Canevas de développement agile pour l'évolution fiable de systèmes logiciels à composants et orientés services

Modern software is characterized by a need for constant and rapid evolution, such as in the mobile domain. To facilitate the development and the rapid evolution of complex systems, software engineering approaches have been proposed, such as software architecture and agile software development. However, current solutions offer poor support to enable the development of a reliable system, i.e, allow its modification while ensuring its compliance with the quality of services requirement and its good overall safety. The contribution of this PhD thesis is CALICO, an agile development framework for the design and evolution of safe component-based and service-oriented software. The agile software development relies on an iterative and incremental development cycle that allows the architect to iterate between the design of the architecture and the debug of the software in its execution context. At each iteration, the architect can evolve its software and check the consistency of its evolution through the execution of static and dynamic analysis tools. Thus, during the design and the evolution of the system, architect can use a set of metamodels to specify the structure of the architecture and its various quality of services requirement. During the deployment, CALICO instantiates the system on the target runtime platform from the models specified and keeps them synchronized with the software during its execution. By this way, the architect still has a conceptual view which allows him to reason on the critical software properties during its evolution. Moreover, in order to check these evolutions, CALICO provides a unifying framework which allows reuse of many static analysis tools of software architectures and dynamic debugging tools, that were scattered in different existing platforms. Thus, each change can be statically analyzed on the conceptual view before being propagated to the software system. Dynamic analysis are based on data values only available during the execution. The capture of these values is done through automatic instrumentation of the software system. Globally, CALICO enables reliable evolution even if the underlying platforms does not natively provide this support. Our contribution is concretized by a multi-platform implementation. The current version handles four component-based and service-oriented platforms. Moreover, the benchmarks that we have performed show that CALICO is usable for the design and development of safe applications up to 10,000 components and services, which corresponds to the maximal load of most runtime platforms.Les systèmes logiciels modernes se caractérisent par un besoin d'évolutions perpétuelles et rapides, comme par exemple dans le monde de l'informatique mobile. Pour faciliter le développe\-ment et l'évolution rapide de systèmes complexes, des approches de génie logiciel ont été proposées, telles que les architectures logicielles et la méthode de conception agile. Néanmoins, les solutions actuelles offrent peu de support pour permettre l'évolution fiable d'un système, c'est-à-dire permettre sa modification tout en garantissant le respect de ses exigences de qualités de service et de bon fonctionnement global. La contribution de cette thèse est CALICO, un canevas de développement agile pour la conception et l'évolution fiable de systèmes logiciels à composants et orientés services. Le développement agile repose sur l'utilisation d'un cycle de développement itératif et incrémental qui permet à l'architecte d'itérer entre les étapes de conception de l'architecture et de débogage du logiciel dans son environnement d'exécution. A chaque itération du cycle, l'architecte peut faire évoluer son logiciel et fiabiliser ses évolutions grâce à l'exécution d'analyses statiques et dynamiques complémentaires. Ainsi, lors de la conception et de l'évolution d'un système, l'architecte dispose d'un ensemble de métamodèles pour spécifier la structure de l'architecture de son logiciel et ses diverses exigences de qualité de services. Lors du déploiement, CALICO utilise les modèles spécifiés pour instancier le système sur la plate-forme d'exécution cible et les garde synchronisés avec le logiciel lors de son exécution. De cette façon, l'architecte dispose toujours d'une vue conceptuelle qui lui permet de raisonner sur les propriétés critiques de son logiciel lors d'une évolution. De plus, pour fiabiliser ces évolutions, CALICO offre un cadre fédérateur qui autorise la réutilisation de nombreux outils d'analyse statique des architectures logicielles et de débogage dynamique qui étaient jusqu'alors dispersés dans différentes plates-formes existantes. Ainsi, chaque évolution peut être analysée statiquement sur la vue conceptuelle avant d'être propagée au système logiciel. Les analyses dynamiques reposent quant à elles sur des valeurs disponibles à l'exécution. La capture de ces valeurs est effectuée grâce à une instrumentation automatique du système logiciel. CALICO permet donc de fiabiliser les évolutions même si les plates-formes d'exécution sous-jacentes ne le proposent pas nativement. Notre contribution se concrétise par une implémentation multi plates-formes. La version actuelle prend en charge quatre plates-formes à composants et une plate-forme à services. Par ailleurs, les tests de performances que nous avons réalisés démontrent que CALICO est utilisable pour la conception et l'évolution fiable de larges applications jusqu'à 10000 composants et services, ce qui correspond à la montée en charge maximale de la plupart des plates-formes d'exécution

Kinetic Characterisation of a Single Chain Antibody against the Hormone Abscisic Acid: Comparison with Its Parental Monoclonal

A single-chain Fv fragment antibody (scFv) specific for the plant hormone abscisic acid (ABA) has been expressed in the bacterium Escherichia coli as a fusion protein. The kinetics of ABA binding have been measured using surface plasmon resonance spectrometry (BIAcore 2000) using surface and solution assays. Care was taken to calculate the concentration of active protein in each sample using initial rate measurements under conditions of partial mass transport limitation. The fusion product, parental monoclonal antibody and the free scFv all have low nanomolar affinity constants, but there is a lower dissociation rate constant for the parental monoclonal resulting in a three-fold greater affinity. Analogue specificity was tested and structure-activity binding preferences measured. The biologically-active (+)-ABA enantiomer is recognised with an affinity three orders of magnitude higher than the inactive (-)-ABA. Metabolites of ABA including phaseic acid, dihydrophaseic acid and deoxy-ABA have affinities over 100-fold lower than that for (+)-ABA. These properties of the scFv make it suitable as a sensor domain in bioreporters specific for the naturally occurring form of ABA

Estimating a Markovian epidemic model using household serial interval data from the early phase of an epidemic

The clinical serial interval of an infectious disease is the time between date of symptom onset in an index case and the date of symptom onset in one of its secondary cases. It is a quantity which is commonly collected during a pandemic and is of fundamental importance to public health policy and mathematical modelling. In this paper we present a novel method for calculating the serial interval distribution for a Markovian model of household transmission dynamics. This allows the use of Bayesian MCMC methods, with explicit evaluation of the likelihood, to fit to serial interval data and infer parameters of the underlying model. We use simulated and real data to verify the accuracy of our methodology and illustrate the importance of accounting for household size. The output of our approach can be used to produce posterior distributions of population level epidemic characteristics.Andrew J. Black, Joshua V. Ros

Measurement-based band allocation in multiband CDMA

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Identifying Flexible Pool Pumps Suitable for Distributed Demand Response Schemes

Demand response will be an important tool as non-dispatchable generation is added to the grid. Swimming pool filtration pumps are a promising appliance for the grid operator to control because, unlike air conditioners, their time of operation can be shifted by a day without affecting their primary role. Although many customers set and forget the timer settings, this paper studies smart meter data and demonstrates that many change the settings frequently. A "care index" is proposed that quantifies how much a customer appears to care about the precise timing of pump operation, which indicates how willing they are likely to be to relinquish control to the grid operator