Testing self-adaptive applications with simulation of context events

Modern trends in mobile computing have raised the expectations of users in terms of such features such as context-awareness and self-adaptiveness. With such capabilities, applications can autonomously sense their context and automate a number of tasks, effectively reducing the attention required by the end users. This paper presents a custom simulation engine, designed to support the testing of applications developed using the MUSIC platform. The simulation tool consists of a platform-independent server module, deployed along with the application, and a client module which is responsible for interpreting and executing the simulation script. The use of the tool is demonstrated in the scope of the SatMotion application, which is designed to assist satellite antenna installers with specialized functionality

Kalimucho: Contextual Deployment for QoS Management

International audienceThe increasing use of mobile technologies last years leads to face to new challenges in order to satisfy people using mobile devices. As they use their favorite applications on their personal computer at home, people wants to use it on their PDA or mobile phone and wants applications can be improve according to location, weather or any contextual information. However, addressing such context-aware systems deals with three main characteristics: context changes, mobility and limited resources of devices. In this article we respond to user requirements and changes of the environment with dynamic adaptations of application deployment guided by QoS respect. We are particularly interested in distributed applications QoS management facing with hardware limitations and mobility of devices, user requirements and usage constraints. We propose a service-based reconfiguration platform named Kalimucho, which implements a contextual-deployment heuristic to find a configuration that matches with context and QoS requirements. Kalimucho was tested on the Osagaia/Korrontea component model and the SunSpot platform; results confirm that Kalimucho provides a satisfying execution time to adapt applications

Kalimucho : Plateforme d'Adaptation des Applications Mobiles

International audienceL'utilisation de plus en plus fréquente des technologies mobiles nous amène à faire face à de nouveaux défis afin de satisfaire les utilisateurs. De la même façon qu'ils utilisent leurs applications favorites sur leur ordinateur, les utilisateurs souhaitent pouvoir également les utiliser sur leur Smartphone ou leur tablette et que les applications prennent compte de leur position, du temps ou de toute autre information contextuelle. Cependant, de tels systèmes sensibles au contexte impliquent de prendre en compte trois principales caractéristiques : la variation du contexte, la mobilité et les ressources limitées des appareils. Dans cet article, nous essayons de traiter ces caractéristiques par l'adaptation dynamique des applications guidée par la qualité de service (QdS). Nous proposons une plateforme de reconfiguration basée service appelée Kalimucho. Elle implémente une heuristique de déploiement contextuel permettant de trouver une configuration satisfaisant les conditions de contexte et de QdS. Kalimucho a été testée avec le modéle de composant Osagaia/Korrontea et plusieurs périphériques ; les résultats confirment que Kalimucho fournit des adaptations en un temps d'exécution satisfaisant

Hands-free wearable system for helping in assembly tasks in aerospace

Las operaciones de mantenimiento tienen un gran impacto en la seguridad y esperanza de vida de cualquier producto, especialmente en ciertas aplicaciones dentro de la industria aeronáutica que tiene que pasar procedimientos muy rigurosos de seguridad. Los sistemas de ayuda llevables (wearable) pueden ayudar a reducir costes y tiempo de trabajo guiando a los operarios en tareas difíciles. El propósito de este trabajo es presentar un sistema de guiado de manos libre y llevable para soporte y ayuda de operarios en tareas de ensamblaje y verificación dentro del campo de la aeronáutica. El operario es capaz de pedir información al sistema sobre una tarea específica de un modo no invasivo así como pedir asistencia técnica al líder del equipo. El sistema desarrollado ha sido probado en una compañía aeronáutica (Airbus Military) y se ha evaluado su implementación en ciertas tareas de ensamblaje. La conclusión de las pruebas ha sido que el sistema ayuda a los operarios a realizar sus tareas de una manera más rápida, precisa y segura.Maintenance operations have a great impact on the safety and life expectancy of any product. This is especially true for certain applications within the aerospace industry, which must pass rigorous security checking procedures. Wearable helping systems can help to reduce costs and working time by guiding workers in some specifi c and diffi cult tasks. The purpose of this work is developing a handless and wearable guided system that supports and helps workers in assembly and verifi cation tasks within the aeronautic fi eld. The worker is able to request information for the specifi c task in a non invasive way and also ask the Team Leader for real time technical support and assistance. The system developed has been tested in an aeronautic company (Airbus Military) and its implementation in specifi c assembly tasks assessed. It was found that the proposed system can help workers to make their tasks faster, more accurate and more secure

On the Design of a SIP-Based Binding Middleware for Next Generation Home Network Services

Abstract. This paper proposes a two-layer component-based middleware frame-work that copes with the complexity of managing and constructing efficient and useful SIP-based home services. In the first layer, the device integration frame-work overcomes the heterogeneity of media home devices by providing protocol-independent components that reify the underlying devices. At the second layer, the binding framework allows constructing open mobile media bindings between SIP and non SIP communication protocol endpoints including media home de-vices. The openness of our framework is motivated by the need of constructing highly flexible home services such as context aware adaptation, session mobility, media session enrichment and QoS. Our framework is implemented as part of a context-aware adaptive middleware on top of the OSGi platform and an illustra-tive use case is shown.

Contributions to the safe execution of dynamic component-based real-time systems

Traditionally, real-time systems have based their design and execution on barely dynamic models to ensure, since design time, the temporal guarantees in the execution of their functionality. Great effort is being applied nowadays to progressively develop more dynamic systems, with the target of changing during their execution and to adapt themselves to their environment. The capability to change and to reconfigure themselves represents remarkable advantages as the capability to fix errors and to add new functionality with on-line updates. This means to be able to be updated without needing to stop the service, that may imply monetary losses in many cases. Design and development techniques based on components have become popular due to the use of components, which allows simplifying the system design, code reusability and updates through the substitution of components. The target of this thesis work is to provide certain degree of dynamism to real-time systems allowing them to replace components, incorporating new functionality of fixing existing bugs. On that purpose, a component-based framework is proposed, as well as the corresponding task in charge of providing dynamism to the system. The main contribution is to provide a framework to allow safe component replacements. Safe meaning that incorrect executions of tasks are avoided even y multiple tasks are executing concurrently and making use of the same data. Also that temporal guarantees are provided for every task. This framework incorporates a generic component model with real-time threads, a components replacement model with execution times that are known and bounded, and different strategies to apply such component replacement model. Some mechanisms to maintain a seamless and safe execution, regarding concurrency, before, during, and after applying the processes in charge of replacing running components are also described. Seamless execution means that components themselves do not perform the replacements, and safe means that temporal guarantees are provided and components are not affected in their execution. Part of these mechanisms are the system schedulability analysis and the framework tasks as well as reserving the needed resources for such scheduling to be correct. ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------Los sistemas de tiempo real han basado tradicionalmente su desarrollo en modelos altamente predecibles ya que estos requieren garantías temporales en su ejecución. A lo largo de los años, la technología de tiempo real ha ido penetrando en diferentes campos de aplicación y ajustándose a paradigmas de desarrollo software más novedosos. Esto ha presentado y presenta en la actualidad un tremendo reto ya que estas aplicaciones suelen tener un alto grado de dinamismo, lo que entra en conflicto con la predictibilidad temporal y, en general la ejecución segura de los mismos. Hoy en dia se esta realizando un gran esfuerzo en el desarrollo de sistemas cada vez más dinamicos que permitan adaptar su estructura en tiempo de ejecución para adaptarse a entornos que presentan condiciones cambiantes. La capacidad de soportar este tipo de dinamismo presenta ventajas descatables como permitir corregir fallos y anadir funcionalidad mediante actualizaciones en caliente, es decir, poder actualizarse sin necesidad de realizar paradas en su servicio, lo que podria implicar costes monetarios en muchos casos o perdidas temporales de servicio. Por otro lado, las técnicas de diseño y desarrollo basadas en componentes se han hecho muy populares y su aplicación a los sistemas de tiempo real gana terreno día a día. Uno de los principales motivos de ellos es que el uso de componentes permite simplificar el diseño del sistema, la reutilizacion de codigo e incluso la actualizacion del mismo mediante la substitucion de componentes. En esta tesis se aborda el objetivo de proveer a los sistemas de tiempo real de cierto grado de dinamismo para poder reemplazar componentes de forma segura, que permita incorporar nuevas funcionalidades o corregir errores existentes. Para ello, en esta tesis se ha elaborado de un marco de trabajo para dar soporte a reemplazos de componentes de forma segura, entendiendo como tal que el hecho de que no se produzcan ejecuciones incorrectas debido a la ejecución concurrente de multiples tareas, asi como el garantizar los tiempos de ejecucion de cada tarea y acotar la duración temporal de los reemplazos. El marco de trabajo propuesto está basado, pues, en componentes de tiempo real, que tiene en cuenta los requisitos temporales en la ejecución de los componentes del sistema y de las tareas propias del marco que dan soporte a estos mecanismos de reemplazo. Este marco de trabajo incorpora un modelo generico de componente con tareas de tiempo real, un modelo de reemplazo de componentes cuyos tiempos de ejecucion son conocidos y limitados en tiempo y diferentes estrategias de aplicacion de dicho modelo de reemplazo de componente. Las contribuciones propuestas integran el analisis de la planificabilidad de los componentes del sistema y de las tareas del marco de componentes para permitir establecer los parámetros de reserva de los recursos necesarios para las tareas del marco. Por último, se realiza una validación empírica en la que se comprueba experimentalmente la validez del modelo tanto de forma genérica como en un escenario específico y determinando también los recursos necesarios para su implementación

A holistic multi-purpose life logging framework

Die Paradigm des Life-Loggings verspricht durch den Vorschlag eines elektronisches Gedächtnisses dem menschlichem Gedächtnis eine komplementäre Assistenz. Life-Logs sind Werkzeuge oder Systeme, die automatisch Ereignisse des Lebens des Benutzers aufnehmen. Im technischem Sinne sind es Systeme, die den Alltag durchdringen und kontinuierlich konzeptuelle Informationen aus der Umgebung des Benutzers erfassen. Teile eines so gesammelten Datensatzes könnten aufbewahrt und für die nächsten Generationen zugänglich gemacht werden. Einige Teile sind es wert zusätzlich auch noch mit der Gesellschaft geteilt zu werden, z.B. in sozialen Netzwerken. Vom Teilen solcher Informationen profitiert sowohl der Benutzer als auch die Gesellschaft, beispielsweise durch die Verbesserung der sozialen Interaktion des Users, das ermöglichen neuer Gruppenverhaltensstudien usw. Anderseits, im Sinne der individuellen Privatsphäre, sind Life-log Informationen sehr sensibel und entsprechender Datenschutz sollte schon beim Design solcher Systeme in Betracht gezogen werden. Momentan sind Life-Logs hauptsächlich für den spezifischen Gebrauch als Gedächtnisstützen vorgesehen. Sie sind konfiguriert um nur mit einem vordefinierten Sensorset zu arbeiten. Das bedeutet sie sind nicht flexibel genug um neue Sensoren zu akzeptieren. Sensoren sind Kernkomponenten von Life-Logs und mit steigender Sensoranzahl wächst auch die Menge der Daten die für die Erfassung verfügbar sind. Zusätzlich bietet die Anordnung von mehreren Sensordaten bessere qualitative und quantitative Informationen über den Status und die Umgebung (Kontext) des Benutzers. Offenheit für Sensoren wirkt sich also sowohl für den User als auch für die Gemeinschaft positiv aus, indem es Potential für multidisziplinnäre Studien bietet. Zum Beispiel können Benutzer Sensoren konfigurieren um ihren Gesundheitszustand in einem gewissen Zeitraum zu überwachen und das System danach ändern um es wieder als Gedächtnisstütze zu verwenden. In dieser Dissertation stelle ich ein Life-Log Framework vor, das offen für die Erweiterung und Konfiguration von Sensoren ist. Die Offenheit und Erweiterbarkeit des Frameworks wird durch eine Sensorklassiffzierung und ein flexibles Model für die Speicherung der Life-Log Informationen unterstützt. Das Framework ermöglicht es den Benützern ihre Life-logs mit anderen zu teilen und unterstützt die notwendigen Merkmale vom Life Logging. Diese beinhalten Informationssuche (durch Annotation), langfristige digitale Erhaltung, digitales Vergessen, Sicherheit und Datenschutz.The paradigm of life-logging promises a complimentary assistance to the human memory by proposing an electronic memory. Life-logs are tools or systems, which automatically record users' life events in digital format. In a technical sense, they are pervasive tools or systems which continuously sense and capture contextual information from the user's environment. A dataset will be created from the collected information and some records of this dataset are worth preserving in the long-term and enable others, in future generations, to access them. Additionally, some parts are worth sharing with society e.g. through social networks. Sharing this information with society benefits both users and society in many ways, such as augmenting users' social interaction, group behavior studies, etc. However, in terms of individual privacy, life-log information is very sensitive and during the design of such a system privacy and security should be taken into account. Currently life-logs are designed for specific purposes such as memory augmentation, but they are not flexible enough to accept new sensors. This means that they have been configured to work only with a predefined set of sensors. Sensors are the core component of life-logs and increasing the number of sensors causes more data to be available for acquisition. Moreover a composition of multiple sensor data provides better qualitative and quantitative information about users' status and their environment (context). On the other hand, sensor openness benefits both users and communities by providing appropriate capabilities for multidisciplinary studies. For instance, users can configure sensors to monitor their health status for a specific period, after which they can change the system to use it for memory augmentation. In this dissertation I propose a life-log framework which is open to extension and configuration of its sensors. Openness and extendibility, which makes the framework holistic and multi-purpose, is supported by a sensor classification and a flexible model for storing life-log information. The framework enables users to share their life-log information and supports required features for life logging. These features include digital forgetting, facilitating information retrieval (through annotation), long-term digital preservation, security and privacy