Algorithmic Based Fault Tolerance Applied to High Performance Computing

We present a new approach to fault tolerance for High Performance Computing system. Our approach is based on a careful adaptation of the Algorithmic Based Fault Tolerance technique (Huang and Abraham, 1984) to the need of parallel distributed computation. We obtain a strongly scalable mechanism for fault tolerance. We can also detect and correct errors (bit-flip) on the fly of a computation. To assess the viability of our approach, we have developed a fault tolerant matrix-matrix multiplication subroutine and we propose some models to predict its running time. Our parallel fault-tolerant matrix-matrix multiplication scores 1.4 TFLOPS on 484 processors (cluster jacquard.nersc.gov) and returns a correct result while one process failure has happened. This represents 65% of the machine peak efficiency and less than 12% overhead with respect to the fastest failure-free implementation. We predict (and have observed) that, as we increase the processor count, the overhead of the fault tolerance drops significantly

Stability of legal situations within actions based on legality

La stabilité des situations juridiques est une exigence de l’ordre juridique dérivée du principe de sécurité juridique, sous l’égide duquel elle contribue à l’État de droit. Supposant que les situations formées sur la base d’actes juridiques puissent se maintenir dans le temps et suivre un cours prévisible, elle peut entrer en conflit avec le principe de légalité qui commande, pour sa part, que les actes illégaux et les situations qu’ils fondent soient anéantis. La dialectique entre ces deux valeurs est au coeur du contentieux de la légalité, dont elle détermine les équilibres procéduraux. La période contemporaine assiste à une révision de ces équilibres en faveur de la stabilité, opérée sous l’influence du juge et du législateur, qui interroge sur l’orientation donnée au contentieux de la légalité et, plus largement, sur la place et les formes du contrôle de la puissance publique au sein de l’État de droit. Le souci de la stabilité des situations juridiques se traduit ainsi, par une prise de distance à l’égard de la conception libérale de l’intérêt pour agir en contentieux de l’excès de pouvoir, ainsi que par une plus grande attention au passage du temps dans l’examen de la recevabilité des recours. Il influence également l’office du juge de la légalité, dont les pouvoirs se sont considérablement développés afin de rechercher une conciliation optimale entre les impératifs concurrents qu’il entend satisfaire. En altérant la conception du recours et de la fonction du juge, l’exigence de stabilité des situations juridiques contribue à des évolutions majeures de la justice administrativeStability of legal situations is a requirement of the legal order, which stems from the principle of legal certainty and contributes, under its aegis, to guaranteeing the rule of law. It implies the situations created by legal acts may last for a time and run a forseeable course. However, it can also contradicts the principle of legality, which demands that illegal acts and situations be undone. The dialectic relationship between these two legal values defines the procedural balance within the actions based on legality. Under the influence of the courts as well as the legislator ,the recent times have witnessed a tendancy to re-examine this balance in favour of stability, which raises questions on the orientations of the actions aiming to restore legality and, in a broader view, on the place and the means of the judicial review of public decisions under the rule of law. The attention to the stability of legal situations lead to a step back from the generous appreciation of locus standi in actions for annulment, as well as a greater care to the course of time in regards to admissibility of claims. It also shaped the judge's duties and powers, the latters having considerably developped in order to offer the optimal balance between the opposite aims they mean to achieve. Altering the way the legal actions are looked upon and the general function vested to the judge, the requirement of stability contributes to major evolutions of the administrative justice

La stabilité des situations juridiques dans le contentieux de la légalité

Stability of legal situations is a requirement of the legal order, which stems from the principle of legal certainty and contributes, under its aegis, to guaranteeing the rule of law. It implies the situations created by legal acts may last for a time and run a forseeable course. However, it can also contradicts the principle of legality, which demands that illegal acts and situations be undone. The dialectic relationship between these two legal values defines the procedural balance within the actions based on legality. Under the influence of the courts as well as the legislator ,the recent times have witnessed a tendancy to re-examine this balance in favour of stability, which raises questions on the orientations of the actions aiming to restore legality and, in a broader view, on the place and the means of the judicial review of public decisions under the rule of law. The attention to the stability of legal situations lead to a step back from the generous appreciation of locus standi in actions for annulment, as well as a greater care to the course of time in regards to admissibility of claims. It also shaped the judge's duties and powers, the latters having considerably developped in order to offer the optimal balance between the opposite aims they mean to achieve. Altering the way the legal actions are looked upon and the general function vested to the judge, the requirement of stability contributes to major evolutions of the administrative justice.La stabilité des situations juridiques est une exigence de l’ordre juridique dérivée du principe de sécurité juridique, sous l’égide duquel elle contribue à l’État de droit. Supposant que les situations formées sur la base d’actes juridiques puissent se maintenir dans le temps et suivre un cours prévisible, elle peut entrer en conflit avec le principe de légalité qui commande, pour sa part, que les actes illégaux et les situations qu’ils fondent soient anéantis. La dialectique entre ces deux valeurs est au coeur du contentieux de la légalité, dont elle détermine les équilibres procéduraux. La période contemporaine assiste à une révision de ces équilibres en faveur de la stabilité, opérée sous l’influence du juge et du législateur, qui interroge sur l’orientation donnée au contentieux de la légalité et, plus largement, sur la place et les formes du contrôle de la puissance publique au sein de l’État de droit. Le souci de la stabilité des situations juridiques se traduit ainsi, par une prise de distance à l’égard de la conception libérale de l’intérêt pour agir en contentieux de l’excès de pouvoir, ainsi que par une plus grande attention au passage du temps dans l’examen de la recevabilité des recours. Il influence également l’office du juge de la légalité, dont les pouvoirs se sont considérablement développés afin de rechercher une conciliation optimale entre les impératifs concurrents qu’il entend satisfaire. En altérant la conception du recours et de la fonction du juge, l’exigence de stabilité des situations juridiques contribue à des évolutions majeures de la justice administrativ

A Component Based Methodology for Description of Complex Systems. An Application to Avionics Systems

In this paper, we present a component based methodology for the description of complex systems and its application to the field of avionics components design. Avionics design involves several engineering branches, namely physics, electronics and computational science. Three viewpoints are extracted from this context: architectural, operating and functional viewpoints. The case study we use to illustrate this paper describes the compositional design of a subsystem of an aircraft's flight controls. We show the description and composition of multiple viewpoints, the expression of critical properties on independent viewpoints, as well as on the resulting composite system. In a second step, we discuss how existing formal specification and verification techniques can be used to achieve requirement meeting verification. An application on the case study is also provided

20 ans de suivi de la contamination chimique des eaux côtières méditerranéennes. Résultats & perspectives

Ce rapport fait le bilan de la surveillance de la contamination chimique opérée par l’Ifremer, en partenariat avec l’agence de l’eau Rhône Méditerranée Corse, entre 1998 et 2018. Il présente sur la forme de graphiques et de cartes les principaux résultats obtenus durant cette période ainsi que l’évolution des méthodes et des stratégies de surveillance des eaux côtières de Méditerranée

Pediatr Nephrol

BACKGROUND: Hemolytic uremic syndrome related to Shiga-toxin-secreting Escherichia coli infection (STEC-HUS) remains a common cause of acute kidney injury in young children. No specific treatment has been validated for this severe disease. Recently, experimental studies highlight the potential role of complement in STEC-HUS pathophysiology. Eculizumab (EC), a monoclonal antibody against terminal complement complex, has been used in severe STEC-HUS patients, mostly during the 2011 German outbreak, with conflicting results. METHODS: On behalf of the French Society of Pediatric Nephrology, we retrospectively studied 33 children from 15 centers treated with EC for severe STEC-HUS. Indication for EC was neurologic involvement in 20 patients, cardiac and neurologic involvement in 8, cardiac involvement in 2, and digestive involvement in 3. Based on medical status at last follow-up, patients were divided into two groups: favorable (n = 15) and unfavorable outcomes (n = 18). RESULTS: Among patients with favorable outcome, 11/14 patients (79%) displayed persistent blockade of complement activity before each EC reinjection. Conversely, in patients with unfavorable outcome, only 9/15 (53%) had persistent blockade (p = n.s.). Among 28 patients presenting neurological symptoms, 19 had favorable neurological outcome including 17 with prompt recovery following first EC injection. Only two adverse effects potentially related to EC treatment were reported. CONCLUSIONS: Taken together, these results may support EC use in severe STEC-HUS patients, especially those presenting severe neurological symptoms. The study, however, is limited by absence of a control group and use of multiple therapeutic interventions in treatment groups. Thus, prospective, controlled trials should be undertaken

The EKiTE network (epidemiology in kidney transplantation - a European validated database): an initiative epidemiological and translational European collaborative research

BACKGROUND: Kidney transplantation is considered to be the treatment of choice for people with end-stage renal disease (ESRD). However, due to the shortage of available organs and the increase in the ESRD prevalence in Europe, it is essential to improve transplantation outcomes by studying the related prognostic factors. Today, there is no European registry collecting data to perform such clinical epidemiology studies. MAIN BODY: Entitled EKiTE, for European cohort for Kidney Transplantation Epidemiology, this prospective and multicentric cohort includes patients from Spanish (Barcelona), Belgian (Leuven), Norwegian (Oslo) and French (Paris Necker, Lyon, Nantes, Nancy, Montpellier, Nice and Paris Saint Louis) transplantation centers and currently contains 13,394 adult recipients of kidney (only) transplantation from 2005 and updated annually. A large set of parameters collected from transplantation until graft failure or death with numbers of post-transplantation outcomes. The long-term follow-up and the collected data enable a wide range of possible survival and longitudinal analyses. CONCLUSION: EKiTE is a multicentric cohort aiming to better assess the natural history of the ESRD in European kidney transplant recipients and perform benchmarking of clinical practices. The data are available for clinical epidemiology studies and open for external investigators upon request to the scientific council. Short-term perspectives are to extend EKITE network to other European countries and collect additional parameters in respect of the common thesaurus.status: publishe