Given a program with assertions, the assertion checking problem is to tell whether there is an execution of the program that violates one of the assertions. One approach to this problem is to explore different paths towards assertion violations, and to learn “blocking” conditions whenever a path is blocked from reaching the violations. The Synergy algorithm of Gulavani et al. [FSE 2006] and the Lazy Annotation algorithm of McMillan [CAV2010] are two recent algorithms that follow this approach to assertion checking. Each technique has its own advantages. Synergy uses concrete tests which are very cheap as compared to theorem prover calls. The tests also help by giving us the place to perform the refinement (called the frontier) for an abstraction which is too coarse. Synergy uses partition refinement while maintaining its abstraction. The Lazy Annotation algorithm basically partitions each location in to regions that are safe and unsafe. The safe regions are those from which we cannot reach the error states, and the unsafe regions are the remaining ones. The annotations that this algorithm maintains correspond to the safe regions. The advantage that annotations have over partition refinement is that annotations can recover from irrelevant predicates used for annotating, where as once a partition is refined with an irrelevant predicate, it cannot recover from it. In this work, we make a theoretical study of the algorithms mentioned above. The aim of the study is to answer questions like: Is one algorithm provably better than the other, in terms of the best-case execution (counting the number of refinement steps) on input programs? Is the termination behavior of one always better than the other? We show that the Synergy and Lazy Annotation algorithms are incomparable, i.e., neither of them is provably better than the other, in terms of their best-case execution times. We also show how we can view the two algorithms on a common ground, in the sense that we show how to translate a snapshot of one algorithm into a snapshot of the other. This allows us to import the heuristics of one algorithm into the other, and there by propose new and potentially improved versions of these algorithms. By viewing them o n a common ground, we are also able to view the final proofs generated by the algorithms in either representation. We go on to study the proposed new versions of the Synergy and Lazy Annotation, comparing their best-case running times and their termination behaviour. We show that the following pairs of algorithms are incomparable: Mod-Syn (Lazy Annotation-style refinement imported into Synergy) and Synergy, Mod-Syn and Lazy Annotation, Synergy and SEAL(Synergy heuristics imported into Lazy Annotation). We show that the SEAL algorithm always performs better than the Lazy Annotation algorithm.

In order to prevent, detect and fix errors in software, various tools for programmers are available, while some of them are able to reason about the behaviour of the program. In the case of C# programming language, the main representatives are Microsoft FxCop, Code Contracts and Pex. Those tools can, indeed, help to build a highly reliable software. However, when a company wants to include them in the software development process, there is a significant overhead involved. Therefore, we created a "light- weight" assertion verification tool called AskTheCode that can help the user to focus on a particular problem at a time that needs to be solved. Because of its goal-driven approach, we decided to implement it using backward symbolic execution. Although it can currently handle only basic C# statements and data types, the evaluation against the existing tools shows that it has the potential to eventually provide significant added value to the user once developed further. Powered by TCPDF (www.tcpdf.org)

Building and discovering useful features when constructing machine learning models is the central task for the machine learning practitioner. Good features are useful not only in increasing the predictive power of a model but also in illuminating the underlying drivers of a target variable. In this research we propose a novel feature learning technique in which Symbolic regression is endowed with a ``Range Terminal'' that allows it to explore functions of the aggregate of variables over time. We test the Range Terminal on a synthetic data set and a real world data in which we predict seasonal greenness using satellite derived temperature and snow data over a portion of the Arctic. On the synthetic data set we find Symbolic regression with the Range Terminal outperforms standard Symbolic regression and Lasso regression. On the Arctic data set we find it outperforms standard Symbolic regression, fails to beat the Lasso regression, but finds useful features describing the interaction between Land Surface Temperature, Snow, and seasonal vegetative growth in the Arctic.

Sans souci de chronologie ou de catégories, cette recherche aborde les œuvres d’art sous la focale du grotesque, révélant une traversée de l’intime à l’universel qui les habite. Ceci débute par un franchissement au-delà du sens, pris dans l’espace du langage et de ses déterminismes. Le grotesque apporte par la contradiction systématique et le déplacement sémantique, une échappée. L’œuvre d’art fonctionne à partir et au-delà de cette illusion du sens à créer du commun, à travers l’anecdote. Une vigilance au « faire » plastique révèle les puissances qui travaillent le corps de l’artiste et mettent en jeu rythme, retournement et instant, où au-delà du visible s’articule l’apparaître, où la création se décrit comme un engagement vital vers ce point d’impossible autour duquel se décide le trait de pinceau, l’acte d’inscription. Dans cette compréhension, l’œuvre d’art est un surplus de fonctionnement, une coupure de la réalité qui origine l’histoire. Des réflexions psychanalytiques approfondissent l’enjeu de cette inscription, qui par le phénomène du transfert réactive la subtilité du processus d’identification. Ceci ouvre le rythme éthique où il est question de place occupée, d’une alternance vie, mort, dont le corps porte la dette séculaire comme sentiment archétypal du vivre ensemble. Ce processus de l’identification réactivé, relance le sujet face à son manque à être, castré, mortel, pris dans ce cycle de temporalité qui le précède et l’excède, face à ce grand Autre, ce « au moins un » qui y échappe.Voici une réflexion temporelle sur le poids du symbolique qui inconsciemment et indépendamment du pathologique peuple nos images et crée ce partage de l’intime à l’universel. / Without regard to chronology or category, this research addresses the Art under the lens of the ludicrousness, revealing a crossing of intimacy to the universal that inhabits them. This starts with a crossing beyond the senses, taken in the space of language and its determinants. Ludicrousness brings the systematic contradiction and movement semantic, a breakaway. The Art works from and beyond the illusion of the senses to create the common, through the story. Vigilance to the "do" plastic reveals the powers that work on the artist's body and involve rhythm, reversal and instant, where beyond the visible articulated the show, where the creation is described as a vital commitment to this point of impossible around which decides the brush stroke, the act of register. In this understanding, the artwork is an operating surplus, a break from reality which origin the story. Psychoanalytic reflections deepen the stake of this registration, which the transference phenomenon reactive the subtlety of the process of identification. This opens up the ethical pace, where it comes to the space occupied, an alternation of life, death, whose body bears the secular debt as archetypal sense of living together. This process of identification reactivated revives the subject facing its lack of being, castrated, fateful, caught in this cycle of temporality that precedes and exceeds him, face to this big Other, this "at least one" that escapes. Here's a temporal thought on the significance of symbolism which people our images unconsciously and independently of the pathological and create this sharing of intimacy to the universal.

The objekt of the study is the title of rector. In Sweden this title was introduced during the Middle Ages together with the first catehedral schools. The same title is being caried into the 21st Century by all local heads of every Swedish primery and secondary school. A summery of he earliest uses of the tittle is presented but the real focus of the thesis commences in 1829 and streches out throught´ten chapters to 1993. Using concepts formulated by Bourdieu -- symbolic capital, cultural capital, habitus, etos, social field -- av chronological inteprentaion is given of how he conferrers, holders and prenders of the title have in different ways contrubuted to the redefinition of the title of rector from an exclusively male title with clear references to State Secondary Schools to a title common to all schoool forms, held primarily by women. The emerical base of the study consists of a comparative study of the profeessional journals that have represented the title hoöders and the pretenders ever since the close of the 19th Century. The closing four chapters of the thesis eal with the central themes og authoruty. masculinity, the nation-sate and the vision of future that through te ages have been a mark og the struggles around the title of rector.

Vector Symbolic Architectures (VSA) combine a hypervector space and a set of operations on these vectors. Hypervectors provide powerful and noise-robust representations and VSAs are associated with promising theoretical properties for approaching high-level cognitive tasks. However, a major drawback of VSAs is the lack of opportunities to learn them from training data. Their power is merely an effect of good (and elaborate) design rather than learning. We exploit high-level knowledge about the structure of reactive robot problems to learn a VSA based on training data. We demonstrate preliminary results on a simple navigation task. Given a successful demonstration of a navigation run by pairs of sensor input and actuator output, the system learns a single hypervector that encodes this reactive behaviour. When executing (and combining) such VSA-based behaviours, the advantages of hypervectors (i.e. the representational power and robustness to noise) are preserved. Moreover, a particular beauty of this approach is that it can learn encodings for behaviours that have exactly the same form (a hypervector) no matter how complex the sensor input or the behaviours are.

Les nombres p-adiques sont un analogue des nombres réels plus proche de l’arithmétique. L’avènement ces dernières décennies de la géométrie arithmétique a engendré la création de nombreux algorithmes utilisant ces nombres. Ces derniers ne peuvent être de manière générale manipulés qu’à précision finie. Nous proposons une méthode, dite de précision différentielle, pour étudier ces problèmes de précision. Elle permet de se ramener à un problème au premier ordre. Nous nous intéressons aussi à la question de savoir quelles bases de Gröbner peuvent être calculées sur les p-adiques. / P-Adic numbers are a field in arithmetic analoguous to the real numbers. The advent during the last few decades of arithmetic geometry has yielded many algorithms using those numbers. Such numbers can only by handled with finite precision. We design a method, that we call differential precision, to study the behaviour of the precision in a p-adic context. It reduces the study to a first-order problem. We also study the question of which Gröbner bases can be computed over a p-adic number field.

No description available.

La toponymie urbaine ou plus précisément l'odonymie en tant qu'objet d'histoire est un outil particulièrement pertinent pour comprendre les mentalités, les représentations et les comportements passés. L'analyse de l'implantation des dénominations urbaines en synchronie et en diachronie permet d'observer les enjeux politiques et mémoriels qui se cristallisent autour de ce support. L'objet de ce travail est de souligner les répercussions des affrontements politiques et symboliques sur le corpus des dénominations urbaines dans l'espace de la France méridionale au cours de la Seconde Guerre mondiale, particulièrement durant la période du régime de Vichy. L'espace de la recherche concerné correspond à la partie méridionale de ce que l'on a surnommé le Royaume du Maréchal, c'est-à-dire les 30 départements de la zone non occupée. Les bornes chronologiques choisies s'étendent de la conférence de Munich en 1938 jusqu'au Coup de Prague de 1948 en passant par la Libération. La collecte et l'analyse des décisions de modification de la toponymie urbaine a pour objectif d'évaluer la pénétration de l'idéologie de la Révolution nationale par le biais de cet instrument de propagande permanent et quotidien qu'est la plaque bleue. Les enlèvements de monuments républicains sont aussi évoqués ainsi que les affrontements mémoriels qui surgissent à la Libération / Urban toponymy, or to be more accurate, odonymy as a subject of history is a tool, particularly relevant in the understanding of the former ways of thinking, representations and behaviours. The analysis of the urban naming establishment both in synchrony and diachrony allows to observe the political and memory-linked concerns at stake, focusing on this medium. The purpose of this study is to highlight the consequences of the political and symbolic confrontations around the corpus of urban namings within Southern France during World War II, especially under the regime of Vichy.The area of the study in question corresponds to the southern part of what was named the Realm of the Marshall, that is to say the 30 departments of the free zone. The chronological markers stretch from the 1938 Munich Conference to the 1948 Coup of Prague, going through the Liberation. Collecting and analysing the decisions of urban naming modifications aims at estimating the diffusion of the National Revolution ideology through the daily and permanent tool that is the blue street plate. The removals of republican monuments are also mentioned as well as the memory-linked confrontations that emerged at the Liberation.

L'étude des ensembles de mots complexité linéaire joue un rôle très important dans la théorie de combinatoire des mots et dans la théorie des systèmes dynamiques symboliques.Cette famille d'ensembles comprend les ensembles de facteurs : d'un mot Sturmien ou d'un mot d'Arnoux-Rauzy, d'un codage d'échange d'intervalle, d'un point fixe d'un morphisme primitif, etc.L'enjeu principal de cette thèse est l'étude de systèmes dynamiques minimales, définis de façon équivalente comme ensembles factoriels de mots uniformément récurrents.Comme résultat principal nous considérons une hiérarchie naturelle de systèmes minimal contenante les ensembles neutres, les tree sets et les ensembles spéculaires.De plus, on va relier ces systèmes au groupe libre en utilisant les mots de retours et les bases de sous-groupes d'indice fini.L'on étude aussi les systèmes symboliques dynamiques engendrés par les échanges d'intervalle et les involutions linéaires, ce qui nous permet d'obtenir des exemples et des interprétations géométriques des familles d'ensembles que définis dans notre hiérarchie.L'un des principal outil utilisé ici est l'étude des extensions possibles d'un mot dans un ensemble, ce qui nous permet de déterminer des propriétés telles que la complexité factorielle.Dans ce manuscrit, nous définissons le graphe d'extension, un graphe non orienté associé à chaque mot $w$ dans un ensemble $S$ qui décrit les extensions possibles de $w$ dans $S$ à gauche et à droite.Dans cette thèse, nous présentons plusieurs classes d'ensembles de mots définis par les formes possibles que les graphes d'extensions des éléments dans l'ensemble peuvent avoir.L'une des conditions les plus faibles que nous allons étudier est la condition de neutralité: un mot $w$ est neutre si le nombre de paires $(a,b)$ de lettres telles que $awb in S$ est égal au nombre de lettres $a$ tel que $aw in S$ plus le nombre de lettres $b$ tel que $wb in S$ moins 1.Un ensemble tel que chaque mot non vide satisfait la condition de neutralité est appelé un ensemble neutre.Une condition plus forte est la condition de l'arbre: un mot $w$ satisfait cette condition si son graphe d'extension est à la fois acyclique et connecté.Un ensemble est appelé un tree set si tout mot non vide satisfait cette condition.La famille de tree sets récurrents apparaît comme fermeture naturelle de deux familles d'ensembles très importants : les facteurs d'un mot d'Arnoux-Rauzy et les ensembles d'échange d'intervalle.Nous présentons également les ensembles spéculaires, une sous-famille remarquable de tree sets.Il s'agit également de sous-ensembles de groupes qui forment une généralisation naturelle des groupes libres.Ces ensembles de mots sont une généralisation abstraite des codages naturelles d'échanges d'intervalle et d'involutions linéaires.Pour chaque classe d'ensembles considéré dans cette thèse, nous montrons plusieurs résultats concernant les propriétés de fermeture (sous décodage maximale bifixe ou par rapport aux mots dérivés), la cardinalité des codes bifixes et les de mots de retour, la connexion entre mots de retour et bases du groupe libre, ainsi qu'entre les codes bifixes et les sous-groupes du groupe libre.Chacun de ces résultats est prouvé en utilisant les hypothèses les plus faibles possibles / Sets of words of linear complexity play an important role in combinatorics on words and symbolic dynamics.This family of sets includes set of factors of Sturmian and Arnoux-Rauzy words, interval exchange sets and primitive morphic sets, that is, sets of factors of fixed points of primitive morphisms.The leading issue of this thesis is the study of minimal dynamical systems, also defined equivalently as uniformly recurrent sets of words.As a main result, we consider a natural hierarchy of minimal systems containing neutral sets, tree sets and specular sets.Moreover, we connect the minimal systems to the free group using the notions of return words and basis of subroups of finite index.Symbolic dynamical systems arising from interval exchanges and linear involutions provide us geometrical examples of this kind of sets.One of the main tool used here is the study of possible extensions of a word in a set, that allows us to determine properties such as the factor complexity.In this manuscript we define the extension graph, an undirected graph associated to each word $w$ in a set $S$ which describes the possible extensions of $w$ in $S$ on the left and the right.In this thesis we present several classes of sets of words defined by the possible shapes that the graphs of elements in the set can have.One of the weakest condition that we will study is the neutrality condition: a word $w$ is neutral if the number of pairs $(a, b)$ of letters such that $awb in S$ is equal to the number of letters $a$ such that $aw in S$ plus the number of letters $b$ such that $wb in S$ minus 1.A set such that every nonempty word satisfies the neutrality condition is called a neutral set.A stronger condition is the tree condition: a word $w$ satisfies this condition if its extension graph is both acyclic and connected.A set is called a tree set if any nonempty word satisfies this condition.The family of recurrent tree sets appears as a the natural closure of two known families, namely the Arnoux-Rauzy sets and the interval exchange sets.We also introduce specular sets, a remarkable subfamily of the tree sets.These are subsets of groups which form a natural generalization of free groups.These sets of words are an abstract generalization of the natural codings of interval exchanges and of linear involutions.For each class of sets considered in this thesis, we prove several results concerning closure properties (under maximal bifix decoding or under taking derived words), cardinality of the bifix codes and set of return words in these sets, connection between return words and basis of the free groups, as well as between bifix codes and subgroup of the free group.Each of these results is proved under the weakest possible assumptions