Pour profiter des nombreux matériels actuellement, les logiciels s'exécutant sur des téléphones mobiles doivent devenir sensibles au contexte, c'est-à-dire, qu'ils doivent surveiller les événements provenant de leur environnement et réagir en conséquence. Nous considérons que ces logiciels peuvent bénéficier d'une approche basée sur les Lignes de Produits Logiciels (LPL). Les LPLs sont définies pour exploiter les points communs par la définition d'éléments réutilisables. Néanmoins, les LPLs ne prennent pas en compte les modifications à l'exécution des applications. Cette thèse propose une ligne de produits logiciels dynamique (LPLD) qui étend une LPL classique en fournissant des mécanismes pour adapter les produits à l'exécution. Notre objectif principal est d'unifier les adaptations à la conception et à l'exécution en utilisant des artefacts logiciels de haut niveau. Concrètement, nous introduisons un modèle de variabilité et un modèle de composition pour modulariser les produits sous forme de modèles d'aspect. Chaque modèle d'aspect a trois parties : l'architecture, les modifications, et le point de coupe. Ensuite, nous proposons deux processus de dérivation du produit : un pour la conception que vise à construire un produit, et un pour l'exécution que vise à adapter un produit. Ce travail de recherche s'est déroulé dans le cadre du projet FUI CAPPUCINO. Nous avons défini une LPLD pour une étude de cas de vente d'un hypermarché sensible au contexte. Le scénario démontre les avantages de notre approche et, en particulier, l'unification réalisée par les modèles d'aspect utilisés à la fois à la conception et à l'exécution.

Unified Modeling Language (UML) is a de-facto standard modeling language with an extensive syntax and notations that can be used to model systems of any kind. However, being a general-purpose language, its semantics are intrinsically under-specified and broad to leave a room for different interpretations. This, in general, hinders the ability to perform formal verification of models produced with a specific domain in mind. In these cases, it is usually more suitable to map the UML models to other domains, where modeling concepts have stricter semantics. Notably, Reactive Objects Language (Rebeca) is an actor-based language with a formal foundation and formal verification support. This paper aims to identify a subset of UML modeling concepts compatible with the domain of reactive and distributed systems as modeled in Rebeca. In this respect, this work proposes a conceptual mapping between a sub-portion of UML and Rebeca, with the goal of enabling formal verification early in the design process. In particular, we investigate Rebeca syntax, and for each Rebeca concept, we provide the corresponding concept in the UML, as part of an iterative process. This process ends when all Rebeca concepts are exhausted and comprehensive mapping procedure emerges. Additionally, validation is an important part of this paper as it aims to establish confidence in the developed mapping procedure (in post-conversion validation) and avoid doing the transformation if the design is not compatible with the mapping procedure (in pre-conversion validation). As part of the pre-conversion validation, in order to establish the compatibility with the mapping procedure, we provide an extensive list of correctness attributes. As part of the post-conversion validation, the mapping procedure is validated by transformation on the provided examples. The results of this transformation show the wide range applicability of the mapping procedure and serve as an assertion of its comprehensiveness.

Model-driven engineering promotes the migration from code-centric to model-based software development. Systems consist of model collections integrating different concerns and perspectives, while semi-automated model transformations generate executable code combining the information from these. Increasing the abstraction level to models required appropriate management technologies supporting the various software development activities. Among these, model comparison represents one of the most challenging tasks and plays an essential role in various modelling activities. Its hardness led researchers to propose a multitude of approaches adopting different approximation strategies and exploiting specific knowledge of the involved models. However, almost no support is provided for their evaluation against specific scenarios and modelling practices. This thesis presents Benji, a framework for the automated generation of model comparison benchmarks. Given a set of differences and an initial model, users generate models resulting from the application of the first on the latter. Differences consist of preconditions, actions and postconditions expressed using a dedicated specification language. The generator converts benchmark specifications to design-space exploration problems and produces the final solutions along with a model-based description of their differences with respect to the initial model. A set of representative use cases is used to evaluate the framework against its design principles, which resemble the essential properties expected from model comparison benchmark generators.

Sistemas embarcados estão presentes em inúmeras atividades realizadas diariamente, por exemplo, eles são parte integrante dos meios de transporte, encontram-se em sistemas de entretenimento como os tablets e telefones celulares e ainda podem estar dentro das pessoas, como nos usuários de marca-passo. Os sistemas embarcados são desenvolvidos em níveis de complexidade bem distintos, variando de sistemas bem simples até sistemas altamente elaborados e complexos. Essa complexidade pode ser atribuída a diversos fatores, incluindo a necessidade de poder executar múltiplas tarefas em unidades de processamento heterogêneas (baseadas em CPU, GPU, DSP e FPGAs) e atendendo aos requisitos exigidos pelos usuários. Em função do aumento da complexidade e da necessidade de manter o tempo e custo do desenvolvimento de novos sistemas embarcados baixo, uma solução que vem sendo discutida é o uso de metodologias de projetos baseadas em modelos. Estas metodologias usam o modelo como fonte principal de informação. As informações contidas nos modelos variam de acordo com o estágio de desenvolvimento do sistema: nos modelos iniciais são descritivas, simples, incompletas mas permitem realizar simulações que podem ser usadas para guiar o desenvolvimento do próprio sistema. Com o amadurecimento do projeto, mais informações são agregadas aos modelos, tornando-os mais próximos do sistema a ser implementado. Este processo reduz o nível de abstração dos modelos até o ponto que é possível gerar, entre outros artefatos, o código fonte. Neste contexto, sistemas de processamento de imagens embarcados são exemplos de sistemas complexos que fazem processamento de dados de forma intensiva. Estes sistemas são tradicionalmente desenvolvidos em um nível de abstração baixo que tipicamente incluem diagramas blocos e diagrama de estados. Para que seja possível administrar o crescente aumento da complexidade, em um baixo tempo de desenvolvimento, destes sistemas é necessário que sejam criados métodos que permitam desenvolvê-los em um nível mais alto de abstração. Além disso é necessário que existam ferramentas que auxiliem no seu desenvolvimento permitindo, entre outras coisas, aumentar o reúso dos blocos parametrizáveis do sistema e a exploração de espaço de projetos em fases iniciais do projeto para guiar o seu próprio desenvolvimento. Neste trabalho é feita uma proposta de um novo método de desenvolvimento de sistemas embarcados de processamento de imagens baseado na metodologia de engenharia dirigida por modelos. São parte integrantes do método proposto: combinar a modelagem de requisitos funcionais (usando modelagem orientada a objetos) e requisitos não-funcionais (usando modelagem orientada a aspectos); a exploração de espaço de projeto baseada em modelos para resolver o problema de alocação das tarefas nas diferentes unidades de processamento; validação funcional dos modelos; e a geração de código em linguagens de programação. O método proposto chama-se HIPAO, do inglês “Hardware Image Processing system based on model driven engineering and Aspect-Oriented modeling”. O ciclo de desenvolvimento de projeto de sistemas de processamento de imagens embarcado inicia com a coleta dos requisitos técnicos em diagramas de requisitos da linguagem SysML A especificação deste requisitos é feita através de um metamodelo para requisitos técnicos de processamento de imagens que foi desenvolvido em conjunto com o método HIPAO. Estes requisitos são transformados automaticamente em modelos independentes de plataforma (PIM) iniciais. Esta transformação é feita a partir da ferramenta HIPAO desenvolvida em linguagem Java como mecanismo de apoio ao método. Os modelos PIM iniciais evoluem de forma iterativa através da adição de informações feita de forma manual e também de forma automática através da costura ou composição de modelos. O método sugere que modelos de plataforma (PM) sejam desenvolvidos de forma semelhante ao proposto para os modelos PIM, porém sua implementação é considerada trabalho futuro e os modelos PM apresentados neste trabalho são fruto de um desenvolvimento manual. De posse dos modelos PIM e PM o método realiza uma etapa de otimização do modelo através da sua transformação (tipo modelo para texto) para um formato compatível com o framework que realiza a exploração de espaço de projetos dirigida por modelos (MD-DSE). Os modelos específicos de plataforma (PSM) são produzidos com o auxílio de informações obtidas a partir de gráficos tipo Fronteira de Pareto que são produzidos pelo framework MD-DSE que realiza a atividade de alocação das tarefas (modelo PIM) na plataforma (modelo PM) com base em algoritmos heurísticos. O ciclo de desenvolvimento do projeto se encerra com a geração de código, de forma semelhante à maioria dos métodos baseados em engenharia dirigida por modelos, a partir de modelos PSM e alguns exemplos são apresentados. Para o uso e validação do método proposto foram realizados dois estudos de caso. O primeiro é um sistema de processamento de imagens para câmeras científicas de alta resolução e alta velocidade. O segundo estudo de caso propõe o desenvolvimento de um sistema de processamento de imagens a ser integrado a um veículo autônomo não-tripulado. / Embedded systems are present in many daily activities, for example, they are found in entertainment systems such as tablets and cell phones and they could even be inside a person’s body, which is the case of a pace-maker. Embedded systems can have very distinct complexity levels, from very simple to very complex and sophisticated ones. This complexity can be attributed to many different sources, which include the need to execute multiple tasks or deploy them in heterogeneous platforms (i.e. CPU, GPU, DSP and FPGAs) while fulfilling the users requirements. In order to cope with the rising system’s complexity and the need to keep the time to market and cost low, some solutions using methodologies based on model driven engineering are being considered. These methodologies use the model as the primary source of information. The information in the model varies based on the system’s development stage: at the beginning the models are descriptive, simple and incomplete, however they enable to simulate the system at a high level which can be used to drive the system’s development. As the project evolves, more information is added to them and the models looks closer to its final system. This process reduces the models abstraction level to the point that is possible to generate many artifacts from them, such as, source code. In this context, embedded image processing systems are examples of complex systems that perform data intensive processing. These systems are traditionally developed in a low level of abstraction, which typically include block diagrams and state charts. In order to handle the rising system’s complexity, while keeping time to market low, it is necessary to develop new methods that enable these systems development at a high abstraction level. Also, it is necessary the development of new tools to support these methods enabling, among other things, increase in the design reuse of its blocks and the design space exploration at an early stage such that it could guide the systems own development. In this work it is proposed a novel design method for embedded image processing systems based on model driven engineering concepts. This method proposes the following: combine functional requirements (using object oriented modeling) and non-functional requirements (using aspect oriented modeling); perform model based design space exploration in order to tackle task allocation in platforms with multiple processing units; functional model validation; and code generation. The proposed method is called HIPAO, which stands for “Hardware Image Processing system based on model driven engineering and Aspect-Oriented modeling”. The development cycle of embedded image processing systems starts starts with the elucidation of technical requirements using SysML requirements diagram. The specification of the image processing technical requirements is done using a metamodel, which has been developed with the HIPAO method. These requirements are transformed automatically into initial platform independent models (PIM). The transformations are performed by the HIPAO tools developed using Java language. The PIM models evolve by adding new information to it, which can be done manually or in some cases automatically by model weaving or composition. The proposed method suggests that the platform models (PM) should be developed in a similar fashion as the PIM models, but this task is considered a future work therefore all PM models presented in this thesis have been developed manually. Once the PIM and PM models are available the method executes an optimization phase that includes the model transformation (model to text) that produces the information needed by the model driven - design space exploration (MD-DSE). The platform specific models (PSM) are produced based on the information presented as Pareto Fronts that are generated the the MD-DSE framework while performing task (PIM model) allocation on the platform (PM model) using heuristic algorithms. The method development cycle ends with code generation from the PSM models using model to text transformations and some examples are presented. Two case-studies were designed to validate the proposed method. The first one consists of an image processing system for high speed, high resolution scientific image sensors. The second case study consists of an image processing system that is deployed in small Unmanned Autonomous Vehicles.

Hoje em dia, desenvolvedores de sistemas embarcados enfrentam uma crescente complexidade de projeto, tanto nas aplicações quanto nas plataformas usadas para executá-las. O uso de plataformas complexas faz com que os engenheiros precisem fazer escolhas não-triviais, e muitas vezes contra-intuitivas durante a fase de projeto. Para permitir que os projetistas gerenciem esta complexidade, o uso de metodologias baseadas em modelos tem atraído atenção, e dentro deste contexto, a metodologia HIPAO2 está sendo desenvolvida dentro da UFRGS. Dentre os problemas que os engenheiros precisam enfrentar, o mapeamento entre tarefas e processadores em sistemas multiprocessados heterogêneos é um problema NP-completo, onde o espaço de projeto rapidamente se torna grande demais para que seja explorado satisfatoriamente de maneira manual. Este trabalho detalha a extensão das ferramentas que suportam a metodologia HIPAO2, de maneira a incluir facilidades de Exploração de Espaço de Projeto semi-automática para a solução deste problema. A ferramenta proposta faz uso de um algoritmo genético multiobjetivo para evidenciar tradeoffs existentes no projeto, e algoritmos de análise de aplicações modeladas como synchronous dataflow para avaliar possíveis mapeamentos sem um custo computacional proibitivo. / Designers of today’s embedded systems are faced with increasing complexity both in the applications being developed and the platforms they run on. The use of complex platforms means that the engineers need to make non-trivial and many times non-intuitive decisions during the design phase. To help developers work with this complexity, model-driven techniques are gaining attention, and in this context, the HIPAO2 model-driven engineering methodology is being developed at UFRGS. Among the problems that designers must solve, the task-to-processor mapping in heterogeneous multiprocessor systems is an NP-complete problem and the design space will quickly become too large to be explored adequately by humans. This work details the extension of the tools that support HIPAO2 to include semiautomatic Design-Space Exploration capabilities for the mapping problem. The proposed tool includes the use of a multiobjective genetic algorithm to make tradeoffs explicit to the designers; it also uses synchronous dataflow analysis algorithms to evaluate potential alternatives with a reasonable computational cost.

Engineering is often described as the application of scientific and technical knowledge to solve problems. In this thesis, I support a more general view that engineering should be treated as a continuous process of learning and action that aims to make well understood improvements within dynamically complex environments of co-evolving social, man-made and natural systems. I argue that this can only be achieved by adopting an approach that systematically develops, manages and integrates the knowledge and expertise of many disciplines to conceive, develop, modify, operate and retire systems. A novel implementation of such an approach, called Aspect-Oriented Thinking, is presented. ¶ Aspect-Oriented Thinking begins with the development and verification of a set of domain Models. Each Domain Model represents knowledge about a separate, autonomous and possibly discipline specific concern or view within a given context. Domain models are developed by engineers, scientists, sociologists, psychologists, lawyers, philosophers, economists and others, using languages and techniques with which they are familiar. Knowledge captured in a set of Domain Models is then woven together, in accordance with a set of separately developed patterns and rules, to construct, modify, operate and retire systems, including models, hardware, software, processes and simulations. This is a continuous process which, in the first instance, involves those systems used to learn about a given context and to make decisions regarding required changes. Later, the process involves those systems used to implement and evaluate the impact of these decisions. ¶ The significance of Aspect-Oriented Thinking lies in its broad applicability to any situation in which the expertise and knowledge of diverse disciplines is required to understand and make improvements within complex multifaceted environments such as those that involve sustainable development and national security. ¶ A proof-of-concept within the context of software engineering is provided to demonstrate the mechanics and viability of Aspect-Oriented Thinking. The results of this demonstration are used to support an argument for future experimentation aimed at evaluating the effectiveness of Aspect-Oriented Thinking in a more general interdisciplinary environment.

The Graphical User Interface (GUI), as the most prevailing type of User Interface (UI) in today’s interactive applications, restricts the interaction with a computer to the visual modality and is therefore not suited for some users (e.g., with limited literacy or typing skills), in some circumstances (e.g., while moving around, with their hands or eyes busy) or when the environment is constrained (e.g., the keyboard and the mouse are not available). In order to go beyond the GUI constraints, the Multimodal (MM) UIs apear as paradigm that provide users with great expressive power, naturalness and flexibility. In this thesis we argue that developing MM UIs combining graphical and vocal modalities is an activity that could benefit from the application of a methodology which is composed of: a set of models, a method manipulating these models and the tools implementing the method. Therefore, we define a design space-based method that is supported by model-to-model colored transformations in order to obtain MM UIs of information systems. The design space is composed of explicitly defined design options that clarify the development process in a structured way in order to require less design effort. The feasability of the methodology is demonstrated through three case studies with different levels of complexity and coverage. In addition, an empirical study is conducted with end-users in order to measure the relative usability level provided by different design decisions.

Identical domain concepts reified in different (meta)modelling projects may be named, represented and connected differently. It turns out that a transformation defined for a particular metamodel cannot be directly used for another metamodel; that is, the reuse of transformations is restricted. To tackle this problem, in this dissertation, we propose a solution for automatically migrating legacy transformations. Such a transformation is adapted to the new metamodel that has a slightly different representation in comparison with the original one, while preserving the original semantics of the transformation. To this end, we first introduce MetaModMap, a Domain Specific Language that allows the description of the correspondences of intended semantics between the elements of two metamodels that model the same domain. Then we provide a rewriting mechanism using these user-defined correspondences to migrate the transformation automatically. The proposed solution uses a graph-based model typing relation that enables safe adaptations. Our approach has been prototyped with MOMENT2 and can be used with any framework based on the same graph transformation paradigm.

This thesis presents a semantic-based modeling approach for describing Service-Oriented Architectures (SOA). Ontologies are utilized as a major representation mechanism for describing various elements available in the architecture. The methodology proposes an architecture specification mechanism to constuct a unified ontology that enables transition from design concerns to the modeling elements. A multi-level modeling is also achieved by employing Model-Driven Engineering (MDE) techniques to describe various models at different stages of the software architecture. This aims to organize service-oriented models within a number of architecture viewpoints in order to provide an architectural perspective for SOA. The use of ontologies for model specification also allows us to make use of ontology mapping to specify the transformation between different models. Additionally, we present a case study to demonstrate the proposed methodology on a real-world healthcare scenario.

Current technologies such as anti-virus software programs and network firewalls provide reasonably secure protection at the host and network levels, but not at the application level. When network and host-level entry points are comparatively secure, public interfaces of web applications become the focus of malicious software attacks. In this thesis, we focus on one of most serious web application vulnerabilities, broken access control. Attackers often try to access unauthorized objects and resources other than URL pages in an indirect way; for instance, using indirect access to back-end resources such as databases. The consequences of these attacks can be very destructive, especially when the web application allows administrators to remotely manage users and contents over the web. In such cases, the attackers are not only able to view unauthorized content,but also to take over site administration. To protect against these types of attacks, we have designed and implemented a security analysis framework for dynamic web applications. A reverse engineering process is performed on an existing dynamic web application to extract a role-based access-control security model. A formal analysis is applied on the recovered model to check access-control security properties. This framework can be used to verify that a dynamic web application conforms to access control polices specified by a security engineer. Our framework provides a set of novel techniques for the analysis and modeling of web applications for the purpose of security verification and validation. It is largely language independent, and based on adaptable model recovery which can support a wide range of security analysis tasks. / Thesis (Ph.D, Computing) -- Queen's University, 2010-04-30 14:30:53.018