Software architectures: multi-scale refinement

We propose a multi-scale modeling approach for complex software system architecture description. The multi-scale description may help to obtain meaningful granularities of these systems and to understand and master their complexity. This vision enables an architect designer to express constraints concerning different description levels, oriented to facilitate adaptability management. We define a correct-by-design approach that allows a given abstract architectural description to be refined into architecture models. We follow a progressive refinement process based on model transformations; it begins with a coarse-grain description and ends with a fine-grain description that specifies design details. The adaptability property management is performed through model transformation operations. The model transformation ensures the correctness of UML description, and the correctness of the modeled system. We experimented our approach with a use case that models a smart home system for the monitoring of elderly and disabled persons at home

An unexpected application of minimization theory to module decompositions

The aim of this work is to show how we can decompose a module (if decomposable) into an indecomposable module with the help of the minimization process.Comment: 15-02-200

Multicystic tuberculosis pericarditis

This case concerns a 43 year-old woman followed for rheumatic mitral-aortic and tricuspid polyvalvulopathy, for which she underwents a double mitral-aortic replacement with mechanical prosthesis and tricuspid annuloplasty in June 2009. She was also treated for cervical ganglion tuberculosis in 2011. The history of her illness had started three months earlier with the appearance of signs of right cardiac failure. Transthoracic echocardiography showed good functioning of the mitral and aortic prostheses, as well as of the tricuspid ring, and good ventricular systolic function, with a thick pericardium full of cysts, associated with signs of adiastole (A). A thoracic CT-scan showed abundant septated pericardial effusion, mullticystic, but without involvement of the pulmonary or ganglion parenchymas (B). An additional MRI was performed, revealing a view of pericardial constriction with numerous pericardial cysts, with intermediate signal intensity on T2-weighted black blood spin-echo images, high signal intensity on T2-weighted STIR sequences, with thickening of the pericardial layers (C), (D). A pericardial biopsy was carried out, which found a granulomatous inflammatory reaction with positive finding for BK virus. After 9 months of anti-bacillary treatment, the patient underwent partial pericardial decortication, in view of the multiple adhesions, associated with the establishment of a pleuro-pericardial window. Anatomopathological analysis of the pericardial fluid as well as of fragments of the pericardium collected, confirmed the diagnosis of a tuberculous pericarditis. The evolution was marked by a clear clinical improvement with disappearance of signs of cardiac failure, and with a weight gain of 16 Kg in 4 months. Postoperative ETT monitoring at 2 months, 4 months and 6 months showed complete disappearance of both the cystic pericardial effusion and the signs of a diastole

Moderate Growth Time Series for Dynamic Combinatorics Modelisation

Here, we present a family of time series with a simple growth constraint. This family can be the basis of a model to apply to emerging computation in business and micro-economy where global functions can be expressed from local rules. We explicit a double statistics on these series which allows to establish a one-to-one correspondence between three other ballot-like strunctures

A Graph Transformation-Based Approach for the Validation of Checkpointing Algorithms in Distributed Systems

International audience—Autonomic Computing Systems are oriented to pre-vente the human intervention and to enable distributed systems to manage themselves. One of their challenges is the efficient monitoring at runtime oriented to collect information from which the system can automatically repair itself in case of failure. Quasi-Synchronous Checkpointing is a well-known technique, which allows processes to recover in spite of failures. Based on this technique, several checkpointing algorithms have been developed. According to the checkpoint properties detected and ensured, they are classified into: Strictly Z-Path Free (SZPF), Z-Path Free (ZPF) and Z-Cycle Free (ZCF). In the literature, the simulation has been the method adopted for the performance evaluation of checkpointing algorithms. However, few works have been designed to validate their correctness. In this paper, we propose a validation approach based on graph transformation oriented to automatically detect the previous mentioned checkpointing properties. To achieve this, we take the vector clocks resulting from the algorithm execution, and we model it into a causal graph. Then, we design and use transformation rules oriented to verify if in such a causal graph, the algorithm is exempt from non desirable patterns, such as Z-paths or Z-cycles, according to the case

Algebraic Elimination of epsilon-transitions

We present here algebraic formulas associating a k-automaton to a k-epsilon-automaton. The existence depends on the definition of the star of matrices and of elements in the semiring k. For this reason, we present the theorem which allows the transformation of k-epsilon-automata into k-automata. The two automata have the same behaviour.Comment: 13 decembre 200

Cause rare du syndrome occlusif: la pneumatose kystique intestinale

La pneumatose kystique intestinale est une Affection rare caractérisée par la présence de kystes gazeux dans la paroi intestinale, pouvant atteindre l'ensemble du tube digestif, avec une prédilection pour l'intestin grêle et le côlon. Le diagnostic est évoqué sur le scanner, permettant d'éviter l'intervention chirurgicale en absence de complications. Les auteurs rapportent une observation rare de pneumatose kystique colique, source de manifestations occlusives imposant l'intervention chirurgicale.Key words: Pneumatose kystique, syndrome occlusif, tomodensitométrie (TDM

An Operational Semantics Dedicated to the Coordination of Cooperating Agents

Abstract. This paper presents a contribution towards rigourous reasoning about coordinating agents. First, it defines formal models for coordination and coordinating agents. These models enable to specify the relations between the concepts of: plan, plan proposal and resource allocation, on the one hand, and concepts of: knowledge, belief and capability, on the other hand. Second, it provides a structured coordination language enabling to specify primitives, protocols and processes of coordination. This language is defined by a precise syntax, and it is formally interpreted using a transition system leading to an operational semantics for coordinating agents

A Pattern based Modelling for Self-Organizing Multi-Agent Systems with Event-B

International audienceSelf-Organizing Multi-Agent Systems (SO-MAS) are defined as a set of autonomous entities called agents interacting together in order to achieve a given task. Generally, the development process of these systems is based on the bottom-up approach which focuses on the design of the entities individual behavior. The main question arising when developing SO-MAS is how to insure that the designed entities, when interacting together, will give rise to the desired behavior? Our proposition to deal with this question is to use formal methods. We propose a correct by construction method for systematic design of SO-MAS based on the use of design patterns and formal stepwise refinements. Our work gives guidelines to assist the designer when developing the individual behavior of the entities and prove its correctness at the early stages of the design process. The method is illustrated with the foraging ants’ case study

Détection moléculaire du Coronavirus du Syndrome Respiratoire du Moyen-Orient (MERS-CoV) chez les dromadaires tunisiens (Camelus dromedarius)

Middle East Respiratory Syndrome Coronavirus (MERS-CoV) was identified in humans in 2012. Dromedary camels were considered as the major reservoir of the virus throw several studies. Tunisian dromedary camels were implicated in a serological survey and a seropositivity reaching 100% was observed among some of them. Therefore, more investigations are necessary to look for the current infection situation. In this study, we aimed to detect the MERS-CoV virus in our camels by molecular technics. Blood and nasal swabs samples from 64 dromedary camels from 4 Tunisian provinces were collected during June 2014 and April 2015. All the animals tested negative by real time reverse transcriptase–polymerase chain reaction assay (RT-PCR). These findings could not confirm the absence of MERS-CoV active shading among the Tunisian camel population and more researches should be carried on to survey dromedary camels in Tunisia and its neighboring countries. Keywords: Middle East respiratory syndrome (MERS), Camels, Tunisia, RT-PCR, animal surveillance, Coronavirus (CoVs), molecular detection.Le Coronavirus du syndrome respiratoire du Moyen-Orient (MERS-CoV) a été identifié chez l’Homme pour la première fois en 2012. A travers plusieurs études, les dromadaires ont été alors considérés comme étant le réservoir majeur du virus. Une enquête sérologique chez les dromadaires en Tunisie a permis de démontrer une séropositivité allant jusqu’à 100% chez certains sujets étudiés. Ainsi, des recherches supplémentaires semblent être nécessaires pour évaluer l’état d’infection actuel du pays. A travers cette étude, nous visons, par le biais de techniques moléculaires, la détection du virus (MERS-CoV) chez nos dromadaires tunisiens. Durant la période s’étalant entre juin 2014 et avril 2015, des échantillons de sang et des écouvillonnages nasaux ont été prélevés à partir de 64 individus prévenant de 4 gouvernorats. L’essai de la détection moléculaire, en utilisant la technique d’amplification génomique en chaîne de polymérase avec transcriptase inverse (RT-PCR), a démontré que tous les sujets étudiés ont donné un réponse négative. Cependant, ces résultats ne peuvent pas confirmer l’absence d’une excrétion active du virus chez la population cameline tunisienne, raison pour laquelle d’autres investigations doivent être enchaînées pour surveiller l’état d’infection cameline par le MERS-CoV non seulement en Tunisie mais également dans les pays voisins. Mots-clés: Le Syndrome Respiratoire du Moyen-Orient (SRMO), dromadaires, Tunisie, RT-PCR, surveillance animale, Coronavirus (CoVs), détection moléculair