A note on CR mappings of positive codimension

We prove the following Artin type approximation theorem for smooth CR mappings: given M a connected real-analytic CR submanifold in C^N that is minimal at some point, M' a real-analytic subset of C^N', and H:M->M' a smooth CR mapping, there exists a dense open subset O in M such that for any q in O and any positive integer k there exists a germ at q of a real-analytic CR mapping H^k:(M,q)->M' whose k-jet at q agrees with that of H up to order k

On formal maps between generic submanifolds in complex space

Let H:(M,p)->(M',p') be a formal mapping between two germs of real-analytic generic submanifolds in C^N with nonvanishing Jacobian. Assuming M to be minimal at p and M' holomorphically nondegenerate at p', we prove the convergence of the mapping H. As a consequence, we obtain a new convergence result for arbitrary formal maps between real-analytic hypersurfaces when the target does not contain any holomorphic curve. In the case when both M and M' are hypersurfaces, we also prove the convergence of the associated reflection function when M is assumed to be only minimal. This allows us to derive a new Artin type approximation theorem for formal maps of generic full rank

The Efficiency of the Current Governance Model for the Amazon

Màster en Diplomàcia i Funció Pública Internacional, Centre d'Estudis Internacionals, Universitat de Barcelona, Curs: 2013-2014, Tutor: Ángel J. RodrigoThe Amazon accounts for more than half of the planet’s rainforests, fauna and flora,1 and the volume of its water basin is equivalent to 20% of the total fresh water supply for the entire world.2 Furthermore, the Amazon is considered the “Lungs of our Planet”,3 since it filters the air by absorbing carbon dioxide and producing oxygen in huge amounts, and contributes significantly to the reduction of global warming. Indeed, it is one of the richest places on Earth in terms of biodiversity and genetic, natural and cultural resources. It is no wonder, then, that it has always attracted substantial attention at both a local and global level. Normally, when one speaks of the Amazon and its governance, the focus underlying the debate is the juxtaposition between the sovereignty of the eight States4 that have jurisdiction over the Amazon5 and the possible limitations on this sovereignty on the part of the international community. The latter worries about the administration of the region, the environmental impact that may flow from mismanagement of the area and the benefits – economic, scientific or otherwise – that may be obtained through resources found in the Amazonian territory. However, this view of the interests in the region – the development and sovereignty of the Amazonian States versus the international community’s concern over and interest in the Amazon – is an oversimplification. Indeed, the attention attracted by the Amazon is manifested in different ways, including not only the preoccupation with the environment and sustainability and a possible menace to sovereignty of a State, but also the self-determination of peoples, advances in science, and the livelihood of local communities..

Mogwaï: a Framework to Handle Complex Queries on Large Models

International audienceWhile Model Driven Engineering is gaining more industrial interest, scalability issues when managing large models have become a major problem in current modeling frameworks. Scalable model persistence has been achieved by using NoSQL backends for model storage, but existing modeling framework APIs have not evolved accordingly, limiting NoSQL query performance benefits. In this paper we present the Mogwaï a scalable and efficient model query framework based on a direct translation of OCL queries to Gremlin, a query language supported by several NoSQL databases. Generated Gremlin expressions are computed inside the database itself, bypassing limitations of existing framework APIs and improving overall performance, as confirmed by our experimental results showing an improvement of execution time up to a factor of 20 and a reduction of the memory overhead up to a factor of 75 for large models

NOTICE: A Framework for Non-functional Testing of Compilers

International audience—Generally, compiler users apply different optimizations to generate efficient code with respect to non-functional properties such as energy consumption, execution time, etc. However, due to the huge number of optimizations provided by modern compilers, finding the best optimization sequence for a specific objective and a given program is more and more challenging. This paper proposes NOTICE, a component-based framework for non-functional testing of compilers through the monitoring of generated code in a controlled sand-boxing environment. We evaluate the effectiveness of our approach by verifying the optimizations performed by the GCC compiler. Our experimental results show that our approach is able to auto-tune compilers according to user requirements and construct optimizations that yield to better performance results than standard optimization levels. We also demonstrate that NOTICE can be used to automatically construct optimization levels that represent optimal trade-offs between multiple non-functional properties such as execution time and resource usage requirements

A Model-Based Approach for Testing Large Scale Systems

This document summarize the author's experience over six years testing large-scale systems.We outline that experience in four points.First, we present a methodology for testing large-scale system. The methodology takes into account three dimensions of these systems: functionality, scalability, and volatility.The methodology proposes to execute tests in different workloads, from a small-scale static system up to a large-scale dynamic system.Experiments show that the alteration of the three dimensional aspects improves code coverage, thus improving the confidence on tests.Second, we introduce a distributed test architecture that uses both, a broadcast protocol to send messages from the test controller to testers and a converge cast protocol to send messages from testers back to the test controller. Experiments show that the architecture is more scalable than traditional centralized architectures when testing systems with more than \num{1000} nodes.Third, we present an approach for using models as dynamic oracles for testing global properties of large-scale systems.This approach focuses on global, liveness, observable and controllable properties. We propose to efficiently keep updating a global model of the system during its execution. This model is then instantiated and evolved at runtime, by monitoring the corresponding distributed system, and serve as oracle for the distributed tests.We illustrate this approach by testing the reliability of two routing algorithms under churn. Results show common flaws in both algorithms.Finally, we present a model-driven approach for software artifacts deployment.We consider software artifacts as a product line and use feature models to represent their configurations and model-based techniques to handle automatic artifact deployment and reconfiguration.Experiments show that this approach reduces network traffic when deploying software on cloud environment

Controlling the Elasticity of Web Applications on Cloud Computing - Extended Version

Web applications are often exposed to unpredictable work-loads, which makes computing resource management di-cult. The resource may be overused when the workload is high and underused when the workload is low. A solution to deal with unpredictable workloads is to migrate Web applications to cloud computing infrastructures, where the resource is varied according to demand, i. e., elasticity. With elasticity, all the resource variations happen during the Web application runtime. To deal with this, the Web application , and its service layers must behave in an elastic manner , which comprises adaptation tasks. These tasks may introduce functional and non-functional errors into the Web application. To nd these errors, we must test the Web application when the adaptation tasks are performed, during the resource variations. Some tests may require a specic sequence of resource variations, which are dicult to be achieved without controllability. Therefore, in this paper, we propose an approach that controls the required resource variations. We validated our approach by conducting several experiments on Amazon EC2 cloud infrastructures. In these experiments, we successfully lead the Web application through the required resource variations

Anàlisi i disseny d'un sistema de còpies de seguretat

Aquest treball presenta el disseny d'un sistema de còpies de seguretat per a una empresa de serveis que presenta dades per a altres empreses. Explica les necessitats de l'empresa i les especificacions que ha de complir el sistema de còpies, i estudia les possibles opcions de programari i maquinari i els aspectes legals.Este trabajo presenta el diseño de un sistema de copias de seguridad para una empresa de servicios que presenta datos para otras empresas. Explica las necesidades de la empresa y las especificaciones que debe cumplir el sistema de copias, y estudia posibles opciones de hardware y software y los aspectos legales.This work presents the design of a backup system for a services company that provides data for other companies. It explains the needs of the company and the specifications that the backup system must comply with, and it studies the possible software and hardware options, in addition to the legal aspects involved