Timber has become more popular as a construction material during recent years. Engineered wood products, such as glued laminated timber and cross-laminated timber, have enabled the construction of multi-storey buildings. Tall buildings with many occupants need to resist a disproportional collapse in case of unexpected exposures, e.g. accidents or terrorism. Structural robustness can improve the collapse resistance of a building. The literature about robustness is comprehensive concerning concrete and steel buildings, but it is rather limited regarding timber. A robust building can mobilise alternative load paths in the structure after the removal of bearing building components. Alternative load paths rely primarily on the connections between components. For timber buildings, few investigations exist to evaluate the alternative load paths after a removal. Analyses usually do not take into account non-linear effects which could influence the capacity of alternative load paths, such as damage of single fasteners, friction,  timber crushing and brittle failure. In particular, the alternative load paths in platform-framed cross-laminated timber buildings are not well understood.  The goals of this thesis are to i) review the concept of robustness in general and determine the state of the art concerning timber buildings in particular, ii) develop a method to analyse the alternative load paths in a platform-framed CLT building taking into account relevant non-linearities, iii) use the method to elicit the alternative load paths in a building after a wall removal, and iv) study the effects of probabilistic variations of model parameters.  The thesis first introduces tall timber buildings and then presents a summary of structural robustness in a collapse resistance framework. The summary includes established analysis methods and specific considerations for timber, whereof a detailed review is provided in Paper I. Paper III additionally provides results of a survey on contemporary practices of professionals around the world concerning robustness.  In the subsequent chapter, the studied 8-storey case building made of platform-framed cross-laminated timber is described including the modelling abstractions. Additionally, the setup of a validation experiment for the modelling approach is described. The following chapter introduces the modelling approach for an alternative load path analysis after a wall removal. The approach is based on the finite element method using the commercial software Abaqus. The deterministic part of the approach includes a non-linear static pushdown analysis of single storeys in a bay and elicits the alternative load paths and their capacity. Finite connector elements in the model substitute single fasteners including their elastic, plastic, damage and rupture behaviour. The 3D models of the walls and floors account for timber crushing, brittle failure and contact friction. A simplified non-linear dynamic model of the entire bay uses the pushdown results as inputs and evaluates the collapse progression among storeys after a sudden element removal. The probabilistic part of the approach models the uncertainty of the input parameters of the dynamic model by varying the parameter values in a Monte Carlo simulation, to evaluate the probability of a collapse.  Paper II applies the approach for a simple pushdown of a single storey and Paper IV applies the pushdown and the dynamic analysis to elicit the alternative load paths after a single wall removal. The thesis shows furthermore the results of a double wall removal in the example building and the results of the Monte Carlo analysis for the single and double wall removal.  For the assumed removals, the developed approach could identify the alternative load paths, determine their capacities and estimate the probability of a collapse under probabilistic variations. The approach might be used to classify various removal scenarios in platform-framed multi-storey cross-laminated timber buildings specifically and predetermine design solutions which could provide a desired level of robustness. The approach might be generalised for multi-storey timber buildings of various construction types.

Les travaux de cette thèse portent sur la stabilisation des systèmes affines commutés. Ces systèmes appartiennent à la classe des systèmes dynamiques hybrides. Ils possèdent de plus la particularité d'avoir des points de fonctionnement non auto-maintenables : il n'existe pas de loi de commutations permettant de maintenir l'état du système en ce point. De ce fait, la stabilisation de ces systèmes en imposant à la loi de commutations une durée minimale entre chaque commutation aboutit à une convergence des trajectoires dans une région de l'espace d'état. Après avoir synthétisé différentes stratégies de commutations échantillonnées construites à partir d'une fonction de commande de Lyapunov en temps continu, nous cherchons à déterminer la région de l'espace dans laquelle converge asymptotiquement l'ensemble des trajectoires du système. Par la résolution d'un problème d'optimisation, une estimation de la taille de cette région est donnée et un lien avec les incertitudes du système y est établi. Un second problème de stabilisation est étudié dans cette thèse, en considérant une stratégie de commande basée observateur par retour de sortie. Cependant, du fait de la nature hybride du système, son observabilité est directement liée à la séquence de commutations. Il est alors nécessaire de garantir à la fois l'observabilité, par une condition algébrique, et la convergence du système vers un point de fonctionnement, par l'existence d'une fonction de commande de Lyapunov / This PhD thesis deals with the stabilization of switched affine systems. These systems belong to the class of hybrid dynamical systems. They exhibit a particular behavior: no switching law exists such that the state can be maintained on a chosen operating point. Hence, assuming a dwell time condition on switchings exists, the stabilization of these systems leads to a convergence of the trajectories to a region of the state space. Based on a control Lyapunov function in continuous time, we synthesize several sampled-data switching strategies. The whole trajectories asymptotically converge to a region which we attempt to determine. Solving an optimization problem, an estimation of the size of this region is given. A link with the system uncertainties is also established. This PhD thesis is dedicated to a second stabilization issue: observer-based output-feedback synthesis. By its hybrid nature, the observability of the system is connected to the switching sequence. Therefore, the synthesis of the switching strategy must respect an observability condition and guarantee the convergence to the operating point. The observability is achieved thanks to an algebraic condition. The convergence property is based on the existence of a control Lyapunov function

Atualmente, diversas empresas e organizações estão cada vez mais empreendendo esforços para transformar rapidamente as suas potenciais ideias em produtos e serviços. Esses esforços também têm estimulado a evolução dos sistemas de informação que passaram a ser apoiados por modelos de alto nível de abstração para descrever a lógica do processo. Neste contexto, destaca-se o sucesso dos Sistemas de Informação cientes de Processos (PAIS, do inglês Process-Aware Information Systems) para o gerenciamento de processos de negócios e automação de processos científicos de larga escala (e-Science). Grande parte do sucesso dos PAIS é devido à capacidade de prover funcionalidades genéricas para modelagem, execução e monitoramento dos processos. Essas características são bem-sucedidas quando os modelos de processos têm um caminho bem-comportado no sentido de atingir os seus objetivos. No entanto, situações anômalas que desviam a execução desse caminho bem-comportado ainda representam um significativo desafio para os PAIS. Por causa dos vários tipos de falhas que desviam a execução do comportamento esperado, prover uma execução robusta e confiável é uma tarefa complexa para os atuais PAIS, uma vez que nem todas as situações de falha podem ser eficientemente descritas dentro da estrutura do fluxo tradicional. Como consequência, o tratamento de tais situações geralmente envolve intervenções manuais nos sistemas por operadores humanos, o que resulta em custos adicionais e significativos para as empresas. Neste trabalho é introduzido um método de composição para recuperação ciente de custos e benefícios que é capaz de encontrar e seguir caminhos alternativos que reduzam os prejuízos financeiros do tratamento de exceções. Do ponto de vista prático, esse método provê o tratamento de exceção automatizado e otimizado ao calcular os custos e benefícios de cada caminho de recuperação e escolher o caminho com a melhor relação custo-benefício disponível. Mais especificamente, o método de recuperação proposto estende a abordagem WED-flow (Workflow, Event processing and Data-flow) para permitir a composição ciente de custos e benefícios de passos de recuperação transacionais backward e forward. Por fim, os experimentos mostram que esse método de recuperação pode ser adequadamente incorporado para manipular exceções em uma ampla variedade de processos. / Nowadays, many corporations and organizations are increasingly making efforts to transform quickly and effectively their potential ideas into products and services. These efforts have also stimulated the evolution of information systems that are now supported by higher-level abstract models to describe the process logic. In this context, several sophisticated Process-Aware Information Systems (PAIS) have successfully been proposed for managing business processes and automating large-scale scientific (e-Science) processes. Much of this success is due to their ability to provide generic functionality for modeling, execution and monitoring processes. These functionalities work well when process models have a well-behaved path towards achieving their objectives. However, anomalous situations that fall outside of the well-behaved execution path still pose a significant challenge to PAIS. Because of the many types of failures that may deviate execution away from expected behaviors, provision of robust and reliable execution is a complex task for current PAIS, since not all failure situations can be efficiently modeled within the traditional flow structure. As a consequence, the treatment for such situations usually involves interventions in systems by human operators, which result in significant additional cost for businesses. In this work, we introduce a cost/benefit-aware recovery composition method that is able to find and follow alternative paths to reduce the financial side effects of exception handling. From a practical point of view, this method provides the automated and optimized exception handling, by calculating the cost and benefits of each recovery path, and choosing the recovery path with the best cost/benefits available. More specifically, our recovery method extends the WED-flow (Workflow, Event processing and Data-flow) approach for enabling cost/benefit-aware composition of forward and/or backward transactional recovery steps. Finally, the experiments point out that this recovery method can be suitably incorporated into exception handling within a wide variety of processes.

Image segmentation consists on its partition into relevant regions, such as to isolate the pixels belonging to desired objects in the image domain, which is an important step for computer vision, medical image processing, and other applications. Many times automatic segmentation generates results with imperfections. The user can correct them by editing manually, interactively or can simply discard the segmentation and try to automatically generate another result by a different method. Interactive methods combine benefits from manual and automatic ones, reducing user effort and using its high-level knowledge. In seed-based methods, to continue or repair a prior segmentation (presegmentation), avoiding the user to start from scratch, it is necessary to solve the Reverse Interactive Segmentation Problem (RISP), that is, how to automatically estimate the seeds that would generate it. In order to achieve this goal, we first divide the segmented object into its composing cores. Inside a core, two seeds separately always produce the same result, making one redundant. With this, only one seed per core is required. Cores leading to segmentations which are contained in the result of other cores are redundant and can also be discarded, further reducing the seed set, a process called Redundancy Analysis. A minimal set of seeds for presegmentation is generated and the problem of interactive repair can be solved by adding new seeds or removing seeds. Within the framework of the Image-Foresting Transform (IFT), new methods such as Oriented Image-Foresting Transform (OIFT) and Oriented Relative Fuzzy Connectedness (ORFC) were developed. However, there were no known algorithms for computing the core of these methods. This work develops such algorithms, with proof of correctness. The cores also give an indication of the degree of robustness of the methods on the positioning of the seeds. Therefore, a hybrid method that combines GraphCut and the ORFC cores, as well as the Robustness Coefficient (RC), have been developed. In this work, we present another developed solution to repair segmentations, which is based on IFT-SLIC, originally used to generate supervoxels. Experimental results analyze, compare and demonstrate the potential of these solutions. / Segmentação de imagem consiste no seu particionamento em regiões, tal como para isolar os pixels pertencentes a objetos de interesse em uma imagem, sendo uma etapa importante para visão computacional, processamento de imagens médicas e outras aplicações. Muitas vezes a segmentação automática gera resultados com imperfeições. O usuário pode corrigi-las editando-a manualmente, interativamente ou simplesmente descartar o resultado e gerar outro automaticamente. Métodos interativos combinam os benefícios dos métodos manuais e automáticos, reduzindo o esforço do usuário e utilizando seu conhecimento de alto nível. Nos métodos baseados em sementes, para continuar ou reparar uma segmentação prévia (presegmentação), evitando o usuário começar do zero, é necessário resolver o Problema da Segmentação Interativa Reversa (RISP), ou seja, estimar automaticamente as sementes que o gerariam. Para isso, este trabalho particiona o objeto da segmentação em núcleos. Em um núcleo, duas sementes separadamente produzem o mesmo resultado, tornando uma delas redundante. Com isso, apenas uma semente por núcleo é necessária. Núcleos contidos nos resultados de outros núcleos são redundantes e também podem ser descartados, reduzindo ainda mais o conjunto de sementes, um processo denominado Análise de Redundância. Um conjunto mínimo de sementes para a presegmentação é gerado e o problema da reparação interativa pode então ser resolvido através da adição de novas sementes ou remoção. Dentro do arcabouço da Transformada Imagem-Floresta (IFT), novos métodos como Oriented Image-Foresting Transform (OIFT) e Oriented Relative Fuzzy Connectedness (ORFC) foram desenvolvidos. Todavia, não há algoritmos para calcular o núcleo destes métodos. Este trabalho desenvolve tais algoritmos, com prova de corretude. Os núcleos também nos fornecem uma indicação do grau de robustez dos métodos sobre o posicionamento das sementes. Por isso, um método híbrido do GraphCut com o núcleo do ORFC, bem como um Coeficiente de Robustez (RC), foram desenvolvidos. Neste trabalho também foi desenvolvida outra solução para reparar segmentações, a qual é baseada em IFT-SLIC, originalmente utilizada para gerar supervoxels. Resultados experimentais analisam, comparam e demonstram o potencial destas soluções.

Our society is heavily dependent on commodities, as water and electricity, supplied to final users by engineered systems, which are known as critical infrastructures. In such context, the understanding of how such systems handle damaging events is an important aspect and is a current concern of researchers, public agents, and society. How much of performance a system loses due to damages is related to its vulnerability, and the ability to absorb and recover successfully from damages is its resilience. In this study, approaches to assess the vulnerability and resilience of power distribution systems by evaluating dynamic features, as the processes of failure and repair, and system reconfiguration for vulnerability, and the effects of extreme weather scenarios for resilience together with the processes of failure of repair are presented. Such approaches were applied on systems previously presented in the literature, and also on a Brazilian power distribution system. A Monte Carlo simulation was applied to evaluate this systems, models for time-to-failure and time-to-repair under different circumstances were obtained from historical data, and a method to use the models of time-to-failure during the vulnerability analysis was introduced. In addition, an assessment of the impact of reconfiguration capability on vulnerability is also carried out, and a resilience assessment under different climate scenarios has been developed. The time-to-failure and repair models highlighted how external factors modifies the Brazilian system failure and repair dynamics, the use of time-to-failure models during vulnerability analysis showed that the consideration of the failure dynamic of the types of elements give different results, and the time domain allows new analysis\' perspectives. The investigation indicated that the vulnerability reduction due to reconfiguration is affected by the number of switches and also the maximum load capacity of the distribution system feeders. The resilience assessment showed that for structural connectivity, larger distribution networks are less resilient, while for electricity delivery, a set of features, related with the topological and electrical organization of such networks, seems to be associated with the network service resilience, such information is useful for system planning and management. The dynamics evaluated in this study are relevant to vulnerability and resilience of such systems, and also to other critical infrastructures. Moreover, the developed approaches can be applied to other systems, as transportation and water distribution. In future studies, other power distribution systems features, as distributed generation and energy storage, will be considered in both, vulnerability and resilience analysis. / Nossa sociedade é altamente dependente de commodities, como água e eletricidade, fornecidas para os usuários por sistemas de engenharia, conhecidos como infraestruturas críticas. A compreensão de como tais sistemas lidam com eventos prejudiciais é uma preocupação atual de pesquisadores, agentes públicos e sociedade. A perda de desempenho de um sistema devido a danos é relacionada à sua vulnerabilidade, e a capacidade de absorver e se recuperar dos danos é a resiliência. Neste estudo, são apresentadas abordagens para avaliar a vulnerabilidade e resiliência de sistemas de distribuição de energia considerando características dinâmicas, como os processos de falha e reconfiguração do sistema, para a vulnerabilidade, e os efeitos de climas extremos na resiliência com os processos de falha e reparo. Tais abordagens foram aplicadas em sistemas previamente apresentados na literatura, e também em um sistema brasileiro. Simulação de Monte Carlo foi utilizada para avaliar as dinâmicas de falha e reparo do sistema utilizando de modelos obtidos a partir de dados históricos, e um método para usar os modelos de tempo-até-falha durante a análise de vulnerabilidade também foi apresentado. Além disso, uma avaliação do impacto da dinâmica de reconfiguração na vulnerabilidade foi realizada e uma avaliação de resiliência sob diferentes cenários climáticos foi desenvolvida. Os modelos tempo-para-falha e reparo destacaram como fatores externos modificam as dinâmicas de falha e reparo do sistema brasileiro, o uso de modelos de confiabilidade na análise de vulnerabilidades mostrou que a consideração dos diferentes tipos de elementos geram resultados diferentes e o domínio de tempo permite novas perspectivas de análise. A investigação da reconfiguração indicou que a redução da vulnerabilidade devido à reconfiguração é afetada pelo número de chaves e também pela máxima capacidade de carga dos alimentadores do sistema de distribuição. A avaliação de resiliência mostrou que, para conectividade estrutural, redes de distribuição maiores são menos resilientes, enquanto que para fornecimento de energia, um conjunto de características, relacionados com a organização topológica e elétrica dessas redes parece ser associado à resiliência do serviço, informação útil para o planejamento. As dinâmicas avaliadas neste estudo são relevantes para a vulnerabilidade e resiliência de tais sistemas, e também para outras infraestruturas críticas. Além disso, essas abordagens podem ser aplicadas a outros sistemas, como transporte e distribuição de água. Em estudos futuros, outras características de sistemas de distribuição de energia, como geração distribuída e armazenamento de energia, serão consideradas nas análises de vulnerabilidade e resiliência.

En 2007, une étude menée par Hamlin, Wynn et Bloom a montré qu’à 6 mois les jeunes enfants disposent de capacités d’évaluation sociale, qui s’illustrent dans leur préférence pour des personnages prosociaux. Depuis, de nombreuses études ont tenté de retrouver la préférence pour un personnage prosocial. Parmi elles, certaines n’ont pas retrouvé ce résultat, questionnant la solidité de ces capacités.L’objectif de cette thèse est de tester l’existence et la robustesse de la préférence pour un comportement prosocial chez les jeunes enfants en manipulant : 1) l’âge (6, 12, 18, 24, 36 mois), le type de scénario social (aide, jeu, partage), et l’apparence faciale des agents prosociaux et antisociaux (familière ou inhabituelle). Dans cet objectif, quatre études ont été réalisées auprès de 446 enfants âgés de 6 à 36 mois qui ont visionné des dessins animés faisant interagir des agents prosociaux et antisociaux. Leurs préférences ont été identifiées par un geste de pointage/atteinte ou à l’aide d’un oculomètre.Nos résultats montrent que la préférence pour un comportement prosocial est observée quasiment à tous les âges testés, et varie en fonction du scénario social. Enfin, dans les situations sensées être conflictuelles au regard des préférences des jeunes enfants, ces derniers n’expriment majoritairement pas de préférence. L’ensemble des résultats remettent en question la solidité d’une préférence précoce pour un comportement prosocial et questionnent les conditions nécessaires à son observation. Les résultats de cette thèse sont discutés à la lumière de questionnements méthodologiques et d’études récentes qui fragilisent les résultats princeps d’Hamlin et ses collaborateurs. / In 2007, a study carried out by Hamlin, Wynn, and Bloom showed that infants aged 6 months are able to make social evaluation, that could be identified through their preference for prosocial characters. Since, a number of studies have tried to confirm this preference for prosocial characters. Of these, some did not find similar result, raising question on the robustness of this ability.This dissertation aims to test the existence and the strength of the preference for prosocial behaviors in infants by manipulating: 1) age (6, 12, 18, 24 and 36 months), the type of the social scenario (help, play, share), and the facial appearance of the prosocial and antisocial agents (familiar or unusual). To that end, four studies have been carried out with 446 infants aged 6 to 36 months who were shown specially designed animated cartoons in which prosocial and antisocial agents interacted. Infants’ preference was identified through their pointing/reaching gesture or assessed by an eye-tracker. Our results show that the preference for the prosocial behaviors was observed in nearly all the tested age, and varied according to the social scenario. Finally, in the situation assumed to be conflicting infants' preferences, infants mostly did not express any preference. All results challenge the strength of the preference for prosocial behaviors as well as the conditions that must be met to observe it. The results of this dissertation are discussed in the light of methodological issues and recent studies that weaken Hamlin and collaborators’ original results.

Hyaluronic acid (HA) is an unbranched polysaccharide consisting of the repeating disaccharide unit β(1→4)-GlcA-β(1→3)-GlcNAc and is a naturally occurring biopolymer in bacteria and vertebras. HA is predominantly found in the extracellular matrix (ECM) and the in vivo function of HA can vary depending on molecular weight (Mw) for instance high Mw HA is reported to be anti-angiogenic while low Mw HA induces angiogenesis. HA is a popular component for hydrogels such as dermal fillers. HA is commonly used in dermal fillers. However, other materials, such as other polymers, can be used as well. The project goal was to investigate different degradation processes for production of target Mw HA. Alkaline and acidic degradation processes in combination with increased temperatures seemed as the most promising methods. Degradation tests performed both in aqueous solution as well as heterogeneously in ethanol were evaluated. The acidic degradation in aqueous solution was proven to have the largest degradation constant. Both a robustness test as well as a Design of Experiments (DoE) was performed to investigate the influence different factors had on the degradation speed. The investigated factors were HA concentration, HCl concentration and temperature. Temperature and HCl concentrations proved to be the most influencing factors and a model was developed in the DoE software MODDE to describe how the factors influenced the degradation constant. The model was established as a good significant model with a Q2 value of 0.998 and relative standard deviation (RSD) value of 0.022 after a logarithmic transformation was performed as well as a simplification of the model by excluding some of the factor interactions. The acidic degradation method also proved to be a highly robust method which easily could be used to produce target Mw HA.

Les travaux effectués dans le cadre de cette thèse « Analyse de robustesse par contraintes intégrales quadratiques - Application aux lanceurs spatiaux » ont été menés en collaboration entre le Département Automatique de Supélec, EADS Astrium ST, l’Agence Spatiale Européenne (ESA) et l’université de Stuttgart. Le but était d’adapter et d’utiliser des méthodes analytiques de validation de loi de commande d'un lanceur en phase balistique pour améliorer les résultats obtenus par l’approche probabiliste fondée sur des simulations, technique actuellement majoritaire dans l’industrie. Dans ce cadre, l’utilisation des contraintes intégrales quadratiques (IQC) a permis de caractériser la stabilité et la performance robuste de la loi de commande d’un modèle représentatif du lanceur. Nous avons étudié l’influence de la dynamique non-linéaire des lanceurs sur la stabilité et la performance robuste. Dans ce cadre, nous avons factorisé les équations du mouvement en prenant en compte les incertitudes de la matrice d’inertie ainsi que les couplages gyroscopiques. Le second axe traita de l’influence des actionneurs de type modulateur de largeur impulsions (PWM) sur la stabilité du système par deux études IQC. La conclusion de ces travaux de thèse met l’accent sur l’importance de l’utilisation de méthodes analytiques dans le domaine spatial. Ces méthodes permettent l’obtention de garanties rigoureuses de stabilité et de performance des systèmes. De plus, toutes les méthodes d’analyse possèdent leur extension pour la synthèse de correcteurs robustes. Ainsi on imagine aisément l’immense gain que pourrait produire l’utilisation de ces méthodes pour la synthèse de correcteurs robustes. / The introduction of analytical techniques along the steps of the development of a space launcher will allow significant reductions in terms of costs and manpower, and will enable, by a more systematical way of tuning and assessing control laws, to get flyable designs much faster. In this scope, IQC based tools already present promising result and show that they may be the most appropriate ones for the robustness analysis of large complex systems. They account for the system structure and allow dealing specifically with each subsystems, it means that we can improve the representation contained in the multipliers easily and reuse the set up to assess the improvements. The flexibility of the method is a huge advantage. We experienced it during two phases. The first was dedicated to the analysis of the three-degree-of-freedom uncertain nonlinear equation of motion of a rigid body. Secondly, we studied the influence of the pulse-width modulator behavior of the attitude control system on the launcher stability. IQC-based stability analysis allowed defining estimations of the stability domain with respect to uncertainties and system parameters. Moreover, the results obtained with IQC can go way beyond stability analysis with performance analysis with description of the particular performance criteria of the field with appropriate multipliers. Later on controller synthesis and merging of IQC method with worst-case search algorithms could extend greatly the frame of use of this analytical tool and give it the influence it deserves.

Multiples techniques d'optimisation ont été implémentées afin de surmonter le compromis entre la complexité des algorithmes du raisonnement et l'expressivité du langage de formulation des ontologies. Cependant les compagnes d'évaluation des raisonneurs continuent de confirmer l'aspect imprévisible et aléatoire des performances de ces logiciels à l'égard des ontologies issues du monde réel. Partant de ces observations, l'objectif principal de cette thèse est d'assurer une meilleure compréhension du comportement empirique des raisonneurs en fouillant davantage le contenu des ontologies. Nous avons déployé des techniques d'apprentissage supervisé afin d'anticiper des comportements futurs des raisonneurs. Nos propositions sont établies sous forme d'un système d'assistance aux utilisateurs d'ontologies, appelé "ADSOR". Quatre composantes principales ont été proposées. La première est un profileur d'ontologies. La deuxième est un module d'apprentissage capable d'établir des modèles prédictifs de la robustesse des raisonneurs et de la difficulté empirique des ontologies. La troisième composante est un module d'ordonnancement par apprentissage, pour la sélection du raisonneur le plus robuste étant donnée une ontologie. Nous avons proposé deux approches d'ordonnancement; la première fondée sur la prédiction mono-label et la seconde sur la prédiction multi-label. La dernière composante offre la possibilité d'extraire les parties potentiellement les plus complexes d'une ontologie. L'identification de ces parties est guidée par notre modèle de prédiction du niveau de difficulté d'une ontologie. Chacune de nos approches a été validée grâce à une large palette d'expérimentations. / Highly optimized reasoning algorithms have been developed to allow inference tasks on expressive ontology languages such as OWL (DL). Nevertheless, reasoning remains a challenge in practice. In overall, a reasoner could be optimized for some, but not all ontologies. Given these observations, the main purpose of this thesis is to investigate means to cope with the reasoner performances variability phenomena. We opted for the supervised learning as the kernel theory to guide the design of our solution. Our main claim is that the output quality of a reasoner is closely depending on the quality of the ontology. Accordingly, we first introduced a novel collection of features which characterise the design quality of an OWL ontology. Afterwards, we modelled a generic learning framework to help predicting the overall empirical hardness of an ontology; and to anticipate a reasoner robustness under some online usage constraints. Later on, we discussed the issue of reasoner automatic selection for ontology based applications. We introduced a novel reasoner ranking framework. Correctness and efficiency are our main ranking criteria. We proposed two distinct methods: i) ranking based on single label prediction, and ii) a multi-label ranking method. Finally, we suggested to extract the ontology sub-parts that are the most computationally demanding ones. Our method relies on the atomic decomposition and the locality modules extraction techniques and employs our predictive model of the ontology hardness. Excessive experimentations were carried out to prove the worthiness of our approaches. All of our proposals were gathered in a user assistance system called "ADSOR".

Submitted by Aline Batista (alinehb.ufpel@gmail.com) on 2018-04-18T14:21:35Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Dissertacao_Rosana_Medina_Zanotelli.pdf: 897398 bytes, checksum: 53b6f15a010386648223058dfc32101b (MD5) / Approved for entry into archive by Aline Batista (alinehb.ufpel@gmail.com) on 2018-04-19T14:42:08Z (GMT) No. of bitstreams: 2 Dissertacao_Rosana_Medina_Zanotelli.pdf: 897398 bytes, checksum: 53b6f15a010386648223058dfc32101b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-04-19T14:42:21Z (GMT). No. of bitstreams: 2 Dissertacao_Rosana_Medina_Zanotelli.pdf: 897398 bytes, checksum: 53b6f15a010386648223058dfc32101b (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-04-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Esta dissertação contribui com a análise da robustez na Lógica Fuzzy, como uma importante fundamentação para modelagem e desenvolvimento de sistemas robustos, estendendo esta abordagem para a lógica intuicionista de Atanassov. Primeiramente, apresenta-se uma introdução à lógica fuzzy, discutindo as negações, funções de agregações, implicações e coimplicações fuzzy, incluindo também os conectivos Xor e derivações. O trabalho também considera a análise da -sensibilidade destes conectivos fuzzy e suas construções duais, essencialmente focados em propriedades algébricas e projeções. Começando com a avaliação da sensibilidade de conectivos fuzzy, a proposta estende os resultados para classes de conectivos fuzzy intuicionistas. Como principal contribuição, formalmente estabelece-se que a robustez preserva as construções duais e as funções de projeção relacionadas a conectivos fuzzy intuicionistas representáveis. Mostra-se que a extensão, do trabalho científico proposto por Y. Li e colaboradores, 2005 em "An Approach to Measure the Robustness of Fuzzy Reasoning", para a classe de conectivos fuzzy intuicionistas é preservada pelas construções duais. A presente pesquisa mostra que a análise de robustez pode ser diretamente verificada a partir de operadores fuzzy usando duas estratégias: (i) a -sensibilidade de operadores fuzzy baseada na análise da monotonicidade de seus argumentos (negações, agregações, implicações e coimplicações); e ainda (ii) a avaliação do comportamento dos operadores fuzzy nos pontos terminais do intervalo unitário, onde a monotonicidade não pode ser aplicada (conectivos Xor, XNor, bi-implicações e bi-coimplicações). / This dissertation contributes to the robustness analysis in fuzzy logic as an important founding for modeling and developing robust systems, extending such approach to the Atanassov’s intuitionistic fuzzy sets. It begins with the introduction of fuzzy logic, discussing negations, aggregation functions, fuzzy implications and bi-implications, also including Xor connectives and derivations. It also considers the -sensitivity analysis of these fuzzy connectives and their dual constructions from a few essentials such as properties and projections. Starting with an evaluation of the sensitivity in representable fuzzy connectives, the results are applied in the intuitionistic connective classes. The main result formally states that the robustness preserves the projection functions of representable intuitionistic fuzzy connectives. It shows an extension of the work in Y. Li et al, 2005 "An Approach to Measure the Robustness of Fuzzy Reasoning" for the class of intuitionistic fuzzy connectives, showing that the robustness of intuitionistic fuzzy sensitivity is preserved by dual constructions. The present research states that robustness analysis of intuitionistic fuzzy operators can be directly verified from fuzzy operators using two strategies: (i) the -sensitivity analysis of fuzzy connectives based on monotonicity of their arguments (negations, aggregations, implications and coimplications); and, otherwise (ii) the evaluation of the behaviour related to fuzzy connectives in endpoints of the unit interval, when the monotonicity property is not applied (Xor, XNor, bi-implications e bi-coimplications fuzzy operators).