Dans cette thèse, nous proposons des modèles logiques pour la représentation des croyances et leur changement dans un cadre multi-agent, en insistant sur l'importance de se fixer un point de vue particulier pour la modélisation. A cet égard, nous distinguons deux approches différentes: l'approche externe, où le modélisateur est quelqu'un d'externe à la situation; l'approche interne, où le modélisateur est l'un des agents. Nous proposons une version interne de la logique épistémique dynamique (avec des modèles d'événements), ce qui nous permet de généraliser facilement la théorie de la révision des croyances d'AGM au cas multi-agent. Ensuite, nous mod´elisons les dynamismes logiques complexes qui soustendent notre interprétation des événements en introduisant des probabilités et des infinitésimaux. Finalement, nous proposons un formalisme alternatif qui n'utilise pas de modèle d'événement mais qui introduit à la place un opérateur d'événement inverse.

In this thesis we study a reasoning module for agents that have cognitive abilities, such as memory, perception, action, and are expected to function autonomously for long periods of time. The module provides the ability to reason about action and change using the language of the situation calculus and variants of the basic action theories. The main focus of this thesis is on the logical problem of progressing an action theory. First, we investigate the conjecture by Lin and Reiter that a practical first-order definition of progression is not appropriate for the general case. We show that Lin and Reiter were indeed correct in their intuitions by providing a proof for the conjecture, thus resolving the open question about the first-order definability of progression and justifying the need for a second-order definition. Then we proceed to identify three cases where it is possible to obtain a first-order progression with the desired properties: i) we extend earlier work by Lin and Reiter and present a case where we restrict our attention to a practical class of queries that may only quantify over situations in a limited way; ii) we revisit the local-effect assumption of Liu and Levesque that requires that the effects of an action are fixed by the arguments of the action and show that in this case a first-order progression is suitable; iii) we investigate a way that the local-effect assumption can be relaxed and show that when the initial knowledge base is a database of possible closures and the effects of the actions are range-restricted then a first-order progression is also suitable under a just-in-time assumption. Finally, we examine a special case of the action theories with range-restricted effects and present an algorithm for computing a finite progression. We prove the correctness and the complexity of the algorithm, and show its application in a simple example that is inspired by video games.

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Semantic interoperability is essential on the Semantic Web to enable different information systems to exchange data. Ontology matching has been recognised as a means to achieve semantic interoperability on the Web by identifying similar information in heterogeneous ontologies. Existing ontology matching approaches have two major limitations. The first limitation relates to similarity metrics, which provide a pessimistic value when considering complex objects such as strings and conceptual entities. The second limitation relates to the role of description logic reasoning. In particular, most approaches disregard implicit information about entities as a source of background knowledge. In this thesis, we first present a new similarity function, called the degree of commonality coefficient, to compute the overlap between two sets based on the similarity between their elements. The results of our evaluations show that the degree of commonality performs better than traditional set similarity metrics in the ontology matching task. Secondly, we have developed the Knowledge Organisation System Implicit Mapping (KOSIMap) framework, which differs from existing approaches by using description logic reasoning (i) to extract implicit information as background knowledge for every entity, and (ii) to remove inappropriate correspondences from an alignment. The results of our evaluation show that the use of Description Logic in the ontology matching task can increase coverage. We identify people interested in ontology matching and reasoning techniques as the target audience of this work

Este trabalho promove um estudo em informática em saúde no qual se analisam laudos de radiologia torácica através de métodos de processamento estatístico de linguagem natural com o intuito de subsidiar a interoperabilidade entre sistemas de saúde. Foram utilizados 2000 laudos de radiologia do tórax para a extração de conhecimento identificando-se as palavras, n-gramas e frases que os compõem. Foi calculado o índice de Zipf e verificou-se que poucas palavras compõem a maioria dos laudos e que a maioria das palavras não tem representatividade estatística A partir dos termos identificados foi realizada a tradução e a comparação da existência desses em um vocabulário médico padronizado com terminologia internacional, o SNOMEDCT. Os termos que tinham uma relação completa e direta com os termos traduzidos foram incorporados nos termos de referência juntamente com a classe à qual o termo pertence e seu identificador. Foram selecionados outros 200 laudos de radiologia de tórax para realizar o experimento de rotulação dos termos em relação à referência. A eficiência obtida neste estágio, que é o percentual de rotulação dos laudos, foi de 45,55%. A partir de então foram incorporados aos termos de referência, sob a classe de conceito de ligação, artigos, preposições e pronomes. É importante ressaltar que esses termos não adicionam conhecimento de saúde ao texto. A eficiência obtida foi de 73,23%, aumentando significativamente a eficiência obtida anteriormente. Finalizamos o trabalho com algumas formas de aplicação dos laudos rotulados para a interoperabilidade de sistemas, utilizando para isto ontologias, o HL7 CDA (Clinical Documents Architecture) e o modelo de arquétipos da Fundação OpenEHR. / This work promotes a study in health informatics technology which analyses reports of chest X-ray through statistical natural language processing methods for the purpose of supporting the interoperability between health systems. Two thousand radiology reports were used for the extraction of knowledge by identifying the words, n-grams and phrases of reports. Zipfs constant was studied and it was determined that few words make up the majority of the reports and that most of the words do not have statistical significance. The translation and comparison with exisiting standardized medical vocabulary with international terminology, called SNOMED-CT, was done based on the terms identified. The terms that had a complete and direct correlation with the translated terms were incorporated into the reference terms along with its class and the word identifier. Another 200 reports of chest x-rays were selected to perform the terms tagging experiment of with respect to the reference. The efficiency obtained, which is the percentage of labeling of the reports, was 45.55%. Subsequentely, articles, prepositions and pronouns were incorporated into the terms of reference under the linkage concept of class. It is important to note that these terms do not carry health knowledge to the text. Thus, the efficiency ratio was 73.23%, significantly increasing the efficiency obtained previously. The study was concluded with some forms of application of the reports tagged for system interoperability, using different ontologies, the HL7 CDA (Clinical Documents Architecture) and the archetypes at OpenEHR Fondation.

La robotique autonome est employée avec succès dans des environnements industriels contrôlés, où les instructions suivent des plans d’action prédéterminés.La robotique domestique est le challenge des années à venir et comporte un certain nombre de nouvelles difficultés : il faut passer de l'hypothèse d'un monde fermé borné à un monde ouvert. Un robot ne peut plus compter seulement sur ses données capteurs brutes qui ne font qu'indiquer la présence ou l'absence d'objets. Il lui faut aussi comprendre les relations implicites entre les objets de son environnement ainsi que le sens des tâches qu'on lui assigne. Il devra également pouvoir interagir avec des humains et donc partager leur conceptualisation à travers le langage. En effet, chaque langue est une représentation abstraite et compacte du monde qui relie entre eux une multitude de concepts concrets et purement abstraits. Malheureusement, les observations réelles sont plus complexes que nos représentations sémantiques simplifiées. Elles peuvent donc rentrer en contradiction, prix à payer d'une représentation finie d'un monde "infini". Pour répondre à ces difficultés, nous proposons dans cette thèse une architecture globale combinant différentes modalités de représentation d'environnement. Elle permet d'interpréter une représentation physique en la rattachant aux concepts abstraits exprimés en langage naturel. Le système est à double entrée : les données capteurs vont alimenter la modalité de perception tandis que les données textuelles et les interactions avec l'humain seront reliées à la modalité sémantique. La nouveauté de notre approche se situe dans l'introduction d'une modalité intermédiaire basée sur la notion d'instance (réalisation physique de concepts sémantiques). Cela permet notamment de connecter indirectement et sans contradiction les données perceptuelles aux connaissances en langage naturel.Nous présentons dans ce cadre une méthode originale de création d'ontologie orientée vers la description d'objets physiques. Du côté de la perception, nous analysons certaines propriétés des descripteurs image génériques extraits de couches intermédiaires de réseaux de neurones convolués. En particulier, nous montrons leur adéquation à la représentation d'instances ainsi que leur usage dans l'estimation de transformation de similarité. Nous proposons aussi une méthode de rattachement d'instance à une ontologie, alternative aux méthodes de classification classique dans l'hypothèse d'un monde ouvert. Enfin nous illustrons le fonctionnement global de notre modèle par la description de nos processus de gestion de requête utilisateur. / Autonomous robotics is successfully used in controled industrial environments where instructions follow predetermined implementation plans.Domestic robotics is the challenge of years to come and involve several new problematics : we have to move from a closed bounded world to an open one. A robot can no longer only rely on its raw sensor data as they merely show the absence or presence of things. It should also understand why objects are in its environment as well as the meaning of its tasks. Besides, it has to interact with human beings and therefore has to share their conceptualization through natural language. Indeed, each language is in its own an abstract and compact representation of the world which links up variety of concrete and abstract concepts. However, real observations are more complex than our simplified semantical representation. Thus they can come into conflict : this is the price for a finite representation of an "infinite" world.To address those challenges, we propose in this thesis a global architecture bringing together different modalities of environment representation. It allows to relate a physical representation to abstract concepts expressed in natural language. The inputs of our system are two-fold : sensor data feed the perception modality whereas textual information and human interaction are linked to the semantic modality. The novelty of our approach is in the introduction of an intermediate modality based on instances (physical realization of semantic concepts). Among other things, it allows to connect indirectly and without contradiction perceptual data to knowledge in natural langage.We propose in this context an original method to automatically generate an ontology for the description of physical objects. On the perception side, we investigate some properties of image descriptor extracted from intermediate layers of convolutional neural networks. In particular, we show their relevance for instance representation as well as their use for estimation of similarity transformation. We also propose a method to relate instances to our object-oriented ontology which, in the assumption of an open world, can be seen as an alternative to classical classification methods. Finally, the global flow of our system is illustrated through the description of user request management processes.

[pt] Este trabalho apresenta um modelo de representação de conhecimento e a arquitetura conceitual de um ambiente de design integrado para apoiar a representação de design rationale e seu uso no design de artefatos de software. Em nossa abordagem de representação propomos o uso da semântica formal dos artefatos, fornecida pelos métodos de design, para representar design rationale usando o vocabulário definido na ontologia Kuaba. Este vocabulário, descrito em uma linguagem formal para especificação de ontologias, permite definir um conjunto de regras e operações computáveis que apóiam o reuso de designs na produção de novos artefatos de software. Esta abordagem de representação possibilita um novo tipo de reuso de design de software em um nível mais alto de abstração, onde rationales podem ser integrados e re- empregados no design de um novo artefato. / [en] This work presents a knowledge representation model and the conceptual architecture of an integrated design environment to support recording design rationale, as well as use of design rationale, during design of software artifacts. In our representation approach, we propose the use of the formal semantics of artifacts provided by design methods to represent design rationale using the vocabulary defined in the Kuaba ontology. This vocabulary described in a formal ontologies specification language allows defining a set of rules and computable operations that support the reuse of designs in the production of new software artifacts. This representation approach enables a type of software design reuse at the highest abstraction level, where rationales can be integrated and re-employed in designing a new artifact.

Dans cette thèse, nous nous intéressons au problème d'interrogation de bases de connaissances composées de données et d'une ontologie, qui représente des connaissances générales sur le domaine d'application. Parmi les différents formalismes permettant de représenter les connaissances ontologiques, nous considérons ici un fragment de la logique du premier ordre appelé règles existentielles (aussi connues sous le nom de ``tuple generating dependencies'' et Datalog+/-). Le problème fondamental de conséquence logique au cœur de cette thèse demande si une requête conjonctive est conséquence d'une base de connaissances. Les règles existentielles étant très expressives, ce problème est indécidable. Toutefois, différentes restrictions sur les ensembles de règles ont été proposées afin d'obtenir sa décidabilité.La contribution de cette thèse est double. Premièrement, nous proposons un outil qui nous permet d'unifier puis d'étendre la plupart des classes de règles connues reposant sur des notions d'acyclicité assurant la finitude du chaînage avant. Deuxièmement, nous étudions la compatibilité des classes décidables de règles existentielles connues avec un type de connaissance souvent nécessaire dans les ontologies: la transitivité de relations binaires. Nous aidons à clarifier le paysage des résultats positifs et négatifs liés à cette question et fournissons une approche permettant de combiner la transitivité avec les règles existentielles linéaires. / In this thesis we investigate the issue of querying knowledge bases composed of data and general background knowledge, called an ontology. Ontological knowledge can be represented under different formalisms and we consider here a fragment of first-order logic called existential rules (also known as tuple-generating dependencies and Datalog+/-).The fundamental entailment problem at the core of this thesis asks if a conjunctive query is entailed by an existential rule knowledge base. General existential rules are highly expressive, however at the cost of undecidability. Various restrictions on sets of rules have been proposed to regain the decidability of the entailment problem.Our specific contribution is two-fold. First, we propose a new tool that allows to unify and extend most of the known existential rule classes that rely on acyclicity conditions to tame infinite forward chaining, without increasing the complexity of the acyclicity recognition. Second, we study the compatibility of known decidable rule classes with a frequently required modeling construct, namely transitivity of binary relations. We help clarifying the picture of negative and positive results on this question, and provide a technique to safely combine transitivity with one of the simplest, yet useful, decidable rule classes, namely linear rules.

L'objectif du problème appelé "Ontology-based data access" (OBDA) est d'améliorer la réponse à des requêtes en prenant en compte des connaissances d'ordre général durant l'évaluation des requêtes. Ces connaissances générales sont représentées à l'aide d'une ontologie, qui est exprimée dans cette thèse grâce à des formules logiques du premier ordre, appelées règles existentielles, et aussi connues sous le nom de "tuple-generating dependencies" et Datalog+/-. L'expressivité des formules utilisées est telle que l'évaluation de requêtes devient un problème indécidable, et cela a conduit la communauté à définir de nombreux cas décidables, c'est-à-dire des restrictions sur les ensembles de règles existentielles considérés. La contribution de cette thèse est double : tout d'abord, nous proposons une vue unifiée sur une grande fraction des cas décidables connus, et fournissons par là même une analyse de complexité et un algorithme optimal dans le pire des cas. Nous considérons également l'approche couramment utilisée de réécriture de requêtes, et proposons un algorithme générique qui permet de surmonter certaines causes évidentes d'explosion combinatoire qui rendent les approches classiques pratiquement inapplicables. / Ontology-based data access (OBDA) aims at enriching query answering by taking general background knowledge into account when evaluating queries. This background knowledge is represented by means of an ontology, that is expressed in this thesis by a very expressive class of first-order formulas, called existential rules (sometimes also tuple-generating dependencies and Datalog+/-). The high expressivity of the used formalism results in the undecidability of query answering, and numerous decidable classes (that is, restrictions on the sets of existential rules) have been proposed in the literature. The contribution of this thesis is two-fold: first, we propose a unified view of a large part of these classes, together with a complexity analysis and a worst-case optimal algorithm for the introduced generic class. Second, we consider the popular approach of query rewriting, and propose a generic algorithm that overcomes trivial causes of combinatorial explosion that make classical approaches inapplicable.

by Wong Ka-sing. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references. / Abstracts in English and Chinese. / Chapter Chapter One --- Introduction --- p.1 / Chapter Chapter Two --- Research in Expertise --- p.4 / Chapter A --- Inherited Traits and Acquisition of Expertise --- p.4 / Chapter B --- Expert-novice Differences : Knowledge --- p.5 / Chapter C --- Practice and Development of Expertise --- p.12 / Chapter Chapter Three --- Expertise in teaching --- p.14 / Importance of Subject Matter Expertise in Relationship to Pedagogical Reasoning and Pedagogical Content Knowledge --- p.18 / Chapter Chapter Four --- Domain knowledge and its representation --- p.24 / Knowledge Representations and Networks --- p.26 / Techniques of Eliciting and Representing Knowledge --- p.29 / Chapter Chapter Five --- The Pathfinder algorithm and research resultsin relationship to education and learning --- p.34 / Chapter A --- Validity of the Pathfinder Network --- p.36 / Chapter B --- The Interpretation of Links in Pathfinder Network --- p.38 / Chapter Chapter Six --- Research findings relevant to the present study --- p.39 / Chapter A --- "Gomez, R. L, Hadfield O. D. and Housner, L D (1996): "" Concept Maps and Simulated Teaching Episodes as Indicators of Competence in Teaching Elementary Mathematics""" --- p.39 / Chapter B --- "Goldsmith, T. E. , Johnson, P.j., and Acton, W. H (1991): "" Assessing structural knowledge""" --- p.43 / Chapter C --- "Acton, W. H., Johnson, P. j. and Goldsmith, T. E (1994): ""Structural knowledge assessment: Comparison of referent structures""" --- p.45 / Chapter D --- "Gonzalvo, P., Canas, J. J., and Bajo. M. T. (1994): "" Structural representations in knowledge acquisition""" --- p.48 / Chapter E --- "Johnson, P. J. Goldsmith, T. E, and Teague, K. W (1994).: "" Locus of predictive advantage in Pathfinder- based representations of classroom knowledge""" --- p.50 / Chapter Chapter Seven --- The research question --- p.52 / Research Hypothesis --- p.53 / The Subjects of this Study --- p.54 / Method of Data Collection --- p.57 / Concepts Used for Rating --- p.58 / Chapter Chapter Eight --- Results and analysis --- p.60 / Qualitative Analysis of Pathfinder Networks and MDS Solutions --- p.60 / Testing of Hypotheses --- p.70 / Discussion --- p.75 / Chapter Chapter Nine --- Limitations of the present study --- p.78