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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.
151

Mouvements verticaux des marges passives d’Afrique australe depuis 130 Ma, étude couplée : stratigraphie de bassin : analyse des formes du relief / Post-rift vertical movements of the southern African passive margins since 130 Ma : a combined approach : basin analysis, landforms study

Baby, Guillaume 23 March 2017 (has links)
Le plateau sud-africain (ou Kalahari) est le plateau anorogénique le plus grand au monde. Sa très grande longueur d’onde (×1000 km) et son altitude moyenne élevée (1000-1500 m) impliquent des processus mantelliques. La cinétique et l’origine de ce relief sont mal comprises. D’un côté, les études géomorphologiques le considèrent comme un relief mis en place à la fin de l’intervalle Cénozoïque (<30 Ma). A l’inverse, les données thermochronologiques montrent deux phases de dénudation pendant l’intervalle crétacé, corrélées à des phases d’accélération du flux silicoclastique sur les marges, qui suggèrent qu’il s’agirait d’un relief plus ancien hérité du Crétacé supérieur. Peu d’études ont porté sur l’évolution du système terre-mer depuis le bassin versant en érosion aux marges en sédimentation. Ce travail de thèse repose donc sur une double approche : une analyse géomorphologique des formes du relief (surfaces d’aplanissement) à terre, basée sur leur (i) cartographie, (ii) chronologie relative, (iii) relation avec les profils d’altération et (iv) datation au moyen des placages sédimentaires et du volcanisme datés qui les fossilisent ; une analyse stratigraphique de l’intervalle post-rift des marges, basée sur l’interprétation de données de sub-surface (lignes sismiques et puits), réévaluées en âge (biostratigraphie), pour (i) identifier, dater et mesurer les déformations des marges et de leur relief amont , (ii) mesurer les flux silicoclastiques, produits de l’érosion continentale. Un calendrier et une cartographie des déformations ont été obtenus sur les marges et mis en relation avec les différentes générations de surfaces d’aplanissement étagées qui caractérisent le relief du plateau sud-africain. Au moins deux périodes de déformation ont été identifiées au Crétacé supérieur (92-70 Ma) et à l’Oligocène (30-15 Ma). L’évolution est la suivante : 100 - 70 Ma (Cénomanien à Campanien) : plateau à très grande longueur d’onde, peu élevé (0-500 m), bordé à l’est par des reliefs plus hauts et plus anciens le long des marges indiennes, qui agissent comme une ligne de partage des eaux entre l’océan Atlantique et l’océan Indien. La déformation est initiée à l’est avec une flexuration brève, à grande longueur d’onde, des marges indiennes aux alentours de ~92Ma. Cette première surrection marque un paroxysme d’érosion enregistré par la mise en place d’un delta géant sur la marge atlantique (delta de l’Orange). La déformation migre ensuite vers l’ouest avec la croissance du bourrelet marginal atlantique entre 81 et 70 Ma. Le relief acquiert sa configuration actuelle comme l’indique une diminution du flux silicoclastique sur la marge atlantique qui traduit un changement majeur du système de drainage ; 70-30 Ma (Crétacé terminal-Paléogène) : période d’apparente non déformation. Le relief est fossilisé et intensément altéré (latérites) ; 30-15 Ma (Oligocène - Miocène inférieur) : deuxième surrection du plateau sud-africain qui acquière sa topographie actuelle. La déformation semble plus importante à l’est du plateau - flexure des marges nord indiennes initiée à ~25 Ma qui alimente les grands deltas de l’océan Indien (Zambèze, Limpopo, Tugela) ; le relief est fossilisé à partir du Miocène moyen, synchrone d’une aridification majeure de l’Afrique australe. / The South African (Kalahari) Plateau is the world's largest non-orogenic plateau. It forms a large-scale topographic anomaly (×1000 km) which rises from sea level to > 1000 m. Most mechanisms proposed to explain its elevation gain imply mantle processes. The age of the uplift and the different steps of relief growth are still debated. On one hand, a Late Cretaceous uplift is supported both by thermochronological studies and sedimentary flux quantifications. On the other hand, geomorphological studies suggest a Late Cenozoic uplift scenario (<30 Ma). However few attentions were paid to the evolution of the overall geomorphic system, from the upstream erosional system to the downstream depositional system. This study is based on two different approaches : onshore, on the mapping and chronology of all the macroforms (weathering surfaces and associated alterites, pediments and pediplains, incised rivers, wave-cut platforms) dated by intersection with the few preserved sediments and the volcanics (mainly kimberlites pipes) ; offshore, on a more classical dataset of seismic lines and petroleum wells, coupled with biostratigraphic revaluations (characterization and dating of vertical movements of the margins - sediment volume measurement). The main result of this study is that the South African Plateau is an old Upper Cretaceous relief (90-70 Ma) reactivated during Oligocene (30-15 Ma) times. Its evolution can be summarized as follows : 100-70 Ma (Cenomanian to Campanian): low elevation plateau (0-500 m) with older and higher reliefs located along the Indian side, acting as a main divide between the Atlantic and the Indian Oceans. First uplift occurred in the east at ~92 Ma, with a fast flexuration of the Indian margins. This initiates a paroxysm of the erosion (90-80 Ma) with the growth of a large delta along the Atlantic margin (Orange delta). Deformation migrated progressively westward and resulted on the growth of the Atlantic marginal bulge between 81 and 70 Ma. Most of the present-day relief was probably created at this time. This is supported by the decrease of the sedimentary flux which suggests a reorganisation of the interior drainage pattern ; 70-30 Ma (Uppermost Cretaceous-Paleogene): most of the relief is fossilized and weathered - relative tectonic quiescence ; 0-15 Ma (Oligocene-Early Miocene): second period of the South African Plateau uplift. Most of the deformation took place along the Indian side of the Plateau (strike flexure) feeding the Zambezi, Limpopo and Tugela deltas ; since at least Middle Miocene times, all those reliefs have been fossilized, with very low erosion rates (x1m/Ma), in response to the major aridification of southern Africa.
152

Habiter la ville sans droits : les travailleurs migrants dans les marges de Beyrouth (Liban) / Dwelling the city without rights

Dahdah, Assaf 03 December 2015 (has links)
Cette thèse de géographie sociale et radicale traite des rapports de domination à Beyrouth à travers l’habiter des travailleurs migrants dans les marges urbaines. Population aux ressources faibles et stigmatisée dans une ville fragmentée, les migrants originaires d’Afrique et d’Asie tentent malgré tout de prendre place dans la capitale libanaise. L’approche micro et croisée de lieux – Bourj Hammoud, Karm al-Zeitoun, Sabra et le camp palestinien de Mar Elias – et de leurs habitants montre l’imbrication des temps longs et courts des migrations, les frottements entre les logiques communautaires et mercantiles des établis et celles plus chaotiques des nouveaux venus. Si les marges beyrouthines constituent des « sas » d’insertion où s’enchevêtrent des dynamiques multi-scalaires, elles n’en restent pas moins des espaces d’exclusion et de pauvreté animées et fragilisées par les injustices sociales et les inégalités citoyennes. À travers l’étude des mobilités, du système locatif et de l’accès au logement, et du dispositif commercial ethnique, ce travail, basé sur une enquête qui mobilise l’observation des espaces, les entretiens réalisés avec les différents acteurs et l’outil vidéo, met en exergue les réalités complexes de ces marges urbaines. Il expose leurs transformations contemporaines, mais également les tensions locales générées par une crise socio-politique libanaise et moyen-orientale, révélées ici via le prisme de la mondialisation migratoire. In fine, cette thèse interroge de manière à la fois décentrée, et ordinaire un ordre urbain généralement apprécié sous l’angle du confessionnalisme politique et questionne en miroir la nature du régime politique libanais. / This thesis of social and radical geography focuses on power relations in Beirut through an analysis of the housing of migrant workers in the outskirts of the city. As a population with few resources and subject to stigmatization, African and Asian migrant workers nevertheless try to find lodgings within the capital. Taking a micro and intersected approach to the study of specific neighbourhoods (Bourj Hammoud, Karm al-Zeitoun, Sabra and the Palestinian camp of Mar Elias) and their inhabitants reveals the interweaving of long- and short-term migrant groups and frictions between the commercial interests of the existing community and those, admittedly more chaotic, of newcomers. While the outskirts of Beirut have now become a transition zone, spaces in which new plural dynamics are emerging at various levels, they are also spaces of exclusion and poverty, where the coexistence of these communities is constantly being challenged and weakened by instances of social injustice and civil inequality. This study of mobility, rental accommodation, access to housing and the ethnic economy draws on observations of spaces, interviews with actors and video films and provides insights into the complex realities within a marginal urban population. It also highlights contemporary transformations and local tensions caused by the social, economic and political crisis in Lebanon and the Middle East through the prism of international migration. In fine, this thesis takes a decentralized and ordinary approach to analysing an urban structure usually observed from the perspective of confessional politics and, at the same time, questions the overall Lebanese political regime.
153

Vesnické osídlení v zázemí vrcholně a pozdně středověké Prahy. Sídelně-historický vývoj a zemědělství v příměstských oblastech / Rural settlements in the hinterland of Prague in high and late middle ages. Settlement and agriculture development in suburban regions

Beránek, Michal January 2013 (has links)
Master's thesis deals with the micro-region Klánovice's forest and its surroundings on the eastern edge of the City Prague. This area has not been given comprehensive attention yet. The findings are based on a critical review of the humble written and archaeological sources relating to the concerned area. In addition, was made, analysis of archaeological excavation, which was carried out on the deserted village Hol and also geophysical survey from the same site. Based on the lessons learned to better classify and discuss the role of this area in the hinterland of high medieval Prague. Keywords: deserted village, Klánovice forest, Hol, geophysical survey, ceramics, agricultural margins land, high middle ages
154

Voces de la periferia : Un estudio sobre la plurivocidad de la narrativa en la novela Cometierra de Dolores Reyes / Voices from the periphery : A study on the plurivocity of the narrative in the novel Cometierra by Dolores Reyes

Hessel, Frida January 2022 (has links)
En este trabajo hemos investigado cómo las múltiples voces en la novela Cometierra (2019), escrita por Dolores Reyes (Argentina, 1978), visibilizan situaciones de violencia y vulnerabilidad a las que están expuestas los habitantes en la periferia urbana latinoamericana, especialmente las mujeres. Entendemos por periferia urbana el espacio geográfico que rodea a una gran metrópolis, históricamente concebida como un lugar de marginalidad y miseria y cuyos habitantes suelen ser estigmatizados y juzgados en relatos mediáticos construidos por personas ajenas a ese mundo. Para analizar la pluralidad de voces, organizadas en torno a la voz de la protagonista, usamos los conceptos de “polifonía” y “dialogismo” de Bajtín (2005). Consideramos que la forma en la que se representa a los personajes femeninos, así como la profundidad y variadas perspectivas que aporta la plurivocidad al relato, contribuyen a la re-significación de la mujer en el espacio periférico, en tanto que se le otorga una voz para contar su propia historia. Sostenemos que la novela se aleja de la concepción reduccionista de la periferia entendida como un lugar de pobreza, para dotarla con una multiplicidad de sentidos y que contribuye a romper con estereotipos construidos en torno a sus habitantes.
155

Дијагностичка вредност мобилне дигиталне радиографије у процени позитивности ресекционих хируршких маргина код карцинома дојке / Dijagnostička vrednost mobilne digitalne radiografije u proceni pozitivnosti resekcionih hirurških margina kod karcinoma dojke / Diagnostic value of mobile digital specimen radiography in evaluation of breast cancer resection margins

Ranisavljević Milan 07 September 2020 (has links)
<p>Karcinom dojke predstavlja najče&scaron;ću malignu neoplazmu među ženskom populacijom, a po&scaron;tedna terapija dojke, preferirani je model lečenja bolesnica u ranom stadijumu bolesti. Smatra se da je optimalna hirur&scaron;ka resekciona margina 2 mm. Opisano je mnogo metoda koje služe za intraoperativnu proveru suficijentnosti resekcione hirur&scaron;ke margine i sve one imaju svoje prednosti i mane. Ciljevi ove studije bili su da se utvrdi, da li postoji statistički značajna razlika u određivanju &scaron;irine negativne resekcione hirur&scaron;ke margine izražene u milimetrima pri operacijama karcinoma dojke upotrebom palpatorne metode i intraoperativne mobilne radiografije, poređenjem nalaza merenja hiruga sa većim i manjim iskustvom u hirurgiji karcinoma dojke kao i nalaza radiologa u odnosu na patohistolo&scaron;ku ex tempore analizu. Istraživanje je sprovedeno kao retrospektivno&ndash;prospektivna studija na Klinici za operativnu onkologiju, Instituta za onkologiju Vojvodine i obuhvatilo je 150 bolesnica kod kojih je preoperativno dijagnostikovan karcinom dojke. Kriterijum za uključenje u studiju bilo je izvođenje po&scaron;tedne operacije dojke sa ili bez disekcije ipsilaterale aksile, dok su iz studije isključene bolesnice kod kojih nije bilo moguće izvesti po&scaron;tednu operaciju dojke, one sa radiolo&scaron;ki potvrđenom diseminovanom bole&scaron;ću, kao i bolesnice koje su ranije operisane zbog karcinoma iste dojke. Kod svih 150 ekstirpiranih karcinoma dojke urađena je procena &scaron;irine resekcione hirur&scaron;ke margine intraoperativno palpatornom metodom, zatim na aparatu za mobilnu digitalnu radiografiju, te radiogram analiziran od strane iskusnog i manje iskusnog hiruga u hirurgiji karcinoma dojke, kao i radiologa te upoređen sa nalazom ex tempore patohistolo&scaron;ke analize. Definitivna &scaron;irina resekcione hirur&scaron;ke margine potvrđena je na parafinskim patohistolo&scaron;kim preparatima. Srednja vrednost praćenja bolesnica, postoperativno, iznosila je 100,97 nedelja. Najveći broj bolesnica pripadao je starijoj životnoj dobi (56,67%). Preoperativna lokalizacija klinički nepalpabilnih tumora u dojci urađena je kod 52 (34,67%) bolesnice. Najče&scaron;će se tumor prezentovao kao solitarni fokus sa okolnim ognji&scaron;tima in situ karcinoma (72, 48%), dok je najče&scaron;ći histolo&scaron;ki subtip bio duktalni invazivni karcinom dojke (112 (74,67%)). Najveći broj operacija dojke okarakterisan je kao kvadrantektomija (85 (56,67)), dok je najučestalija operacija aksile bilo određivanje limfnog čvora stražara (119 (79,33%). Analizom rada aparata za mobilnu digitalnu radiografiju do&scaron;li smo do saznanja da nema statistički značajne razlike u oceni kvaliteta radiograma i &scaron;irine resekcione hirur&scaron;ke margine merene na aparatu za mobilnu digitalnu radiografiju između iskusnog hirurga i radiologa. Statistički značajna razlika nije uočena ni pri merenju &scaron;irine resekcione hirur&scaron;ke margine izražene u milimetrima na aparatu za mobilnu digitalnu radiografiju od strane iskusnog hirurga i radiologa u odnosu na ex tempore patohistolo&scaron;ku analizu, dok je ista uočena nakon definitivne patohistolo&scaron;ke analize. &Scaron;ansa doresekcije tkiva dojke nakon merenja na aparatu za mobilnu digitalnu radiografiju je 1,4 puta veća nego nakon patohistolo&scaron;ke ex tempore analize. Lokalni recidiv javio se kod jedne pacijentkinje tokom perioda praćenja. Ne postoji statistički značajna razlika u određivanju &scaron;irine resekcione hirur&scaron;ke margine izražene u milimetrima upotrebom aparata za mobilnu digitalnu radiografiju od strane iskusnog hirurga i radiologa u odnosu na patohistolo&scaron;ku ex tempore analizu, dok ista postoji nakon analize radiograma od strane manje iskusnog hirurga. Palpatorna metoda se ne može smatrati sigurnom metodom u određivanju &scaron;irine hirur&scaron;ke resekcione margine. Ne postoji statistički značajna razlika u broju doresekcije tkiva dojke između hirurga sa različitim hirur&scaron;kim iskustvom.</p> / <p>Breast cancer is the most common malignant neoplasm in the female population, and conservative breast therapy is the preferred treatment model for patients in early stages of the disease. The optimal surgical resection margin, from healthy breast tissue around the primary tumor is 2 mm. Many methods have been described that serve to check the resection margin during breast conservative surgery and all of them have their advantages and disadvantages. The aim of this study was to determine whether there was a statistically significant difference in the determination of the width of the negative resection margin expressed in millimeters in breast cancer surgery using palpatory method and intraoperative mobile specimen radiography, comparing the findings of measuring of surgeons with greater and lesser experience in breast cancer surgery as well as the findings of the radiologist in relation to histopathological ex tempore and definitive histopathological analysis. The study was conducted as a retrospective - prospective study at the Clinic for Operative Oncology, Oncology Institute of Vojvodina and included 150 patients who were preoperatively diagnosed with breast cancer. The criterion for inclusion in the study was the opportunity to perform breast conservative surgery with or without complete axillary lymph node dissection. Patients that were treated with breast amputation, those with radiological confirmed disseminated disease, as well as patients previously operated from cancer were excluded from the study. For all 150 extirpated breast cancers, an estimate of the width of the resection surgical margin was performed intraoperatively with a palpatory method, followed by measuring on device for mobile specimen digital radiography, and a radiogram was analyzed by an experienced and less experienced surgeon in breast cancer surgery, as well as by a radiologist and compared with an ex tempore histopathological analysis. The definitive width of the resection surgical margin was confirmed on histopathological preparations. The mean follow-up, postoperatively, was 100.97 weeks. The majority of patients belonged to the elderly age (56.67%). Preoperative localization of clinically impalpable breast tumors was performed in 52 (34.67%) patients. Most often the tumor was presented as a solitary focus with surrounding foci of in situ cancer (72, 48%), while the most common histological subtype was invasive ductal breast cancer (112 (74.67%)). The majority of breast operations were characterized like quadrantectomy (85 (56.67)), while the most frequent axillary surgery was the determination of the sentinel lymph node (119 (79.33%). No significant difference was observed in the evaluation of radiography quality and the width of the resection surgical margin measured on the mobile digital radiography device between the experienced surgeon and the radiologist. No statistically significant difference was observed in the measurement of the width of the resection surgical margin expressed in millimeters on the mobile digital radiography device by the experienced surgeon and radiologist versus ex tempore histopathological analysis, while the statistical difference was observed after definite histopathological analysis. The chance of breast tissue reexcision after measurement on a mobile digital radiography device is 1.4 times higher than after histopathological ex tempore analysis. Local relapse occurred in one patient during the follow-up period. There is no statistically significant difference in the determination of the width of the resection surgical margin expressed in millimeters using a mobile digital radiography device by an experienced surgeon in breast cancer surgery and radiologist with respect to histopathological ex tempore analysis. However, the statistical difference exists after radiogram analysis by a less experienced surgeon. The palpatory method cannot be considered as a safe method in determining the width of a surgical resection margin. There is no statistically significant difference in the number of breast tissue additional resections between surgeons with different surgical experience.</p>
156

Explicit robust constrained control for linear systems : analysis, implementation and design based on optimization / Commande robuste, explicite pour des systemes linéaires : analyse, implémentation et synthèse fondée sur l'optimalité

Nguyen, Ngoc Anh 26 November 2015 (has links)
Les lois de commande affines par morceaux ont attiré une grande attention de la communauté d'automatique de contrôle grâce à leur pertinence pour des systèmes contraints, systèmes hybrides; également pour l'approximation de commandes nonlinéaires. Pourtant, leur mise en oeuvre est soumise à quelques difficultés. Motivé par l'intérêt à cette classe de commandes, cette thèse porte sur leur analyse, mise en oeuvre et synthèse.La première partie de cette thèse a pour but le calcul de la marge de robustesse et de la marge de fragilité pour une loi de commande affine par morceaux donnée et un système linéaire discret. Plus précisément, la marge de robustesse est définie comme l'ensemble des systèmes linéaires à paramètres variants que la loi de commande donnée garde les trajectoires dans de la région faisable. D'ailleurs, la marge de fragilité comprend toutes les variations des coefficients de la commande donnée telle que l'invariance de la région faisable soit encore garantie. Il est montré que si la région faisable donnée est un polytope, ces marges sont aussi des polytopes.La deuxième partie de ce manuscrit est consacrée au problème de l'optimalité inverse pour la classe des fonctions affines par morceaux. C'est-à-dire, l'objective est de définir un problème d'optimisation pour lequel la solution optimale est équivalente à la fonction affine par morceaux donnée. La méthodologie est fondée sur le convex lifting, i.e., un variable auxiliaire, scalaire, qui permet de définir un ensemble convex à partir de la partition d'état de la fonction affine par morceaux donnée. Il est montré que si la fonction affine par morceaux donnée est continue, la solution optimale de ce problème redéfini sera unique. Par contre, si la continuité n'est pas satisfaite, cette fonction affine par morceaux sera une solution optimale parmi les autres du problème redéfini.En ce qui concerne l’application dans la commande prédictive, il sera montré que n'importe quelle loi de commande affine par morceaux continue peut être obtenue par un autre problème de commande prédictive avec l'horizon de prédiction au plus égal à 2. A côté de cet aspect théorique, ce résultat sera utile pour faciliter la mise en oeuvre des lois de commandes affines par morceaux en évitant l'enregistrement de la partition de l'espace d'état. Dans la dernière partie de ce rapport, une famille de convex liftings servira comme des fonctions de Lyapunov. En conséquence, ce "convex lifting" sera déployé pour synthétiser des lois de commande robustes pour des systèmes linéaires incertains, également en présence de perturbations additives bornées. Des lois implicites et explicites seront obtenues en même temps. Cette méthode permet de garantir la faisabilité récursive et la stabilité robuste. Cependant, cette fonction de Lyapunov est limitée à l'ensemble λ −contractive maximal avec une constante scalaire 0 ≤ λ < 1 qui est plus petit que l'ensemble contrôlable maximal. Pour cette raison, une extension de cette méthode pour l'ensemble contrôlable de N − pas, sera présentée. Cette méthode est fondée sur des convex liftings en cascade où une variable auxiliaire sera utilisée pour servir comme une fonction de Lyapunov. Plus précisément, cette variable est non-négative, strictement décroissante pour les N premiers pas et égale toujours à 0 − après. Par conséquent, la stabilité robuste est garantie. / Piecewise affine (PWA) feedback control laws have received significant attention due to their relevance for the control of constrained systems, hybrid systems; equally for the approximation of nonlinear control. However, they are associated with serious implementation issues. Motivated from the interest in this class of particular controllers, this thesis is mostly related to their analysis and design.The first part of this thesis aims to compute the robustness and fragility margins for a given PWA control law and a linear discrete-time system. More precisely, the robustness margin is defined as the set of linear time-varying systems such that the given PWA control law keeps the trajectories inside a given feasible set. On a different perspective, the fragility margin contains all the admissible variations of the control law coefficients such that the positive invariance of the given feasible set is still guaranteed. It will be shown that if the given feasible set is a polytope, then so are these robustness/fragility margins.The second part of this thesis focuses on inverse optimality problem for the class of PWA controllers. Namely, the goal is to construct an optimization problem whose optimal solution is equivalent to the given PWA function. The methodology is based on emph convex lifting: an auxiliary 1− dimensional variable which enhances the convexity characterization into recovered optimization problem. Accordingly, if the given PWA function is continuous, the optimal solution to this reconstructed optimization problem will be shown to be unique. Otherwise, if the continuity of this given PWA function is not fulfilled, this function will be shown to be one optimal solution to the recovered problem.In view of applications in linear model predictive control (MPC), it will be shown that any continuous PWA control law can be obtained by a linear MPC problem with the prediction horizon at most equal to 2 prediction steps. Aside from the theoretical meaning, this result can also be of help to facilitate implementation of PWA control laws by avoiding storing state space partition. Another utility of convex liftings will be shown in the last part of this thesis to be a control Lyapunov function. Accordingly, this convex lifting will be deployed in the so-called robust control design based on convex liftings for linear system affected by bounded additive disturbances and polytopic uncertainties. Both implicit and explicit controllers can be obtained. This method can also guarantee the recursive feasibility and robust stability. However, this control Lyapunov function is only defined over the maximal λ −contractive set for a given 0 ≤ λ < 1 which is known to be smaller than the maximal controllable set. Therefore, an extension of the above method to the N-steps controllable set will be presented. This method is based on a cascade of convex liftings where an auxiliary variable will be used to emulate a Lyapunov function. Namely, this variable will be shown to be non-negative, to strictly decrease for N first steps and to stay at 0 afterwards. Accordingly, robust stability is sought.
157

Polarimetric Stokes Imaging for the Detection of Tumor Margins and Segmentation

Narayan, Chaya January 2013 (has links)
No description available.
158

Les jeux du dissemblable : folie, marge et féminin en littérature haïtienne contemporaine

Martelly, Stéphane 02 1900 (has links)
Depuis la deuxième moitié du XXe siècle et le tournant du millénaire, pourquoi se multiplient des figures de la folie et du féminin dans le paysage littéraire haïtien ? En remarquant les grandes tendances qui font coïncider l’expression de la catastrophe, de la défaite du sens et l’apparition de personnages et de figures féminins majeurs dans des œuvres de tous genres, mon interrogation porte sur la folie, la marge et le féminin dans la littérature haïtienne contemporaine en tant qu’expressions concourantes de la dissemblance. Je me penche ainsi, dans des œuvres marquantes, sur le jeu rhétorique des postures de la dissemblance et la manière dont elles pointent depuis le texte vers un au-delà de l’œuvre, soit ce qui en elle indique l’ «espace ménagé» de sa propre faillite ainsi que le travail de la lecture et de la création. Pour cela, il a fallu, à partir des limites (de l’œuvre, de la norme), construire une réflexion capable d’aménager aussi l’espace de sa propre contestation. Dans le premier chapitre, à partir du récit fondateur « Folie », de Marie Chauvet, je pose le problème de la folie en me penchant sur les configurations inaugurales qui me semblent mettre la scène du littéraire contemporain haïtien. J’en profite pour préciser l’approche rhétorique qui me permettra d’aborder les textes littéraires, tout en réfléchissant sur les enjeux théoriques posés par une lecture de la folie comme absence d’œuvre. En m’appuyant sur Chauvet et sur les travaux de Felman, je définis les modalités d’une lecture impliquée. Dans le second chapitre, je brosse un portrait complexe du contemporain haïtien, tel qu’il est médié et rendu à travers les « anthologies » essentielles de Davertige et de Frankétienne. Ces deux œuvres sont l’occasion de poursuivre une interrogation sur les limites en remarquant les formes et les enjeux mobilisés dans le littéraire par les élaborations de la marge, de la mémoire traumatique et de la folie. Une telle approche est aussi l’occasion d’une réflexion de fond sur le contemporain haïtien, abordé d’emblée comme panorama et comme problème façonné et façonnant des sujets d’écriture. Enfin, dans le troisième chapitre, je me penche sur les filiations larvées qui permettent aux configurations précédemment décrites de persister, alors que le féminin, comme dissemblance, négocie sa place du côté de la marge ou de la folie, dans les textes plus récents de Jan Dominique et de Lyonel Trouillot. Les réflexions que je propose sur les destinations, sur l’œuvre impossible ou absente (Foucault) me permettent de distinguer les processus de différenciation spécifiques de la marge et de la folie, mais surtout d’apercevoir, au cœur du texte littéraire, la folie comme l’absence essentielle où se risque et se joue la création. Le dissemblable devient alors cet objet fuyant d’une lecture impliquée dans laquelle, le regard critique s’adossant à une écriture littéraire chargée d’en interrompre systématiquement le flux, constitue en effet ce « moment insolite de la théorie» (Felman), qui, dévoilant son propre jeu rhétorique, maintient la théorie en échec tout en la faisant parler. / Since the second half of the twentieth century and the turn of the millennium, why have representations of madness and the feminine proliferated in the Haitian literary landscape? Whilst reflecting on the broad tendencies that brought together the expression of catastrophe, the unravelling of meaning and the emergence of important feminine characters and figures in works of all genres, I will question madness, margins and the feminine in contemporary Haitian literature as concurring expressions of dissimilarity. Examining Haitian literary works, I want to propose a reading on the rhetoric postures and performances of dissimilarity and the manner in which they point towards an outsideness of literature: the unspeakable “thing” that signals – from within – the (im)possibility of the text, the (im)possibility of reading and creation. To achieve this purpose, I have chosen to construct a reading on limits (of the text, of the norm) that also considers its own contestation. Chapter one is built around the novel « Folie » by Marie Chauvet. It addresses the topic and rhetoric of madness while taking note of important aesthetic configurations that I suggest set the stage for contemporary Haitian literature. I also address methodological problems arising when “reading” madness as “absence d’œuvre” (Foucault). Intersecting Chauvet’s writing with the theoretical contributions of Felman, I specify my approach as a compromised or involved reading. In the second chapter, I paint the portrait of the contemporary Haitian general context using the essential anthologies of Davertige and Frankétienne. These two works allow me to address the notion of “limits” while considering the forms and issues created by the fabrications of margins, traumatic memory and madness. I therefore approach the contemporary Haitian context as a complex panorama and as a problem, both shaped by and shaping literary subjectivities. Finally, in the third chapter, analysing the more recent texts of Jan Dominique and Lyonel Trouillot, I reflect on hidden genealogies that perpetuate previously identified configurations when the feminine, as dissimilarity, negotiate a place on the side of margins or madness. The reflection I propose on destinations, the absent or impossible oeuvre allows me to differentiate the specificities of margins and madness, and most importantly, to glimpse, while reading the literary text, at the essential absence where creation risks itself. Thus, dissimilarity becomes the fleeting object of my compromised reading. A critical reading, which compromises itself with creative writing, in a decisive attempt to subvert theory, forcing it to unveil its own rhetorical play, to reveal its possible failure while making it eloquent.
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Le rôle du comportement des banques dans la libéralisation financière : le cas du Malawi, 1987-1999 / The role of the behavior of banks in financial liberalization : the case of Malawi, 1987-1999

Mlachila, Montfort 26 June 2013 (has links)
Notre étude a été inspirée par l’observation que malgré les efforts considérables en matière de la libéralisation financière au Malawi à partir de la fin des années 1980, les résultats apparents étaient plutôt médiocres, notamment en ce qui concerne la persistance de marges d’intermédiation (spreads) élevés. L’objectif central de notre travail est d’essayer d’élucider pourquoi. Notre hypothèse centrale est que si l’on ne tient pas compte du comportement des banques en matière de leurs réactions vis-à-vis de leurs incitations et leurs contraintes dans la mise en place de la politique de la libéralisation financière, on est voué à la déception en matière des résultats. L’étude montre que dans une situation économique caractérisée par une instabilité macroéconomique, les banques ont moins d’incitations à être plus efficientes du point de vue macroéconomique, c’est à dire en agissant dans la direction de l’approfondissement financier et de l’octroi de crédit au secteur privé. Bien au contraire, tout en agissant de manière rationnelle, elles sont tentées de rechercher des rentes faciles et sûres qui viennent du financement des déficits publics. Ceci leur permet d’accomplir deux objectifs : maximiser leur profit et minimiser leur risque-crédit, notamment en repoussant les « contraintes externes » imposées par les conditions économiques -notamment les taux d’escompte élevées- à leur clients à travers la combinaison d’une augmentation de taux d'intérêt sur les prêts et d’une faible augmentation des taux d'intérêt sur les dépôts. / This study was inspired by the observation that despite the considerable efforts in financialliberalization in Malawi from the late 1980s, the apparent results were mediocre, especially with regardto the persistence of high intermediation margins (spreads). The central objective of this study is to tryto investigate why. The key hypothesis is that if one does not take into account of bank behavior interms of how banks react vis-à-vis their incentives and constraints during the process of financialliberalization, the results are likely to be disappointing. The study shows that in an economic situationcharacterized by macroeconomic instability, banks have less incentive to be more efficient from amacroeconomic perspective, i.e., by enhancing financial deepening through higher credit to the privatesector. On the contrary, while acting rationally, they are tempted to look for easy and safe returnscoming from financing government deficits. This allows them to accomplish two objectives: maximizingprofit and minimizing credit risk, notably by pushing the "external constraints" imposed by economicconditions - including high rediscount rates- to their customers through a combination of an increasein interest rates on loans and a smaller increase in interest rates on deposits.Keywords: financial liberalization, bank behavior, intermediation margins, bank
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Arcabouço crustal profundo da parte Centro-Norte da margem de Angola: modelo de afinamento e contato de crostas / Deep crustal framework of North-Central margin of Angola: a model for thinning and crustal transition

Luiz Carlos Lucena Empinotti 27 October 2011 (has links)
Este trabalho tem como objetivo a identificação de feições que permitam (1) a construção do arcabouço crustal profundo e da porção superior do manto em parte da Costa de Angola, (2) a comparação deste arcabouço com o embasamento aflorante e (3) a tentativa de adequar estes resultados aos modelos de ruptura continental já publicados. Para alcançar estes objetivos foi feita a interpretação de cinco linhas sísmicas de reflexão profundas (25 Km de profundidade) na costa de Angola, nas Bacias de Kwanza e Baixo Congo, adquiridas pela ION-GXT. As feições identificadas na sísmica de reflexão auxiliaram na determinação dos limites da crosta continental superior e inferior, no reconhecimento das camadas que compõem a crosta oceânica e na identificação da Descontinuidade de Mohorovicic (que marca o limite entre crosta e manto). A interpretação sísmica associada a dados da literatura (que proporcionaram valores de densidade para os pacotes identificados na interpretação sísmica) permitiram a realização de uma modelagem gravimétrica que foi comparada ao dado gravimétrico adquirido durante a aquisição sísmica. A modelagem gravimétrica serviu para validar a interpretação sísmica, atuando como um controle de qualidade para a interpretação. Caso a anomalia gravimétrica gerada pela modelagem não estivesse de acordo com a anomalia medida, a interpretação sísmica era revista na tentativa de um melhor ajuste entre o resultado modelado e o medido. Este ajuste, no entanto, sempre foi feito honrando os refletores que estavam bem marcados na sísmica. Somado a isto, ainda foi utilizado o dado magnético adquirido no campo, no auxilio da interpretação. O arcabouço crustal obtido com a utilização deste método permitiu a comparação dos resultados da interpretação com os modelos de evolução de margens passivas existentes na literatura, mostrando muitos pontos em comum aos modelos que defendem a possibilidade de ocorrência de manto exumado em margens passivas pobres em magmatismo. A interpretação final destes dados mostrou um domínio proximal marcado por uma crosta continental espessa porém pouco afinada em contato com um domínio distal marcado por uma crosta continental muito afinada (crosta hiper-estirada) e, em direção ao centro do oceano, uma região em que ocorre a exumação do manto. A passagem do domínio proximal para o distal ocorre de forma rápida em uma região denominada Zona de Estrangulamento. À oeste do manto exumado é possível identificar a crosta oceânica. O cruzamento dos resultados obtidos neste trabalho com dados do embasamento aflorante no continente africano sugerem um controle do deste nos valores finais de afinamento da crosta continental sob a bacia e nas regiões de manto exumado. Trabalhos recentes realizados na costa de Angola e do Brasil mostram feições semelhantes às identificadas nesta dissertação. / The main objectives of this study are to identify features on seismic data that allow (1) the building of a deep crustal framework and of the upper portion of the mantle, in part of the Angolan margin; (2) to compare this framework with the adjacent outcropping basement of the African continent and; (3) to try to fit these results to the published continental breakup models. In order to achieve these objectives, five deep reflection seismic lines (25 km of depth) situated in the in Kwanza and Lower Congo Basins on the passive margin of Angola were interpreted. The features identified on seismic were useful to recognize the tripartite division that caracterize the oceanic crust and in defining the Mohorovicic Discontinuity (that represents the limit between crust and mantle). The seismic interpretation associated with the data obtained from the scientific literature (that provided density values for the packages identified on seismic interpretation) allowed the establishment of a gravity modeling that was compared to the gravity data acquired during the seismic acquisition. The gravity model was useful to validate the seismic interpretation, acting as a quality control of the latter. In case of the gravity anomaly generated by the modeling not being in accordance with the measured anomaly, the seismic interpretation was revised in order to obtain a better adjustment between the modeled and the measured result. This adjustment, however, was always done honoring the reflectors that were clearly positioned on seismic. In addition, the magnetic data acquired on the field was used to help on interpretation. The crustal framework obtained by the methodology described above was compared with the passive margin evolution models found on scientific literature, showing some points in common with the models that postulate the occurrence of exhumed mantle in magma-poor passive margins. The final interpretation of these data showed the existence of a proximal domain characterized by a thick continental crust slightly thinned in contact with a distal domain marked by a hyper-extended continental crust. Oceanwards there is a region where the exhumation of the mantle took place. The passage of the proximal to the distal domain is abrupt, here termed as a Necking Zone. Oceanic crust is identified to the west of exhumed mantle. The comparison of the results obtained in this study with data from the outcropping basement on the African continent suggests a basement control on the vales of continental crust thinning attained under the basins and on the regions of exhumed mantle. Recent works done on the Angolan and Brazilian margins show features similar to the ones identified on this dissertation.

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