.lucas@unioeste.br) on 2018-02-22T14:23:15Z No. of bitstreams: 2 Felipe_Crestani_dos_Santos_2017.pdf: 5495370 bytes, checksum: 82f81445874bba45497cda5c8d784d2f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5)
Made available in DSpace on 2018-02-22T14:23:15Z (GMT). No. of bitstreams: 2 Felipe_Crestani_dos_Santos_2017.pdf: 5495370 bytes, checksum: 82f81445874bba45497cda5c8d784d2f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-11-17
The main line of research of this work is the study of approaches for supporting the development and analysis of the Power System Protection. In general, this process is carried out through of a large number of simulations involving various operating scenarios. The main limitation of this technique is the impossibility of coverage of all behavior of the system under analysis. In this context, this work proposes the use of Model Checking as a tool to support the procedure of development of power system protection schemes, principally in the sense of proving the security requirements and temporal deterministic expected behavior. Model Checking is a verification technique that explores exhaustively and automatically all possible system states, checking if this model meets a given specification. This work focuses on this two pillars of the Model Checking: to choose an appropriate modeling formalism for representation of the power system protection and how to describe the specification in temporal-logic for the verification process. With regard to the modeling formalism, the power system protection will be represented by the Hybrid Automata theory, while the verification tool adopted will be Statistical Model Checking, by the UPPAAL STRATEGO toolkit. It is underlined that this work is limited to the modeling of individual components of the power system protection, such that 18 models of the devices and protocols like communication bus (LAN), time synchronization protocol (PTP) and IEC 61850 communication protocols (SV and GOOSE) and Logical Nodes of power system protection, and 13 auxiliaries models, which emules the stochastic behavior to subsidise the verification process. The methodology of modelling adopted guarantees the effective representation of the components behaviour of power system protection. For this, the results of Model Checking process were compared with behavioral requirements defined by standards, conformance testings and paper related to the area. With regard to the contributions of this work, were identified three researches areas that could use the models developed in this work: i) implementation of power system protection schemes; ii) achievement of conformance testing; and iii) indication of the parameterization error of the power protection system scheme.
A linha de pesquisa abordada neste trabalho aponta para o estudo e desenvolvimento de ferramentas que subsidiem a proposição e validação de Sistemas de Proteção de Sistemas de Energia Elétrica. Em geral, este processo é realizado mediante simulações computacionais envolvendo diversos cenários de operação e distúrbios, tendo como principal limitação a impossibilidade de representar todos os caminhos de evolução do sistema em análise. Nesse contexto, propõe-se o emprego da técnica de Modelagem e Verificação Formal como ferramenta de suporte ao projeto, análise e implementação de estratégias de proteção, principalmente no sentido de comprovar se a estratégia atende os requisitos de segurança e comportamento determinístico temporal esperado. Em síntese, o método consiste na verificação de propriedades descritas em lógicas temporais, sob uma abstração apropriada (formalismo) do comportamento do sistema. Esta dissertação possui enfoque nestes dois requisitos: modelagem do sistema de proteção através de um formalismo adequado e tradução dos requisitos do comportamento desejado em propriedades descritas em lógica temporal. Com relação ao formalismo de apoio, a modelagem do sistema de proteção é baseada em uma abstração de Autômatos Temporizados Híbridos. Como ferramenta de validação, adota-se a técnica de Verificação Formal Estatística, através do software UPPAAL STRATEGO. Salienta-se que este trabalho se delimita apenas na modelagem e validação individual dos principais equipamentos de um sistema de proteção, sendo 18 modelos de dispositivos e protocolos como barramentos de comunicação (LAN), protocolo de sincronização de tempo PTP, protocolos de comunicação baseados em IEC 61850 e funções de proteção, e 13 modelos auxiliares que implementam um comportamento estocástico para subsidiar o processo de validação do sistema de proteção. O desenvolvimento dos modelos se deu através de uma abordagem sistemática envolvendo processos de simulação e verificação das propriedades sob o modelo em análise. Através desta metodologia, garante-se que os modelos desenvolvidos representam o comportamento esperado de seus respectivos dispositivos. Para isso, os resultados do processo de verificação foram comparados com requisitos comportamentais definidos por normas, testes de conformidade em equipamentos/protocolos e trabalhos acadêmicos vinculados à área. Com relação às contribuições do trabalho, identificou-se três linhas de pesquisa que podem fazer o uso dos modelos desenvolvidos: i) implementação de novas estratégias de proteção; ii) realização de testes de conformidade em equipamentos externos à rede de autômatos; e iii) indicação de erros de parametrização do sistema de proteção.

APA, Harvard, Vancouver, ISO, and other styles

27

LOPEZ, MEDINA MARCO ANTONIO 787172, and MEDINA MARCO ANTONIO LOPEZ. "Diseño de un algoritmo para el conteo de modelos de formulas booleanas en dos forma normal conjuntiva." Tesis de maestría, Universidad Autónoma del Estado de México, 2018. http://hdl.handle.net/20.500.11799/98902.

Full text

Abstract:

Tesis de Maestría para obtención de grado
El conteo de modelos sobre fórmulas booleanas es el problema conocido como #SAT, el cual forma parte de los problemas catalogados como #P-Completos. #2SAT es una restricción a #SAT, donde las cláusulas que componen una fórmula contienen a lo m as dos variables, uno de los métodos usados para resolver este problema es la descomposición de la fórmula, la cual puede realizarse por la asignación de valores de verdad a una variable o a una cláusula. La descomposición de una fórmula por variable requiere un procedimiento de selección para la variable o cláusula a eliminar, el método m as utilizado es seleccionar la variable que tiene una mayor aparición en la fórmula, de esta forma se puede reducir el número de cláusulas dado el número de apariciones de la variable seleccionada. Por otro lado, la descomposición de una fórmula por cláusula requiere un método para seleccionar la cláusula m as viable a eliminar, este segundo método permite reducir la cantidad de procesos de descomposición de la fórmula con respecto a la descomposición por variable. Si se quieren eliminar dos variables por el primer procedimiento es necesario generar cuatro subfórmulas, sin embargo, con el segundo procedimiento es posible generar tres subfórmulas aprovechando la relación existente entre las dos variables que se encuentran dentro de la cláusula. El objetivo de la descomposición de la fórmula es aplicar el método de forma iterativa hasta encontrar subfórmulas que puedan ser resueltas en tiempo polinomial. Una clase de fórmulas en las cuales existe un procedimiento polinomial para calcular #2SAT es aquella en la cual sus variables aparecen a lo m as cuatro veces en la fórmula. En esta tesis se estudian clases de fórmulas cuyo conteo de modelos puede realizarse en tiempo polinomial, además se desarrollan métodos para resolverlas basados en la topología inducida por su gr a ca signada. Las topologías para las cuales se presentan algoritmos polinomiales se conocen como cactus y outerplanar. As mismo, demostramos experimentalmente que los algoritmos obtenidos son competitivos respecto a la herramienta más reciente reportada en la literatura que es sharpSAT tanto en fórmulas cactus y outerplanar como en instancias generales.
Conacyt

APA, Harvard, Vancouver, ISO, and other styles

28

Meuter, Cédric. "Development and validation of distributed reactive control systems." Doctoral thesis, Universite Libre de Bruxelles, 2008. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/210552.

Full text

Abstract:

A reactive control system is a computer system reacting to certain stimuli emitted by its environment in order to maintain it in a desired state. Distributed reactive control systems are generally composed of several processes, running in parallel on one or more computers, communicating with one another to perform the required control task. By their very nature, distributed reactive control systems are hard to design. Their distributed nature and/or the communication scheme used can introduce subtle unforeseen behaviours. When dealing with critical applications, such as plane control systems, or traffic light control systems, those unintended behaviours can have disastrous consequences. It is therefore essential, for the designer, to ensure that this does not happen. For that purpose, rigorous and systematic techniques can (and should) be applied as early as possible in the development process. In that spirit, this work aims at providing the designer with the necessary tools in order to facilitate the development and validation of such distributed reactive control systems. In particular, we show how using a dedicated language called dSL (Distributed Supervision language) can be used to ease the development process. We also study how validations techniques such as model-checking and testing can be applied in this context.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished

APA, Harvard, Vancouver, ISO, and other styles

29

Beauquis, Yann. "Modélisation et simulation d'un processus métallurgique de mise en forme en vue de sa commande." Grenoble INPG, 1993. http://www.theses.fr/1993INPG0188.

Full text

Abstract:

Cette these propose une modelisation et une simulation d'un processus metallurgique de mise en forme dans un but de commande. Une description du procede en question est d'abord exposee. Puis nous analysons la commande et nous mettons en evidence l'interet de modeliser le procede. Notre volonte a ete d'etablir un modele physique simplifie : d'une part le modele doit contenir assez de physique pour faire de la prediction, d'autre part le modele doit etre exploitable et sa parametrisation compatible avec les donnees disponibles. Nous avons decompose le processus metallurgique de mise en forme en trois modeles. La conception de ces trois modeles est alors presentee, chaque modele faisant l'objet d'une etude particuliere. Les deux premiers modeles s'appuient essentiellement sur la theorie hydraulique, donc sur la theorie physique du processus, alors que le troisieme est davantage une representation simplifiee. Enfin cette modelisation est veritablement validee a partir de donnees de fabrication, dans un but d'utilisation en temps reel. Un logiciel de simulation a ete cree a partir de ce modele. La modelisation et la simulation ont permis d'obtenir une representation conceptuelle, ainsi qu'une meilleure connaissance du processus metallurgique de mise en forme.

APA, Harvard, Vancouver, ISO, and other styles

30

Falcó, Gimeno Albert. "Coalition Governance: Causes and consequences." Doctoral thesis, Universitat Pompeu Fabra, 2011. http://hdl.handle.net/10803/38361.

Full text

Abstract:

Els governs de coalició poden, per una banda, dividir-se les tasques i funcionar de forma compartimentalitzada, on cada soci decideixi sol les polítiques sota les seves jurisdiccions ministerials. Per contra, també poden optar pel compromís entre els partits i decidir col•lectivament en cada àrea sectorial, amb independència del repartiment de carteres. En el seu primer paper, aquesta tesis ofereix un marc teòric per entendre aquesta variació, amb la intenció d’identificar les condicions sota les quals és més probable un tipus de governança coalicional o altra. El segon paper testa empíricament les implicacions d’aquests arguments sobre la manera com els membres d’una coalició es vigilen mútuament mitjançant l’ús de mecanismes de control. Finalment, en el tercer paper s’ofereix un exercici empíric on s’analitza fins a quin punt els votants jutgen de manera diferent cada un dels socis de govern en funció del tipus de coalició a què s’enfronten.
At an extreme, coalition partners can divide tasks and individually decide policy in their ministerial jurisdictions in a compartmentalized way. At the other extreme, parties sharing office can compromise and collectively set policy in each dimension regardless of portfolio allocation. In its first paper, this dissertation provides a theoretical account of this variation, trying to unravel the conditions under which one type of governance is more likely than the other. The second paper tests empirically the implications of these arguments on the way coalition partners keep tabs on each other through the establishment of control mechanisms. Finally, an empirical exercise is offered in the third paper to study the extent to which voters assess each coalition partner differently depending on the type of coalition they face. Variation in the types of coalition governance, we conclude, is an important factor to take into account in political science research in the field.

APA, Harvard, Vancouver, ISO, and other styles

31

Py, Frédéric. "Contrôle d'exécution dans une architecture hiérarchisée pour systèmes autonomes." Toulouse 3, 2005. http://www.theses.fr/2005TOU30199.

Full text

Abstract:

Il y a un besoin grandissant d'autonomie dans des complexes tels que les robots ou les satelli-tes. Ceci met en avant un problème non trivial : d'un côté il y a des systèmes complexes - donc difficiles à valider - avec une intervention de l'humain réduite, de l'autre nous avons des domai-nes où la sûreté fonctionnellement est nécessaire. A partir de là comment être sûr qu'un sys-tème autonome avec un pouvoir décisionnel fort, n'aura pas un comportement pouvant menacer le déroulement de la mission? Nous présentons ici les travaux effectués pour intégrer un contrô-leur d'exécution dans une architecture hiérarchisée. Nous décrivons la nécessité et le rôle d'un tel composant. Nous introduisons le R2C, notre contrôleur basé sur les hypothèses synchrones, ainsi que l'outil permettant sa génération. Enfin nous discutons de la nécessité de prendre en compte les composants décisionnels dans le contrôle. Les résultats obtenus durant des expéri-mentations confirment les idées issues de ce travail et permettent d'en tirer les conclusions et perspectives sur le contrôle en ligne de ces systèmes
There is an increasing need for advanced autonomy in complex embedded real-time systems such as robots or satellites. Still, this raises a major problem : on one side we have complex sys-tems - therefore, hard to validate - with little human intervention, on the other side these systems are used in domains where safety is critical. How can we guaranty that an autonomous system, with high level decisional capabilities, will exhibit a proper behavior and will not jeopardize the mission? The work we present here integrate an on-line execution control component for hierar-chical architectures. We first describe the role of this program. Then we introduce the R2C, our controller based on synchronous hypothesis, and the tool used to generate it. We then discuss why it is important to take into account the decisional components in our controller. We eventu-ally illustrate our contribution with some experimental results. We then conclude and give some possible future work in this area

APA, Harvard, Vancouver, ISO, and other styles

32

Forkel, Matthias [Verfasser], Christiane Akademischer Betreuer] Schmullius, Markus [Akademischer Betreuer] Reichstein, and Wolfgang [Akademischer Betreuer] [Lucht. "Controls on global greening, phenology and the enhanced seasonal CO2 amplitude : integrating decadal satellite observations and global ecosystem models / Matthias Forkel. Gutachter: Christiane Schmullius ; Markus Reichstein ; Wolfgang Lucht." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2015. http://d-nb.info/108052200X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Forkel, Matthias Verfasser], Christiane [Akademischer Betreuer] Schmullius, Markus [Akademischer Betreuer] Reichstein, and Wolfgang [Akademischer Betreuer] [Lucht. "Controls on global greening, phenology and the enhanced seasonal CO2 amplitude : integrating decadal satellite observations and global ecosystem models / Matthias Forkel. Gutachter: Christiane Schmullius ; Markus Reichstein ; Wolfgang Lucht." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2015. http://d-nb.info/108052200X/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Faraut, Gregory. "Commutations sûres de mode pour les systèmes à événements discrets." Phd thesis, INSA de Lyon, 2010. http://tel.archives-ouvertes.fr/tel-00945172.

Full text

Abstract:

Le travail présenté dans ce mémoire concerne une démarche de conception appliquée à une gestion modale pour les systèmes à événements discrets (SED). Un mode est une configuration particulière du système où celui-ci exploite un ensemble de composants et doit respecter un ensemble de spécifications. La problématique de la gestion de mode porte principalement sur la conception des modes et sur leurs commutations. Notre objectif est de proposer une démarche de conception complètement définie où les spécifications sont assurément respectées, et où seules les commutations désirées entre modes peuvent se produire. Il est également vérifié que toute commutation dans un mode mène de manière sûre dans un autre mode. Pour réaliser cet objectif, nous utilisons la théorie de contrôle par supervision qui permet de concevoir des modèles sûrs par construction tel que les spécifications utilisées pour la construction soient respectées. La démarche proposée possède plusieurs étapes séparant ainsi les différentes études de conception. La première concerne la formalisation du cahier des charges en modèles automate à états. L'étude suivante concerne le comportement interne où celui-ci doit respecter les spécifications propres aux modes, indépendamment des autres modes. Cette étape valide le comportement de chaque mode, avant d'étudier leurs commutations. La troisième étape étudie le comportement commutatif tel que les spécifications de commutations soient respectées. Cette étape spécifie les commutations désirées, et inversement celles non voulues. L'étape suivante est l'exécution d'une fonction de suivi de trajectoire qui vérifie que toutes les commutations mènent bien dans un autre mode. Dans le cas contraire, la fonction de suivi identifie et caractérise les commutations problématiques afin d'aider le concepteur dans la résolution de ces situations. Enfin, une étape de fusion d'états finalise la démarche afin de fournir un modèle par mode qui représente le comportement de celui-ci. Pour montrer l'applicabilité de la démarche proposée, et sa faculté à être utilisée en milieu industriel, nous l'utilisons sur un exemple de taille importante utilisée dans la littérature.

APA, Harvard, Vancouver, ISO, and other styles

35

Dang, Kim Dung. "Aide à la réalisation de systèmes de pilotage de narration interactive : validation d'un scénario basée sur un modèle en logique linéaire." Phd thesis, Université de La Rochelle, 2013. http://tel.archives-ouvertes.fr/tel-01066720.

Full text

Abstract:

L'objectif de cette thèse est de fournir un modèle, une méthode et un outil d'aide à la réalisation de scénarios interactifs. Cette solution répond au problème de l'opposition entre la maîtrise du déroulement d'un jeu vidéo et son niveau d'interactivité. En d'autres termes, notre but est d'aider à réaliser des jeux vidéo dont l'évolution satisfait les intentions des auteurs tout en autorisant un déroulement influencé par les choix du joueur (exprimés aux travers de ses actions). Pour cela, notre proposition permet à l'utilisateur de produire un modèle de scénario de jeu de bonne qualité qui est : (a) riche - le scénario fournit suffisamment d'options pertinentes aux personnages joueur/non-joueur de sorte que le joueur puisse déterminer le déroulement du jeu et sente toujours que le discours créé est intéressant, (b) valide - tous les discours possibles dans le scénario sont cohérents et répondent aux effets désirés par les auteurs, (c) opérationnel - la représentation du scénario est exécutable. Ce scénario est ensuite employé comme l'entrée d'un système de pilotage de narration interactive assurant le contrôle de la gestion du déroulement du jeu. Par conséquent, l'évolution des jeux, qui sont dirigés par un tel système de pilotage, garantit que l'exécution du jeu respecte les souhaits des auteurs, et en même temps, autorise la liberté des actions du joueur. Pour répondre au problème exposé ci-dessus, nous appuyons notre solution sur un modèle mathématique calculable (la logique linéaire) qui offre des mécanismes de déductions rigoureux et automatiques.Nous avons fait un tour d'horizon des approches existantes concernant le pilotage de narration interactive et la validation de scénario. Ceci nous permet d'identifier les principes nécessaires à notre solution, tels que les éléments d'architecture d'un système de pilotage ; la construction,la représentation, l'exécution de scénarios narratifs ; les propriétés de narration importantes ; l'évolution de référence des paramètres dramatiques ; la structuration de discours ; la stratégie pour la validation d'un scénario ; les informations qualitatives et statistiques nécessaires... Nos contributions portent (1) sur la définition d'un ensemble de propriétés de narration spécifiant la qualité des scénarios de jeu ; (2) sur la proposition de modèles, algorithmes et outils pour écrire des modèles de scénario respectant ces propriétés. Nous validons nos résultats par la réalisation de deux exemples. Le premier est un extrait d'un jeu éducatif expliquant comment appliquer notre outil en vue de produire un modèle de scénario de jeu valide, qui est exprimé par un séquent de logique linéaire dont la représentation est conforme à un métamodèle du calcul des séquents. Pour le second exemple, nous décrivons le processus de production complet d'un jeu vidéo réel basé sur l'histoire " Le Petit Chaperon rouge ", mettant en oeuvre un prototype de système de pilotage que nous avons proposé, ce qui permet de dérouler le jeu selon le scénario valide produit, donc son évolution satisfait les intentions des auteurs, et en même temps, dépend des actions du joueur.

APA, Harvard, Vancouver, ISO, and other styles

36

Rance, Guillaume. "Commande H∞ paramétrique et application aux viseurs gyrostabilisés." Thesis, Université Paris-Saclay (ComUE), 2018. http://www.theses.fr/2018SACLS152/document.

Full text

Abstract:

Cette thèse porte sur la commande H∞ par loop-shaping pour les systèmes linéaires à temps invariant d'ordre faible avec ou sans retard et dépendant de paramètres inconnus. L'objectif est d'obtenir des correcteurs H∞ paramétriques, c'est-à-dire dépendant explicitement des paramètres inconnus, pour application à des viseurs gyrostabilisés.L'existence de ces paramètres inconnus ne permet plus l'utilisation des techniques numériques classiques pour la résolution du problème H∞ par loop-shaping. Nous avons alors développé une nouvelle méthodologie permettant de traiter les systèmes linéaires de dimension finie grâce à l'utilissation de techniques modernes de calcul formel dédiées à la résolution des systèmes polynomiaux (bases de Gröbner, variétés discriminantes, etc.).Une telle approche présente de multiples avantages: étude de sensibilités du critère H∞ par rapport aux paramètres, identification de valeurs de paramètres singulières ou remarquables, conception de correcteurs explicites optimaux/robustes, certification numérique des calculs, etc. De plus, nous montrons que cette approche peut s'étendre à une classe de systèmes à retard.Plus généralement, cette thèse s'appuie sur une étude symbolique des équations de Riccati algébriques. Les méthodologies génériques développées ici peuvent s'étendre à de nombreux problèmes de l'automatique, notamment la commande LQG, le filtrage de Kalman ou invariant
This PhD thesis deals with the H∞ loop-shaping design for low order linear time invariant systems depending on unknown parameters. The objective of the PhD thesis is to obtain parametric H∞ controllers, i.e. controllers which depend explicitly on the unknown model parameters, and to apply them to the stabilization of gyrostabilized sights.Due to the unknown parameters, no numerical algorithm can solve the robust control problem. Using modern symbolic techniques dedicated to the solving of polynomial systems (Gröbner bases, discriminant varieties, etc.), we develop a new methodology to solve this problem for finite-dimensional linear systems.This approach shows several advantages : we can study the sensibilities of the H∞ criterion to the parameter variations, identify singular or remarquable values of the parameters, compute controllers which depend explicitly on the parameters, certify the numerical computations, etc. Furthermore, we show that this approach can be extended to a class of linear time-delay systems.More generally, this PhD thesis develops an algebraic approach for the study of algebraic Riccati equations. Thus, the methodology obtained can be extended to many different problems such as LQG control and Kalman or invariant filtering

APA, Harvard, Vancouver, ISO, and other styles

37

Park, DongGook. "Cryptographic protocols for third generation mobile communication systems." Thesis, Queensland University of Technology, 2001.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

38

Jabri, Sana. "Génération de scénarios de tests pour la vérification de systèmes complexes et répartis : application au système européen de signalisation ferroviaire (ERTMS)." Phd thesis, Ecole Centrale de Lille, 2010. http://tel.archives-ouvertes.fr/tel-00584308.

Full text

Abstract:

Dans les années 90, la commission européenne a sollicité la mise au point d'un système de contrôle commande et de signalisation ferroviaire commun à tous les réseaux des états membres : le système ERTMS " European Railway Traffic Management System ". Il s'agit d'un système réparti complexe dont le déploiement complet est long et coûteux. L'objectif global consiste à diminuer les coûts de validation et de certification liés à la mise en œuvre de ce nouveau système en Europe. La problématique scientifique réside dans la modélisation formelle de la spécification afin de permettre la génération automatique des scénarios de test. Les verrous scientifiques, traités dans cette thèse, sont liés d'une part à la transformation de modèle semi-formel en modèle formel en préservant les propriétés structurelles et fonctionnelles des constituants réactifs du système réparti, et d'autre part à la couverture des tests générés automatiquement. Les constituants sont sous la forme de boîte noire. L'objectif consiste à tester ces derniers à travers la spécification ERTMS. Nous avons développé une approche de modélisation basée sur le couplage de modèles semi-formels (UML) et de modèles formels (Réseaux de Petri). Ce couplage se fait à travers une technique de transformation de modèles. Nous avons développé ensuite une méthode de génération automatique de scénarios de test de conformité à partir des modèles en réseaux de Petri. Les scénarios de test ont été considérés comme une séquence de franchissement filtrée puis réduite du réseau de Petri interprété représentant la spécification. Ces scénarios ont été exécutés sur notre plateforme de simulation ERTMS

APA, Harvard, Vancouver, ISO, and other styles

39

Scarlato, Michele. "Sicurezza di rete, analisi del traffico e monitoraggio." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/3223/.

Full text

Abstract:

Il lavoro è stato suddiviso in tre macro-aree. Una prima riguardante un'analisi teorica di come funzionano le intrusioni, di quali software vengono utilizzati per compierle, e di come proteggersi (usando i dispositivi che in termine generico si possono riconoscere come i firewall). Una seconda macro-area che analizza un'intrusione avvenuta dall'esterno verso dei server sensibili di una rete LAN. Questa analisi viene condotta sui file catturati dalle due interfacce di rete configurate in modalità promiscua su una sonda presente nella LAN. Le interfacce sono due per potersi interfacciare a due segmenti di LAN aventi due maschere di sotto-rete differenti. L'attacco viene analizzato mediante vari software. Si può infatti definire una terza parte del lavoro, la parte dove vengono analizzati i file catturati dalle due interfacce con i software che prima si occupano di analizzare i dati di contenuto completo, come Wireshark, poi dei software che si occupano di analizzare i dati di sessione che sono stati trattati con Argus, e infine i dati di tipo statistico che sono stati trattati con Ntop. Il penultimo capitolo, quello prima delle conclusioni, invece tratta l'installazione di Nagios, e la sua configurazione per il monitoraggio attraverso plugin dello spazio di disco rimanente su una macchina agent remota, e sui servizi MySql e DNS. Ovviamente Nagios può essere configurato per monitorare ogni tipo di servizio offerto sulla rete.

APA, Harvard, Vancouver, ISO, and other styles

40

Huamán, Bustamante Jesús Omar. "Implementación de un controlador difuso de temperatura prototipo usando la inferencia difusa de Takagi Sugeno." Universidad Nacional de Ingeniería. Programa Cybertesis PERÚ, 2007. http://cybertesis.uni.edu.pe/uni/2007/huaman_bj/html/index-frames.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Karimi, Vahid Reza. "A Uniform Formal Approach to Business and Access Control Models, Policies and their Combinations." Thesis, 2012. http://hdl.handle.net/10012/6831.

Full text

Abstract:

Access control represents an important part of security in software systems, since access control policies determine which users of a software system have access to what objects and operations and under what constraints. One can view access control models as providing the basis for access control rules. Further, an access control policy can be seen as a combination of one or more rules, and one or more policies can be combined into a set of access control policies that control access to an entire system. The rules and resulting policies can be combined in many different ways, and the combination of rules and policies are included in policy languages. Approaches to access control (AC) policy languages, such as XACML, do not provide a formal representation for specifying rule- and policy-combining algorithms or for classifying and verifying properties of AC policies. In addition, there is no connection between the rules that form a policy and the general access control and business models on which those rules are based. Some authors propose formal representations for rule- and policy-combining algorithms. However, the proposed models are not expressive enough to represent formally classes of algorithms related to history of policy outcomes including ordered-permit-overrides, ordered-deny-overrides, and only-one-applicable. In fact, they are not able to express formally any algorithm that involves history including the class related to consensus such as weak-consensus, weak-majority, strong-consensus, strong-majority, and super-majoritypermit. In addition, some other authors propose a formal representation but do not present an approach and automated support for the formal verification of any classes of combining algorithms. The work presented in this thesis provides a uniform formal approach to business and access control models, policies and their combinations. The research involves a new formal representation for access control rules, policies, and their combination and supports formal verification. In addition, the approach explicitly connects the rules to the underlying access control model. Specically, the approach • provides a common representation for systematically describing and integrating business processes, access control models, their rules and policies, • expresses access control rules using an underlying access control model based on an existing augmented business modeling notation, • can express and verify formally all known policy- and rule-combining algorithms, a result not seen in the literature, • supports a classification of relevant access control properties that can be verified against policies and their combinations, and • supports automated formal verification of single policies and combined policy sets based on model checking. Finally, the approach is applied to an augmented version of the conference management system, a well-known example from the literature. Several properties, whose verification was not possible by prior approaches, such as ones involving history of policy outcomes, are verified in this thesis.

APA, Harvard, Vancouver, ISO, and other styles

42

Hindle, Abram James. "SCQL : a formal model and a query language for source control repositories." 2005. http://hdl.handle.net/1828/780.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Shin, Dongmin. "A formal model for analysis and control of human-involved computer integrated manufacuring systems." 2005. http://etda.libraries.psu.edu/theses/approved/WorldWideIndex/ETD-969/index.html.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Wecki, António. "Taw : o modelo de Karasek e a mediação pelo engagement como forma de prever o bem-estar." Master's thesis, 2015. http://hdl.handle.net/10451/20715.

Full text

Abstract:

Tese de mestrado, Psicologia (Secção de Psicologia dos Recursos Humanos, do Trabalho e das Organizações), Universidade de Lisboa, Faculdade de Psicologia, 2015
O século XX é marcado por novas tendências do mercado que levaram á flexibilidade do trabalho. As organizações recorrem assim a formas de trabalho que permitam flexibilidade na contratação e dispensa de colaboradores; recorrendo, frequentemente, a empresas de trabalho temporário, originando a uma relação jurídica triangular que nem sempre é a melhor: os trabalhadores queixam-se que a empresa de trabalho temporário não tem em conta os seus interesses e que na empresa utilizadora não são tratados da mesma forma que os colaboradores com contratos diretos. Este estudo procura analisar se as características de trabalho temporários têm influencia na seu bem-estar, e se o engagement tem um efeito mediador entre estas características e a satisfação geral com a vida. Estudos anteriores mostram que os trabalhadores encontram-se sujeitos a características de trabalho (controlo vs. exigências) diferentes dos restantes trabalhadores o que irá ter efeitos nem sempre positivos na sua satisfação geral. Enquanto o burnout tem sido um tópico quente na análise de amostra de trabalhadores temporários, este estudo decidiu-se focar-se no seu “oposto”, engagement. Isto para ajudar a compreender o efeito mediador do mesmo entre o controlo/exigências e a satisfação geral com a vida. No presente trabalho recorreu-se a um questionário para recolher dados junto de uma amostra de 4450 trabalhadores de uma empresa de trabalho temporário portuguesa, confirmando, no geral, a hipótese: 1) As características do trabalho relacionam-se com o bem-estar dos TAW; e confirmando de forma parcial a hipótese: 2) O engagement tem um papel mediador entre as características do trabalho e o bem-estar dos TAW.
The twentieth century is marked by new market trends that led to flexible working. Organizations thus resort to ways of working that allow the hiring and dismissal of employees; using often the temporary employment agencies, leading to a triangular legal relationship that is not always the best: workers complain that the temporary employment agency does not take account of their interests and in the working companies they are not treated as employees with direct contracts. This study seeks to examine whether the temporary employment characteristics have influence on their well-being, and if the engagement has a mediating effect between these features and the overall satisfaction with life. Previous studies show that workers are subject to labor characteristics (control vs. demands) different from other workers, which will not always have positive effects on their overall satisfaction. While burnout has been a hot topic in the sample analysis of temporary workers, this study decided to focus on its "opposite," engagement. This to help understand the mediating effect of the same between the control / demands and the overall satisfaction with life. In this work we used to a questionnaire to collect data from a sample of 4450 workers from a Portuguese temporary employment agency, confirming, in general, the hypothesis: 1) The job characteristics are related to the welfare of TAW; and confirming partially the hypothesis: 2) The engagement has a mediating role between job characteristics and the welfare of TAW.

APA, Harvard, Vancouver, ISO, and other styles

45

Duong, Maggie. "Access control model and labelling scheme for efficient querying and updating XML data." Thesis, 2010. https://vuir.vu.edu.au/15506/.

Full text

Abstract:

In this thesis, we make two major contributions that help the tasks of querying, updating, and managing XML data become quick and safe. First, we propose a new labelling scheme for dynamic XML data that supports the representation of the ancestor – descendant relationship and sibling relationship between nodes. Our unique way of labelling codes can also help users easily determine the depth (level) of the XML tree. Moreover, it also supports the process of updating XML data without the need of re-labelling existing labels, hence facilitating fast update. Some experimental works have been conducted to show its effectiveness. Secondly, for XML security purposes, we propose a fine-grained access control model, named SecureX, which supports read and write privileges. With our novel access control concept, various access types are introduced, including those for determining if a user has the right to change XML structure. SecureX ensures that, crucial information will be accessible only to authorized entities. Furthermore, SecureX can be integrated well with a dynamic labelling scheme to eliminate repetitive labelling and pruning processes when determining a user view. This brings about advantages of speeding up searching and querying processes.

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'Formal control models'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles