The aim of this thesis is to create a tool for formal verification of systems specified using textual use- cases. The tool should allow for automated verification of temporal invariants specified in temporal logic (CTL and LTL formulae). The textual specification is transformed to a formal model that is verified using the NuSMV symbolic model-checker. Potential errors are shown to the user in the form of an HTML report. Using this feedback, the user is able to iteratively develop valid textual use-case specifications. The tool's architecture should be focused on reusability of its components and extensibility. Powered by TCPDF (www.tcpdf.org)

Neste trabalho apresentamos uma implementação de revisão de crenças baseada em comparação de modelos (estados) em uma ferramenta de verificação automática de sistemas de estados finitos. Dada uma fórmula (na lógica CTL) inconsistente com o modelo do sistema, revisamos esse modelo de tal maneira que essa fórmula temporal se torne verdadeira. Como temos oito operadores temporais (AG, AF, AX, AU, EG, EF, EX e EU), foram criados algoritmos especícos para cada um deles. Como o modelo do sistema deriva do seu código na linguagem SMV, a sua revisão passa obrigatoriamente por mudanças na sua descrição. A nossa implementação contempla três tipos de mudanças: acréscimo de linhas, eliminação de linhas e mudança no estado inicial, sendo que as duas primeiras provocam modicações nas transições entre os estados que compõe o modelo. Alguns testes foram aplicados para comprovar a contribuição da revisão de crenças (revisão de modelos) como ferramenta de auxílio ao usuário durante o processo de modelagem de sistemas. / In this work we present an implementation of belief revision based on comparison of models (states) in a tool for automatic verication of nite state systems. Given a formula (in the language of CTL) inconsistent with the model of the system, we revise this model in such way that the temporal formula becomes valid. As we have eight temporal operators (AG, AF, AX, AU, EG, EF, EX and EU), specic algorithms for each one of them have been created. As the model of the system is related with its code in SMV language, its revision forces changes in its description. Our implementation contemplates three types of change: addition of lines, elimination of lines and change in the initial state, where the rst two cause modications in the transitions between the states of the model. Some tests were applied to prove the contribution of the belief revision (model revision) as aid-tool to the user during the process of systems modeling.

Neste trabalho apresentamos uma implementação de revisão de crenças baseada em comparação de modelos (estados) em uma ferramenta de verificação automática de sistemas de estados finitos. Dada uma fórmula (na lógica CTL) inconsistente com o modelo do sistema, revisamos esse modelo de tal maneira que essa fórmula temporal se torne verdadeira. Como temos oito operadores temporais (AG, AF, AX, AU, EG, EF, EX e EU), foram criados algoritmos especícos para cada um deles. Como o modelo do sistema deriva do seu código na linguagem SMV, a sua revisão passa obrigatoriamente por mudanças na sua descrição. A nossa implementação contempla três tipos de mudanças: acréscimo de linhas, eliminação de linhas e mudança no estado inicial, sendo que as duas primeiras provocam modicações nas transições entre os estados que compõe o modelo. Alguns testes foram aplicados para comprovar a contribuição da revisão de crenças (revisão de modelos) como ferramenta de auxílio ao usuário durante o processo de modelagem de sistemas. / In this work we present an implementation of belief revision based on comparison of models (states) in a tool for automatic verication of nite state systems. Given a formula (in the language of CTL) inconsistent with the model of the system, we revise this model in such way that the temporal formula becomes valid. As we have eight temporal operators (AG, AF, AX, AU, EG, EF, EX and EU), specic algorithms for each one of them have been created. As the model of the system is related with its code in SMV language, its revision forces changes in its description. Our implementation contemplates three types of change: addition of lines, elimination of lines and change in the initial state, where the rst two cause modications in the transitions between the states of the model. Some tests were applied to prove the contribution of the belief revision (model revision) as aid-tool to the user during the process of systems modeling.

Ce mémoire propose des représentations formelles pour contrôleurs logiques industriels qui visent à améliorer le passage à l'échelle des techniques de model-checking. Ces vérifications, focalisées sur les propriétés extrinsèques, permettent d'améliorer la sûreté et aident à la certification de ces contrôleurs. Premièrement, la représentation de contrôleurs ne comprend que les états qui sont pertinents pour la preuve de propriétés et minimise le nombre de variables qui caractérisent chaque état. Puis une représentation de chaque bloc fonctionnel, décrit dans un nouveau langage formel adapté à nos besoins, est incluse dans la représentation du contrôleur. Ces représentations permettent la vérification formelle du contrôleur, même avec des programmes de grande taille. La comparaison avec de précédentes représentations, ainsi que leur utilisation dans un contexte industriel, valide nos représentations et quantifie leur efficacité.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-07-12T13:26:23Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) SergioBarzaDissertation.pdf: 2147656 bytes, checksum: 5c75fe2262be1d224538c1ad6a575ebb (MD5) / Made available in DSpace on 2017-07-12T13:26:23Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) SergioBarzaDissertation.pdf: 2147656 bytes, checksum: 5c75fe2262be1d224538c1ad6a575ebb (MD5) Previous issue date: 2016-02-25 / Software Maintainability (SM) has been studied since it became one of the key componentes of the software quality model accepted around the world. Such models support researchers and practitioners to evaluate the quality level of his systems. Therefore, many researchers have proposed a lot of metrics to be used as SM indicators. On the other hand, there is a suspicious that using SM metrics on industry is different from the academic context. In this case, practitioners do not adopt the metrics proposed/used by academia. Consequently, the goal of this research is to investigate the SM metrics adoption and applicability scenario on the Brazilian industrial context. This study will allow confirming if the practitioners use the SM metrics proposed by academics around the globe or if they propose their own metrics for SM measurement. As empirical method for data assessment, we used survey, divided in two steps. The first one was focused in gathering information that allowed us to design a specific scenario about the use and applicability of SM metrics. To achieve this goal, it was chosen, as research instrument, semi-structured interviews. The next step focused in a more general scenario, compassing the Brazillian software production industrial context. An online questionnaire was used as research instrument. Practitioners with different positions in several companies participated of this work. Data from requirements engineers, quality analysts, testers, developers and project managers were collected. 7 software companies participated in the first part of the study and 68 valid answers were collected on the second moment, resulting in 31 SM metrics listed. The results showed us that about 90% of the companies perform maintenance on their software products. However, only 60% confirms using maintainability metrics, resulting in a discrepancy regarding software maintenance vs SM metrics. Nearly half of the companies researched have used well-defined processes to collect these metrics. Nevertheless, there are those that do not have any formal methodology. Instead of it, they have used SM metrics that best fit to the needs of a specific project. The conclusions of this study point to an issue that is nothing new in the academic researchers around the world. Many of the academics results conducting, mainly, in the universities, are not coming to the software industries and this fact is also a truth when the subject is software maintenance. The results of this research may lead to discussions on how SM metrics are being proposals nowadays. / Manutenibilidade de Software (MS) é estudada desde que se tornou um dos componente de modelos de qualidade aceitos globalmente. Tais modelos auxiliam pesquisadores e profissionais do mercado na avaliação do nível de qualidade dos seus sistemas. Como consequência, muitos pesquisadores vêm propondo métricas que podem ser utilizadas como indicadores de MS. Por outro lado, existe uma suspeita que o uso de métricas de MS ocorre de maneira diferente da academia. Neste caso, as empresas não estão adotando as métricas que estão sendo propostas no ambiente acadêmico. O objetivo desta pesquisa é investigar o cenário de adoção e aplicação de métricas de manutenibilidade de software sob o contexto industrial brasileiro. Este estudo permitirá afirmar se estas empresas utilizam atributos de MS propostos por acadêmicos ao redor do mundo ou se elas propõem suas próprias métricas para medição de MS. Para ter acesso aos dados desta pesquisa, foi utilizado o método empírico survey, dividido em duas etapas. A primeira etapa objetivou levantar informações que permitissem um panorama mais específico sobre a utilização e aplicação de tais métricas. Para isto, foi escolhido, como instrumento de pesquisa, entrevistas semi-estruturadas. A segunda etapa apresenta um enfoque mais amplo, englobando todo o cenário industrial de produção de software brasileira. Um questionário online foi utilizado como instrumento de pesquisa. Profissionais de diferentes posições em várias empresas participaram desta pesquisa. Foram coletados dados de engenheiros de requisitos, analista de qualidade, testadores, desenvolvedores, gerente de projetos, entre outros. Sete empresas participaram da primeira etapa da pesquisa e 68 respostas válidas foram levantadas no segundo momento. Com isto, 31 métricas de MS foram identificadas. Os resultados mostram que cerca de 90% das empresas realizam manutenção em seus produtos de software. Porém somente 60% (aproximadamente) afirmaram fazer uso de métricas de MS, resultando em uma discrepância com relação à manutenção de software vs. uso de métricas. Quase metade das empresas possuem processos bem definidos para coletar estas métricas. Entretanto, muitas delas ainda não apresentam tais processos formais de coleta. Neste último caso, elas utilizam aqueles atributos que melhor se adaptam às necessidades de um projeto específico. As conclusões deste estudo apontam para problemas que não é novidade nas pesquisas acadêmicas ao redor do mundo. Pela amostra investigada neste trabalho, reforça-se a suspeita de que muitos dos resultados das pesquisas científicas realizadas nas universidades não estão chegando na indústria e este fato se reflete quando o assunto é manutenção de software. Os resultados deste estudo apresentam dados que poderão ocasionar discussões sobre a forma como as métricas de manutenibilidade são propostas atualmente.

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.

One problem with computers is that the operating system automatically trusts any externallyconnected peripheral. This can result in abuse when a peripheral technically can violate the security model because the peripheral is trusted. Because of that the security is an important issue to look at.The aim of our project is to see in which cases hardware peripherals can be trusted. We built amodel of the universal asynchronous transmitter/receiver (UART), a model of the main memory(RAM) and a model of a DMA controller. We analysed interaction between hardware peripherals,user processes and the main memory.One of our results is that connections with hardware peripherals are secure if the hardware is properly configured. A threat scenario could be an eavesdropper or man-in-the-middle trying to steal data or change a cryptographic key.We consider the use-cases of DMA and protecting a cryptographic key. We prove the well-behavior of the algorithm. Some error-traces resulted from incorrect modelling that was resolved by adjusting the models. Benchmarks were done for different memory sizes.The result is that a peripheral can be trusted provided a configuration is done. Our models consist of finite state machines and their corresponding SMV modules. The models represent computer hardware with DMA. We verified the SMV models using the model checkers NuSMV and nuXmv. / Målet med vårt projekt är att verifiera olika specifikationer av externa enheter som ansluts till datorn. Vi utför formell verifikation av sådan datorutrustning och virtuellt minne. Verifikation med temporal logik, LTL, utförs. Specifikt verifierar vi 4 olika use-case och 9 formler för seriell datakommunikation, DMA och virtuellt minne. Slutsatsen är att anslutning av extern hårdvara är säker om den är ordentligt konfigurerad.Vi gör jämförelser mellan olika minnesstorlekar och mätte tidsåtgången för att verifiera olika system. Vi ser att tidsåtgången för verifikation är långsammare än linjärt beroende och att relativt små system tar relativt lång tid att verifiera.

In the recent trends, automated systems are increasingly seen to be embedded in human life with the increase of human dependence on software to perform safetycritical tasks like airbag deployment in automobiles to real-time mission planning in UAVs (Unmanned Aircraft Vehicles). The safety-critical nature of the aerospace domain demands for a software without any errors to perform these tasks. Therefore the field of computer science needs to address these challenges by providing necessary formalisms, techniques, and tools that will ensure the correctness of systems despite their complexity. DO-178C/EC-12C is a standard that governs the certification of software for airborne systems in commercial aircraft. The additional supplement DO- 333 enables us to use the formal methods in our technique of verifying the autonomous behaviour of UAV’s. The Mission Manager system is primarily responsible for the execution of behaviour sequence in online and offline mission planning of UAV. This work presents the process of software verification by making use of formal modelling using model checking of the Mission Manager component of ARTIS (Autonomous Rotorcraft Testbed for Intelligent Systems) UAV by gaining advantages from a generic modelling approach. The main idea is to make use of the designed generic models into specific cases like ARTIS in our case. The generic models are designed using the ALFU(R)S (Autonomy Levels For Unmanned Rotorcraft System) framework that delineates the commonalities of several UAVs considered around the world which also includes the ARTIS UAV. Furthermore this work walks through every process involved in model checking like requirements extraction and documentation using a template based method, requirements specification using the temporal logics like LTL and CTL, developing a formal model using NuSMV as a model checking tool to analyze the requirements against the model for the Mission Manager component of MiPlEx (Mission Planning and Execution). Additionally as a validation approach, test sequences are generated by using trap properties or negation properties. This aids for a test generation approach by harnessing counterexample generating capabilities of the NuSMV Model Checker.

In the recent trends, automated systems are increasingly seen to be embedded in human life with the increase of human dependence on software to perform safetycritical tasks like airbag deployment in automobiles to real-time mission planning in UAVs (Unmanned Aircraft Vehicles). The safety-critical nature of the aerospace domain demands for a software without any errors to perform these tasks. Therefore the field of computer science needs to address these challenges by providing necessary formalisms, techniques, and tools that will ensure the correctness of systems despite their complexity. DO-178C/EC-12C is a standard that governs the certification of software for airborne systems in commercial aircraft. The additional supplement DO- 333 enables us to use the formal methods in our technique of verifying the autonomous behaviour of UAV’s. The Mission Manager system is primarily responsible for the execution of behaviour sequence in online and offline mission planning of UAV. This work presents the process of software verification by making use of formal modelling using model checking of the Mission Manager component of ARTIS (Autonomous Rotorcraft Testbed for Intelligent Systems) UAV by gaining advantages from a generic modelling approach. The main idea is to make use of the designed generic models into specific cases like ARTIS in our case. The generic models are designed using the ALFU(R)S (Autonomy Levels For Unmanned Rotorcraft System) framework that delineates the commonalities of several UAVs considered around the world which also includes the ARTIS UAV. Furthermore this work walks through every process involved in model checking like requirements extraction and documentation using a template based method, requirements specification using the temporal logics like LTL and CTL, developing a formal model using NuSMV as a model checking tool to analyze the requirements against the model for the Mission Manager component of MiPlEx (Mission Planning and Execution). Additionally as a validation approach, test sequences are generated by using trap properties or negation properties. This aids for a test generation approach by harnessing counterexample generating capabilities of the NuSMV Model Checker.

Le développement croissant des réseaux et en particulier l'Internet a considérablement développé l'écart entre les systèmes d'information hétérogènes. En faisant une analyse sur les études de l'interopérabilité des systèmes d'information hétérogènes, nous découvrons que tous les travaux dans ce domaine tendent à la résolution des problèmes de l'hétérogénéité sémantique. Le W3C (World Wide Web Consortium) propose des normes pour représenter la sémantique par l'ontologie. L'ontologie est en train de devenir un support incontournable pour l'interopérabilité des systèmes d'information et en particulier dans la sémantique. La structure de l'ontologie est une combinaison de concepts, propriétés et relations. Cette combinaison est aussi appelée un graphe sémantique. Plusieurs langages ont été développés dans le cadre du Web sémantique et la plupart de ces langages utilisent la syntaxe XML (eXtensible Meta Language). Les langages OWL (Ontology Web Language) et RDF (Resource Description Framework) sont les langages les plus importants du web sémantique, ils sont basés sur XML.Le RDF est la première norme du W3C pour l'enrichissement des ressources sur le Web avec des descriptions détaillées et il augmente la facilité de traitement automatique des ressources Web. Les descriptions peuvent être des caractéristiques des ressources, telles que l'auteur ou le contenu d'un site web. Ces descriptions sont des métadonnées. Enrichir le Web avec des métadonnées permet le développement de ce qu'on appelle le Web Sémantique. Le RDF est aussi utilisé pour représenter les graphes sémantiques correspondant à une modélisation des connaissances spécifiques. Les fichiers RDF sont généralement stockés dans une base de données relationnelle et manipulés en utilisant le langage SQL ou les langages dérivés comme SPARQL. Malheureusement, cette solution, bien adaptée pour les petits graphes RDF n'est pas bien adaptée pour les grands graphes RDF. Ces graphes évoluent rapidement et leur adaptation au changement peut faire apparaître des incohérences. Conduire l'application des changements tout en maintenant la cohérence des graphes sémantiques est une tâche cruciale et coûteuse en termes de temps et de complexité. Un processus automatisé est donc essentiel. Pour ces graphes RDF de grande taille, nous suggérons une nouvelle façon en utilisant la vérification formelle " Le Model checking ".Le Model checking est une technique de vérification qui explore tous les états possibles du système. De cette manière, on peut montrer qu'un modèle d'un système donné satisfait une propriété donnée. Cette thèse apporte une nouvelle méthode de vérification et d'interrogation de graphes sémantiques. Nous proposons une approche nommé ScaleSem qui consiste à transformer les graphes sémantiques en graphes compréhensibles par le model checker (l'outil de vérification de la méthode Model checking). Il est nécessaire d'avoir des outils logiciels permettant de réaliser la traduction d'un graphe décrit dans un formalisme vers le même graphe (ou une adaptation) décrit dans un autre formalisme