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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
111

Un système déclaratif de types pour PROLOG

Nguyen Phuong, Lan 23 September 1992 (has links) (PDF)
Cette thèse présente un système de types pour le langage Prolog, intégrant la notion de mode, c'est-à-dire le degré d'instanciation des termes. Le type d'un prédicat est caractérisé par les types d'appel et de retour de ses arguments, ce qui permet d'en spécifier plus finement le comportement. Le système est déclaratif : l'utilisateur doit fournir les types de tous les prédicats. Un langage de types est défini, permettant d'exprimer la notion de polymorphisme paramétrique, ainsi que la relation d'inclusion entre types. Une condition suffisante de bon typage est présentée et validée théoriquement. Cette condition permet de vérifier qu'un programme a un comportement compatible avec les spécifications de types de ses prédicats. Un prototype du système a été réalisé, permettant une validation pratique de la condition de bon typage.
112

Schemas for safe and efficient XML processing

Colazzo, Dario 08 September 2011 (has links) (PDF)
Ce manuscrit d'Habilitation à Diriger des Recherches présente des résultats que j'ai obtenus dans le cadre d'activités de recherche menées depuis 2005 en tant que Maître de Conférences à l'Université Paris-Sud XI. Au début de cette période XML ( eXtensible Markup Language) était déjà reconnus comme le standard pour la représentation de données semi structurées. En même temps, XML c'est aussi affirmé comme format de représentation dans le contexte de l'intégration et l'échange de données. Pendant cette période mes intérêts de recherche se sont situés à la confluence des langages des bases de données et langages de programmation, et se sont focalisé sur l'utilisation des systèmes de types pour assurer la sureté et optimisation des programmes manipulant les données XML. Plus en détails, je me suis principalement intéressé à trois axes de recherche: i) optimisation de requêtes et mise à jours XML via la projection de données, ii) vérification de la correction des mappings entre deux schémas XML, iii) algorithmes efficaces pour la vérification d'inclusion entre schémas XML (une propriété qui est à la base des systèmes de types pour requêtes et mises à jour XML). Ce manuscrit d'Habilitation à Diriger des Recherches est consacré à ces trois axes de recherche, et présente le contexte, les motivations et résultats obtenus pour chacun des axes.
113

Boolean Classes

McAllester, David, Zabih, Ramin 01 September 1986 (has links)
Object-oriented programming languages all involve the notions of class and object. We extend the notion of class so that any Boolean combination of classes is also a class. Boolean classes allow greater precision and conciseness in naming the class of objects governed by a particular method. A class can be viewed as a predicate which is either true or false of any given object. Unlike predicates however classes have an inheritance hierarchy which is known at compile time. Boolean classes extend the notion of class, making classes more like predicates, while preserving the compile time computable inheritance hierarchy.
114

Types for Detecting XML Query-Update Independence

Ulliana, Federico 12 December 2012 (has links) (PDF)
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.
115

Focus expressions in Foodo

Fiedler, Ines January 2007 (has links)
This paper aims at presenting different ways of expressing focus in Foodo, a Guang language. We can differentiate between marked and unmarked focus strategies. The marked focus expressions are first syntactically characterized: the focused constituent is in sentence-initial position and is second always marked obligatorily by a focus marker, which is nɩ for non-subjects and N for subjects. Complementary to these structures, Foodo knows an elliptic form consisting of the focused constituent and a predication marker gɛ́. It will be shown that the two focus markers can be analyzed as having developed out of the homophone conjunction nɩ and that the constraints on the use of the focus markers can be best explained by this fact.
116

Morphological focus marking in Gùrùntùm (West Chadic)

Hartmann, Katharina, Zimmermann, Malte January 2006 (has links)
The paper presents an in-depth study of focus marking in Gùrùntùm, a West Chadic language spoken in Bauchi Province of Northern Nigeria. Focus in Gùrùntùm is marked morphologically by means of a focus marker a, which typically precedes the focus constituent. Even though the morphological focus-marking system of Gùrùntùm allows for a lot of fine-grained distinctions in information structure (IS) in principle, the language is not entirely free of focus ambiguities that arise as the result of conflicting IS- and syntactic requirements that govern the placement of focus markers. We show that morphological focus marking with a applies across different types of focus, such as newinformation, contrastive, selective and corrective focus, and that a does not have a second function as a perfectivity marker, as is assumed in the literature. In contrast, we show at the end of the paper that a can also function as a foregrounding device at the level of discourse structure.
117

Hydrosalinity Fluxes in a Small Scale Catchment of the Berg River (Western Cape).

Bugan, Richard. January 2008 (has links)
<p><font face="Times New Roman"> <p align="left">The objective of this study was to determine the hydrosalinity fluxes associated with overland and subsurface (vadose zone) flow for different soils and land uses. For this purpose, the following data were collected during 2005 and 2006 in a typical small scale catchment located near the town of Riebeeck-Wes: weather data, hydrological and water quality measurements, soil water contents and chemistry, and vegetation growth. The area is characterized by a Mediterranean climate receiving winter rainfall of approximately 300 mm a <font face="Times New Roman">catchment is conservative, with Na</font> <font face="Times New Roman" size="1"><font face="Times New Roman" size="1">+ </font></font><font face="Times New Roman">and Cl</font><font face="Times New Roman" size="1"><font face="Times New Roman" size="1">- </font></font><font face="Times New Roman">being the dominant ions.</font></p> </font></p>
118

Housing Themselves : Transformations, Modernisation and Spatial qualities in Informal Settlements in Dar es Salaam, Tanzania

Nguluma, Huba January 2003 (has links)
This thesis is an attempt to address issues of housingtransformation in informal settlements. Transformation ofhouses is seen to be associated with modernisation forceswhereby people adapt their houses to suit their needs anddesires. On one hand the desire to own a“modernhouse”may lead to deterioration of spatial qualities, onthe other hand fulfilment of the desire may contribute to themodernisation of urban settlements. The informal settlement ofHanna Nassif was chosen as a case study to illustrate theprocess of housing transformations in informal settlement.Knowledge on the transformation processes serves as animportant tool to address issues of spatial qualities, housingmodernisation, actors in the processes of transformation anduse of space. The results show that there is a wide range oftransformation activities that have been taking place in termsof extensions and alterations. The desire to modernise theirhouses impels developers to use modern building materials. Insome instances houses constructed with traditional buildingmaterials are replaced with industrially produced materials.Through transformation processes new house types emerge. Thestudy identifies problems as well as positive aspectsassociated with the whole process of housing transformation.The positive aspects are those of increased indoor space,increase of rooms for renting and in other cases separation offunctions. The problems emerging from this process include:decrease of outdoor space, increase of housing density,blockage of ventilation and light in the transformedhouses. The study concludes that housing transformation being oneway in which lowincome earners strive to get access to housingdeserves government support, particularly in the absence ofalternative housing supply. It is further observed that todatemany urban dwellers have managed to secure housing as a directresult of house extensions effected by house owners. The houseextensions are being carried out outside the established formalplanning regulations. It is in the light of these developmentsthat there is a cause for government intervention to guidehousing development processes in informal settlements.Professionals like planners and architects should also assume arole for quality and sustainability to prevail. The study alsosuggests specific problem areas for further investigation. <b>Key words:</b>Tanzania, housing transformation, informalsettlements, modernisation, spatial qualities and housetypes.
119

The effect of back stage information in services advertisements on consumers' services intangibility and perceived risk

Cheng, Kai-da 30 July 2007 (has links)
This study examines whether back stage information in services advertisements would significantly influence intangibility of services and consumers¡¦ perceived risk by experimental design, and whether ¡§back stage information-perceived risk¡¨ relation would mediated by intangibility. The researcher provides back stage information by print advertisements. The presentation of back stage information, the types of services, and the attributes of services are considered and included in research design to explore their roles in ¡§back stage information-intangibility-perceived risk¡¨ relation. The result shows that intangibility of services and consumers¡¦ perceived risk are significantly lower after consumers reading advertisements with back stage information contrast with those without back stage information. Intangibility has partial mediating effect on ¡§back stage information-perceived risk¡¨ relation. Though, presenting back stage information simultaneously by picture and text has a slightly better effect than by text alone, however, the difference is not significant. The type and attribute of services have no moderation on ¡§back stage information-perceived risk¡¨ and ¡§intangibility-perceived risk¡¨ relations respectively.
120

Type-based detection of XML query-update independence

Ulliana, Federico 15 December 2012 (has links) (PDF)
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.

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