Doctor of Philosophy / Precision Agriculture (PA) strives towards holistic production and environmental management. A fundamental research challenge is the continuous expansion of ideas about how PA can contribute to sustainable agriculture. Some associated pragmatic research challenges include quantification of spatio-temporal variation of crop yield; crop growth simulation modelling within a PA context and; evaluating long-term financial and environmental outcomes from site-specific crop management (SSCM). In Chapter 1 literature about managing whole farms with a mind towards sustainability was reviewed. Alternative agricultural systems and concepts including systems thinking, agro-ecology, mosaic farming and PA were investigated. With respect to environmental outcomes it was found that PA research is relatively immature. There is scope to thoroughly evaluate PA from a long-term, whole-farm environmental and financial perspective. Comparatively, the emphasis of PA research on managing spatial variability offers promising and innovative ways forward, particularly in terms of designing new farming systems. It was found that using crop growth simulation modelling in a PA context is potentially very useful. Modelling high-resolution spatial and temporal variability with current simulation models poses a number of immediate research issues. This research focused on three whole farms located in Australia that grow predominantly grains without irrigation. These study sites represent three important grain growing regions within Australia. These are northern NSW, north-east Victoria and South Australia. Note-worthy environmental and climatic differences between these regions such as rainfall timing, soil type and topographic features were outlined in Chapter 2. When considering adoption of SSCM, it is essential to understand the impact of temporal variation on the potential value of managing spatial variation. Quantifying spatiotemporal variation of crop yield serves this purpose; however, this is a conceptually and practically challenging undertaking. A small number of previous studies have found that the magnitude of temporal variation far exceeds that of spatial variation. Chapter 3 of this thesis dealt with existing and new approaches quantifying the relationship between spatial and temporal variability in crop yield. It was found that using pseudo cross variography to obtain spatial and temporal variation ‘equivalents’ is a promising approach to quantitatively comparing spatial and temporal variation. The results from this research indicate that more data in the temporal dimension is required to enable thorough analysis using this approach. This is particularly relevant when questioning the suitability of SSCM. Crop growth simulation modelling offers PA a number of benefits such as the ability to simulate a considerable volume of data in the temporal dimension. A dominant challenge recognised within the PA/modelling literature is the mismatch between the spatial resolution of point-based model output (and therefore input) and the spatial resolution of information demanded by PA. This culminates into questions about the conceptual model underpinning the simulation model and the practicality of using point-based models to simulate spatial variability. iii The ability of point-based models to simulate appropriate spatial and temporal variability of crop yield and the importance of soil available water capacity (AWC) for these simulations were investigated in Chapter 4. The results indicated that simulated spatial variation is low compared to some previously reported spatial variability of real yield data for some climate years. It was found that the structure of spatial yield variation was directly related to the structure of the AWC and interactions between AWC and climate. It is apparent that varying AWC spatially is a reasonable starting point for modelling spatial variation of crop yield. A trade-off between capturing adequate spatio-temporal variation of crop yield and the inclusion of realistically obtainable model inputs is identified. A number of practical solutions to model parameterisation for PA purposes are identified in the literature. A popular approach is to minimise the number of simulations required. Another approach that enables modelling at every desired point across a study area involves taking advantage of high-resolution yield information from a number of years to estimate site-specific soil properties with the inverse use of a crop growth simulation model. Inverse meta-modelling was undertaken in Chapter 5 to estimate AWC on 10- metre grids across each of the study farms. This proved to be an efficient approach to obtaining high-resolution AWC information at the spatial extent of whole farms. The AWC estimates proved useful for yield prediction using simple linear regression as opposed to application within a complex crop growth simulation model. The ability of point-based models to simulate spatial variation was re-visited in Chapter 6 with respect to the exclusion of lateral water movement. The addition of a topographic component into the simple point-based yield prediction models substantially improved yield predictions. The value of these additions was interpreted using coefficients of determination and comparing variograms for each of the yield prediction components. A result consistent with the preceding chapter is the importance of further validating the yield prediction models with further yield data when it becomes available. Finally, some whole-farm management scenarios using SSCM were synthesised in Chapter 7. A framework that enables evaluation of the long-term (50 years) farm outcomes soil carbon sequestration, nitrogen leaching and crop yield was established. The suitability of SSCM across whole-farms over the long term was investigated and it was found that the suitability of SSCM is confined to certain fields. This analysis also enabled identification of parts of the farms that are the least financially and environmentally viable. SSCM in conjunction with other PA management strategies is identified as a promising approach to long-term and whole-farm integrated management.

<p>It is often beneficial for an autonomous agent that operates in a complex environment to make use of different types of mathematical models to keep track of unobservable parts of the world or to perform prediction, planning and other types of reasoning. Since a model is always a simplification of something else, there always exists a tradeoff between the model’s accuracy and feasibility when it is used within a certain application due to the limited available computational resources. Currently, this tradeoff is to a large extent balanced by humans for model construction in general and for autonomous agents in particular. This thesis investigates different solutions where such agents are more responsible for balancing the tradeoff for models themselves in the context of interleaved task planning and plan execution. The necessary components for an autonomous agent that performs its abstractions and constructs planning models dynamically during task planning and execution are investigated and a method called DARE is developed that is a template for handling the possible situations that can occur such as the rise of unsuitable abstractions and need for dynamic construction of abstraction levels. Implementations of DARE are presented in two case studies where both a fully and partially observable stochastic domain are used, motivated by research with Unmanned Aircraft Systems. The case studies also demonstrate possible ways to perform dynamic abstraction and problem model construction in practice.</p> / Report code: LiU-Tek-Lic-2008:21.

Doctor of Philosophy / Precision Agriculture (PA) strives towards holistic production and environmental management. A fundamental research challenge is the continuous expansion of ideas about how PA can contribute to sustainable agriculture. Some associated pragmatic research challenges include quantification of spatio-temporal variation of crop yield; crop growth simulation modelling within a PA context and; evaluating long-term financial and environmental outcomes from site-specific crop management (SSCM). In Chapter 1 literature about managing whole farms with a mind towards sustainability was reviewed. Alternative agricultural systems and concepts including systems thinking, agro-ecology, mosaic farming and PA were investigated. With respect to environmental outcomes it was found that PA research is relatively immature. There is scope to thoroughly evaluate PA from a long-term, whole-farm environmental and financial perspective. Comparatively, the emphasis of PA research on managing spatial variability offers promising and innovative ways forward, particularly in terms of designing new farming systems. It was found that using crop growth simulation modelling in a PA context is potentially very useful. Modelling high-resolution spatial and temporal variability with current simulation models poses a number of immediate research issues. This research focused on three whole farms located in Australia that grow predominantly grains without irrigation. These study sites represent three important grain growing regions within Australia. These are northern NSW, north-east Victoria and South Australia. Note-worthy environmental and climatic differences between these regions such as rainfall timing, soil type and topographic features were outlined in Chapter 2. When considering adoption of SSCM, it is essential to understand the impact of temporal variation on the potential value of managing spatial variation. Quantifying spatiotemporal variation of crop yield serves this purpose; however, this is a conceptually and practically challenging undertaking. A small number of previous studies have found that the magnitude of temporal variation far exceeds that of spatial variation. Chapter 3 of this thesis dealt with existing and new approaches quantifying the relationship between spatial and temporal variability in crop yield. It was found that using pseudo cross variography to obtain spatial and temporal variation ‘equivalents’ is a promising approach to quantitatively comparing spatial and temporal variation. The results from this research indicate that more data in the temporal dimension is required to enable thorough analysis using this approach. This is particularly relevant when questioning the suitability of SSCM. Crop growth simulation modelling offers PA a number of benefits such as the ability to simulate a considerable volume of data in the temporal dimension. A dominant challenge recognised within the PA/modelling literature is the mismatch between the spatial resolution of point-based model output (and therefore input) and the spatial resolution of information demanded by PA. This culminates into questions about the conceptual model underpinning the simulation model and the practicality of using point-based models to simulate spatial variability. iii The ability of point-based models to simulate appropriate spatial and temporal variability of crop yield and the importance of soil available water capacity (AWC) for these simulations were investigated in Chapter 4. The results indicated that simulated spatial variation is low compared to some previously reported spatial variability of real yield data for some climate years. It was found that the structure of spatial yield variation was directly related to the structure of the AWC and interactions between AWC and climate. It is apparent that varying AWC spatially is a reasonable starting point for modelling spatial variation of crop yield. A trade-off between capturing adequate spatio-temporal variation of crop yield and the inclusion of realistically obtainable model inputs is identified. A number of practical solutions to model parameterisation for PA purposes are identified in the literature. A popular approach is to minimise the number of simulations required. Another approach that enables modelling at every desired point across a study area involves taking advantage of high-resolution yield information from a number of years to estimate site-specific soil properties with the inverse use of a crop growth simulation model. Inverse meta-modelling was undertaken in Chapter 5 to estimate AWC on 10- metre grids across each of the study farms. This proved to be an efficient approach to obtaining high-resolution AWC information at the spatial extent of whole farms. The AWC estimates proved useful for yield prediction using simple linear regression as opposed to application within a complex crop growth simulation model. The ability of point-based models to simulate spatial variation was re-visited in Chapter 6 with respect to the exclusion of lateral water movement. The addition of a topographic component into the simple point-based yield prediction models substantially improved yield predictions. The value of these additions was interpreted using coefficients of determination and comparing variograms for each of the yield prediction components. A result consistent with the preceding chapter is the importance of further validating the yield prediction models with further yield data when it becomes available. Finally, some whole-farm management scenarios using SSCM were synthesised in Chapter 7. A framework that enables evaluation of the long-term (50 years) farm outcomes soil carbon sequestration, nitrogen leaching and crop yield was established. The suitability of SSCM across whole-farms over the long term was investigated and it was found that the suitability of SSCM is confined to certain fields. This analysis also enabled identification of parts of the farms that are the least financially and environmentally viable. SSCM in conjunction with other PA management strategies is identified as a promising approach to long-term and whole-farm integrated management.

Integration is one of the driving themes in database and applied computing research. Starting with the development of Federated Information Systems and passing over to Enterprise Application Integration, the integration of distributed systems receives a lot of attention with the development of Web services these days. Integration on an architecture independent level can be cast to the integration of autonomous object oriented systems which requires the integration of object structure and object behaviour. Past research has mainly addressed the structural aspects meaning the integration of class attributes and relations. This thesis is addressing the integration of object behaviour and proposes a structured, model-driven approach for the integration of business processes specifying software application behaviour. It consists of the identification of correspondences between business processes on different levels of abstraction and associates the correspondences with integration patterns that lead to a specific technical integration. One advantage of the approach is that correspondences and patterns are defined separately, which enhances the re-usability of patterns in different integration scenarios. Integration scenarios can be distinguished between horizontal and vertical integration, and within or across enterprise borders. Within an enterprise, horizontal integration consists of integrating systems on the same level of abstraction and vertical integration consists of integrating systems on different levels of abstractions, whereas across enterprise borders, horizontal integration consists of determining the most appropriate systems, from among a set of functionally equivalent ones, and vertical integration consists of defining an appropriate combination of systems to create a new one. So far, there exist no approach that attempts to support all integration scenarios within a framework. This thesis proposes an integration approach that is able to support all integration scenarios mentioned before. The approach is built on a meta-meta layer architecture and provides generic methods and techniques for the logical integration of object behaviour based on a domain independent framework. The thesis proposes two alternative outcomes of an integration. First one creates a new global behaviour that integrates local behaviour and can be supported by a service oriented architecture. Second alternative outcome are synchronisation points between business process, so-called inter-process dependencies, that can be supported by an event-driven architecture. The advantages and disadvantages of both are discussed in detail.

Récemment, les ontologies ont été largement adoptées par différentes entreprises dans divers domaines. Elles sontdevenues des composantes centrales dans bon nombre d'applications. Ces modèles conceptualisent l'univers du discours auxmoyens de concepts primitifs et parfois redondants (calculés à partir de concepts primitifs). Au début, la relation entreontologies et base de données a été faiblement couplée. Avec l'explosion des données sémantiques, des solutions depersistance assurant une haute performance des applications ont été proposées. En conséquence, un nouveau type de base dedonnées, appelée base de données à base ontologique (BDBO) a vu le jour. Plusieurs types de BDBO ont été proposés, ilsutilisent différents SGBD. Chaque BDBO possède sa propre architecture et ses modèles de stockage dédiés à la persistancedes ontologies et de ses instances. A ce stade, la relation entre les bases de données et les ontologies devient fortementcouplée. En conséquence, plusieurs études de recherche ont été proposées sur la phase de conception physique des BDBO.Les phases conceptuelle et logique n'ont été que partiellement traitées. Afin de garantir un succès similaire au celui connupar les bases de données relationnelles, les BDBO doivent être accompagnées par des méthodologies de conception et desoutils traitant les différentes étapes du cycle de vie d'une base de données. Une telle méthodologie devrait identifier laredondance intégrée dans l'ontologie. Nos travaux proposent une méthodologie de conception dédiée aux bases de données àbase ontologique incluant les principales phases du cycle de vie du développement d'une base de données : conceptuel,logique, physique ainsi que la phase de déploiement. La phase de conception logique est réalisée grâce à l'incorporation desdépendances entre les concepts ontologiques. Ces dépendances sont semblables au principe des dépendances fonctionnellesdéfinies pour les bases de données relationnelles. En raison de la diversité des architectures des BDBO et la variété desmodèles de stockage utilisés pour stocker et gérer les données ontologiques, nous proposons une approche de déploiement àla carte. Pour valider notre proposition, une implémentation de notre approche dans un environnement de BDBO sousOntoDB est proposée. Enfin, dans le but d'accompagner l'utilisateur pendant le processus de conception, un outil d'aide à laconception des bases de données à partir d'une ontologie conceptuelle est présenté / Recently, ontologies have been widely adopted by small, medium and large companies in various domains. Theyhave become central components in many applications. These models conceptualize the universe of discourse by means ofprimitive and sometimes redundant concepts (derived from primitive concepts). At first, the relationship between ontologiesand database was loosely coupled. With the explosion of semantic data, persistence solutions providing high performanceapplications have been proposed. As a consequence, a new type of database, called ontology-based database (OBDB) isborn. Several types of OBDB have been proposed including different architectures of the target DBMS and storage modelsfor ontologies and their instances. At this stage, the relationship between databases and ontologies becomes strongly coupled.As a result, several research studies have been proposed on the physical design phase of OBDB. Conceptual and logicalphases were only partially treated. To ensure similar success to that known by relational databases, OBDB must beaccompanied by design methodologies and tools dealing with the different stages of the life cycle of a database. Such amethodology should identify the redundancy built into the ontology. In our work, we propose a design methodologydedicated to ontology-based databases including the main phases of the lifecycle of the database development: conceptual,logical and physical as well as the deployment phase. The logical design phase is performed thanks to the incorporation ofdependencies between concepts and properties of the ontologies. These dependencies are quite similar to the functionaldependencies in traditional databases. Due to the diversity of the OBDB architectures and the variety of the used storagemodels (triplet, horizontal, etc.) to store and manage ontological data, we propose a deployment ‘à la carte. To validate ourproposal, an implementation of our approach in an OBDB environment on OntoDB is proposed. Finally, in order to supportthe user during the design process, a tool for designing databases from a conceptual ontology is presented.

It is often beneficial for an autonomous agent that operates in a complex environment to make use of different types of mathematical models to keep track of unobservable parts of the world or to perform prediction, planning and other types of reasoning. Since a model is always a simplification of something else, there always exists a tradeoff between the model’s accuracy and feasibility when it is used within a certain application due to the limited available computational resources. Currently, this tradeoff is to a large extent balanced by humans for model construction in general and for autonomous agents in particular. This thesis investigates different solutions where such agents are more responsible for balancing the tradeoff for models themselves in the context of interleaved task planning and plan execution. The necessary components for an autonomous agent that performs its abstractions and constructs planning models dynamically during task planning and execution are investigated and a method called DARE is developed that is a template for handling the possible situations that can occur such as the rise of unsuitable abstractions and need for dynamic construction of abstraction levels. Implementations of DARE are presented in two case studies where both a fully and partially observable stochastic domain are used, motivated by research with Unmanned Aircraft Systems. The case studies also demonstrate possible ways to perform dynamic abstraction and problem model construction in practice. / <p>Report code: LiU-Tek-Lic-2008:21.</p>

Over the past decade the capabilities of autonomous systems have been steadily increasing. Unmanned systems are moving from systems that are predominantly remotely operated, to systems that include a basic decision making capability. This is a trend that is expected to continue with autonomous systems making decisions in increasingly complex environments, based on more abstract, higher-level missions and goals. These changes have significant implications for how these systems should be designed and engineered. Indeed, as the goals and tasks these systems are to achieve become more abstract, and the environments they operate in become more complex, are current approaches to verification and validation sufficient? Domain Specific Modelling is a key technology for the verification of autonomous systems. Verifying these systems will ultimately involve understanding a significant number of domains. This includes goals/tasks, environments, systems functions and their associated performance. Relational Model Transformations provide a means to utilise, combine and check models for consistency across these domains. In this thesis an approach that utilises relational model transformation technologies for systems verification, Systems MDD, is presented along with the results of a series of trials conducted with an existing relational model transformation language (QVT-Relations). These trials identified a number of problems with existing model transformation languages, including poorly or loosely defined semantics, differing interpretations of specifications across different tools and the lack of a guarantee that a model transformation would generate a model that was compliant with its associated meta-model. To address these problems, two related solvers were developed to assist with realising the Systems MDD approach. The first solver, MMCS, is concerned with partial model completion, where a partial model is defined as a model that does not fully conform with its associated meta-model. It identifies appropriate modifications to be made to a partial model in order to bring it into full compliance. The second solver, TMPT, is a relational model transformation engine that prioritises target models. It considers multiple interpretations of a relational transformation specification, chooses an interpretation that results in a compliant target model (if one exists) and, optionally, maximises some other attribute associated with the model. A series of experiments were conducted that applied this to common transformation problems in the published literature.

This master thesis looks at the use of business capabilities within enterprisearchitecture, and investigates how the concept is used within the Swedish pension managingcompany Folksam. Based on interviews with stakeholders an enterprise architecture metamodelcentred on the business capability is constructed. The meta-model is then edited andrevised according to a questionnaire aimed at removing irrelevant elements, and a secondset of interviews discussing a capability's health status and well being. This second set ofinterviews resulted in the removal of elements not aecting the well being of a capability.The nal meta-model has the business capability and the capability health status at itscore. It consists of the Capability element, with two attributes, surrounded by nine otherelements connected by eleven relations in total. / Detta examensarbete undersoker hur verksamhetsformagor anvandsinom enterprisearkitektur, och vidare hur formage-konceptet anvands pa det svenska pensionsforetaget Folksam. Baserat pa intervjuer med intressenter skapas en metamodell medverksamhetsformagan i centrum. Metamodellen revideras och andras sedan enligt ett frageformular vars mal var att ta bort ej relevanta element, och enligt en andra omgang intervjuerdar en formagas halsa diskuteras. Denna andra omgang intervjuer resulterade i att elementsom inte paverkade formagans halsa togs bort. Den slutgiltiga metamodellen har verksamhetsformagan och dess halsostatus i fokus. Den bestar av formage-elementet, med tvaattribut, omgardat av nio andra element som binds ihop av totalt elva olika relationer.

La simulation opérationnelle a déjà été développée pour diverses activités dont l'exercice en conditions réelles peut s'avérer coûteux voire dangereux : le pilotage d'avion, les interventions chirurgicales, etc. L'idée consiste à remplacer la réalité par une simulation suffisamment réaliste pour donner l'impression aux utilisateurs qu'ils réalisent réellement l'activité.Le Contrôle Non-Destructif (CND) regroupe l'ensemble des méthodes mises en œuvre pour tester l'intégrité des pièces mécaniques sans les altérer. Dans ce domaine, la simulation opérationnelle n'a été introduite que très récemment par un brevet déposé par Airbus. Cette approche permet de simuler numériquement la présence de défauts sans avoir à les ajouter réellement dans les pièces. Les pièces aéronautiques étant coûteuses, la simulation opérationnelle permet de réduire les coûts liés à la formation des opérateurs, à l'évaluation des performances des méthodes ou aux tests en conditions réelles de nouvelles procédures.La présente thèse vise à développer les outils scientifiques et technologiques nécessaires à donner vie au concept de simulation opérationnelle en CND. Pour remplacer la réalité par la simulation, les défis à relever sont de trois ordres : le réalisme de la simulation, la rapidité des calculs et l'instrumentation. Nous avons choisi d'illustrer ces trois aspects dans le cadre de l'inspection par ultrasons de pièces en matériaux composites. Les modèles de simulation couramment employés --- basés sur la résolution des équations de la physique --- n'offrent pas des temps de calculs suffisamment courts pour satisfaire les pré-requis de la simulation opérationnelle. Par ailleurs, le réalisme des simulations souffre parfois de la difficulté à paramétrer correctement les modèles. Nous explorons donc une autre approche : les modèles sont construits à partir de données expérimentales. Cette stratégie est exploitée pour traiter différents types de phénomènes tels que l'endommagement par impact, le trou à fond plat ou encore les perturbations de la micro-structure des matériaux. Par ailleurs, une solution matérielle et logicielle sont proposées et un premier prototype de simulateur opérationnel est mis au point. Ce système permet d'exploiter les modèles développés et de montrer que les signaux synthétiques peuvent sembler aussi réalistes que la réalité. Cette thèse court ainsi du concept jusqu'au prototype. / Several fields have already adopted the concept of operational simulation to limit risks and costs. For instance, part of the training phase of airline transport pilots or surgerons can now rely on simulations instead of real-life situations.Non-Destructive Testing (NDT) assesses the integrity of structural and mechanical components without damaging them. Operational simulation has drawn attention of the NDT community only recently through an Airbus patent. In this field, the operational simulation can be used to simulate the presence of a defect in a component without actually inserting the defect. For expensive parts such as aeronautical structures, this approach can reduce the costs of training operators, evaluating NDT method performances or testing new procedures in real-conditions.This thesis work aims to apply the concept of operational simulation to NDT. Three main scientific and technological challenges are to be tackled: the simulation realism, the computation speed and the instrumentation. We chose to focus this study on the ultrasound NDT technique applied to composite materials. Classical simulation approaches based on physical equations are not fast enough for a real-time synthesis of ultrasound signals. Moreover, the realism is often limited by the fidelity of the inspection set-up description. For instance, the material properties are not always well-known and bring to a drop of realism. Thus, we investigate an alternative way: the models are built directly from experimental data. This strategy is applied to model the effect of several phenomena such as impact damages, flat bottom holes or material micro-structure. Hardware and software solutions are also studied to propose a first prototype. We have shown that the replacement of real signals by on-the-fly simulated ones is achievable: the simulation is realistic enough to be considered as reality by operators. thus, this thesis work brings the concept to a first prototype dedicated to ultrasound NDT.

La recherche en génie logiciel a depuis longtemps tenté de mieux comprendre le processus de développement logiciel, minimalement, pour en reproduire les bonnes pratiques, et idéalement, pour pouvoir le mécaniser. On peut identifier deux approches majeures pour caractériser le processus. La première approche, dite transformationnelle, perçoit le processus comme une séquence de transformations préservant certaines propriétés des données à l’entrée. Cette idée a été récemment reprise par l’architecture dirigée par les modèles de l’OMG. La deuxième approche consiste à répertorier et à codifier des solutions éprouvées à des problèmes récurrents. Les recherches sur les styles architecturaux, les patrons de conception, ou les cadres d’applications s’inscrivent dans cette approche. Notre travail de recherche reconnaît la complémentarité des deux approches, notamment pour l’étape de conception: dans le cadre du développement dirigé par les modèles, nous percevons l’étape de conception comme l’application de patrons de solutions aux modèles reçus en entrée. Il est coutume de définir l’étape de conception en termes de conception architecturale, et conception détaillée. La conception architecturale se préoccupe d’organiser un logiciel en composants répondant à un ensemble d’exigences non-fonctionnelles, alors que la conception détaillée se préoccupe, en quelque sorte, du contenu de ces composants. La conception architecturale s’appuie sur des styles architecturaux qui sont des principes d’organisation permettant d’optimiser certaines qualités, alors que la conception détaillée s’appuie sur des patrons de conception pour attribuer les responsabilités aux classes. Les styles architecturaux et les patrons de conception sont des artefacts qui codifient des solutions éprouvées à des problèmes récurrents de conception. Alors que ces artefacts sont bien documentés, la décision de les appliquer reste essentiellement manuelle. De plus, les outils proposés n’offrent pas un support adéquat pour les appliquer à des modèles existants. Dans cette thèse, nous nous attaquons à la conception détaillée, et plus particulièrement, à la transformation de modèles par application de patrons de conception, en partie parce que les patrons de conception sont moins complexes, et en partie parce que l’implémentation des styles architecturaux passe souvent par les patrons de conception. Ainsi, nous proposons une approche pour représenter et appliquer les patrons de conception. Notre approche se base sur la représentation explicite des problèmes résolus par ces patrons. En effet, la représentation explicite du problème résolu par un patron permet : (1) de mieux comprendre le patron, (2) de reconnaître l’opportunité d’appliquer le patron en détectant une instance de la représentation du problème dans les modèles du système considéré, et (3) d’automatiser l’application du patron en la représentant, de façon déclarative, par une transformation d’une instance du problème en une instance de la solution. Pour vérifier et valider notre approche, nous l’avons utilisée pour représenter et appliquer différents patrons de conception et nous avons effectué des tests pratiques sur des modèles générés à partir de logiciels libres. / Software engineering researchers have long tried to understand the software process development to mechanize it or at least to codify its good practices. We identify two major approaches to characterize the process. The first approach—known as transformational—sees the process as a sequence of property-preserving transformations. This idea was recently adopted by the OMG’s model-driven architecture (MDA). The second approach consists in identifying and codifying proven solutions to recurring problems. Research on architectural styles, frameworks and design patterns are part of this approach. Our research recognizes the complementarity of these two approaches, in particular in the design step. Indeed within the model-driven development context, we view software design as the process of applying codified solution patterns to input models. Software design is typically defined in terms of architectural design and detailed design. Architectural design aims at organizing the software in modules or components that meet a set of non-functional requirements while detailed design is—in some way—concerned by the contents of the identified components. Architectural design relies on architectural styles which are principles of organization to optimize certain quality requirements, whereas detailed design relies on design patterns to assign responsibilities to classes. Both architectural styles and design patterns are design artifacts that encode proven solutions to recurring design problems. While these design artifacts are documented, the decision to apply them remains essentially manual. Besides, once a decision has been made to use a design artifact, there is no adequate support to apply it to existing models. As design patterns present an ‘‘easier’’ problem to solve, and because architectural styles implementation relies on design patterns, our strategy for addressing these issues was to try to solve the problem for design patterns first, and then tackle architectural styles. Hence, in this thesis, we propose an approach for representing and applying design patterns. Our approach is based on an explicit representation of the problems solved by design patterns. Indeed, and explicit representation of the problem solved by a pattern enables to: 1) better understand the pattern, 2) recognize the opportunity of applying the pattern by matching the representation of the problem against the models of the considered system, and 3) specify declaratively the application of the pattern as a transformation of an instance of the problem into an instance of the solution. To verify and validate the proposed approach, we used it to represent and apply several design patterns. We also conducted practical tests on models generated from open source systems.