Dans cette thèse, nous présentons de nouvelles méthodes permettant l’extraction de chaînes de mots (segments textuels) relatives à des catégories (thématiques, rôles des locuteurs, opinions). Nous proposons, dans un premier temps, une méthode basée su rune métrique de recherche de collocations, que nous appliquons de manière distincte sur les documents liés à la même catégorie et qui, par itérations, nous permet d’obtenir des chaînes caractéristiques de cette catégorie. Ces chaînes sont alors employées pour améliorer les performances de systèmes de catégorisation de textes ou dans un but d’extraction de connaissances (faire ressortir des éléments textuels tels que des expressions employées par un type de locuteurs, des sous-thématiques liées à la catégorie,...). Nous proposons ensuite une seconde méthode permettant de rechercher, dans un corpus d’opinions, des n-grammes exprimant des jugements sur des sujets prédéfinis.Nous pouvons alors extraire des segments textuels représentant l’expression d’une opinion sur un des sujets cibles.Ces méthodes sont validées par un certain nombre d’expériences effectuées dans des contextes différents : écrits de blogs, transcriptions manuelles de parole spontanée,critiques de produits culturels, enquêtes de satisfaction EDF, en français ou en anglais, ... / Non communiqué

Zugl.: Passau, Universiẗat, Diss.

Pour répondre à une demande sans cesse croissante en capacité et débit pour la télévision HD, la sécurité civile, les télécommunications haut débit etc., les opérateurs satellites doivent accroître de manière importante la capacité de leurs nouveaux satellites. Ces nouvelles capacités sont obtenues au prix d'une complexité accrue.La maîtrise de cette complexité impose la définition de nouvelles méthodes de conception et le développement de nouveaux outils informatiques associes.La conception des charges utiles de télécommunication répond aux contraintes particulières à l'environnement spatial qui se traduisent par des exigences draconiennes quant à la ¯abilit¶e, la masse des équipements à embarquer ou encore la limitation de la puissance disponible. EADS Astrium a ainsi développé une gamme de visant a valider et à optimiser les designs des satellites. Ces logiciels sont bases sur des et des méthodes standards d'optimisation de la recherche opérationnelle. Ils sont utilises lors des phases de conception,notamment pour traiter deux problématiques d'optimisation :{ La validation de la robustesse d'une charge utile nécessite la validation de plusieurs centaines de millions,voire plusieurs dizaines de milliards de cas dégradées. Pour chacun des cas dégradés envisages, il faut e®effectuer un calcul de reconfiguration de la charge utile de fa»con a valider la robustesse du design a cette anomalie. Pour permettre une validation exhaustive d'une charge utile en un temps raisonnable, un calcul de recon¯ ne doit pas dépasser quelques millisecondes.{ L’aménagement des équipements sur les murs d'un satellite est un processus complexe trµes contraint. nécessite de respecter le positionnement des ¶équipements selon des zones chaudes et des zones froides préalablement d¶e¯nies. A¯n de garantir un niveau d'ampli¯cation optimal, la longueur des guides d'ondes reliant les équipements doit ^être limitées et des contraintes de montage/démontage des guides doivent ^être respectées. Avec l'accroissement de la complexité des nouvelles générations rations de satellites, il devient critique pour EADS Astrium de d¶e¯nir de nouvelles méthodes d'optimisation de la charge utile. Nous nous proposons d'étudier ici ces deux problématiques. Une première problématique d’aménagement de guides d'ondes se rapporte une problématique de multi-routage dans un espace continu en trois dimensions. L'objectif est de fournir une estimation des pertes auto-référentielles directement déduite des longueurs des guides d'ondes obtenues lors du routage. Cette problématique s'inscrit dans le cadre de problématique de type Pipe Routing (littéralement,routage de canalisation).la seconde problématique concerne la validation de la robustesse d'une charge utile a un nombre de pannes préalablement ¯x¶e. Du fait d'une méthode de validation choisie, bas¶ee sur une énumération exhaustive des cas dépannes, cette problème¶s'apparente a la résolution successive de millions voire de milliards de problèmes de satisfaction de contraintes. Avec l'augmentation de la complexité¶des charges utiles, il devient urgent de proposer des améliorations significatives de l'outil de validation existant, a savoir SWITCHWORKS / Nc

Ce travail de thèse s’inscrit dans le cadre des problématiques liées au phénotypage haut débit des plantes au champ. L’objectif est de réaliser des mesures non destructives à distance, rapides et pertinentes pour caractériser le peuplement végétal ainsi que les organes (feuilles, tiges, épis) qui le constituent. Ce travail de thèse s’articule en deux axes : Un axe plutôt opérationnel où les méthodes existantes, généralement issues de la communauté de télédétection peuvent être adaptées à cette nouvelle problématique. A l’échelle de l’organe (la feuille) l’inversion du modèle de transfert radiatif PROSPECT est testée pour discriminer les variétés de blé. Nous montrons que cette méthode permet d’obtenir une meilleure discrimination par rapport à celle obtenue à partir des mesures destructives classiques. A l’échelle du peuplement végétal, un système semi-automatique permettant de mesurer un grand nombre de micro-parcelles expérimentales est présenté. Les mesures acquises décrivent la dynamique de la fraction de vert, du FIPAR ainsi que d’indices sensible au LAI et à la chlorophylle au cours du cycle du blé. Cette première partie s’achève sur une discussion des améliorations nécessaires pour optimiser la chaîne d’acquisition et d’interprétation des mesures pour le phénotypage haut débit au champ. Le second axe, plus académique, se concentre sur l’amélioration de la connaissance des propriétés directionnelles des feuilles de blé. Un instrument, le conosocope, est utilisé pour mesurer le facteur de réflectance directionnelle sur un grand nombre de feuilles et de directions. On montre que le système vasculaire parallèle des feuilles de blé crée une anisotropie azimutale peu décrite auparavant dans la littérature. Ce phénomène est modélisé en adaptant un modèle physique de micro-facettes caractérisée par une distribution azimutale anisotrope. La rugosité perpendiculaire au système vasculaire apparaît être deux fois supérieure à celle observée parallèlement. Finalement ce modèle est couplé à un modèle de lancer de rayon pour évaluer l’effet de l’anisotrope des propriétés de la feuille sur celles observées au niveau du couvert. Cette avancée dans la compréhension des processus du transfert radiatif au niveau de la feuille ouvre la voie à une interprétation plus fine des mesures radiométriques réalisées à différentes échelles et en particulier pour le phénotypage haut-débit. / Nc

Zugl.: Paderborn, Universiẗat, Diss., 1996.

This PhD began by attempting to locate the Epic of Gilgamesh within a contemporary landscape and using a comparison of Michael Ayrton and Sidney Nolan as a means of creating a body of narrative based drawing. Initial work, however, illustrated rather than illuminated the text. As the research evolved, analysis of the text as a model for thinking and the different approaches to landscape from Ayrton and Nolan, clarified that the metaphorical journey of Gilgamesh required a different drawing practice. The Epic of Gilgamesh was written in cuneiform script on clay tablets some four thousand years ago. The fragmented and incomplete tablets have survived by chance. Failure, evident in Gilgamesh’s quest, suggested exploring contingency and failure as agents of creative practice. The opportunity to draw directly from the clay tablets in the collection of the British Museum generated the insight that the apprehension of physical objects and their recording as image through drawing, also works as a process of visual translation. The original clay tablets became a source for making drawings possessing a physical equivalence beyond the normative approaches to translation and narrative. This was the central aspect of the final research, superseding the narrative drive that had been the original starting point. Models of working allusively with narrative and landscape were also provided by unique access to the archives of Sidney Nolan at The Rodd, in Herefordshire, and by analysing in parallel the work of Michael Ayrton. This aspect of the research developed as a way of asserting that in the liminal space of the studio, equivalence can be found with the complex and contingent aspects of quest narrative as exemplified by Gilgamesh. Working large scale, the final works produced for this PhD explore translation and transcription in drawing through the surface accretions of material, gesture, intuition and fold.

In recent decades there has been a rapid development of technology in manufacturing industries, in particular through the increasing use of ever more powerful and sophisticated Computer Numerical Controlled (CNC) machines to manufacture complex parts. These machines are supported by a chain of computer based software solutions amongst which manufacturing information is exchanged. With the need for information exchange, interoperability between various computer-aided systems (CAx) has become an important research area. In CNC part programing, innovations by various hardware manufacturers and their reflection in their software have led to the necessity for the existence of different part programs for each machine. Creating these is a time consuming and economically inefficient activity. Implementing genuine interoperability between CNC machines is a way of eliminating this deficiency but, to achieve this, CNC programmers must be able to write a CNC program for a specific machine and effortlessly convert that program to work for other machines. The aim of this research was to enable the exchange of CNC programmes across machines with different technologies and demonstrate this between a C-axis CNC turn-mill machine and a 4-axis CNC machining centre. This has been achieved by designing a cross-technology interoperability framework that is capable of supporting systems that can work with the different types of CNC machines. This framework is the core contribution to knowledge from this PhD research. In order to fully identify the context for the research, this thesis presents a review of existing literature on machining of turn-mill parts and interoperability for CNC manufacturing. This is followed by the specification and realisation of a novel framework for cross-technology interoperability for CNC manufacturing. The demonstration is conducted using test components that can be manufactured using different CNC technologies.

In recent years the demand for spectrum has been steadily growing. With the limited amount of spectrum available, Spectrum Pooling has gained immense popularity. As a result of various studies, it has been established that most of the licensed spectrum remains underutilized. Spectrum Pooling or spectrum sharing concentrates on making the most of these whitespaces in the licensed spectrum. These unused parts of the spectrum are usually available in chunks. A secondary user looking to utilize these chunks needs a device capable of transmitting over distributed frequencies, while not interfering with the primary user. Such a process is known as Dynamic Spectrum Access (DSA) and a device capable of it is known as Cognitive Radio. In such a scenario, multicarrier communication that transmits data across the channel in several frequency subcarriers at a lower data rate has gained prominence. Its appeal lies in the fact that it combats frequency selective fading. Two methods for implementing multicarrier modulation are non-contiguous orthogonal frequency division multiplexing (NCOFDM)and filter bank multicarrier modulation (FBMC). This thesis aims to implement a novel FBMC transmitter using software defined radio (SDR) with modulated filters based on a lowpass prototype. FBMCs employ two sets of bandpass filters called analysis and synthesis filters, one at the transmitter and the other at the receiver, in order to filter the collection of subcarriers being transmitted simultaneously in parallel frequencies. The novel aspect of this research is that a wireless transmitter based on non-contiguous FBMC is being used to design spectrally agile waveforms for dynamic spectrum access as opposed to the more popular NC-OFDM. Better spectral containment and bandwidth efficiency, combined with lack of cyclic prefix processing, makes it a viable alternative for NC-OFDM. The main aim of this thesis is to prove that FBMC can be practically implemented for wireless communications. The practicality of the method is tested by transmitting the FBMC signals real time by using the Simulink environment and USRP2 hardware modules.

This practice-based thesis aims to explore and demonstrate the conflict that exists between traditional, male-oriented attitudes and feminist perceptions of the female nude within the context of life drawing practices. The research interrogates the problematisation of life-drawing practice for female practitioners, proposing that perceived tensions and conflicts can be resolved through practice-based enquiry. In response to this, practice has been devised and tested, that negotiates this opposition, evolving an innovative system of projective geometry for drawing and painting which considers representations of the female nude in a way that is compatible with a specifically female viewpoint. The methodology includes: 1. The development of a portfolio of paintings and drawings of the female nude produced in the life drawing room by a female practitioner. This body of work is integral to the submission. 2. Qualitative questionnaires and discussion groups which inform, support and substantiate findings. 3. A literature review which considers the historical background of life drawing and the role played by female practitioners in academic life-drawing leading to an explanation and practical enquiry of sight-sized drawing that epitomises the habitual rituals of the life drawing class in relation to the researcher’s gendered interests. Conclusions and outcomes: The literature review together with other findings are analysed and synthesized, leading to an overview of four interrelated waves of feminism and feminist theory. The emergence and influence of a Negative Feminist Critique of the Female Nude is shown as related to the subjective female identity and interests of the artist. Through the creation of a feminist strategy, demonstrated to be antagonistic to the traditions of the female nude, have resulted in an alternative canon of the female nude that hinges on the interpretation of artworks and affects, but is distinct from, the experience of practitioners. Interactions with the model are identified as crucial to negotiating existing precepts of the female nude in female-directed life drawing practice. Questioning if linear perspective is intrinsically voyeuristic and analogous to a peep show reveals this position as socially- rather than materially-constructed. The extended drawings articulate multiple viewpoints without fragmentation and prioritise experiential understanding of process over external critiques of content. A series of extended paintings is examined in relation to the artist’s formally based material interests in painting and stitch combined with socially-formed interactions of collaboration and empathy. Resultant art works intervene in the field of existing life-drawing conventions and demonstrate a recognisably female sensibility in their representation of the female nude. These findings will be used to inform future life-drawing practice and pedagogy.

Cartoons have traditionally occupied an important place in French visual culture, and are now a permanent feature in even the most prestigious publications, including Le Monde, where they appear on the front page. Moreover, there is a long tradition of political cartooning which is firmly situated within the historical context of caricature and lampooning, which over the years has contributed to public debates on key issues such as politics, religion and social change. In this thesis, I focus on political cartoons and argue that the political cartoon is still significant as a cultural product and as a powerful journalistic medium at a time when the existence of the print media is threatened by new technological developments. In order to understand how cartoons remain a powerful mode of expression in the twenty-first century, I begin by examining the historical development of cartooning, tracing its origins in grotesque art, physiognomy and caricature. I then explore a number of events in early modern European history such as the Reformation and the French Revolution to show that the medium was used as a means of mass communication, to inform a largely illiterate public, incite protest and instigate rebellion through propaganda. I show how political graphics were used as effective political weapons against the ruling authorities, in the face of tight regulation such as censorship, and underline the French artists' commitment to defend their right of expression. As I demonstrate, this commitment continues to be pursued by contemporary French cartoonists such as Plantu who is dedicated to fighting for freedom of expression and promoting peace issues, under the banner of Le Monde and the United Nations. In analysing a corpus of Plantu's editorial creations, I underline theoretical perspectives for ‘reading' cartoons and illuminate the visual rhetoric used by cartoonists to communicate serious issues. I conclude with an assessment of the significant role that French cartoonists played during the 2006 Cartoons War to further highlight the impact of cartoons as a vehicle for political communication, and as a catalyst for debate in the twenty first century.