Programs are more distributed and concurrent today than ever before, and structural communications are at the core. Constructing and debugging such programs are hard due to the lack of formal specifications and verifications of concurrency. Recent advances in type systems allow us to specify the structures of communications as session types, thus enabling static type checking of the usages of communication channels against protocols. The soundness of session type systems implies communication fidelity and absence of deadlock. This work proposes to formalize multiparty dependent session types as an expressive and practical type discipline for enforcing communication protocols. The type system is formulated in the setting of multi-threaded λ-calculus with inspirations from multirole logic. It is sound, and it provides linearity and coherence guarantees entirely statically. The type system supports recursion and polymorphism. The formulation is particularly suitable for practical implementation, and this work provides such a runtime implementation.

The logical framework LF and its metalogic Twelf can be used to encode and reason about a wide variety of logics, languages, and other deductive systems in a formal, machine-checkable way. Recent studies have shown that ML-like languages can profitably be extended with a notion of subtyping called refinement types. A refinement type discipline uses an extra layer of term classification above the usual type system to more accurately capture certain properties of terms. I propose that adding refinement types to LF is both useful and practical. To support the claim, I exhibit an extension of LF with refinement types called LFR,work out important details of itsmetatheory, delineate a practical algorithmfor refinement type reconstruction, andpresent several case studies that highlight the utility of refinement types for formalized mathematics. In the end I find that refinement types and LF are a match made in heaven: refinements enable many rich new modes of expression, and the simplicity of LF ensures that they come at a modest cost.

L'objectif de cette étude consiste en la caractérisation de types de discours dans des situations de travail. Nous avons tenté de définir des types de discours à partir de critères linguistiques et en considérant les cadres actionnels qui sous-tendent les discours. Dans un premier temps, nous précisons le cadre théorique et méthodologique de notre travail en nous positionnant sur le concept de « type de discours » que nous différencions de celui de « genre ». En outre, pour définir notre cadre théorique, nous avons mené une réflexion sur l'histoire de la place du langage dans les activités de travail depuis le XVIIè siècle, et nous nous sommes appuyée sur des analyses de pratiques langagières en situation de travail menées au sein de différentes disciplines. À partir de ce cadre théorique pluridisciplinaire, nous avons pu développer une méthodologie pour le recueil et la constitution de corpus et une méthodologie d'analyse fondée sur un découpage séquentiel des discours. Notre recherche a fait sept types de séquence regroupés en trois types linguistiques (langage expositif, langage de co-action et langage péri-professionnel) et correspondant à trois types de discours (langage sur le travail, langage comme travail et langage dans le travail). Chaque type de séquence est caractérisé par des critères linguistiques récurrents soumis à une analyse qualitative et quantitative. Le type de séquence dominant détermine le type linguistique majeur et donc le type de discours. Cette analyse, couplée avec une analyse du cadre actionnel des activités, nous permet de mettre en évidence l?interdépendance entre langage et activité, et nous conduit à caractériser des types de discours en lien avec le type d'activité. / The purpose of this study is to characterise the types of discourse to be found in work situations. I have tried to define discourse types on the basis of linguistic criteria, taking into account the "actional frameworks" that underpin the discourse. Firstly I have outlined the theoretical and methodological framework of my research and I have opted for the concept of "discourse types" as distinct from "genres". To further develop my theoretical framework, I have investigated the history of language in the workplace since the 17th century with the help of analyses of language practice in work situations in different disciplines. On the basis of this multidisciplinary theoretical framework, I have developed a methodology for the constitution of my corpus and for an analysis based on a sequential division of the discourse. My research has identified seven types of discourse sequences based on three linguistic types (expository language, co-actional language and peri-professional language). Each type of sequence is characterised by recurring linguistic criteria which have been subjected to qualitative and quantitative analyses. The predominant type of sequence determines the major linguistic type and therefore the discourse type. This analysis, in conjunction with an analysis of the "actional framework" of the activities, has revealed the interdependence of language and activity and led to a characterisation of discourse types in relation to types of activity.

Dependent types can be used to capture useful properties about programs at compile time. However, developing dependently typed programs can be difficult in current systems. Capturing interesting program properties usually requires the user to write proofs, where constructing the latter can be both a difficult and tedious process. Additionally, finding and fixing errors in program scripts can be challenging. This thesis concerns ways in which functional programming with dependent types can be made easier. In particular, we focus on providing help for developing programs that incorporate user-defined types and user-defined functions. For the purpose of supporting dependently typed programming, we have designed a framework that provides improved proof automation and error feedback. Proof automation is provided with the use of heuristic based tactics that automate common patterns of proofs that arise when programming with dependent types. In particular, we use heuristics for generalising goals and employ the rippling heuristic for guiding inductive and non-inductive proofs. The automation we describe includes features for caching and reusing lemmas proven during proof search and, whenever proof search fails, the user can assist the prover by providing high-level hints. We concentrate on providing improved feedback for the errors that occur when there is a mismatch between the specification of a program, described with the use of dependent types, and the behaviour of the program. We employ a QuickCheck-like testing tool for automatically identifying these forms of errors, where the counter examples generated are used as error messages. To demonstrate the effectiveness of our framework for supporting dependently typed programming, we have developed a prototype based around the Coq theorem prover. We demonstrate that the framework as a whole makes program development easier by conducting a series of case studies. In these case studies, which involved verifying properties of tail recursive functions, sorting functions and a binary adder, a significant number of the proofs required were automated.

The term 'underground music' in my account, connects various forms of music-making that exist largely outside 'mainstream' cultural discourse, such as Drone Metal, Free Improvisation, Power Electronics, and DIY Noise, amongst others. Its connotations of concealment and obscurity indicate what I argue to be the music's central tenets of cultural reclusion, political independence, and aesthetic experiment. In response to a lack of scholarly discussion of this music, my thesis provides a cultural, political, and aesthetic mapping of the underground, whose existence as a coherent entity is being both argued for and 'mapped' here. Outlining the historical context, but focusing on the underground in the digital age, I use a wide range of interdisciplinary research methodologies, including primary interviews, musical analysis, and a critical engagement with various pertinent theoretical sources. In my account, the underground emerges as a marginal, 'antermediated' cultural 'scene' based both on the web and in large urban centres, the latter of whose concentration of resources facilitates the growth of various localised underground scenes. I explore the radical anti-capitalist politics of many underground figures, whilst also examining their financial ties to big business and the state(s). This contradiction is critically explored, with three conclusions being drawn. First, the underground is shown in Part II to be so marginal as to escape, in effect, post-Fordist capitalist subsumption. Second, the practice of 'co-determination' is seen to allow politically engaged underground artists to channel public and private funds into various practices of contestation. Third, and finally, I argue across Part III that in its distinctive musical and iconographic forms, the underground offers a kind of profaning, deforming, sublimating aesthetic 'counter-magic', where radical aesthetic modes and radical practices of representation communicate a kind of 'reconfiguration of the sensible' to audiences. I argue that this 'reconfiguration' might yield emancipatory political readings, whilst also reflecting the kinds of experimental and exploratory musical practices typical in the underground.

Objective: To determine the magnitude of the skeletal and dental movements in subjects with different facial patterns following Class II correction using the XbowTM appliance. Materials and Methods: A retrospective sample of 134 subjects exhibiting Class II malocclusions was used. Subjects were categorized into three growth types according to pre-treatment cephalometric variables (MPA and Y-axis), which yielded 27 brachycephalic, 70 mesocephalic, and 37 dolichocephalic subjects. A ANOVA test statistic was used to investigate the differences between the three facial groups at pre and post-treatment time points. Results: Dental changes induced by the XbowTM appliance included: proclination of the lower incisors (L1-MP 7.3-12.3o±1.0o), protrusion of the lower incisors (L1-APo 2.1-3.8mm±0.3mm), mesial movement of the mandibular first molar (5.5-6.9mm±0.7mm) and retrusion of the maxillary incisor (2.4-3.1mm±0.4mm). Retroclination of the maxillary incisor (U1-PP 0.2-0.8o±0.7o) and distal movement of the maxillary molar (0.4-0.7mm±0.3mm) were not significantly influenced by XbowTM treatment. Reduction of the skeletal Class II relationship was represented by a significant decrease of the Wits value (2.4-4.5mm±0.5mm) in all three groups. The p value was considered significant at <0.05. Conclusions: Class II correction with the XbowTM appliance is the result of mesial movement of the mandibular molar, proclination/protrusion of the lower incisor and retrusion of the upper incisor. Skeletal correction must be validated by more than one cephalometric variable. Facial growth pattern appears to be unrelated to the amount of dental movement and there is a trend for pronounced dental movements of the lower incisor in brachycephalic patients.

Objective: To determine the magnitude of the skeletal and dental movements in subjects with different facial patterns following Class II correction using the XbowTM appliance. Materials and Methods: A retrospective sample of 134 subjects exhibiting Class II malocclusions was used. Subjects were categorized into three growth types according to pre-treatment cephalometric variables (MPA and Y-axis), which yielded 27 brachycephalic, 70 mesocephalic, and 37 dolichocephalic subjects. A ANOVA test statistic was used to investigate the differences between the three facial groups at pre and post-treatment time points. Results: Dental changes induced by the XbowTM appliance included: proclination of the lower incisors (L1-MP 7.3-12.3o±1.0o), protrusion of the lower incisors (L1-APo 2.1-3.8mm±0.3mm), mesial movement of the mandibular first molar (5.5-6.9mm±0.7mm) and retrusion of the maxillary incisor (2.4-3.1mm±0.4mm). Retroclination of the maxillary incisor (U1-PP 0.2-0.8o±0.7o) and distal movement of the maxillary molar (0.4-0.7mm±0.3mm) were not significantly influenced by XbowTM treatment. Reduction of the skeletal Class II relationship was represented by a significant decrease of the Wits value (2.4-4.5mm±0.5mm) in all three groups. The p value was considered significant at <0.05. Conclusions: Class II correction with the XbowTM appliance is the result of mesial movement of the mandibular molar, proclination/protrusion of the lower incisor and retrusion of the upper incisor. Skeletal correction must be validated by more than one cephalometric variable. Facial growth pattern appears to be unrelated to the amount of dental movement and there is a trend for pronounced dental movements of the lower incisor in brachycephalic patients.

Th.--Math. appl.--Nancy--I.N.P.L., 1982.

Pendant la dernière décennie, le format de données XML est devenu l'un des principaux moyens de représentation et d'échange de données sur le Web. La détection de l'indépendance entre une requête et une mise à jour, qui a lieu en absence d'impact d'une mise à jour sur une requête, est un problème crucial pour la gestion efficace de tâches comme la maintenance des vues, le contrôle de concurrence et de sécurité. Cette thèse présente une nouvelle technique d'analyse statique pour détecter l'indépendance entre requête et mise à jour XML, dans le cas où les données sont typées par un schéma. La contribution de la thèse repose sur une notion de type plus riche que celle employée jusqu'ici dans la littérature. Au lieu de caractériser les éléments d'un document XML utiles ou touchés par une requête ou mise à jour en utilisant un ensemble d’étiquettes, ceux-ci sont caractérisés par un ensemble de chaînes d'étiquettes, correspondants aux chemins parcourus pendant l'évaluation de l’expression dans un document valide pour le schéma. L'analyse d'indépendance résulte du développement d'un système d'inférence de type pour les chaînes. Cette analyse précise soulève une question importante et difficile liés aux schémas récursifs: un ensemble infini de chaînes pouvant être inférées dans ce cas, est-il possible et comment se ramener à une analyse effective donc finie. Cette thèse présente donc une technique d'approximation correcte et complète assurant une analyse finie. L'analyse de cette technique a conduit à développer des algorithmes pour une implantation efficace de l'analyse, et de mener une large série de tests validant à la fois la qualité de l'approche et son efficacité. / In the last decade XML became one of the main standards for data storage and exchange on the Web. Detecting XML query-update independence is crucial to efficiently perform data management tasks, like those concerning view-maintenance, concurrency control, and security. This thesis presents a novel static analysis technique to detect XML query-update independence, in the presence of a schema. Rather than types, the presented system infers chains of types. Each chain represents a path that can be traversed on a valid document during query/update evaluation. The resulting independence analysis is precise, although it raises a challenging issue: recursive schemas may lead to infer infinitely many chains. This thesis presents a sound and complete approximation technique ensuring a finite analysis in any case, together with an efficient implementation performing the chain-based analysis in polynomial space and time.

Made available in DSpace on 2014-06-12T15:52:47Z (GMT). No. of bitstreams: 2 arquivo4748_1.pdf: 788444 bytes, checksum: bf529ae650fd6acfbf8f43c0335c33fd (MD5) license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) Previous issue date: 2003 / Lewitzka, Steffen; José Guerra Barreto de Queiroz, Ruy. Contributions to the investigations of Lascar strong types in simple theories. 2003. Tese (Doutorado). Programa de Pós-Graduação em Ciência da Computação, Universidade Federal de Pernambuco, Recife, 2003.