Contracts and Behavioral Patterns for SoS: The EU IP DANSE approach

This paper presents some of the results of the first year of DANSE, one of the first EU IP projects dedicated to SoS. Concretely, we offer a tool chain that allows to specify SoS and SoS requirements at high level, and analyse them using powerful toolsets coming from the formal verification area. At the high level, we use UPDM, the system model provided by the british army as well as a new type of contract based on behavioral patterns. At low level, we rely on a powerful simulation toolset combined with recent advances from the area of statistical model checking. The approach has been applied to a case study developed at EADS Innovation Works.Comment: In Proceedings AiSoS 2013, arXiv:1311.319

Les affections dentaires chez le cheval

Ce travail vise à présenter de façon pragmatique les affections dentaires les plus fréquentes chez le cheval afin d'en faciliter le diagnostic et d'en améliorer le traitement. Le premier chapitre aborde la morphologie dentaire afin de décrire rigoureusement les structures dentaires, prélude essentiel à la détermination de l'âge par lecture des tables dentaires et à la compréhension de la physiologie dentaire. La deuxième partie présente les anomalies dentaires et les maladies dentaires dans leur détail suivi dans une troisième partie de leur diagnostic. Enfin dans une quatrième partie, il est question des traitements réalisé en clientèle vétérinaire traditionnelle, des fréquences des contrôles et des soins chirurgicaux envisageables et en devenir

Comparaison de strategies de calcul de bornes sur NoC

The Kalray MPPA2-256 processor integrates 256 processing cores and 32 management cores on a chip. Theses cores are grouped into clusters, and clusters are connected by a high-performance network on chip (NoC). This NoC provides some hardware mechanisms (egress traffic limiters) that can be configured to offer bounded latencies. This paper presents how network calculus can be used to bound these latencies while computing the routes of data flows, using linear programming. Then, its shows how other approaches can also be used and adapted to analyze this NoC. Their performances are then compared on three case studies: two small coming from previous studies, and one realistic with 128 or 256 flows. On theses cases studies, it shows that modeling the shaping introduced by links is of major importance to get accurate bounds. And when packets are of constant size, the Total Flow Analysis gives, on average, bounds 20%-25% smaller than all other methods

The relationship between epilithic biofilm stability and its associated meiofauna under two patterns of flood disturbance

Habitat stability is an important driver of ecological community composition and development. River epilithic biofilms are particularly unstable habitats for the establishment of benthic communities because they are regularly disturbed by floods. Our aim was to determine the influence of habitat instability on meiobenthic organisms. We hypothesized that hydrologic variables are the most important predictors of meiofauna distribution. We monitored epilithic communities (meiofauna and microalgae) with a high sampling frequency during 2 sampling periods with contrasting hydrodynamic patterns in a temperate river (the Garonne, France). Nematodes and rotifers dominated meiofaunal assemblages. The critical flow velocity threshold for their maintenance in the biofilm was ,30 cm/s, a result suggesting that meiofauna can resist higher flow velocity within the biofilm than within sediments. Nematode distribution was primarily influenced by the duration of undisturbed periods, whereas rotifer distribution was also correlated with the thickness of the biofilm. During the periods after floods, rotifers were faster colonizers than nematodes. Collectively, our results show that flow regime was an essential driver for biofilm community development

Contracts and Behavioral Patterns for Systems of systems: The EU IP DANSE approach

This report presents some of the results of the first year of Danse, one of the first EU IP projects dedicated to System of Systems. Concretely, we offer a tool chain that allows to specify SoS and SoS requirements at high level, and analyse them using powerful toolsets coming from the formal verification area. At the high level, we use UPDM, the system model provided by the british army as well as a new type of contract based on behavioral patterns. At low level, we rely on a powerful simulation toolset combined with recent advances from the area of statistical model checking. The approach has been applied to a case study developed at EADS Innovation Works.Ce document présente les résultats de la première année du projet Danse, un des premiers projets IP de recherche portant sur les systèmes de Systèmes (SoS en anglais). Concrètement, une chaîne d'outils a été développée de façon à spécifier à "haut niveau" puis à analyser formellement un SoS avec un ensemble prérequis, c'est à dire un ensemble de propriétés que le SoS doit valider. L'analyse du SoS repose sur l'utilisation d'outils efficaces de vérification formelle. À "haut niveau", le SoS est décrit en UPDML, le langage dédié à la modélisation des SoS que l'armée britannique à développé, alors que les prérequis du SoS sont spécifiés au moyen d'un langage de contrats décrivant les comportements attendus du systèmes. Cette spécification "haut niveau" est compilée en une représentation "bas-niveau" qui est simulée et analysée grâce à des outils émanant des récentes techniques de vérification statistique. L'approche a en particulier été appliquée sur un cas d'étude développé par EADS Innovation Works

Verifying Temporal Regular Properties of Abstractions of Term Rewriting Systems

The tree automaton completion is an algorithm used for proving safety properties of systems that can be modeled by a term rewriting system. This representation and verification technique works well for proving properties of infinite systems like cryptographic protocols or more recently on Java Bytecode programs. This algorithm computes a tree automaton which represents a (regular) over approximation of the set of reachable terms by rewriting initial terms. This approach is limited by the lack of information about rewriting relation between terms. Actually, terms in relation by rewriting are in the same equivalence class: there are recognized by the same state in the tree automaton. Our objective is to produce an automaton embedding an abstraction of the rewriting relation sufficient to prove temporal properties of the term rewriting system. We propose to extend the algorithm to produce an automaton having more equivalence classes to distinguish a term or a subterm from its successors w.r.t. rewriting. While ground transitions are used to recognize equivalence classes of terms, epsilon-transitions represent the rewriting relation between terms. From the completed automaton, it is possible to automatically build a Kripke structure abstracting the rewriting sequence. States of the Kripke structure are states of the tree automaton and the transition relation is given by the set of epsilon-transitions. States of the Kripke structure are labelled by the set of terms recognized using ground transitions. On this Kripke structure, we define the Regular Linear Temporal Logic (R-LTL) for expressing properties. Such properties can then be checked using standard model checking algorithms. The only difference between LTL and R-LTL is that predicates are replaced by regular sets of acceptable terms

Compositional proofs in differential dynamic logic dL

International audienceModularity and composability are essential properties to facilitate and scale the design of cyber-physical systems from the specification of hybrid, discrete and continuous, components. Modularity is essential to break down a system model into comprehensible and manageable component specifications. Composability is essential to design a system from component models while preserving their verified properties, expressed as assume-guarantee contracts. In this paper, we address the specification of hybrid system using Platzer's differential dynamic logic (dL). Our contribution is threefold: (1) We define a new composition operator in dL and prove that it is associative and commutative (AC). Prior notions of composition in dL were not associative. (2) We provide a theorem which characterizes necessary conditions to automate the proof that composed components satisfy the composition of their individual contracts, enabling modular and compositional verification. (3) We case-study our AC composition operator by considering the modular and detailed specification of a cruise controller in KeYmaera X, the latest implementation of dL, to demonstrate the proof automation capability of our contribution and exemplify a compositional design methodology

Adaptation of genetically monomorphic bacteria: evolution of copper resistance through multiple horizontal gene transfers of complex and versatile mobile genetic elements

Copper-based antimicrobial compounds are widely used to control plant bacterial pathogens. Pathogens have adapted in response to this selective pressure. Xanthomonas citri pv. citri, a major citrus pathogen causing Asiatic citrus canker, was first reported to carry plasmid-encoded copper resistance in Argentina. This phenotype was conferred by the copLAB gene system. The emergence of resistant strains has since been reported in Réunion and Martinique. Using microsatellite-based genotyping and copLAB PCR, we demonstrated that the genetic structure of the copper-resistant strains from these three regions was made up of two distant clusters and varied for the detection of copLAB amplicons. In order to investigate this pattern more closely, we sequenced six copper-resistant X. citri pv. citri strains from Argentina, Martinique and Réunion, together with reference copper-resistant Xanthomonas and Stenotrophomonas strains using long-read sequencing technology. Genes involved in copper resistance were found to be strain-dependent with the novel identification in X. citri pv. citri of copABCD and a cus heavy metal efflux resistance-nodulation-division system. The genes providing the adaptive trait were part of a mobile genetic element similar to Tn3-like transposons and included in a conjugative plasmid. This indicates the system's great versatility. The mining of all available bacterial genomes suggested that, within the bacterial community, the spread of copper resistance associated to mobile elements and their plasmid environments was primarily restricted to the Xanthomonadaceae family

Central vein catheter-related thrombosis in intensive care patients: incidence, risks factors, and relationship with catheter-related sepsis.

peer reviewed[en] OBJECTIVE: To evaluate the incidence and risk factors for catheter-related central vein thrombosis in ICU patients. DESIGN: Observational prospective multicenter study. SETTING: An 8-bed surgical ICU, a 10-bed surgical cardiovascular ICU, and a 10-bed medical-surgical ICU. PATIENTS: During an 18-month period, 265 internaljugular or subclavian catheters were included. Veins were explored by duplex scanning performed just before or < 24 h after catheter removal. Suspected risk factors of catheter-related central vein thrombosis were recorded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Fifty-seven catheters were excluded from the analysis. Therefore 208 catheters were analyzed. Mean age of patients was 64+/-15 years, simplified acute physiologic score was 12+/-5, organ system failure score at insertion was 1+/-1, and mean duration of catheterization was 9+/-5 days. A catheter-related internal jugular or subclavian vein thrombosis occurred in 33% of the cases (42% [95% confidence interval (CI), 34 to 49%] and 10% [95% CI, 3 to 18%], respectively). Thrombosis was limited in 8%, large in 22%, and occlusive in 3% of the cases. Internal jugular route (relative risk [RR], 4.13; 95% CI, 1.72 to 9.95), therapeutic heparinization (RR 0.47; 95% CI, 0.23 to 0.99), and age >64 years (RR, 2.44; 95% CI, 2.05 to 3.19) were independently associated with catheter-related thrombosis. Moreover, the risk of catheter-related sepsis was 2.62-fold higher when thrombosis occurred (p=0.011). CONCLUSIONS: Catheter-related central vein thrombosis is a frequent complication of central venous catheterization in ICU patients and is closely associated with catheter-related sepsis

A 3D Data Intensive Tele-immersive Grid

International audienceNetworked virtual environments like Second Life enable distant people to meet for leisure as well as work. But users are represented through avatars controlled by keyboards and mouses, leading to a low sense of presence especially regarding body language. Multi-camera real-time 3D modeling offers a way to ensure a significantly higher sense of presence. But producing quality geometries, well textured, and to enable distant user tele-presence in non trivial virtual environments is still a challenge today. In this paper we present a tele-immersive system based on multi-camera 3D modeling. Users from distant sites are immersed in a rich virtual environment served by a parallel terrain rendering engine. Distant users, present through their 3D model, can perform some local interactions while having a strong visual presence. We experimented our system between three large cities a few hundreds kilometers apart from each other. This work demonstrate the feasibility of a rich 3D multimedia environment ensuring users a strong sense of presence