Researchers in the field of Swahili studies have noted the need for a comprehensive, detailed catalogue of the Swahili manuscripts at the School of Oriental and African Studies (SOAS, University of London). They have had occasion to make this recommendation in print (see, for example, Omar and Frankl 1994 and Frankl 1999) and - presumably many more times, and to no specified audience - in life, as they pored over unitemised or inaccurately labelled files of eminent scholars in the field. It is precisely this need for a comprehensive, widely accessible catalogue that the Swahili Manuscripts Project at SOAS was established, in October 2001, to address. In this article, the present authors undertake to describe the catalogue being created and to discuss problems they have encountered and observations they have had opportunity to make in the course of their work.

Researchers in the field of Swahili studies have noted the need for a comprehensive, detailed catalogue of the Swahili manuscripts at the School of Oriental and African Studies (SOAS, University of London). They have had occasion to make this recommendation in print (see, for example, Omar and Frankl 1994 and Frankl 1999) and - presumably many more times, and to no specified audience - in life, as they pored over unitemised or inaccurately labelled files of eminent scholars in the field. It is precisely this need for a comprehensive, widely accessible catalogue that the Swahili Manuscripts Project at SOAS was established, in October 2001, to address. In this article, the present authors undertake to describe the catalogue being created and to discuss problems they have encountered and observations they have had opportunity to make in the course of their work.

Since the early 2000s, Service Oriented Architectures (SOAs) have played a key role in the development of complex applications within a virtual organization (VO) context. Grids and workflows have emerged as vital technologies for addressing the (SOA) paradigm. Given the variety of Grid middleware, scientific workflow systems and Grid workflows available, bringing the two technologies together in a flexible, reusable and generalized way has been largely overlooked, particularly from a scientific end user perspective. The lack of domain focus in this area has led to a slow uptake of Grid technologies. This thesis aims to design a framework for Grid-enabling workflows, which identifies the essential technological components, how these components fit together in layered architecture and the interactions between them. To produce such a framework, this thesis first investigates the definition of a Grid-workflow architecture and mapping Grid functionality to workflow nodes, focusing on striking a balance between performance, usability and the Grid functionality supported. Next, it presents an examination of framework extensions for supporting various forms of Grid heterogeneity, essential for ii VO based collaboration. Given the complex nature of Grid technologies, the work presented here investigates abstracting Grid based workflows through high-level definitions and resolution using semantic technologies. Finally, this thesis presents a way to resolves abstract Grid workflows using semantic technologies and intelligent, autonomous agents. The frameworks presented in this thesis are tested and evaluated within the context of domain-based case studies defined in the SIMDAT, BRIDGE and ARGUGRID EU funded research projects.

Este trabalho compreende a modelagem hidrológica da bacia hidrográfica do rio Muriaé (BHRM). As simulações hidrológicas foram realizadas com o modelo hidrológico TOPMODEL com medições de precipitação de estimativa de vazão da rede telemétrica da Rede Hidrometeorológica Nacional (RHN). Utilizou-se também as respectivas estimativas de precipitação por satélite com o método CMORPH, e a análise de precipitação integrada entre a precipitação medida pela telemetria e a estimada por satélite por meio da análise objetiva estatística (ANOBES). A calibração e a validação do modelo TOPMODEL foram realizadas para eventos hidrológicos entre 2016 e 2018. A calibração do modelo TOPMODEL com as séries de dados de precipitação acima foi avaliada por meio do coeficiente de Nash-Sutcliffe (NSE), que variou entre 0,7 e 0,9. A validação do modelo TOPMODEL com séries independentes resultou em NSE de -0,8 a 0,3. Este resultado em grande parte se deve ao pequeno número de eventos hidrológicos desde o início das medições telemétricas na BHRM. O TOPMODEL também foi utilizado para simular vazões em séries com período anual entre 2009 e 2013. A calibração e validação com séries anuais resultaram em NSE ~ 0,6. Notadamente, as simulações com CMORPH tendem a subestimar as vazões, enquanto que com ANOBES o desempenho foi melhor, em especial para períodos de cheia. Portanto, os resultados sugerem a aplicabilidade do modelo TOPMODEL para simulações hidrológicas da Bacia do Rio Muriaé, com os melhores resultados obtidos quando a modelagem iniciou em um período de estiagem e o dado de precipitação representou a variabilidade espacial da chuva. / This study comprises the hydrological modeling of the Muriaé river basin. Hydrologic simulations were performed with the TOPMODEL hydrological model, with precipitation measurements and discharge estimation from the Brazilian Hydrometeorology Network (RHN). It was also used satellite precipitation estimates with the CMORPH method, and the integrated precipitation analysis between the precipitation measured by the telemetry and the estimated by satellite through objective statistical analysis (SOAS). The calibration and validation of the TOPMODEL model were performed for hydrological events between 2016 and 2018. The calibration of the TOPMODEL model with the above precipitation data series was evaluated using the Nash-Sutcliffe coefficient (NSE), which ranged from 0,7 and 0,9. Validation of the TOPMODEL model with independent series resulted in NSE from -0,8 to 0,3. This result is largely due to the small number of hydrological events since the beginning of telemetry measurements at the Muriaé river basin. TOPMODEL was also used to simulate flows in series with annual period between 2009 and 2013. Calibration and validation with annual series resulted in NSE ~ 0.6. Notably, CMORPH simulations tend to underestimate flow rates, while with SOAS the performance was better, especially for flood periods. Therefore, the results suggest the applicability of the TOPMODEL model for hydrological simulations of the Muriaé river basin, with the best results obtained when the modeling started in a drought period and the rainfall data represented the spatial variability of the rainfall.

Since the early 2000s, Service Oriented Architectures (SOAs) have played a key role in the development of complex applications within a virtual organization (VO) context. Grids and workflows have emerged as vital technologies for addressing the (SOA) paradigm. Given the variety of Grid middleware, scientific workflow systems and Grid workflows available, bringing the two technologies together in a flexible, reusable and generalized way has been largely overlooked, particularly from a scientific end user perspective. The lack of domain focus in this area has led to a slow uptake of Grid technologies. This thesis aims to design a framework for Grid-enabling workflows, which identifies the essential technological components, how these components fit together in layered architecture and the interactions between them. To produce such a framework, this thesis first investigates the definition of a Grid-workflow architecture and mapping Grid functionality to workflow nodes, focusing on striking a balance between performance, usability and the Grid functionality supported. Next, it presents an examination of framework extensions for supporting various forms of Grid heterogeneity, essential for ii VO based collaboration. Given the complex nature of Grid technologies, the work presented here investigates abstracting Grid based workflows through high-level definitions and resolution using semantic technologies. Finally, this thesis presents a way to resolves abstract Grid workflows using semantic technologies and intelligent, autonomous agents. The frameworks presented in this thesis are tested and evaluated within the context of domain-based case studies defined in the SIMDAT, BRIDGE and ARGUGRID EU funded research projects.

L’amplification optique large bande à base de SOA est devenue indispensable pour la montée en débit des systèmes de transmissions optiques et pour pouvoir exploiter au mieux la bande optique des fibres optiques. Ce travail présente une étude théorique et expérimentale d’un SOA large bande passante développé par Alcatel Thales III-V Lab dans le cadre des projets ANR AROME et UltraWIDE. Dans cette thèse, nous avons d’abord effectué une modélisation semi-phénoménologique du gain matériau et du coefficient de gain d’une structure à base de multi-puits quantiques avec un nombre réduit de paramètres. L’intégration de notre modèle dans un modèle de SOA déjà développé au laboratoire a montré son efficacité pour restituer quantitativement le comportement statiques (gain, facteur de bruit) des nouvelles structures SOA large bande sur une large plage de longueurs d’onde (> 110 nm), de courants d’alimentation et de puissances optiques. A l’aide de ce modèle, nous avons étudié l’influence de la structure du SOA sur la bande passante pour un gain cible en jouant sur la longueur, le nombre d’électrode et le courant d’alimentation du SOA. Nous avons mis en évidence qu’une structure bi-électrodes n’apportait pas d’amélioration de la bande passante optimisée par rapport au cas mono-électrode. En revanche, la structure bi-électrode permet d’optimiser la puissance de saturation et le facteur de bruit du SOA, sans sacrifier ni le gain maximal ni la bande passante optique. Nous avons aussi montré que, pour ce type de composants, une augmentation de la puissance optique injectée pouvait être compensée par une augmentation du courant d’alimentation pour maintenir une large bande passante optique. Nous avons également mis en place deux techniques d’élargissement de la bande passante optique de SOA à large bande. La première technique est fondée sur le filtrage en réflexion spectralement sélectif (ESOA). Le dispositif expérimental a permis d’amplifier simultanément 8 canaux CWDM dans une bande passante (définie à −1 dB) de 140 nm. La deuxième technique, basée sur un amplificateur hybride Raman-SOA, a fourni une bande passante optique (définie à −1 dB) de 89 nm avec un gain de 17 dB. Nous avons ainsi pu réaliser une transmission simultanée de 5 canaux CWDM allant jusqu’à 10 Gb/s sur 100 km. / SOA-based optical amplification became crucial for increasing optical system capacity and to benefit from the broad bandwidth of optical fibers. In this work we present both theoretical and experimental studies for a new broadband SOA developed by Alcatel Thales III-V lab in the framework of AROME and UltraWIDE ANR projects.We developed firstly a semi-phenomenological model for both the material gain and the gain coefficient of a multi-quantum well -based SOA structure with a reduced set of parameters. This material gain model has been integrated in an existing SOA model and proved its performance in reproducing steady state behavior of this new broadband SOA (gain and noise figure) for a wide range of wavelengths, input powers and bias currents. Thanks to this model, we studied the influence of the SOA geometrical structure on the optical bandwidth for a given target gain, by varying length, number of electrodes and bias current. We showed that two-electrode SOA structures do not provide any improvement of the bandwidth compared to the one-electrode case. However, the two-electrode structure allows the optimization of both the SOA saturation power and the noise figure, without sacrificing neither the maximum gain nor the optical bandwidth. We have also shown that for this kind of component, an increase in the injected optical power could be compensated by an increase in the supply current to maintain a wide optical bandwidth.We have also investigated two techniques to widen the optical bandwidth of our broadband SOA. The first one is based on a modification of the SOA structure by introducing a selective reflection filter (ESOA). Its experimental implementation allowed the amplification of an 8-CWDM-channel comb in a bandwidth (defined at -1 dB) of 140 nm. The second one, based on a hybrid Raman-SOA amplifier, provided an optical bandwidth (defined at -1 dB) of 89 nm with a gain of 17 dB. With this last technique, we were able to achieve a 5-CWDM-channel comb transmission up to 10 Gb/s over 100 km.

L’objectif de ce travail de thèse est d’améliorer l’état de nos connaissances sur les processus de formation et du devenir de l’AOS, en lien avec la réactivité des COVB avec les oxydants de l’atmosphère et en particulier l’ozone, en utilisant le potentiel de l’écosystème landais en tant que source d'AOS biogénique. Pour cela, des campagnes de terrain ont été menées sur un site de mesure en forêt landaise, écosystème particulièrement approprié pour l’étude de la formation et du devenir des AOS. Au cours de ces campagnes, différents paramètres physico-chimiques complémentaires ont été mesurés, tels que les concentrations et les flux de particules, d’oxydants et de COVB. Des épisodes nocturnes de formation de nouvelles particules ont été mis en évidence, ce qui constitue un résultat original car les évènements rapportés jusqu’ici dans la littérature étaient principalement diurnes. La contribution importante de l’ozonolyse des monoterpènes émis par les pins maritimes, dominés par l’α- et le β-pinène, à la formation nocturne de nouvelles particules a également été démontrée. Les mesures de flux de particules réalisées suggèrent que les particules formées au cours de la nuit sont transférées depuis la canopée vers les plus hautes couches de l’atmosphère. Une production d’ozone a également été démontrée par la comparaison des mesures de flux d’ozone à un modèle physique de dépôt. Cette source d’ozone pourrait être liée à la photooxidation des COVB / Forest ecosystems affect air quality and climate, especially through the emissions and the reactions of biogenic volatile organic compounds (BVOCs) with the atmospheric oxidants, known to generate Secondary Organic Aerosols (SOAs). This work aims to improve our knowledge on the processes involved in biogenic SOA formation and fate. Two field campaigns have been conducted in the Landes forest. In a first step, the measurement site was characterized by a statistical study of local meteorological conditions. During these campaigns, complementary physical and chemical measurements have been carried out, implying measurements of fluxes and concentrations of particles, BVOCs and oxidants. The results evidenced nocturnal new particle formation, which is an original result as this process was usually only reported during daytime. The strong contribution of BVOCs (dominated by α- and β-pinene) ozonolysis to nocturnal new particle formation has been demonstated. Particle flux measurements suggested that particles are transfered from the canopy to the higher atmospheric surface layer. The comparison between ozone fluxes and a physical ozone deposition model also highlighted an ozone production source. This ozone production might be related to BVOC photooxidation.