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International audience; The memory models used in the Real-Time Specification for Java (RTSJ) can incur high amounts of overhead; It is possible to reduce this overhead by taking advantages of hardware features. This paper provides an indepth analytical investigation of the overhead of write barriers in RTSJ VMs, and describes and analyzes some solutions to reduce the overhead of write barriers.

International audience; This chapter presents a set of methods related to the recovery of camera motion parameters and to the segmentation of mobile objects in video documents for content indexing. This includes methods for the segmentation of video documents into continuous shots, methods for motion analysis, methods for extracting reliable trajectories within shots, and two different methods for the recovery of the camera motion (relatively to the main background), the first one for a camera maintained at a fixed location with rotational and zoom degrees of freedom, and the second one for a camera of arbitrary motion but assuming a fixed focal length. The first camera motion recovery method is based on the search of an optimal projective transform between consecutive images combined with an iterative background / mobile objects segmentation process. The second one is based on a paraperspective factorization method for shape and motion recovery. The presented methods are illustrated in the context of a video indexing system developed at CLIPS-IMAG into which they are integrated. The system also attempts to classify shots or sub-segments of shots into one of the following categories of ''no motion'', ''non mobile camera motion'', ''mobile camera motion'' or ''other type of motion''. Further sub-categorization can be done for each recovered type. Sample results are presented using sequences extracted from video documents of the ISIS GDR-PRC GT10/AIM test corpus.

International audience; The use of middleware is the current practice for developing distributed systems. Developers compose reusable services provided by standard middleware infrastructures, e.g., CORBA 1, DCOM2, Java RMI & re- lated services3, etc., to deal with problems like distribution, security, transactional processing, fault tolerance, etc.. The development process gets even easier after the evolution of the originally proposed Object-Oriented middleware paradigm, towards nowadays component-based middleware paradigm, e.g., CCM1, MTS2, EJB3. Developers do not have to burden with the, sometimes considerably complex, composition of different middleware services. Instead they build their middleware components and deploy them within of-the-shelf middleware containers realizing a customizable composition of middleware services. However, things are not as simple as they seem. Middleware vendors have to design and implement complex architectures combining available middleware services into a flexible/customizable way. Different ways of composing middleware services into a middleware architecture that satisfies application requirements are possible. The resulting compositions should be supported by the configurable middleware architecture that is provided by vendors to customers. Moreover, of-the-shelf middleware architectures should come along with a quality assessment of the different possible compositions they support. This shall give customers clues for selecting the most suitable middleware compositions for their particular systems. In this paper we address the above issues. More specifically, we present a developer-oriented environment that facilitates the design and quality analysis of flexible/configurable middleware architectures. The environment provides support for modelling middleware architectures. It further comprises a repository that is populated by a middleware vendor with basic middleware architectural patterns describing the use of individual services provided by the vendor's infrastructure. The environment further provides a tool which constructs all possible valid compositions of a set of basic middleware architectural patterns. Finally, the environment includes tool support for the automated generation of traditional quality models for the performance and reliability analysis of the different valid compositions of middleware architectural patterns. Those models serve as input to existing performance and reliability analysis tools, which are integrated into the environment.

International audience; This paper introduces principled methods for the reliability analysis of business processes that rely on web services. The input to the problem is the BPEL specification of a business process and the output is the prediction of the process's reliability. The first step to this end involves a method for the translation of the BPEL specification to its corresponding UML model. The second step of the reliability analysis involves a principled way for the annotation of the UML model with the necessary extensions for the specification of reliability properties that characterise the behaviour of the elements that constitute the process. The third step of the analysis comprises the systematic mapping of the extended UML model to block diagrams and Markov models which are subsequently used to compute the reliability of the process.

Service-oriented computing is now acknowledged as a central paradigm for Internet computing, supported by tremendous research and technology development over the last 10 years. However, the evolution of the Internet, and in particular, the latest Future Internet vision, challenges the paradigm. Indeed, service-oriented computing has to face the ultra large scale and heterogeneity of the Future Internet, which are orders of magnitude higher than those of today’s service-oriented systems. This article aims at contributing to this objective by identifying the key research directions to be followed in light of the latest state of the art. This article more specifically focuses on research challenges for service-oriented middleware design, therefore, investigating service description, discovery, access, and composition in the Future Internet of services.

International audience; B3G is an emerging network technology which conceives the convergence of telecommunication and IP-based networks for providing enhanced services able to transfer both voice and non-voice data through wired and wireless networks. Moreover, B3G networks can be no longer considered as “passive” entities which only transport data between endpoints, but they must be considered as “active” parties that have their own behavior and provide services. This creates a completely new application domain where applying current software engineering design tools, such as software architectures, fails. In fact, dealing with B3G networks requires to explicit low-level details usually abstracted by the architectural descriptions. To this extent, we present an ongoing work on investigating B3Goriented application modeling. In particular, we propose an enhanced UML profile to define and analyze software architectures that explicitly exploit the B3G domain properties.

International audience; Self-adaptation enables software systems to respond to changing environmental contexts that may not be fully understood at design time. Designing a dynamically adaptive system (DAS) to cope with this uncertainty is challenging, as it is impractical during requirements analysis and design time to anticipate every environmental condition that the DAS may encounter. Previously, the RELAX language was proposed to make requirements more tolerant to environmental uncertainty, and Claims were applied as markers of uncertainty that document how design assumptions affect goals. This paper integrates these two techniques in order to assess the validity of Claims at run time while tolerating minor and unanticipated environmental conditions that can trigger adaptations. We apply the proposed approach to the dynamic reconfiguration of a remote data mirroring network that must diffuse data while minimizing costs and exposure to data loss. Results show RELAXing Claims enables a DAS to reduce adaptation costs.

This paper focuses on the development of a principled methodology for the dependability analysis of composite Web services. The first step of the methodology involves a UML representation for the architecture specification of composite Web services. The proposed representation is built upon BPEL and introduces necessary extensions to support the second step of the methodology, which comprises the specification of properties, characterizing the failure behavior of the elements that constitute the composite Web services. The automated mapping of this extended UML model to Block Diagrams and Markov models is introduced as the third step of the methodology. A comparative analysis of the aforementioned dependability analysis techniques in terms of precision and complexity is also performed. On the Move to Meaningful Internet Systems 2004: Coopls, Doa, and Odbase, Pt 2, Proceedings

Coordination and Adaptation are two key issues when developing complex distributed systems. Coordination focuses on the interaction among software entities. Adaptation focuses on solving the problems that arise when the interacting entities do not match properly. This is the report of the third edition of the WCAT workshop, that took place in Nantes jointly with ECOOP 2006. In this third edition, the topics of interest of the participants covered a large number of fields where coordination and adaptation have an impact: models, requirements identification, interface specification, extra-functional properties, automatic generation, frameworks, middleware, and tools.

International audience; Highly dynamic and heterogeneous distributed systems are challenging today's middleware technologies. Existing middleware paradigms are unable to deliver on their most central promise, which is offering interoperability. In this paper, we argue for the need to dynamically synthesise distributed system infrastructures according to the current operating environment, thereby generating "Emergent Middleware'' to mediate interactions among heterogeneous networked systems that interact in an ad hoc way. The paper outlines the overall architecture of Enablers underlying Emergent Middleware, and in particular focuses on the key role of learning in supporting such a process, spanning statistical learning to infer the semantics of networked system functions and automata learning to extract the related behaviours of networked systems.

International audience; Pervasive environments are characterised by highly heterogeneous services and mobile devices with dynamic availability. Approaches such as that proposed by the Connect project provide means to enable such systems to be discovered and composed, through mediation where necessary. As services appear and disappear, the set of feasible compositions changes. In such a pervasive environment, a designer encounters two related challenges: what goals it is reasonable to pursue in the current context and how to use the services presently available to achieve his goals. This paper proposes an approach to design service compositions, facilitating an interactive process to find the trade-off between the possible and the desirable. Following our approach, the system finds at runtime, where possible, compositions related to the developer's requirements. This process can realise the intent the developer specifies at design time, taking into account the services available at runtime, without a prohibitive level of pre-specification, inappropriate for such dynamic environments.

International audience; Security-by-Contract (S×C) is a paradigm providing security assurances for mobile applications. In this work, we present the an extension of S×C, called Security-by-Contract-with-Trust (S×C×T). Indeed, we enrich the S×C architecture by integrating a trust model and adding new modules and configurations for managing contracts. Indeed, at deploy-time, our system decides the run-time configuration depending on the credentials of the contract provider. The run-time environment can both enforce a security policy and monitor the declared contract. According to the actual behaviour of the running program our architecture updates the trust level associated with the contract provider. We also present a possible application of our framework in the scenario of a mobile application marketplace, e.g., Apple AppStore, Cydia, Android Market, that, nowadays, are considered as one of the most attractive e-commerce activity for both mobile application developers and industries of mobile devices. Since the number of applications increases, Mobile Applications Marketplace (MAMp) sets up recommendation systems that rank and highlight mobile applications by category, social activity, etc. The S×C×T framework we propose is applied in this scenario for providing security on cus- tomers' mobile devices as well as help Mobile Applications Marketplaces to enhance their recommendation systems with security feedback. The main advantage of this method is an automatic management of the level of trust of software and contract releasers and a unified way for dealing with both security and trust.