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

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)

Toward a Behavioral Decomposition for Context-awareness and Continuity of Services

International audienceMany adaptative context-aware middleware exist and most of them rely on so-called vertical architectures that offer a functional decomposition for contextawareness. This architecture has a weak point: it does not allow the system handling both dynamics of the changing environment and applications. To avoid this, we propose an approach for context-awareness based on a behavioral decomposition, and because each behavior must complete all functionalities necessary for contextawareness, we introduce an hybrid decomposition. It consists in a functional decomposition into a behavioral decomposition. This approach derives benefits from both decomposition, first allowing to handle environment and application's dynamics, second introducing reusability and modularity into behaviors

Context-Sensitive Authorization in Interaction Patterns

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, and what are the implications when applied to interaction patterns. We experiment and validate our approach using context as an authorization factor for eventing in Web service for device (like UPnP or DPWS)

WComp, a Middleware for Ubiquitous Computing

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A Symmetric Compositional Approach for Adaptive Ubiquitous Systems

International audienceIn ubiquitous computing, systems evolve surrounded by a heterogeneous smart-devices and software services, offering functionalities that enable new applications to be created. In such system, we need to consider the unpredictability of software infrastructure changes. To tackle the issue of the dynamic variation of the software infrastructure, compositional adaptation is now often used. The problem is that adaptation entities are independent-written. In such case, they may interfere when they are composed. In this paper, we propose a formal approach that allows composing applications at run time and managing these interferences. The formal model of the system and adaptations are defined in term of graphs. In particular, we demonstrate the symmetry property of our composition proces

MergeIA: A Service for Dynamic Merging of Interfering Adaptations in Ubiquitous System

International audienceThe composition of adaptations with system’s application does not always yield to the desired behavior. Each adaptation occurs correctly when it is separated but it may interact with other adaptations when they are combined. These interactions can affect the final behavior after adaptation; we call this an interference. This paper presents an on-going work, which aims to build a generic approach for the dynamic resolution of adaptation interferences in ubiquitous applications. We represent application and adaptation details by graphs; then we apply graph transformation rules on these graphs to resolve interferences. This allows us to express our approach independently of any implementation details of applications and adaptations

WComp, Middleware for Ubiquitous Computing and System Focused Adaptation

International audienceUbiquitous computing relies on computers present everywhere, at any times and in any things. Indeed with recent years advance in mobile communication technologies and the miniaturization of computer hardware, processing units are becoming invisible and a part of the environment. Middlewares for ubiquitous computing have to manage three main features specific to their environment: devices’ mobility, devices’ heterogeneity and environment’s dynamicity. The devices’ mobility, due to motion of users and their associated devices, forbids to assume that entities are known and will always be available. The second concept, entity’s heterogeneity, outlines the diversity between devices’ capabilities and functionalities provided by new smart objects. Finally, the environment high dynamicity illustrates the ubiquitous world entropy with the appearance and disappearance of devices. Devices used to create applications are thus unknown before discovering them. Then, ubiquitous computing must deal with such a dynamic software environment (called software infrastructure afterwards). As a result, future ubiquitous computing architectures must take into account those three constraints to solve ubiquitous computing challenges.Our model of middleware WComp is based on three parts: a software infrastructure, a service composition architecture, and a compositional adaptation mechanism