A Dependable Autonomic Computing Environment for Self-Testing of Complex Heterogeneous Systems

AbstractThis paper is part of a R&D project aiming at the definition and implementation of an environment for dependable autonomic computing. The primary goal of the study is the increase of dependability of digital systems using self-healing techniques. Mobile agents implement self-testing policies for complex and heterogeneous systems. The aim of this paper is to present the general ideas of the project, describe the design decisions and a detailed view of the current architecture. The research includes design and development of a working prototype

Contribution à la Spécification et à la Vérification des Exigences Temporelles (Proposition d'une extension des SRS d'ERTMS niveau 2)

Les travaux développés dans cette thèse visent à assister le processus d ingénierie des exigences temporelles pour les systèmes complexes à contraintes de temps. Nos contributions portent sur trois volets : la spécification des exigences, la modélisation du comportement et la vérification. Pour le volet spécification, une nouvelle classification des exigences temporelles les plus communément utilisées a été proposée. Ensuite, afin de cadrer l utilisateur durant l expression des exigences, une grammaire de spécification à base de motifs prédéfinis en langage naturel est développée. Les exigences générées sont syntaxiquement précises et correctes quand elles sont prises individuellement, néanmoins cela ne garantie pas la cohérence de l ensemble des exigences exprimées. Ainsi, nous avons développé des mécanismes capables de détecter certains types d incohérences entre les exigences temporelles. Pour le volet modélisation du comportement, nous avons proposé un algorithme de transformation des state-machine avec des annotations temporelles en des automates temporisés. L idée étant de manipuler une notation assez intuitive et de générer automatiquement des modèles formels qui se prêtent à la vérification. Finalement, pour le volet vérification, nous avons adopté une technique de vérification à base d observateurs et qui repose sur le model-checking. Concrètement, nous avons élaboré une base de patterns d observation (ou observateurs) ; chacun des patterns développés est relatif à un type d exigence temporelle dans la nouvelle classification. Ainsi, la vérification est réduite à une analyse d accessibilité des états correspondants à la violation de l exigence associéeThe work developed in this thesis aims to assist the engineering process of temporal requirements for time-constrained complex systems. Our contributions concern three phases: the specification, the behaviour modelling and the verification. For the specification of temporal requirements, a new temporal properties typology taking into account all the common requirements one may meet when dealing with requirements specification, is introduced. Then, to facilitate the expression, we have proposed a structured English grammar. Nevertheless, even if each requirement taken individually is correct, we have no guarantee that a set of temporal properties one may express is consistent. Here we have proposed an algorithm based on graph theory techniques to check the consistency of temporal requirements sets. For the behaviour modelling, we have proposed an algorithm for transforming UML State Machine with time annotations into Timed Automata (TA). The idea is to allow the user manipulating a quite intuitive notation (UML SM diagramsduring the modelling phase and thereby, automatically generate formal models (TA) that could be used directly by the verification process. Finally, for the verification phase, we have adopted an observer-based technique. Actually, we have developed a repository of observation patterns where each pattern is relative to a particular temporal requirement class in our classification. Thereby, the verification process is reduced to a reachability analysis of the observers KO states relatives to the requirements violationVILLENEUVE D'ASCQ-ECLI (590092307) / SudocSudocFranceF

An Approach for Testing Mobile Agents Using the Nets within Nets Paradigm

Among all the different architectures being researched in the field of multi-agent systems, the mobile agent has shown to be one of the most challenging and most critical systems. With more applications being developed, there is a need to ensure large and complicated mobile agent systems are functioning correctly, with minimum or no errors. Moreover, the model-based testing technique has gained attention with the popularization of models in software design and development. Since the paradigm on nets within nets is well suited to express the dynamics of open mobile agents, it is retained as an abstract model from which abstract test cases are generated. Those test cases are then concretized and addressed to the system under test. The responses of the system under test are, finally, compared to the expected results derived from the abstract test model. As a case study, we modeled a packet world example on which different colored packets are scattered. Agents that live in this virtual world have to collect those packets and bring them to their right destination.For further information, please visit this web site