Reliable and efficient data transfer on the Internet is an important issue. Since late 70's the protocol responsible for that has been the de facto standard TCP, which has proven to be successful through out the years, its self-managed congestion control algorithms have retained the stability of the Internet for decades. However, the variety of existing new technologies such as high-speed networks (e.g. fibre optics) with high-speed long-delay set-up (e.g. cross-Atlantic links) and wireless technologies have posed lots of challenges to TCP congestion control algorithms. The congestion control research community proposed solutions to most of these challenges. This dissertation adds to the existing work by: firstly tackling the highspeed long-delay problem of TCP, we propose enhancements to one of the existing TCP variants (part of Linux kernel stack). We then propose our own variant: TCP-Gentle. Secondly, tackling the challenge of differentiating the wireless loss from congestive loss in a passive way and we propose a novel loss differentiation algorithm which quantifies the noise in packet inter arrival times and use this information together with the span (ratio of maximum to minimum packet inter arrival times) to adapt the multiplicative decrease factor according to a predefined logical formula. Finally, extending the well-known drift model of TCP to account for wireless loss and some hypothetical cases (e.g. variable multiplicative decrease), we have undertaken stability analysis for the new version of the model.

Dans un contexte de croissance du trafic aérien et dans le but de réduire la consommation de carburant ainsi que les émissions de polluants dans l’atmosphère, l’avion de demain se doit d’être plus respectueux de l’environnement. Dans un objectif d’optimisation de ses performances aérodynamiques,d’importantes activités de recherche sont menées dans le monde pour étudier de nouveaux dispositifs de contrôle actif des écoulements en temps réel. Depuis une dizaine d’années, l’utilisation de la décharge à barrière diélectrique surfacique comme actionneur plasma pour le contrôle d’écoulements suscite un intérêt grandissant. Ce type d’actionneur permet de créer un plasma non-thermique capable de générer un écoulement basse vitesse, appelé vent ionique, qui interagit avec l’écoulement naturel en proche paroi pour l’amener dans un état souhaité. Les études expérimentales présentées dans cette thèse portent, d’une part, sur la caractérisation de l’actionneur plasma sous atmosphère contrôlée pour étudier le rôle de l’azote et de l’oxygène sur le comportement de la décharge et d’autre part, sur l’évaluation des potentialités de cet actionneur à contrôler le décollement massif naissant au bord d’attaque d’un profil d’aile placé à forte incidence. Les résultats mettent en évidence l’importance du rôle joué par O2 dans l’amorçage des filaments de plasma et dans la production de vent ionique. Le taux de production d’ozone de l’actionneur plasma a été quantifié en fonction de la puissance électrique. Les essais en soufflerie, réalisés dans le cadre du projet européen PLASMAERO, montrent l’effet de la fréquence de pulsation du signal d’alimentation haute tension sur la réponse de l’écoulement décollé et des ses instabilités naturelles. Il est ainsi possible, pour le profil placé à des incidences au-delà de l’incidence de décrochage naturel, d’augmenter la portance du profil en supprimant le décollement ou en favorisant la formation de tourbillons portants à l’extrados du profil. / To reduce power consumption and pollutant emissions in the atmosphere due to the increase of aerial traffic jam, tomorrow’s plane must be environnement-friendly. To enhance aerodynamic airfoil performance, worldwide studies have been carried out to study reel time active flow control actuators. For a decade, the interest in using a dielectric barrier discharge for flow control is increasing. Such a discharge is able to create a non thermal plasma which can induce a low velocity airflow, called ionic wind, which interacts with natural flow close to the wall to change its behavior. Experimental studies detailled in this thesis can be divided in two parts. On one hand, plasma actuator caracterization is performed at atmospherical pressure to study the influence of oxygen and nitrogen on the discharge behavior. On the other hand, abilities of the actuator to control a massive flow separation at the leading-edge of an airfoil in a deep post-stall regime are investigated. Results underlines that plasma filaments ignition and ionic wind generation is mainly governed by O2. Besides, the ozone procution rate of the dischage is measured as a function of electrical power. Wind tunnel tests, performed in the PLASMAERO project, underline that separated air flow and its instabilities can be drive by the burst frequency of the high voltage signal. For a deep post-stall regime, a lift enhancement can by obtained by reattaching the air flow or inducing lifting vortexes on the wing upper surface.

L’énergie éolienne est une source d’énergie propre et renouvelable qui fait partie des moyens pour réduire les émissions de gaz à effet de serre et contrer le réchauffement climatique dans le domaine de la production électrique.L’objectif de la thèse est d’optimiser la production d’énergie éolienne par la réduction des fluctuations de charge induites par la turbulence de la couche limite atmosphérique. Ces fluctuations augmentent la fatigue des pales et réduisent la durée de vie des rotors.Cette réduction des fluctuations de charge est réalisée par le biais d’une approche expérimentale et à l’échelle du laboratoire. Deux actionneurs non conventionnels sont étudiés et testés au sein d’un écoulement contrôlé ensoufflerie: il s’agit d’actionneurs plasma et de jets fluidiques. L’objectif est d’effectuer un contrôle de circulation par une action proche du bord de fuite arrondi de la pale afin de modifier la portance du profil.Dans le cadre du projet SMARTEOLE, les deux stratégies sont d’abord testées en parallèle sur un profil bidimensionnel. Pour cette thèse, les actionneurs plasma sont implémentés autour du bord de fuite arrondi afin d’augmenter ou de réduire la portance. Les performances aérodynamiques ont été modifiées dans la partie linéaire de la courbe de portance. Pour des raisons d’efficacité et de fiabilité, le projet est poursuivi avec des jets fluidiques pour aller vers l’étude des pales et du contrôle d’écoulement en rotation. Ces pales sont préalablement testées dans une configuration translationnelle pour évaluer l’effet du contrôle sans les effets de la rotation. Finalement,les pales sont montées sur le banc éolien du laboratoire. Les effets du contrôle sont mis en évidence par les mesures de pression pariétale et de moment de flexion en pied de pale. Le contrôle induit des réductions importantes de fatigue qui motivent la poursuite des travaux dans le domaine du contrôle d’écoulement appliqué aux pales d’éolienne. / Wind energy is a clean and renewable source of energy that remains one of the solutions to cut carbon emissions and curb global warming in the field of power generation. The present thesis objective is the optimisation of wind energy production by the all eviation of blade load fluctuations induced by shear and turbulence in the atmospheric boundary layer. These fluctuations increase the blade fatigue and reduce the life duration of the rotors.This load fluctuation all eviation is assessed with an experimental approach and at a laboratory scale. Two not conventional flow control strategies, plasma actuators and fluidic jets, are implemented and tested in the controlled environment of a wind-tunnel to perform a circulation control by acting in the vicinity of the rounded trailing-edge of the blade in order to modify its lift force.In the scope of the SMARTEOLE project, both plasma and fluidic strategies are, as a first step, tested in parallel on a 2D-airfoil. For this thesis, plasma actuators are implemented over the airfoil trailing-edge to increase ordecrease the lift force. Airfoil performances are indeed modified in the linear part of the lift curve. For efficiency and reliability reasons, it is chosen to pursue the work towards the rotational configuration with the fluidic strategy. Blades are then manufactured and tested first in a translational configuration to evaluate the potentialof the fluidic actuation without rotational effects. Then, blades are mounted in the wind turbine bench of the laboratory. The effects of the actuation are demonstrated through surface pressure and flapwise bending moment measurements. Actuation shows important fatigue reduction motivating the pursue of the investigations on active flow control applied to wind turbine blades.

A adoção de lojas de aplicativos e Open APIs por um número crescente de empresas, muitas nem mesmo atuantes no ramo de tecnologia, revela o interesse das mesmas em exteriorizar a concepção e desenvolvimento de software corporativo. Com isso, as empresas almejam multiplicar as funcionalidades disponíveis a seus clientes, utilizando uma fração do custo e do tempo que seriam tradicionalmente gastos para fazê-lo. Ao mesmo tempo, o acesso a dados e sistemas corporativos por softwares de desenvolvedores potencialmente desconhecidos suscita preocupações de segurança, tornando-se imperativo garantir a adequação desses softwares às políticas de segurança institucionais. Entretanto, carece-se de meios automáticos capazes de garantir a mencionada adequação nas plataformas móveis, seja nos seus ambientes de execução ou em seus kits de desenvolvimento de software. Este trabalho, utilizando de ideias recentes da área de Controle de Fluxo de Informação, propõe a arquitetura de um ambiente de execução para aplicativos móveis que garante por construção a adequação dos mesmos a determinadas políticas de confidencialidade e integridade de dados, mesmo na presença de código malicioso. A praticidade de tal arquitetura é validada através da implementação de um aplicativo exemplo. Tal implementação ilustra o funcionamento dos mecanismos de segurança propostos e a compatibilidade dos mesmos a um conjunto de funcionalidades adequado ao cenário de manipulação de dados corporativos. / The adoption of application stores and Open APIs by a growing number of companies, many of them not even related to the technology business, reveals their interest in externalizing the conception and development of corporate software. By doing so, these companies expect to multiply the number of functionalities available to their customers, spending a fraction of the traditionally required time and cost. On the other hand, access to corporate data and services by software developed by potentially unknown parties raises security concerns, making it imperative to ensure the adequacy of the mentioned software to the institutional security policies. Nevertheless, there is a lack of automatic tools capable of guaranteeing the mentioned adequacy in mobile platforms, either in their runtime environments or in their software development kits. This work, using recent ideas from the Information Flow Control area, proposes the architecture of a run-time environment for mobile applications that guarantees by construction their adequacy to some confidentiality and integrity policies, even in the presence of malicious code. The practicality of this architecture is validated by the implementation of an example application. This implementation illustrates the working of the proposed security mechanisms and their compatibility to a set of functionalities relevant to the scenario of corporate data manipulation.

Recently, the wavy leading edge airfoils, inspired by the humpback whale´s flipper, have been investigated, as flow control mechanisms, at low Reynolds numbers in order to improve aerodynamic performance in this particular flow regime. The overall aim of this work is to investigate the airfoil geometric effects on wavy leading edge phenomena in the low Reynolds number regime. Experimental investigations were carried out correlating force measurements with mini-tuft and oil visualizations in order to understand the airfoil thickness effects on wavy leading edge phenomena. Three sets of airfoil thickness were tested (NACA 0012, NACA 0020 and NACA 0030), each set consisting of smooth plus three wavy configurations (A=0.11c, ?=0.40c; A=0.03c, ?=0.40c and A=0.03c, ?=0.11c); Reynolds number was varied between 50,000 and 290,000. The results present many findings that were not possible in previous studies due the fact that these investigations were constrained to specific geometries and/or flow conditions. At higher Reynolds number, the decrease in airfoil thickness leads the airfoils to leading edge stall characteristics causing the lowest aerodynamic deterioration for the thinnest wavy airfoil as compared to smooth configuration in the pre-stall regime. In addition, the results show impressive tubercle performance in the lowest Reynolds number. For any tubercle geometry and airfoil thickness, the wavy leading edge airfoils present higher maximum lift values as compared to smooth configurations showing an unprecedented increase in performance for a full-span model tested in the literature. The flow visualizations present two flow mechanisms triggered by secondary flow: three-dimensional laminar separation bubbles and vortical structures. Regarding three-dimensional laminar bubbles, the results confirm some of the few previous experimental and numerical studies, and presents for the first time these structures as a very efficient flow control mechanism in the post-stall regime justifying the impressive increase in maximum lift in the lowest Reynolds number. Besides that, two characteristics of laminar bubbles, \"tipped-bubbles\" and \"elongated-bubbles\", are identified with different effects in the pre-stall regime. This thesis presents higher tubercle performance for thinner airfoils (NACA 0012) and/or lower Reynolds number conditions (Re=50,000) showing clearly that an optimum performance lead the \"tubercles\" to operate under conditions of leading edge flow separation conditions. Therefore, a design space for tubercles conducted to leading edge stall characteristics confirming the hypothesis of Stanway (2008) eight years before. / Recentemente, aerofólios com bordo de ataque ondulados, inspirados na nadadeira da baleia jubarte, tem sido investigados como mecanismo de controle de escoamento para baixo número de Reynolds com a finalidade de se aumentar o desempenho aerodinâmico neste específico regime de escoamento. O objetivo geral deste trabalho é investigar os efeitos geométricos do aerofólio nos fenômenos do bordo de ataque ondulado na condição de baixo número de Reynolds. Investigações experimentais foram realizadas correlacionando medições de forças com visualizações de lã e óleo a fim de compreender os efeitos da espessura do aerofólio sobre os fenômenos de bordo de ataque ondulado. Três conjuntos de espessura de aerofólios foram testados (NACA 0012, NACA 0020 e NACA 0030) na faixa de número de Reynolds entre 50,000 e 290,000, onde cada conjunto tem um aerofólio liso e três ondulados (A = 0.11c, ? = 0.40c; A = 0.03c, ? = 0.40c e A = 0.03c, 0.11c ? =0.11c). O dados experimentais mostram importantes resultados que não foram possíveis em estudos anteriores devido às investigações serem restritas à geometria ou/e condição de escoamento específicas. O resultados de medida de força mostram que a diminuição da espessura do aerofólio conduz às características de separação de escoamento de bordo de ataque que causam menor deterioração aerodinâmica nos aerofólios ondulados finos quando comparados aos lisos no regime de pré-stall. Além disso, os resultados mostram um desempenho destacado do bordo de ataque ondulado para condição de menor número de Reynolds. Em quaisquer espessuras de aerofólio, os bordos ondulados apresentam valores de sustentação máxima maiores quando comparado aos aerofólios lisos mostrando assim resultado inédito na literatura para modelos ondulados bi-dimensionais. As visualizações de óleo evidenciaram dois mecanismos de controle de escoamento desencadeadas pelo escoamento secundário: bolhas de separação laminar tridimensionais e estruturas vorticais. Os resultados confirmam alguns poucos estudos experimentais e numéricos anteriores relacionadas com bolhas tridimensionais, e apresenta pela primeira vez estas estruturas como um mecanismo muito eficiente de controle de escoamento em regime de pós-stall justificando o aumento de máxima sustentação para o menor número de Reynolds. Adicionalmente, foram identificadas duas estruturas de bolhas tridimensionais nomeados aqui como \"bolhas com pontas\" e \"bolhas alongadas\" que causam distintos efeitos no regime de pré-stall. Esta tese apresenta como resultado maior desempenho para aerofólios ondulados com menor espessura (NACA 0012) e/ou para condições de menor número de Reynolds (Re=50,000)mostrando claramente que estas características levam as ondulações a operarem em condições de stall de bordo de ataque assim tendo um desempenho superior. Portanto, um espaço de projeto para tubérculos conduz às características de stall de bordo de ataque confirmando a suposição de Stanway (2008) oitos anos antes.

This thesis describes the unstable dynamics of a gas jet impinging on a falling liquid film. This flow configuration is encountered in the jet wiping process, used in continuous coating applications such as the hot-dip galvanizing to control the thickness of a liquid coat on a moving substrate. The interaction between these flows generates a non-uniform coating layer, of great concern for the quality of industrial products, and results from a complex coupling between the interface instabilities of the liquid film and the confinement-driven instabilities of the impinging jet.Combining experimental and numerical methods, this thesis studied the dynamics of these flows on three simplified flow configurations, designed to isolate the key features of their respective instabilities and to provide complementary information on their mutual interaction. These configurations include the gas jet impingement on a falling liquid film perturbed with controlled flow rate pulsation, the gas jet impingement on a solid interface reproducing stable and unstable liquid film interfaces and a laboratory scaled model of the jet wiping process. Each of these configurations was reproduced on dedicated experimental set-up, instrumented for non-intrusive measurement techniques such as High-Speed Flow Visualization (HSFV) and Time-resolved Particle Image Velocimetry (TR-PIV) for the gas jet flow analysis, Laser Induced Fluorescence (LIF) tracking of the liquid interface, and 3D Light Absorption (LAbs) measurement of the liquid film thickness. To optimize the performances of these measurement techniques, several advanced data processing routines were developed, including a novel image pre-processing method for background removal in PIV and a dynamic feature tracking for the automatic detection of the jet flow and the liquid film interface from HSFV, LIF, and PIV videos.To identify the flow structures driving the unstable response of the jet flow, a novel data-driven modal decomposition was developed. This decomposition, referred to as Multiscale Proper Orthogonal Decomposition (mPOD), was validated on synthetic, numerical and experimental test cases and allowed for better feature extraction than classical alternatives such as Proper Orthogonal Decomposition (POD) or Dynamic Mode Decomposition (DMD).The experimental work on these laboratory models was complemented with the analysis of several numerical simulations, including a classical 2D Unsteady Reynolds Averaged Navier Stokes (URANS) modeling of the gas jet impingement on a fixed interface, a 2D Variational Multiscale Simulation (VMS) with anisotropic mesh refinement of the gas jet impingement on a pulsing interface, and a 3D simulation of the jet wiping process combining Large Eddy Simulation (LES) on the gas side with Volume of Fluid (VOF) treatment of the liquid film flow. The experimental modal analysis on the dynamic response of the gas jet and the characterization of the pressure-velocity coupling in the numerical investigation allowed for a complete picture of the mechanism driving the jet oscillation and its possible impact on the liquid film.In parallel, several flow control strategies to prevent the jet oscillation were developed, tested numerically and experimentally in simplified conditions, and later implemented on the design of a new nozzle for the jet wiping process. This new nozzle was finally tested on a laboratory scale of the wiping process and its performances compared to single jet and multiple jet wiping configurations. In these three cases, the experimental work presents the modal analysis of the gas field using TR-PIV and mPOD, the liquid interface tracking via LIF, and the final coating thickness characterization via LAbs.The large spatiotemporally resolved experimental database allowed to give a detailed description of the jet wiping instability and to provide new insights on this fascinating fundamental and applied problem of fluid dynamics. / Doctorat en Sciences de l'ingénieur et technologie / info:eu-repo/semantics/nonPublished

Aujourd’hui, la fabrication des turbomachines est conditionnée par des normes de plus en plus restrictives. L'enjeu industriel pour les chercheurs est d'envisager des solutions optimales visant à réduire les sources de perte d'énergie, d'instabilité et du bruit, en particulier l'écoulement de jeu (débit de fuite). Des actions préliminaires ont été élaborées à Arts & Métiers ParisTech sur le rotomoulage du ventilateur axial de refroidissement d'automobile. L'idée de ce travail est d'utiliser la forme creuse induite par le rotomoulage afin de l'exploiter dans le controle de l'écoulement de jeu radial par soufflage rotatif. Pour cela, la virole comporte des trous d'injection orientés de façon à réduire simultanément le débit de fuite et le couple. Dans ce travail, trois parties ont été traité. La première concerne la réalisation du ventilateur par rotomoulage. La deuxième concerne l'étude expérimentale menée dans le banc d'essai ISO 5801. Cette étude comporte la réalisation d'un montage dédié au contrôle par soufflage rotatif, la métrologie menée pour la détermination des performances globales et la caractérisation de la vitesse axiale du sillage proche. La troisième partie traite la modélisation numérique des conditions expérimentales rentables ensuite l'extrapolation du travail vers des taux d'injection importants. Pour ce dernier, on arrive à annuler le débit de fuite avec un gain considérable du couple mettant ainsi le ventilateur en autorotation. / Nowadays, the manufacture of turbomachinery is conditioned by more and more restrictive rules. The industrial challenge for researchers has to consider optimal solutions to reduce sources of energy loss, instability and noise, particularly the tip clearance flow (leakage flow rate). Preliminary actions have been developed at Arts & ParisTech on rotational molding process used for the automobile cooling axial fan. The idea of this work is to use the hollow shape induced by rotational molding process in order to exploit it in the control of tip clearance flow through rotary steady air injection. For this, the shroud ring is composed of injection holes oriented in such away to reduce both of leakage flow rate and the torque. In this work, the thesis focuses on three parts. The first concerns the build of the fan by rotational molding process. The second concerns the experimental study carried out in the ISO 5801 test bench. This study involves the realization of drive system dedicated to rotary steady air injection, metrology for performance determination and the characterization of the near wake axial velocity. The third part deals with the numerical modeling of efficient experimental conditions, then the extrapolation of work towards high injection rates. For this latter, it is possible to cancel leakage flow rate with a considerable gain of the torque thus putting the fan in autorotation.

An increasing number of network applications use reliable transport protocols. Applications with constant data transmission recover from loss without major performance disruption, however, applications that send data sporadically, in small packets, also called thin-streams, experience frequently high latencies due to 'Bufferbloat', that reduce the application performance. Active Queue Management mechanisms were proposed to dynamically manage the queues in routers by dropping packets early and reduce these, hence reducing latency. While their deployment to the internet remains an open issue, the proper investigation into how their functioning mechanism impacts latency is the main focus of this work and research questions have been devised to investigate the AQM impact on latency. A range of AQM mechanisms has been evaluated by the research, exploring performance of the methods for latency sensitive network applications. This has explored new single queue AQM mechanisms such as Controlled Delay (CODEL) and Proportional Integral Enhanced (PIE) and Adaptive RED (ARED). The evaluation has shown great improvements in queuing latency when AQM are used over a range of network scenarios. Scheduling AQM algorithms such as FlowQueue CODEL (FQ-CODEL) isolates traffic and minimises the impact of Bufferbloat on flows. The core components of FQ-CODEL, still widely misunderstood at the time of its inception, have been explained in depth by this study and their contribution to reducing latency have been evaluated. The results show significant reductions in queuing latency for thin streams using FQ-CODEL. When TCP is used for thin streams, high application latencies can arise when there are retransmissions, for example after dropping packets by an AQM mechanism. This delay is a result of TCP's loss-based congestion control mechanism that controls sender transmission rate following packet loss. ECN, a marking sender-side improvement to TCP reduces applicationlayer latency without disrupting the overall network performance. The thesis evaluated the benefit of using ECN using a wide range of experiments. The findings show that FQ-CODEL with ECN provides a substantial reduction of application latency compared to a drop-based AQM. Moreover, this study recommends the combination of FQ-CODEL with other mechanisms, to reduce application latency. Mechanisms such as ABE, have been shown to increase aggregate throughput and reduce application latency for thin-stream applications.

De nombreuses recherches sont actuellement menées afin de réduire les émissions polluantesdes aéronefs. Le contrôle actif des écoulements aérodynamiques est une piste envisagéepour répondre à ces enjeux. Parmi les technologies de contrôle en développement, lestechnologies plasma offrent plusieurs avantages, dont la compacité, la simplicité de mise enoeuvre et la réactivité. Ce travail de thèse a été consacré à l’étude d’un actionneur plasmade type jet synthétique. Il se présente sous la forme d’une petite cavité insérée en paroiet reliée à l’extérieur par une tuyère. Un arc électrique est généré dans la cavité, ce quientraîne une augmentation de la pression de l’air dans celle-ci. Par conséquent, un jet estproduit à la sortie de la tuyère, et celui-ci peut interagir avec l’écoulement extérieur. A lasuite de cette phase d’éjection, de l’air extérieur est naturellement aspiré par la cavité, cequi permet au processus d’être répété à des fréquences pouvant atteindre plusieurs kilohertz.L’objectif de ce travail de thèse est de construire un modèle numérique capable dereproduire ces phénomènes physiques. Pour cela, un calcul aérodynamique de type LargeEddy Simulation est mis en oeuvre. L’action du plasma d’arc est prise en compte au traversde termes sources dans l’équation de l’énergie. Ces derniers sont notamment calculés grâceà l’hypothèse d’équilibre thermodynamique local dans le plasma. De plus, l’augmentationde la température dans la partie solide de l’actionneur est simulée lorsque celui-ci est opéréà haute-fréquence. Les résultats du modèle numérique sont comparés à des mesures de vitesseeffectuées lorsque l’actionneur fonctionne dans un environnement extérieur au reposet lorsque celui-ci interagit avec une couche limite. / Nowadays, many studies are conducted in order to decrease greenhouse gases and noiseemissions from aircrafts. Active aerodynamic flow control is a way considered to meet thesechallenges. Among developed technologies of control, plasma actuators offer several advantages,including compactness, easy implementation and fast response. This thesis is devotedto the study of a plasma synthetic jet actuator which comes in the form of a small cavityinserted in wall and connected to the environment through a nozzle. An electrical arc isgenerated in the cavity, resulting in an increase of the cavity air pressure. Consequently,a jet is produced at the nozzle exhaust that can interact with the external flow. After thisejection phase, an aspiration phase naturally occurs, allowing the process to be repeatedat a frequency that can reach several kilohertz. This thesis aims at building a numericalmodel able to reproduce these physical phenomena. To do so, a Large Eddy Simulationis performed. The action of the plasma arc is taken into account through source terms inthe energy equation. In particular, these source terms are calculated using the assumptionof local thermodynamic equilibrium in the plasma. In addition, the heating of the actuatormaterials is simulated when it is operated at high frequency. The results from the numericalmodel are compared with velocity measurements, carried out when the actuator works ina quiescent environment and when it interacts with a boundary layer.

A adoção de lojas de aplicativos e Open APIs por um número crescente de empresas, muitas nem mesmo atuantes no ramo de tecnologia, revela o interesse das mesmas em exteriorizar a concepção e desenvolvimento de software corporativo. Com isso, as empresas almejam multiplicar as funcionalidades disponíveis a seus clientes, utilizando uma fração do custo e do tempo que seriam tradicionalmente gastos para fazê-lo. Ao mesmo tempo, o acesso a dados e sistemas corporativos por softwares de desenvolvedores potencialmente desconhecidos suscita preocupações de segurança, tornando-se imperativo garantir a adequação desses softwares às políticas de segurança institucionais. Entretanto, carece-se de meios automáticos capazes de garantir a mencionada adequação nas plataformas móveis, seja nos seus ambientes de execução ou em seus kits de desenvolvimento de software. Este trabalho, utilizando de ideias recentes da área de Controle de Fluxo de Informação, propõe a arquitetura de um ambiente de execução para aplicativos móveis que garante por construção a adequação dos mesmos a determinadas políticas de confidencialidade e integridade de dados, mesmo na presença de código malicioso. A praticidade de tal arquitetura é validada através da implementação de um aplicativo exemplo. Tal implementação ilustra o funcionamento dos mecanismos de segurança propostos e a compatibilidade dos mesmos a um conjunto de funcionalidades adequado ao cenário de manipulação de dados corporativos. / The adoption of application stores and Open APIs by a growing number of companies, many of them not even related to the technology business, reveals their interest in externalizing the conception and development of corporate software. By doing so, these companies expect to multiply the number of functionalities available to their customers, spending a fraction of the traditionally required time and cost. On the other hand, access to corporate data and services by software developed by potentially unknown parties raises security concerns, making it imperative to ensure the adequacy of the mentioned software to the institutional security policies. Nevertheless, there is a lack of automatic tools capable of guaranteeing the mentioned adequacy in mobile platforms, either in their runtime environments or in their software development kits. This work, using recent ideas from the Information Flow Control area, proposes the architecture of a run-time environment for mobile applications that guarantees by construction their adequacy to some confidentiality and integrity policies, even in the presence of malicious code. The practicality of this architecture is validated by the implementation of an example application. This implementation illustrates the working of the proposed security mechanisms and their compatibility to a set of functionalities relevant to the scenario of corporate data manipulation.