La dérive de pulvérisation peut être mesurée au champ ou en soufflerie. Paradoxalement, les tests au champ sont sujets à de grandes variations dues aux conditions atmosphériques mais peuvent être plus facilement réalisés contrairement aux tests en soufflerie. Ainsi les principaux modèles de dérive sont basés sur des mesures au champ alors que peu de modèles s’inspirent de mesures en soufflerie. L’objectif de ce travail a été de définir un ou des descripteurs de la dérive sur la base de l’analyse de courbes de dépôts obtenues dans la soufflerie d’IRSTEA Montpellier. Par rapport aux souffleries existantes, un protocole d’exposition de longue durée a été utilisé avec une forte densité d’échantillonnage. Un plan expérimental comprenant 99 modalités a été réalisé en tenant compte de différents types de buses (FF, AI, AI Twin jet), différente hauteurs de rampe de 40 à 80cm, différentes positions de la rampe (frontale, latérale et angles intermédiaires) et différentes vitesses de vent entre 2 et 7.5m s-1. Les résultats ont montré que le taux de dérive à 5m sous le vent (DR5) correspond au descripteur le plus robuste si l’on tient compte du large spectre de paramètres et de réglages. Des modèles de premier ordre ont été définis pour l’expression de l’effet de la vitesse du vent ainsi que de la hauteur de rampe selon le temps de vol des gouttes (ToF). Ainsi il est possible de comparer des résultats issus de conditions expérimentales différentes et de simuler l’effet de la vitesse du vent et la hauteur de la rampe pour un type donné de buse. Des mesures in situ de taille de gouttes ont confirmé la pertinence du temps de vol comme base de l’expression des résultats. / Spray drift might be measured either infield or in a wind tunnel through specific sampling strategies. Paradoxically field tests are subjected to a high variability due to the atmospheric conditions but can be more easily conducted in the absence of a wind tunnel. The result is that most of spray drift models are based on infield measurements. Conversely very few models were developed on the basis of wind tunnel measurements. The objective of this work was to define spray drift descriptors from the analysis of drift curves in IRSTEA wind tunnel. Compared to the majority of existing wind tunnels, a long duration exposure protocol was applied with a high sampling density. A large experimental plan of 99 modalities were conducted including nozzle types (FF, AI, AI Twin jet), boom heights from 40 to 80cm, boom positions (frontal, lateral, and intermediate angles) and wind velocities from 2 to 7.5ms-1. Results showed that the drift ratio at 5m (DR5) was the most robust drift indicator considering the wide range of parameters and operations conditions (wind velocity, boom height). First order models were drawn for the expression of the effect of the wind velocity and the boom height according to the droplet time of flight (ToF). As a result it was possible to compare data from different experimental conditions and to simulate the effect of the wind velocity and the boom height for a given type of nozzle. In situ droplet size measurements confirmed the relevance of the time of flight expression.

This dissertation proposes stress testing of a bank’s corporate credit portfolio in a Basel Internal Ratings Based (IRB) framework, using publicly available macroeconomic variables. Corporate insolvencies are used to derive a credit cycle index, which is linked to macroeconomic variables through a multiple regression model. Probability of default (PD) and loss given default (LGD) that are conditional on the worst state of the credit cycle are derived from through-the-cycle PDs and LGDs. These are then used as stressed inputs into the Basel regulatory and Economic capital calculation for credit risk. Contrary to the usual expert judgement stress testing approaches, where management apply their subjective view to stress the portfolio, this approach allows macroeconomic variables to guide the severity of selected stress testing scenarios. The result is a robust stress testing framework using Rösch and Scheule (2008) conditional LGD that is correlated to the stressed PD. The downturn LGD used here is an alternative to the widely used Federal Reserve downturn LGD which assumes no correlation between PDs and LGDs. / Dissertation (MSc)--University of Pretoria, 2014. / gm2014 / Mathematics and Applied Mathematics / Unrestricted

This paper will talk about the videos and sculptural installation in my thesis exhibition. Shooting videos outside of the studio developed into a project overarching any individual video or its particular signs. Thus, this paper will focus on the video project with examples that follow a timeline of development, rather than the actual 6 videos on display in the exhibit. The two-part sculpture "Deer in the Headlights" is created in the context of these videos, and coexists with them in a specific architectural space. This space, as well as the clichéd meaning of the deer's gaze, have a relation to the title of the show.

The photographic series Ideal Cities that I started in 2011 is inspired by the conflict between my idea of the “west” and my evolving experience in the United States. What struck me was the popularity of what I see as model experience – a spatial experience controlled by the Spectacle. In the terms of the Situationist International and its most prominent figure Guy Debord, the Spectacle is the collapse of reality into the streams of images, products and activities sanctioned by centralized monopolist business or state bureaucracy. Thus, personal experience is replaced with preconceived notions, which control the way people perceive and understand their surroundings.

Text in English and Arabic / In pre-colonial Africa, the Southwestern Sahara which includes Mauritania, Mali and Senegal belonged to what was then referred to as the Sudan and extended from the Atlantic seaboard to the Red Sea. The advent of Islam and the Arabic language to West Africa in the 11th century heralded an intellectual marathon whose literary output still fascinates us today. At a time when Europe was emerging from the dark ages and Africa was for most Europeans a terra incognita, indigenous African scholars were composing treatises as diverse as mathematics, agriculture and the Islamic sciences. A twentieth century Mauritanian, Arabic monograph, Irshād al- Muqallidīn ʿinda ikhtilāf al-Mujtahidīn1, written circa 1910/1332, by a yet unknown Mauritanian jurist of the Mālikī School, Bāba bin al-Shaykh Sīdī al- Shinqīṭī al-Ntishā-ī (d.1920/1342), a member of the muchacclaimed Shinqīṭī fraternity of scholars, is a fine example of African literary accomplishment. This manuscript hereinafter referred to as the Irshād, is written within the legal framework of Islamic jurisprudence (usūl al-fiqh). A science that relies for the most part on the intellectual and interpretive competence of the independent jurist, or mujtahid, in the application of the methodologies employed in the extraction of legal norms from the primary sources of the sharīʿah. The subject matter of the Irshād deals with the question of juristic differences. Juristic differences invariably arise when a mujtahid exercises his academic freedom to clarify or resolve conundrums in the law and to postulate legal norms. Other independent jurists (mujtahidūn) may posit different legal norms because of the exercise of their individual interpretive skills. These differences, when they are deemed juristically irreconcilable, are called ikhtilāfāt (pl. of ikhtilāf). The author of the Irshād explores a corollary of the ikhtilāf narrative and posits the hypothesis that there ought not to be ikhtilāf in the sharīʿah. The proposed research will comprise an annotated translation of the monograph followed by a synopsis and commentary on its dominant themes. / Religious Studies and Arabic / D. Litt. et Phil. (Islamic Studies)