Vues de sécurité xml : requêtes, mises à jour, et schémas. Les évolutions technologiques ont consacré l'émergence des services web et du stockage des données en ligne, en complément des bases de données traditionnelles. Ces évolutions facilitent l'accès aux données, mais en contrepartie soulèvent de nouvelles problématiques de sécurité. La mise en œuvre de politiques de contrôle d'accès appropriées est une des approches permettant de réduire ces risques.Nous étudions ici les politiques de contrôle d'accès au niveau d'un document XML, politiques que nous modélisons par des vues de sécurité XML (non matérialisées) à l'instar de Fan et al. Ces vues peuvent être représentées facilement par des alignements d'arbres grâce à l'absence d'opérateurs arithmétiques ou de restructuration. Notre objectif est par conséquent d'examiner comment manipuler efficacement ce type de vues, à l'aide des méthodes formelles, et plus particulièrement des techniques de réécriture de requêtes et la théorie des automates d'arbres. Trois directions principales ont orienté nos recherches: nous avons tout d'abord élaboré des algorithmes pour évaluer l'expressivité d'une vue, en fonction des requêtes qui peuvent être exprimées à travers cette vue. Il s'avère que l'on ne peut décider en général si une vue permet d'exprimer une requête particulière, mais cela devient possible lorsque la vue satisfait des hypothèses générales. En second lieu, nous avons considéré les problèmes soulevés par la mises à jour du document à travers une vue. Enfin, nous proposons des solutions pour construire automatiquement un schéma de la vue. En particulier, nous présentons différentes techniques pour représenter de façon approchée l'ensemble des documents au moyen d'une DTD.

Beschreibungslogiken (Description logics, DLs) sind eine Klasse von Wissensrepraesentationsformalismen mit wohldefinierter, logik-basierter Semantik und entscheidbaren Schlussfolgerungsproblemen, wie z.B. dem Erfuellbarkeitsproblem. Zwei wichtige Entscheidungsverfahren fuer das Erfuellbarkeitsproblem von DL-Ausdruecken sind Tableau- und Automaten-basierte Algorithmen. Diese haben aufgrund ihrer unterschiedlichen Arbeitsweise komplementaere Eigenschaften: Tableau-Algorithmen eignen sich fuer Implementierungen und fuer den Nachweis von PSPACE- und NEXPTIME-Resultaten, waehrend Automaten sich besonders fuer EXPTIME-Resultate anbieten. Zudem ermoeglichen sie eine vom Standpunkt der Theorie aus elegantere Handhabung von unendlichen Strukturen, eignen sich aber wesentlich schlechter fuer eine Implementierung. Ziel der Dissertation ist es, die Gruende fuer diese Unterschiede zu analysieren und Moeglichkeiten aufzuzeigen, wie Eigenschaften von einem Ansatz auf den anderen uebertragen werden koennen, um so die positiven Eigenschaften von beiden Ansaetzen miteinander zu verbinden. Unter Anderem werden Methoden entwickelt, mit Hilfe von Automaten PSPACE-Resultate zu zeigen, und von einem Tableau-Algorithmus automatisch ein EXPTIME-Resultat abzuleiten. / Description Logics (DLs) are a family of knowledge representation languages with well-defined logic-based semantics and decidable inference problems, e.g. satisfiability. Two of the most widely used decision procedures for the satisfiability problem are tableau- and automata-based algorithms. Due to their different operation, these two classes have complementary properties: tableau algorithms are well-suited for implementation and for showing PSPACE and NEXPTIME complexity results, whereas automata algorithms are particularly useful for showing EXPTIME results. Additionally, they allow for an elegant handling of infinite structures, but they are not suited for implementation. The aim of this thesis is to analyse the reasons for these differences and to find ways of transferring properties between the two approaches in order to reconcile the positive properties of both. For this purpose, we develop methods that enable us to show PSPACE results with the help of automata and to automatically derive an EXPTIME result from a tableau algorithm.

La vérification automatique est aujourd'hui devenue un domaine central de recherche en informatique. Depuis plus de 25 ans, une riche théorie a été développée menant à de nombreux outils, à la fois académiques et industriels, permettant la vérification de propriétés booléennes -- celles qui peuvent être soit vraies soit fausses. Les besoins actuels évoluent vers une analyse plus fine, c'est-à-dire plus quantitative. L'extension des techniques de vérification aux domaines quantitatifs a débuté depuis 15 ans avec les systèmes probabilistes. Cependant, de nombreuses autres propriétés quantitatives existent, telles que la durée de vie d'un équipement, la consommation énergétique d'une application, la fiabilité d'un programme, ou le nombre de résultats d'une requête dans une base de données. Exprimer ces propriétés requiert de nouveaux langages de spécification, ainsi que des algorithmes vérifiant ces propriétés sur une structure donnée. Cette thèse a pour objectif l'étude de plusieurs formalismes permettant de spécifier de telles propriétés, qu'ils soient dénotationnels -- expressions régulières, logiques monadiques ou logiques temporelles -- ou davantage opérationnels, comme des automates pondérés, éventuellement étendus avec des jetons. Un premier objectif de ce manuscript est l'étude de résultats d'expressivité comparant ces formalismes. En particulier, on donne des traductions efficaces des formalismes dénotationnels vers celui opérationnel. Ces objets, ainsi que les résultats associés, sont présentés dans un cadre unifié de structures de graphes. Ils peuvent, entre autres, s'appliquer aux mots et arbres finis, aux mots emboîtés (nested words), aux images ou aux traces de Mazurkiewicz. Par conséquent, la vérification de propriétés quantitatives de traces de programmes (potentiellement récursifs, ou concurrents), les requêtes sur des documents XML (modélisant par exemple des bases de données), ou le traitement des langues naturelles sont des applications possibles. On s'intéresse ensuite aux questions algorithmiques que soulèvent naturellement ces résultats, tels que l'évaluation, la satisfaction et le model checking. En particulier, on étudie la décidabilité et la complexité de certains de ces problèmes, en fonction du semi-anneau sous-jacent et des structures considérées (mots, arbres...). Finalement, on considère des restrictions intéressantes des formalismes précédents. Certaines permettent d'étendre l'ensemble des semi-anneau sur lesquels on peut spécifier des propriétés quantitatives. Une autre est dédiée à l'étude du cas spécial de spécifications probabilistes : on étudie en particulier des fragments syntaxiques de nos formalismes génériques de spécification générant uniquement des comportements probabilistes.

Tree automata, and their applications to verification from the common thread of this thesis In the first part, we definie a complete model-cheking framework.[...] The second part focus on an important aspect of the automata involved: constraints.[...] Finaly, we also study the very different variety of tree-walking automata which have tight connections with navigational languages on semi-structured documents.

A expansão da Internet e o crescente desenvolvimento de tecnologias para a Web fazem com que um grande número de pessoas com necessidades distintas procurem nelas as informações de que necessitam, utilizando a Internet como um meio de ensino e aprendizagem. Motivado por isso, procura-se atender a comunidade surda com a obtenção de um Animador de Gestos aplicado à Língua de Sinais, o AGA-Sign, disponível em ambiente Web, com o objetivo de auxiliar na prática da escrita de sinais e na familiarização com a língua. Este trabalho apresenta uma aplicação para geração automatizada de animações de gestos aplicado à Língua de Sinais a partir de textos escritos em SignWriting - sistema de escrita para Língua de Sinais que dispõe de expressões gráficas para descrever os movimentos das mãos, dos braços, além de expressões faciais, fazendo com que o sistema possa representar qualquer língua de sinais. Os sinais usados para o desenvolvimento da aplicação foram elaborados a partir da LIBRAS por ser a língua oficial dos surdos brasileiros e as animações foram geradas através do modelo AGA (animação gráfica baseada na Teoria dos Autômatos). / The Internet expansion and the increasing development of Web technologies make a great audience with distinct necessities search the information they need, using the Internet as a mean for teaching and learning. In this context, this work tries to support the deaf community by developing a Gesture Animator applied to the Sign Language, the AGA-Sign, available in the Web environment, which goal is assisting the writing practice of signs and the familiarization with the language. This work presents an application for automatic generation of gestures animations applied to the Sign Language from texts written in SignWriting - a Sign Language writing system that uses graphical expressions to describe hands and arms movements, beyond face expressions, which makes the system capable of representing any sign language. The signs used for the development of the application were elaborated based in LIBRAS, that is the official brazilian deaf language and the animations were generated through AGA model (graphical animation based in the Automata Theory).

A expansão da Internet e o crescente desenvolvimento de tecnologias para a Web fazem com que um grande número de pessoas com necessidades distintas procurem nelas as informações de que necessitam, utilizando a Internet como um meio de ensino e aprendizagem. Motivado por isso, procura-se atender a comunidade surda com a obtenção de um Animador de Gestos aplicado à Língua de Sinais, o AGA-Sign, disponível em ambiente Web, com o objetivo de auxiliar na prática da escrita de sinais e na familiarização com a língua. Este trabalho apresenta uma aplicação para geração automatizada de animações de gestos aplicado à Língua de Sinais a partir de textos escritos em SignWriting - sistema de escrita para Língua de Sinais que dispõe de expressões gráficas para descrever os movimentos das mãos, dos braços, além de expressões faciais, fazendo com que o sistema possa representar qualquer língua de sinais. Os sinais usados para o desenvolvimento da aplicação foram elaborados a partir da LIBRAS por ser a língua oficial dos surdos brasileiros e as animações foram geradas através do modelo AGA (animação gráfica baseada na Teoria dos Autômatos). / The Internet expansion and the increasing development of Web technologies make a great audience with distinct necessities search the information they need, using the Internet as a mean for teaching and learning. In this context, this work tries to support the deaf community by developing a Gesture Animator applied to the Sign Language, the AGA-Sign, available in the Web environment, which goal is assisting the writing practice of signs and the familiarization with the language. This work presents an application for automatic generation of gestures animations applied to the Sign Language from texts written in SignWriting - a Sign Language writing system that uses graphical expressions to describe hands and arms movements, beyond face expressions, which makes the system capable of representing any sign language. The signs used for the development of the application were elaborated based in LIBRAS, that is the official brazilian deaf language and the animations were generated through AGA model (graphical animation based in the Automata Theory).

A expansão da Internet e o crescente desenvolvimento de tecnologias para a Web fazem com que um grande número de pessoas com necessidades distintas procurem nelas as informações de que necessitam, utilizando a Internet como um meio de ensino e aprendizagem. Motivado por isso, procura-se atender a comunidade surda com a obtenção de um Animador de Gestos aplicado à Língua de Sinais, o AGA-Sign, disponível em ambiente Web, com o objetivo de auxiliar na prática da escrita de sinais e na familiarização com a língua. Este trabalho apresenta uma aplicação para geração automatizada de animações de gestos aplicado à Língua de Sinais a partir de textos escritos em SignWriting - sistema de escrita para Língua de Sinais que dispõe de expressões gráficas para descrever os movimentos das mãos, dos braços, além de expressões faciais, fazendo com que o sistema possa representar qualquer língua de sinais. Os sinais usados para o desenvolvimento da aplicação foram elaborados a partir da LIBRAS por ser a língua oficial dos surdos brasileiros e as animações foram geradas através do modelo AGA (animação gráfica baseada na Teoria dos Autômatos). / The Internet expansion and the increasing development of Web technologies make a great audience with distinct necessities search the information they need, using the Internet as a mean for teaching and learning. In this context, this work tries to support the deaf community by developing a Gesture Animator applied to the Sign Language, the AGA-Sign, available in the Web environment, which goal is assisting the writing practice of signs and the familiarization with the language. This work presents an application for automatic generation of gestures animations applied to the Sign Language from texts written in SignWriting - a Sign Language writing system that uses graphical expressions to describe hands and arms movements, beyond face expressions, which makes the system capable of representing any sign language. The signs used for the development of the application were elaborated based in LIBRAS, that is the official brazilian deaf language and the animations were generated through AGA model (graphical animation based in the Automata Theory).

In this thesis we will introduce multioperator weighted monadic datalog (mwmd), a formal model for specifying tree series, tree transformations, and tree languages. This model combines aspects of multioperator weighted tree automata (wmta), weighted monadic datalog (wmd), and monadic datalog tree transducers (mdtt). In order to develop a rich theory we will define multiple versions of semantics for mwmd and compare their expressiveness. We will study normal forms and decidability results of mwmd and show (by employing particular semantic domains) that the theory of mwmd subsumes the theory of both wmd and mdtt. We conclude this thesis by showing that mwmd even contain wmta as a syntactic subclass and present results concerning this subclass.

Beschreibungslogiken (Description logics, DLs) sind eine Klasse von Wissensrepraesentationsformalismen mit wohldefinierter, logik-basierter Semantik und entscheidbaren Schlussfolgerungsproblemen, wie z.B. dem Erfuellbarkeitsproblem. Zwei wichtige Entscheidungsverfahren fuer das Erfuellbarkeitsproblem von DL-Ausdruecken sind Tableau- und Automaten-basierte Algorithmen. Diese haben aufgrund ihrer unterschiedlichen Arbeitsweise komplementaere Eigenschaften: Tableau-Algorithmen eignen sich fuer Implementierungen und fuer den Nachweis von PSPACE- und NEXPTIME-Resultaten, waehrend Automaten sich besonders fuer EXPTIME-Resultate anbieten. Zudem ermoeglichen sie eine vom Standpunkt der Theorie aus elegantere Handhabung von unendlichen Strukturen, eignen sich aber wesentlich schlechter fuer eine Implementierung. Ziel der Dissertation ist es, die Gruende fuer diese Unterschiede zu analysieren und Moeglichkeiten aufzuzeigen, wie Eigenschaften von einem Ansatz auf den anderen uebertragen werden koennen, um so die positiven Eigenschaften von beiden Ansaetzen miteinander zu verbinden. Unter Anderem werden Methoden entwickelt, mit Hilfe von Automaten PSPACE-Resultate zu zeigen, und von einem Tableau-Algorithmus automatisch ein EXPTIME-Resultat abzuleiten. / Description Logics (DLs) are a family of knowledge representation languages with well-defined logic-based semantics and decidable inference problems, e.g. satisfiability. Two of the most widely used decision procedures for the satisfiability problem are tableau- and automata-based algorithms. Due to their different operation, these two classes have complementary properties: tableau algorithms are well-suited for implementation and for showing PSPACE and NEXPTIME complexity results, whereas automata algorithms are particularly useful for showing EXPTIME results. Additionally, they allow for an elegant handling of infinite structures, but they are not suited for implementation. The aim of this thesis is to analyse the reasons for these differences and to find ways of transferring properties between the two approaches in order to reconcile the positive properties of both. For this purpose, we develop methods that enable us to show PSPACE results with the help of automata and to automatically derive an EXPTIME result from a tableau algorithm.

In this thesis, we investigate different theoretical questions concerning weighted automata models over tree-like input structures. First, we study exact and approximated determinisation and then, we turn to Kleene-like and Büchi-like characterisations. We consider multiple weighted automata models, including weighted tree automata over semirings (Chapters 3 and 4), weighted forest automata over M-monoids (Chapter 5), and rational weighted tree languages with storage (Chapter 6). For an explanation as to why the last class can be considered as a weighted automaton model, we refer to page 188 of the thesis. We will now summarise the main contributions of the thesis. In Chapter 3, we focus on the determinisation of weighted tree automata and present our determinisation framework, called M-sequentialisation, which can model different notions of determinisation from the existing literature. Then, we provide a positive M-sequentialisation result for the case of additively idempotent semirings or finitely M-ambiguous weighted tree automata. Another important contribution of Chapter 3 is Theorem 77, where we provide a blueprint theorem that can be used to find determini- sation results for more classes of semirings and weighted tree automata easily. In fact, instead of repeating an entire determinisation construction, Theorem 77 allows us to prove a determinisation result by finding certain finite equivalence relations. This is a very potent tool for future research in the area of determinisation. In Chapter 4, we move from exact determinisation towards approximate determini- sation. We lift the formalisms and the main results from one approach from the literature from the word case to the tree case. This successfully results in an approximated determinisation construction for weighted tree automata over the tropical semiring. We provide a formal mathematical description of the approximated determinisation construction, rather than an algorithmic description as found in the related approach from the literature. In Chapter 5, we turn away from determinisation and instead consider Kleene-like and Büchi-like characterisations of weighted recognisability. We introduce weighted forest automata over M-monoids, which are a generalisation of weighted tree automata over M-monoids and weighted forest automata over semirings. Then, we prove that our recognisable weighted forest languages can be decomposed into a finite product of recognisable weighted tree languages. We also prove that the initial algebra semantic and the run semantic for weighted forest automata are equivalent under certain conditions. Lastly, we define rational forest expressions and forest M-expressions and and prove that the classes of languages generated by these formalisms coincide with recognisable weighted forest languages under certain conditions. In Chapter 6, we consider rational weighted tree languages with storage, where the storage is introduced by composing rational weighted tree languages without storage with a storage map. It has been proven in the literature that rational weighted tree languages with storage are closed under the rational operations. In Chapter 6, we provide alternative proofs of these closure properties. In fact, we prove that our way of introducing storage to rational weighted tree languages preserves the closure properties from rational weighted tree languages without storage.:1 Introduction 2 Preliminaries 2.1 Languages 2.2 WeightedLanguages 2.3 Weighted Tree Automata 3 A Unifying Framework for the Determinisation of Weighted Tree Automata 3.1 Introduction 3.2 Preliminaries 3.3 Factorisation in Monoids 3.3.1 Ordering Multisets over Monoids 3.3.2 Cayley Graph and Cayley Distance 3.3.3 Divisors and Rests 3.3.4 Factorisation Properties 3.4 Weighted Tree Automata over M_fin(M) and the Twinning Property 3.4.1 Weighted Tree Automata over M_fin(M) 3.4.2 The Twinning Property 3.5 Sequentialisation of Weighted Tree Automata over M_fin(M) 3.5.1 The Sequentialisation Construction 3.5.2 The Finitely R-Ambiguous Case 3.6 Relating WTA over M_fin(M) and WTA over S 3.7 M-Sequentialisation of Weighted Tree Automata 3.7.1 Accumulation of D_B 3.7.2 M-Sequentialisation Results 3.8 Comparison of our Results to the Literature 3.8.1 Determinisation of Unweighted Tree Automata 3.8.2 The Free Monoid Case 3.8.3 The Group Case 3.8.4 The Extremal Case 3.9 Conclusion 4 Approximated Determinisation of Weighted Tree Automata 125 4.1 Introduction 4.2 Preliminaries 4.3 Approximated Determinisation 4.3.1 The Approximated Determinisation Construction 4.3.2 Correctness of the Construction 4.4 The Approximated Twinning Property 4.4.1 Implications for Approximated Determinisability 4.4.2 Decidability of the Twinning Property 4.5 Conclusion 5 Kleene and Büchi Theorems for Weighted Forest Languages over M-Monoids 5.1 Introduction 5.2 Preliminaries 5.3 WeightedForestAutomata 5.3.1 Forests 5.3.2 WeightedForestAutomata 5.3.3 Rectangularity 5.3.4 I-recognisable is R-recognisable 5.4 Kleene’s Theorem 5.4.1 Kleene’s Theorem for Trees 5.4.2 Kleene’s Theorem for Forests 5.4.3 An Inductive Approach 5.5 Büchi’s Theorem 5.5.1 Büchi’s Theorem for Trees 5.5.2 Büchi’s Theorem for Forests 5.6 Conclusion 6 Rational Weighted Tree Languages with Storage 6.1 Introduction 6.2 Preliminaries 6.3 Rational Weighted Tree Languages with Storage 6.4 The Kleene-Goldstine Theorem 6.5 Closure of Rat(S¢,Σ,S) under Rational Operations 6.5.1 Top-Concatenation, Scalar Multiplication, and Sum 6.5.2 α-Concatenation 6.5.3 α-Kleene Star 6.6 Conclusion 7 Outlook References