Context-aware Authorization in Highly Dynamic Environments

Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. Context is a key to adapt suiting user needs. On the other hand, standard access control trusts users once they have authenticated, despite the fact that they may reach unauthorized contexts. We analyse how taking into account dynamic information like context in the authorization subsystem can improve security, and how this new access control applies to interaction patterns, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS), in smart home security

Aspects of Assembly and Cascaded Aspects of Assembly: Logical and Temporal Properties

Highly dynamic computing environments, like ubiquitous and pervasive computing environments, require frequent adaptation of applications. This has to be done in a timely fashion, and the adaptation process must be as fast as possible and mastered. Moreover the adaptation process has to ensure a consistent result when finished whereas adaptations to be implemented cannot be anticipated at design time. In this paper we present our mechanism for self-adaptation based on the aspect oriented programming paradigm called Aspect of Assembly (AAs). Using AAs: (1) the adaptations process is fast and its duration is mastered; (2) adaptations' entities are independent of each other thanks to the weaver logical merging mechanism; and (3) the high variability of the software infrastructure can be managed using a mono or multi-cycle weaving approach.Comment: 14 pages, published in International Journal of Computer Science, Volume 8, issue 4, Jul 2011, ISSN 1694-081

Leveraging ambient applications interactions with their environment to improve services selection relevancy

Semantic web technologies are gaining momentum in the WoT (Web of Things) community for its promising ability to manage the increasing semantic heterogeneity between devices (Semantic Web of Things, SWoT). However, most of the approaches rely on ad-hoc and static knowledge models (ontologies) designed for specific domains and applications. While it is a solution for handling the semantic heterogeneity issue, it offers no perspective in term of ontology evolution over time. We study in this poster several approaches allowing: (1) to handle the semantic heterogeneity issue; (2) to capitalize the knowledge contributions throughout the life of the system allowing it to potentially better assist people in their environment over time. One of the approaches is validated on a real use-case

Dynamic knowledge model evolution in SWoT: a way to improve services selection relevancy over time

Semantic web technologies are gaining momentum in the WoT (Web of Things) community for its promising ability to manage the increasing semantic heterogeneity between devices (Semantic Web of Things, SWoT) in ambient environments. However, most of the approaches rely on ad-hoc and static knowledge models (ontologies) designed for specific domains and applications. While it is a solution for handling the semantic heterogeneity issue, it offers no perspective in term of ontology evolution over time. We study in this paper several approaches allowing: (1) to handle the semantic heterogeneity issue; (2) to capitalize the knowledge contributions throughout the life of the system allowing it to potentially better assist people in their environment over time. One of the approaches is validated on two real use-cases

Discrete Event Modeling and Simulation for IoT Efficient Design Combining WComp and DEVSimPy Framework

International audienceOne of today's challenges in the framework of ubiquitous computing concerns the design of ambient systems including sensors, smart-phones, interconnected objects, computers, etc. The major difficulty is to propose a compositional adaptation which aims to integrate new features that were not foreseen in the design, remove or exchange entities that are no longer available in a given context. In order to provide help to overcome this difficulty, a new approach based on the definition of strategies validated using discrete-event simulation is proposed. Such strategies make it possible to take into account conflicts and compositional adaptation of components in ambient systems. These are defined and validate using a discrete-event formalism to be integrated into a prototyping and dynamic execution environment for ambient intelligence applications. The proposed solution allows the designers of ambient systems to define the optimum matching of all components to each other. One pedagogical example is presented (switch-lamp system) as a proof of the proposed approach

Smart Geographic object: Toward a new understanding of GIS Technology in Ubiquitous Computing

One of the fundamental aspects of ubiquitous computing is the instrumentation of the real world by smart devices. This instrumentation constitutes an opportunity to rethink the interactions between human beings and their environment on the one hand, and between the components of this environment on the other. In this paper we discuss what this understanding of ubiquitous computing can bring to geographic science and particularly to GIS technology. Our main idea is the instrumentation of the geographic environment through the instrumentation of geographic objects composing it. And then investigate how this instrumentation can meet the current limitations of GIS technology, and offers a new stage of rapprochement between the earth and its abstraction. As result, the current research work proposes a new concept we named Smart Geographic Object SGO. The latter is a convergence point between the smart objects and geographic objects, two concepts appertaining respectively to

Context-sensitive authorization for asynchronous communications

Main requirement of recent computing environments, like mobile and then ubiquitous computing, is to adapt applications to context. On the other hand, access control generally trust users once they have authenticated, despite the fact that they may reach unauthorized situations. We analyse how dynamic information can be used to improve security in the authorization process, especially in the case of asynchronous communications, like messaging or eventing. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS)

Utilisation des Random Forests pour la reconnaissance d'activité humaine: une étude complète avec le jeu de données d'Opportunity

International audienceUn grand nombre de recherches existent pour la reconnaissance d'activité humaine. Cependant, la plupart d'entre elles utilisent un ensemble statique et immuable de capteurs connus par avance. Cette approche ne fonctionne pas lorsqu'elle est appliquée à un système ubiquitaire, car nous ne connaissons alors pas par avance quels capteurs seront disponibles dans l'environnement de l'utilisateur. C'est pourquoi nous considérons ici une approche opportuniste où chaque capteur est entrainé individuellement et capable d'apporter sa propre connaissance. Nous considérons toutes les étapes de la chaîne de reconnaissance d'activité et nous montrons comment ce processus peut être amélioré à chacune de ces étapes. Plus précisément, nous prenons en compte les étapes telles que le prétraitement, la segmentation, l'extraction de caractéristiques et l'apprentissage. Nous proposons également d'évaluer à la fois l'efficacité des Random Forests (RF) pour entrainer des capteurs et la robustesse de la fusion des résultats basée sur le vote à la majorité en comparant les résultats obtenus à ceux du projet Opportunity. Nous montrons ainsi que les RF donnent de meilleurs résultats plus robustes que les algorithmes d'apprentissage testés par Opportunity