A Systematic Approach to Model Objectives in Predevelopment Projects

This contribution presents a systematic for the elicitation of objectives and the utilization of objectives to identify reference products. The systematic is based on existing meta models. The model of objectives as proposed in this research eases decision-making and outlines the next validation activities. A key success factor is the project transferability between teams, which is often necessary in predevelopment. This is ensured through comprehensibility of objectives which benefits from the linkage between the model of objectives and the knowledge base. The proposed systematic is applied to a predevelopment project which is used as case study. In the case study it has been shown that objectives can be used to identify reference products. The approach is validated in a live-lab setting with seven engineering teams with six graduate students, two engineers of an industrial partner and a research associate. Several workshops were used to train all members of the teams in the systematic. The effects of the systematic are assessed in dedicated interviews, a survey as well as with observation of the engineering teams during milestones and engineering activities between milestones

Virtual user in the IoT: definition, technologies and experiments

Virtualization technologies are characterizing major advancements in the Internet of Things (IoT) arena, as they allow for achieving a cyber-physical world where everything can be found, activated, probed, interconnected, and updated at both the virtual and the physical levels. We believe these technologies should apply to human users other than things, bringing us the concept of the Virtual User (VU). This should represent the virtual counterpart of the IoT users with the ultimate goal of: (i) avoiding the user from having the burden of following the tedious processes of setting, configuring and updating IoT services the user is involved in; (ii) acting on behalf of the user when basic operations are required; (iii) exploiting to the best of its ability the IoT potentialities, always taking always account the user profile and interests. Accordingly, the VU is a complex representation of the user and acts as a proxy in between the virtual objects and IoT services and application; to this, it includes the following major functionalities: user profiling, authorization management, quality of experience modeling and management, social networking and context management. In this respect, the major contributions of this paper are to: provide the definition of VU, present the major functionalities, discuss the legal issues related to its introduction, provide some implementation details, and analyze key performance aspects in terms of the capability of the VU to correctly identify the user profile and context

Méthode pour la définition des langages dédiés basée sur le métamodèle ISO/IEC 24744

Au cours des dernières années, il y a eu un intérêt croissant pour les langages dédiés (Domain Specific Languages (DSL)). Cet intérêt est motivé par l'émergence d'approches telles que l’ingénierie dirigée par les modèles, l’architecture dirigée par les modèles, les lignes de produits logiciels (SPL), les usines à logiciels et le développement dirigé par les modèles. Alors qu’au fond l'objectif de ces approches est d'élever le niveau d'abstraction du développement logiciel et d’augmenter le degré d’automatisation en utilisant des modèles de domaine précis et facilement exploitables par les machines, on constate que ces approches manquent de langages capables de produire de tels modèles et qu’elles sont toujours à la recherche de solutions pour mieux soutenir le développement selon ce nouveau paradigme. À cet égard, beaucoup de spécialistes considèrent les langages dédiés comme une solution capable d’aller au delà des modèles limités à la documentation et de produire des modèles précis prêts à être traités automatiquement par la machine. Les langages dédiés ont démontré un grand potentiel pour augmenter la productivité, améliorer la maintenabilité, élever le niveau d'abstraction, et produire des modèles exécutables. Toutefois, le développement de langages dédiés fiables et intègres est une activité difficile et coûteuse qui demande à la fois une connaissance du domaine et des compétences en développement des langages. Ainsi, l’établissement d’une infrastructure rendant le développement de DSL plus facile et plus accessible constituera une étape importante vers la concrétisation et la consolidation des approches dirigées par les modèles. Afin de développer cette infrastructure, nous pensons que les efforts doivent être axés sur trois domaines principaux : 1) les processus qui permettent d’offrir une approche disciplinée en matière de développement des DSL, 2) les outils pour soutenir le développement et la maintenance de ces DSL et 3) les standards pour assurer l’unification du développement et l’interopérabilité entre les outils. Cette thèse est une contribution au domaine des processus. Nous y proposons une méthode de développement de DSL basée sur la norme ISO/IEC 24744 (Software Engineering-Metamodel for Development Methodologies - SEMDM). La méthode est générée à partir du métamodèle décrit dans la norme. Elle décrit, entre autres, les activités et les tâches à exécuter lors du développement d’un DSL, les artefacts à manipuler (créer, utiliser ou modifier) et les personnes impliquées. La méthode fournit également, lorsque possible, des techniques et des lignes directrices expliquant comment certains éléments de la méthode peuvent être utilisés

Ubiquitous Computing

The aim of this book is to give a treatment of the actively developed domain of Ubiquitous computing. Originally proposed by Mark D. Weiser, the concept of Ubiquitous computing enables a real-time global sensing, context-aware informational retrieval, multi-modal interaction with the user and enhanced visualization capabilities. In effect, Ubiquitous computing environments give extremely new and futuristic abilities to look at and interact with our habitat at any time and from anywhere. In that domain, researchers are confronted with many foundational, technological and engineering issues which were not known before. Detailed cross-disciplinary coverage of these issues is really needed today for further progress and widening of application range. This book collects twelve original works of researchers from eleven countries, which are clustered into four sections: Foundations, Security and Privacy, Integration and Middleware, Practical Applications

Assessing and improving the quality of model transformations

Software is pervading our society more and more and is becoming increasingly complex. At the same time, software quality demands remain at the same, high level. Model-driven engineering (MDE) is a software engineering paradigm that aims at dealing with this increasing software complexity and improving productivity and quality. Models play a pivotal role in MDE. The purpose of using models is to raise the level of abstraction at which software is developed to a level where concepts of the domain in which the software has to be applied, i.e., the target domain, can be expressed e??ectively. For that purpose, domain-speci??c languages (DSLs) are employed. A DSL is a language with a narrow focus, i.e., it is aimed at providing abstractions speci??c to the target domain. This makes that the application of models developed using DSLs is typically restricted to describing concepts existing in that target domain. Reuse of models such that they can be applied for di??erent purposes, e.g., analysis and code generation, is one of the challenges that should be solved by applying MDE. Therefore, model transformations are typically applied to transform domain-speci??c models to other (equivalent) models suitable for di??erent purposes. A model transformation is a mapping from a set of source models to a set of target models de??ned as a set of transformation rules. MDE is gradually being adopted by industry. Since MDE is becoming more and more important, model transformations are becoming more prominent as well. Model transformations are in many ways similar to traditional software artifacts. Therefore, they need to adhere to similar quality standards as well. The central research question discoursed in this thesis is therefore as follows. How can the quality of model transformations be assessed and improved, in particular with respect to development and maintenance? Recall that model transformations facilitate reuse of models in a software development process. We have developed a model transformation that enables reuse of analysis models for code generation. The semantic domains of the source and target language of this model transformation are so far apart that straightforward transformation is impossible, i.e., a semantic gap has to be bridged. To deal with model transformations that have to bridge a semantic gap, the semantics of the source and target language as well as possible additional requirements should be well understood. When bridging a semantic gap is not straightforward, we recommend to address a simpli??ed version of the source metamodel ??rst. Finally, the requirements on the transformation may, if possible, be relaxed to enable automated model transformation. Model transformations that need to transform between models in di??erent semantic domains are expected to be more complex than those that merely transform syntax. The complexity of a model transformation has consequences for its quality. Quality, in general, is a subjective concept. Therefore, quality can be de??ned in di??erent ways. We de??ned it in the context of model transformation. A model transformation can either be considered as a transformation de??nition or as the process of transforming a source model to a target model. Accordingly, model transformation quality can be de??ned in two di??erent ways. The quality of the de??nition is referred to as its internal quality. The quality of the process of transforming a source model to a target model is referred to as its external quality. There are also two ways to assess the quality of a model transformation (both internal and external). It can be assessed directly, i.e., by performing measurements on the transformation de??nition, or indirectly, i.e., by performing measurements in the environment of the model transformation. We mainly focused on direct assessment of internal quality. However, we also addressed external quality and indirect assessment. Given this de??nition of quality in the context of model transformations, techniques can be developed to assess it. Software metrics have been proposed for measuring various kinds of software artifacts. However, hardly any research has been performed on applying metrics for assessing the quality of model transformations. For four model transformation formalisms with di??fferent characteristics, viz., for ASF+SDF, ATL, Xtend, and QVTO, we de??ned sets of metrics for measuring model transformations developed with these formalisms. While these metric sets can be used to indicate bad smells in the code of model transformations, they cannot be used for assessing quality yet. A relation has to be established between the metric sets and attributes of model transformation quality. For two of the aforementioned metric sets, viz., the ones for ASF+SDF and for ATL, we conducted an empirical study aiming at establishing such a relation. From these empirical studies we learned what metrics serve as predictors for di??erent quality attributes of model transformations. Metrics can be used to quickly acquire insights into the characteristics of a model transformation. These insights enable increasing the overall quality of model transformations and thereby also their maintainability. To support maintenance, and also development in a traditional software engineering process, visualization techniques are often employed. For model transformations this appears as a feasible approach as well. Currently, however, there are few visualization techniques available tailored towards analyzing model transformations. One of the most time-consuming processes during software maintenance is acquiring understanding of the software. We expect that this holds for model transformations as well. Therefore, we presented two complementary visualization techniques for facilitating model transformation comprehension. The ??rst-technique is aimed at visualizing the dependencies between the components of a model transformation. The second technique is aimed at analyzing the coverage of the source and target metamodels by a model transformation. The development of the metric sets, and in particular the empirical studies, have led to insights considering the development of model transformations. Also, the proposed visualization techniques are aimed at facilitating the development of model transformations. We applied the insights acquired from the development of the metric sets as well as the visualization techniques in the development of a chain of model transformations that bridges a number of semantic gaps. We chose to solve this transformational problem not with one model transformation, but with a number of smaller model transformations. This should lead to smaller transformations, which are more understandable. The language on which the model transformations are de??ned, was subject to evolution. In particular the coverage visualization proved to be bene??cial for the co-evolution of the model transformations. Summarizing, we de??ned quality in the context of model transformations and addressed the necessity for a methodology to assess it. Therefore, we de??ned metric sets and performed empirical studies to validate whether they serve as predictors for model transformation quality. We also proposed a number of visualizations to increase model transformation comprehension. The acquired insights from developing the metric sets and the empirical studies, as well as the visualization tools, proved to be bene??cial for developing model transformations

Test et évaluation de la robustesse de la couche fonctionnelle d'un robot autonome

La mise en oeuvre de systèmes autonomes nécessite le développement et l'utilisation d'architectures logicielles multi-couches qui soient adaptées. Typiquement, une couche fonctionnelle renferme des modules en charge de commander les éléments matériels du système et de fournir des services élémentaires. Pour être robuste, la couche fonctionnelle doit être dotée de mécanismes de protection vis-à-vis de requêtes erronées ou inopportunes issues de la couche supérieure. Nous présentons une méthodologie pour tester la robustesse de ces mécanismes. Nous définissons un cadre général pour évaluer la robustesse d'une couche fonctionnelle par la caractérisation de son comportement vis-à-vis de requêtes inopportunes. Nous proposons également un environnement de validation basé sur l'injection de fautes dans le logiciel de commande d'un robot simulé. Un grand nombre de cas de tests est généré automatiquement par la mutation d'une séquence de requêtes valides. Les statistiques descriptives des comportements en présence de requêtes inopportunes sont analysées afin d'évaluer la robustesse du système sous test. ABSTRACT : The implementation of autonomous systems requires the development and the using of multi-layer software architecture. Typically, a functional layer contains several modules that control the material of the system and provide elementary services. To be robust, the functional layer must be implemented with protection mechanisms with respect to erroneous or inopportune requests sent from the superior layer. We present a methodology for robustness testing these mechanisms. We define a general framework to evaluate the robustness of a functional layer by characterizing its behavior with respect to inappropriate requests. We also propose an validation environment based on fault injection in the control software of a simulated robot. A great number of test cases is generated automatically by the mutation of a sequence of valid requests. The descriptive statistics of the behaviors in the presence of inappropriate requests are analyzed in order to evaluate the robustness of the system under test