Les systèmes temps-réels modernes ont tendance à obtenir la criticité mixte, dans le sens où ils intègrent sur une même plateforme de calcul plusieurs applications avec différents niveaux de criticités. D'un côté, cette intégration permet de réduire le coût, le poids et la consommation d'énergie. Ces exigences sont importantes pour des systèmes modernes comme par exemple les drones (UAV). De l'autre, elle conduit à des complications majeures lors de leur conception. Ces systèmes doivent être certifiés en prenant en compte ces différents niveaux de criticités. L'ordonnancement temps réel des systèmes avec différents niveaux de criticités est connu comme étant l’un des plus grand défi dans le domaine. Les techniques traditionnelles nécessitent une isolation complète entre les niveaux de criticité ou bien une certification globale au plus haut niveau. Une telle solution conduit à un gaspillage des ressources, et à la perte de l’avantage de cette intégration. Ce problème a suscité une nouvelle vague de recherche dans la communauté du temps réel, et de nombreuses solutions ont été proposées. Parmi elles, l'une des méthodes la plus utilisée pour ordonnancer de tels systèmes est celle d'Audsley. Malheureusement, elle a un certain nombre de limitations, dont nous parlerons dans cette thèse. Ces limitations sont encore beaucoup plus accentuées dans le cas de l'ordonnancement multiprocesseur. Dans ce cas précis, l'ordonnancement basé sur la priorité perd des propriétés importantes. C’est la raison pour laquelle, les algorithmes d'ordonnancement avec différents niveaux de criticités pour des architectures multiprocesseurs ne sont que très peu étudiés et ceux qu’on trouve dans la littérature sont généralement construits sur des hypothèses restrictives. Cela est particulièrement problématique car les systèmes industriels temps réel cherchent à migrer vers plates-formes multi-cœurs. Dans ce travail nous proposons une approche différente pour résoudre ces problèmes. / Modern real-time systems tend to be mixed-critical, in the sense that they integrate on the same computational platform applications at different levels of criticality. Integration gives the advantages of reduced cost, weight and power consumption, which can be crucial for modern applications like Unmanned Aerial Vehicles (UAVs). On the other hand, this leads to major complications in system design. Moreover, such systems are subject to certification, and different criticality levels needs to be certified at different level of assurance. Among other aspects, the real-time scheduling of certifiable mixed critical systems has been recognized to be a challenging problem. Traditional techniques require complete isolation between criticality levels or global certification to the highest level of assurance, which leads to resource waste, thus loosing the advantage of integration. This led to a novel wave of research in the real-time community, and many solutions were proposed. Among those, one of the most popular methods used to schedule such systems is Audsley approach. However this method has some limitations, which we discuss in this thesis. These limitations are more pronounced in the case of multiprocessor scheduling. In this case priority-based scheduling looses some important properties. For this reason scheduling algorithms for multiprocessor mixed-critical systems are not as numerous in literature as the single processor ones, and usually are built on restrictive assumptions. This is particularly problematic since industrial real-time systems strive to migrate from single-core to multi-core and many-core platforms. Therefore we motivate and study a different approach that can overcome these problems.A restriction of practical usability of many mixed-critical and multiprocessor scheduling algorithms is assumption that jobs are independent. In reality they often have precedence constraints. In the thesis we show the mixed-critical variant of the problem formulation and extend the system load metrics to the case of precedence-constraint task graphs. We also show that our proposed methodology and scheduling algorithm MCPI can be extended to the case of dependent jobs without major modification and showing similar performance with respect to the independent jobs case. Another topic we treated in this thesis is time-triggered scheduling. This class of schedulers is important because they considerably reduce the uncertainty of job execution intervals thus simplifying the safety-critical system certification. They also simplify any auxiliary timing-based analyses that may be required to validate important extra-functional properties in embedded systems, such as interference on shared buses and caches, peak power dissipation, electromagnetic interference etc..The trivial method of obtaining a time-triggered schedule is simulation of the worst-case scenario in event-triggered algorithm. However, when applied directly, this method is not efficient for mixed-critical systems, as instead of one worst-case scenario they have multiple corner-case scenarios. For this reason, it was proposed in the literature to treat all scenarios into just a few tables, one per criticality mode. We call this scheduling approach Single Time Table per Mode (STTM) and propose a contribution in this context. In fact we introduce a method that transforms practically any scheduling algorithm into an STTM one. It works optimally on single core and shows good experimental results for multi-cores.Finally we studied the problem of the practical realization of mixed critical systems. Our effort in this direction is a design flow that we propose for multicore mixed critical systems. In this design flow, as the model of computation we propose a network of deterministic multi-periodic synchronous processes. Our approach is demonstrated using a publicly available toolset, an industrial application use case and a multi-core platform.

Structural engineers and architects have a responsibility for incorporating fire safety into their building designs in order to minimize loss of life and property. To meet this requirement, extensive research has been carried out, aimed at obtaining better understanding of the performance of steel and composite structures under fire conditions. Recent research indicates that the robustness of steel connections is vitally important to the fire resistance of steel-framed composite buildings. The development of effective connection models is a key issue in this research field. This PhD research is focused on the development of robust connection elements, for modelling steel connections at elevated temperatures. In this work, a robust simplified two-node connection element has been developed, for modelling the behaviour of the bolted end-plate connections between steel beam and column at elevated temperatures. The proposed numerical procedure is based on the model proposed by Huang (2011), incorporating additional developments to more precisely determine the tension, compression, and bending moment capacities of end-plate connections in fire. The proper failure criteria are proposed to calculate the tension capacity for each individual bolt row. In this new model, the connection failure due to bending, axial tension, compression and shear are considered. The influence of the axial force of the connected beam on the connection is also taken into account. This new model has the advantages of both the simple and component-based models. A total of 22 tests are used to validate the model. From these validations, it is evident that this new connection model has ability to accurately predict the behaviour of the end-plate connection at elevated temperatures, and can be used to represent the end-plate connections in supporting performance-based fire resistance design of steel-framed composite buildings. For modelling the behaviour of partial end-plate connections between steel beams and columns under fire conditions, a simplified robust 2-node connection element has also been developed. The rotational response of a partial end-plate connection at elevated temperatures comprises of two stages. These stages are due to the shift of the compression centre of the connection from the end of end-plate, to the centre of the beam bottom flange at large rotation. The model proposed in this research accounts for these two stage behaviours, representing the partial end-plate iv connection as a 2-node non-linear spring element. Characteristics of the spring, such as stiffness, tension, compression, shear strengths and bending moment resistance, are determined based on a component-based approach. This model therefore retains the advantages of both the simple and component-based models. Compared to normal component-based models, this simplified model has very good numerical stability under static solver condition, and is computationally efficient. Fourteen tests are used to validate the model, showing that the model is capable of accurately predicting the behaviour of partial end-plate connections under fire conditions. A series of numerical studies has been conducted on a 2D steel frame, subjected to ISO834 Fire and Natural Fire, in order to investigate the influences of the connections on the behaviour of steel structures. It is clear that the model can be used to represent the partial end-plate connections in performance-based fire resistance design of steel-framed composite buildings. According to full-scale fire tests, tensile membrane action within the concrete floor slabs plays an important role in affecting the fire resistance of composite buildings. It is well known that the development of tensile membrane actions relies on the vertical support along the edges of the slab panel. However, there is at present a lack of research into how vertical supports influence the tensile membrane actions of the slab. In this thesis, the performance of a generic three dimensional 45m x 45m composite floor subjected to ISO834 Fire and Natural Fire are investigated. Different vertical support conditions and three steel meshes are applied, in order to assess the impact of vertical supports on tensile membrane action of floor slabs. Unlike other existing large scale modelling which assumed that the connections behave as pinned or rigid for simplicity, the two robust 2-node connection element models described above are used to model the semi-rigid behaviour of end-plate and partial end-plate connections within the fire compartment. The impact of connections on the 3D behaviour of composite floors is taken into consideration. The load-transfer mechanisms of a composite floor, when connections fail due to axial tension, vertical shear and bending are investigated. Based on the results obtained, some design recommendations are proposed for enhancing the fire resistance of composite buildings.

Compared to other disciplines, software engineering as of today is still dependent on craftsmanship of highly-skilled workers. However, with constantly increasing complexity and efforts, existing software engineering approaches appear more and more inefficient. A paradigm shift towards industrial production methods seems inevitable. Recent advances in academia and practice have lead to the availability of industrial key principles in software development as well. Specialization is represented in software product lines, standardization and systematic reuse are available with component-based development, and automation has become accessible through model-driven engineering. While each of the above is well researched in theory, only few cases of successful implementation in the industry are known. This becomes even more evident in specialized areas of software engineering such as systems integration. Today’s IT systems need to quickly adapt to new business requirements due to mergers and acquisitions and cooperations between enterprises. This certainly leads to integration efforts, i.e. joining different subsystems into a cohesive whole in order to provide new functionality. In such an environment. the application of industrial methods for software development seems even more important. Unfortunately, software development in this field is a highly complex and heterogeneous undertaking, as IT environments differ from customer to customer. In such settings, existing industrialization concepts would never break even due to one-time projects and thus insufficient economies of scale and scope. This present thesis, therefore, describes a novel approach for a more efficient implementation of prior key principles while considering the characteristics of software development for systems integration. After identifying the characteristics of the field and their affects on currently-known industrialization concepts, an organizational model for industrialized systems integration has thus been developed. It takes software product lines and adapts them in a way feasible for a systems integrator active in several business domains. The result is a three-tiered model consolidating recurring activities and reducing the efforts for individual product lines. For the implementation of component-based development, the present thesis assesses current component approaches and applies an integration metamodel to the most suitable one. This ensures a common understanding of systems integration across different product lines and thus alleviates component reuse, even across product line boundaries. The approach is furthermore aligned with the organizational model to depict in which way component-based development may be applied in industrialized systems integration. Automating software development in systems integration with model-driven engineering was found to be insufficient in its current state. The reason herefore lies in insufficient tool chains and a lack of modelling standards. As an alternative, an XML-based configuration of products within a software product line has been developed. It models a product line and its products with the help of a domain-specific language and utilizes stylesheet transformations to generate compliable artefacts. The approach has been tested for its feasibility within an exemplarily implementation following a real-world scenario. As not all aspects of industrialized systems integration could be simulated in a laboratory environment, the concept was furthermore validated during several expert interviews with industry representatives. Here, it was also possible to assess cultural and economic aspects. The thesis concludes with a detailed summary of the contributions to the field and suggests further areas of research in the context of industrialized systems integration.

Šio darbo tikslas yra sukurti metodą, kuris teiktų galimybę kuo didesnę vartotojo sąsajos dalį apibrėžti deklaratyviai (komponentų kūrimas, įvykių klausytojų registravimas, komponentų tarpusavio sąryšių apibrėžimas ir vizualus komponentų išdėstymas languose). Darbe išanalizuotos įvairios komponentinės architektūros bei išraiškingą vartotojo sąsajos apibrėžimą įgalinantys sprendimai. Apibrėžta ir įgyvendinta architektūra leidžianti kurti deklaratyviai apibrėžiamus vartotojo sąsajos komponentus, kurie deklaruoja savo elgesį ir gali bendrauti tarpusavyje pranešimų pagalba. Rezultate buvo sukurta sistema, kuri leidžia kurti taikomąsias programas su Java Swing vartotojo sąsaja, naudojantis beveik vien tik deklaratyviais taikomosios programos dalių apibrėžimais. Sukurtos sistemos konfigūracijos galimybės leidžia sumažinti komponentų manipuliacijai skirto Java kodo poreikį. / A part of a user interface can be created using declarative means. The main goal of this paper is to maximize that portion. To do that, said means would be used to create components, register event listeners, describe relationships between components and layout them in windows. Various component-based architectures and existing solutions for declarative user interface definition were analyzed. As a result, an architecture was defined which allows user interface components to be created using a declarative approach. These components define their behavior and use messages to communicate with each other. The outcome was a system, which can create Java Swing applications using mostly declarative definitions of various parts of said applications. This system provides various configuration options that reduce the need of writing Java code for component manipulation.

This thesis develops a trainable object-recognition algorithm. This algorithm represents objects using their salient features. The algorithm applies an attention mechanism to speed up feature detection. A trainable component-based object recognition system which implements the developed algorithm has been created. This system has two layers. The first layer contains several individual feature classifiers. They detect salient features which compose higher level objects from input images. The second layer judges if those detected features form a valid object. An object is represented by a feature map which stores the geometrical and hierarchical relations among features and higher level objects. It is the input to the second layer. The attention mechanism is applied to improve feature detection speed. This mechanism will lead the system to areas with a higher likelihood of containing features when a few features are detected. Therefore the feature detection will be sped up. Two major experiments are conducted. These experiments applied the de- veloped system to discriminate faces from non-faces and to discriminate people from backgrounds in thermal images. The results of these experiments show the success of the implemented system. The attention mechanism displays a positive effect on feature detection. It can save feature detection time, especially in terms of classifier calls.

The major problem of robotics research today is that there is a barrier to entry into robotics research. Robot system software is complex and a researcher that wishes to concentrate on one particular problem often needs to learn about details, dependencies and intricacies of the complete system. This is because a robot system needs several different modules that need to communicate and execute in parallel. Today there is not much controlled comparisons of algorithms and solutions for a given task, which is the standard scientific method of other sciences. There is also very little sharing between groups and projects, requiring code to be written from scratch over and over again. This thesis proposes a general framework for robotics. By examining successful systems and architectures of past and present, yields a number of key properties. Some of these are ease of use, modularity, portability and efficiency. Even though there is much consensus on that the hybrid deliberate/reactive is the best architectural model that the community has produced so far, a framework should not stipulate a specific architecture. Instead the framework should enable the building of different architectures. Such a scheme implies that the modules are seen as common peers and not divided into clients and servers or forced into a set layering. Using a standardized middleware such as CORBA, efficient communication can be carried out between different platforms and languages. Middleware also provides network transparency which is valuable in distributed systems. Component-based Software Engineering (CBSE) is an approach that could solve many of the aforementioned problems. It enforces modularity which helps to manage complexity. Components can be developed in isolation, since algorithms are encapsulated in components where only the interfaces need to be known by other users. A complete system can be created by assembling components from different sources. Comparisons and sharing can greatly benefit from CBSE. A component-based framework called ORCA has been implemented with the following characteristics. All communication is carried out be either of three communication patterns, query, send and push. Communication is done using CORBA, although most of the CORBA code is hidden for the developer and can in the future be replaced by other mechanisms. Objects are transported between components in the form of the CORBA valuetype. A component model is specified that among other things include support for a state-machine. This also handles initialization and sets up communication. Configuration is achieved by the presence of an XML-file per component. A hardware abstraction scheme is specified that basically route the communication patterns right down to the hardware level. The framework has been verified by the implementation of a number of working systems.

Les langages dédiés (DSL) sont de plus en plus utilisés parce qu’ils permettent aux utilisateurs qui ne sont pas des experts en programmation d’exprimer des solutions avec des langages simples qui capturent l’expertise de leur domaine. C’est encore plus vrai pour les langages dédiés graphiques (DSML) qui ont un niveau d’abstraction plus élevé que les langages dédiés de programmation. Implémenter un DSML revient généralement à fournir un éditeur dédié qui permette aux utilisateurs de manipuler les abstractions de leur domaine (d’instancier le langage). Les expériences ont montré que l’implémentation d’un tel éditeur dédié graphique est coûteuse en termes de temps et de ressources humaines. Nous constatons que la plupart des plates-formes permettant de construire ce type d’éditeur (EMF/GMF, DSL Tools, Obeo Designer, ...) sont génériques. Elles essayent d’adresser le maximum de domaines possibles, ce qui les rend complexes et inadaptées à des cas d’utilisation spécifiques. Si la spécialisation aux domaines a été un succès pour les langages, pourquoi ne pas l’appliquer aux plates-formes de construction d’éditeurs ? Cela reviendrait à concevoir pour un domaine donné, une plate-forme permettant de construire facilement des éditeurs dédiés pour ce domaine. Cette plate-forme n’aurait pas les défauts d’une plate-forme totalement générique parce qu’elle serait restreinte au domaine ciblé. Ce type de plate-forme spécifique à un domaine, nous l’appelons Domain Specific Modeling Framework (DSMF). Le principal inconvénient d’un DSMF est qu’on ne peut l’utiliser que dans le cadre du domaine pour lequel il a été conçu. Cela implique qu’il faille construire un DSMF par domaine et c’est une solution coûteuse. Toutefois, nous pensons que cette approche sur les DSMF peut être généralisée afin d’adresser un grand nombre de domaines. Cette thèse a donc consisté à concevoir et à implanter un environnement qui permet de construire des DSMF de façon modulaire. / Domain Specific Languages (DSLs) are increasingly used in many fields as they allow users to express strategies without being programming experts. This is particularly true for graphical DSLs called Domain Specific Modeling Languages (DSMLs) which are more intuitive than programming DSLs. Implementing a DSML means providing a specific editor which allow users to express the language’s constructions (instantiate the language). Many experiments showed that implementing specific graphical editors is much manpower consuming. Our analysis is that most frameworks for building such editors (e.g. EMF/GMF) are generic, i.e. aim at fulfilling the requirements of any field, which leads to increased complexity and costs a lot in terms of development time. If domain specialization was successful for languages, why don’t we apply it to frameworks ? Specializing such a framework according to the constraints of a domain would allow keeping the definition of a specific editor simple, while fulfilling the requirements of the considered domain. Domain specific frameworks for building DSML editors in specific application fields is a promising approach. Such a framework does not have the limits of generic frameworks because it is restricted to a particular domain. It is more intuitive and simpler to use as it only proposes abstraction of the domain for building DSMLs. We call this type of framework Domain Specific Modeling Framework (DSMF). For example, if we consider the component domain, there are several DSMLs in this domain which share the same layout requirements. We implemented a DSMF for this family of DSMLs. This DSMF is specialized according to the constraints and layout requirements of the component domain (Components, connectors, Bindings, . . .). This specialization allows simple and rapid generation of specific editors devoted to component-based architectures. The principal drawback of a DSMF is its restricted scope to one specific domain. This approach requires to develop one DSMF per domain and the development cost can be significant. A solution may be to generalise the DSMF approach in order to address many application fields. We designed a Generic framework for building DSMFs in a modular way. This thesis is based on the implementation of this framework.

The Common Tutor Object Platform (CTOP) was designed as a lightweight component framework for creating and deploying applications relating to Intelligent Tutoring Systems. The CTOP supports a runtime for intelligent tutoring system content deployment, a content development environment, an extensive reporting tool, and other smaller applications. The CTOP was designed with future development in mind, allowing easy specification of new base objects and extension points for future development. It has been used as the foundation of the Assistments Project, a wide scale server based ITS deployment. This thesis documents the software engineering aspects of the project. The Assistments Project is capable of supporting a quarter of targeted students in Massachusetts, and optimistically scalable to the entire state and beyond.

Dans cette thèse, nous nous sommes intéressés aux design, vérification et implémentation des systèmes à base de composants. Nous proposons d'abord une méthodologie de design et de vérification compositionelle et incrémentale à base de contrats pour les systèmes de composants. Nous proposons ensuite une implémentation distribuée qui permet de préserver certaines properiétés globales de ces systèmes. La méthodologie de design proposée utilise les contrats comme un moyen de contraindre, raffiner et d'implémenter les systèmes. Elle est basée sur un formalisme de contracts générique, que nous instancions pour un formalisme de composants permettant la description des propriétés de progrés. Nous étendons cette méthodologie pour raisonner sur des systèmes de taille arbitraire et nous prouvons son utilité pour vérifier des propriétés de sûreté et de progrés d'un réseau de noeuds distribués. Dans le contexte des systèmes distribués, les systèmes doivent être implémenter de manière distribuée. Nous proposons dans cette thèse un protocole qui permet l'exécution distribuée des systèmes tout en préservant certaines propriétés globales à savoir des synchronisations et des priorités et où les composants interagissent par échange de messages. Nous proposons également une implémentation du protocole pour une plateforme particulière. / The goal of the thesis is to provide theory, methods and tools for the design and implementation of component-based systems. To master the complexity of systems of components, we first propose a contract-based design and verification approach which is both compositional and incremental. Then we provide a distributed implementation of these systems allowing to preserve some global properties. The proposed verification approach uses contracts as a means to constrain, refine and implement systems. It is based on a generic contract framework that we instantiate for a component framework allowing to express progress properties. We also extend the approach to reason about systems of arbitrary size and we show its usefulness for proving safety and progress properties in networked systems. In the context of distributed settings, these systems must later be executed in a distributed fashion. We also propose in this thesis a protocol that allows executing systems in a distributed way while preserving some global requirements namely priorities and synchronizations and where components interact by message exchange. Then, we provide an implementation of this protocol in a particular platform.

In software product line engineering, the construction of an architecture for a product family is still an outstanding engineering challenge. In current practice, a framework is used for configuring individual products by combining solution space artefacts into products with specified features according to a feature model. No architectures are created. In contrast, an architecture for a product family would define the architectures for all the products in the family, allowing engineers to reason at a higher level of abstraction. In this thesis, we present a component model that can be used to define architectures for product families, by incorporating explicit variation points.