A Mechanized Semantic Framework for Real-Time Systems

International audienceConcurrent systems consist of many components which may execute in parallel and are complex to design, to analyze, to verify, and to implement. The complexity increases if the systems have real-time constraints, which are very useful in avionic, spatial and other kind of embedded applications. In this paper we present a logical framework for defining and validating real-time formalisms as well as reasoning methods over them. For this purpose, we have implemented in the Coq proof assistant well known semantic domains for real-time systems based on labelled transitions systems and timed runs. We experiment our framework by considering the real-time CSP-based language fiacre, which has been defined as a pivot formalism for modeling languages (aadl, sdl, ...) used in the TOPCASED project. Thus, we define an extension to the formal semantic models mentioned above that facilitates the modeling of fine-grained time constraints of fiacre. Finally, we implement this extension in our framework and provide a proof method environment to deal with real-time system in order to achieve their formal certification

Seguridad e higiene en el sector de la construcción: el comienzo del fin de una indignidad

In a presentation of the reality in terms of prevention, safety and labour health in the construction sector and in the process of works execution considering the intervention in event of the "inevitable and excessive risk" of "the Administrations and Promotors", of "the Technical Designers of the Project", of the "Construction Companies" and lastly of "the workers".Es una presentación de la realidad en aspectos de prevención, seguridad y salud laboral en el sector de la construcción y en el proceso de ejecución de obra planteándose la intervención en el ''riesgo evitable y excesivo" de "las Administraciones y los Promotores'', de "los Técnicos Diseñadores del Proyecto'', de las "Empresas Constructoras" y, por último, de "los Trabajadores"

An Automatic Technique for Checking the Simulation of Timed Systems

International audienceIn this paper, we suggest an automatic technique for checking the timed weak simulation between timed transition systems. The technique is an observation-based method in which two timed transition systems are composed with a timed observer. A μ-calculus property that captures the timed weak simulation is then verified on the result of the composition. An interesting feature of the suggested technique is that it only relies on an untimed μ-calculus model-checker without any specific algorithm needed to analyze the result of the composition. We also show that our simulation relation supports interesting results concerning the trace inclusion and the preservation of linear properties. Finally, the technique is validated using the FIACRE/TINA toolset

Modelo experimental de prescripción del ejercicio aplicado al ámbito del Fitness Recreativo

El objeto de este estudio fue analizar los efectos que produce un modelo experimental de prescripción del ejercicio combinado de la RPE y diversos componentes esenciales del proceso de entrenamiento deportivo. este modelo experimental fue aplicado a dos programas diferentes de entrenamiento en circuito: tradicional con resistencia vs. inestabilidad con Bosu y TRX. Todos los participantes del programa de entrenamiento eran varones, estudiantes de Ciencias de la Actividad Física y del Deporte, que fueron asignados aleatoriamente a tres grupos: 2 experimentales (entrenamiento con resistencias e inestabilidades) y un grupo control. Los resultados del estudio demostraron que la aplicación de un modelo experimental de prescripción del ejercicio permite optimizar el estado de condición física y saludable, relacionados con el sistema cardiorrespiratorio y la fuerza de las extremidadesDepartamento de Didáctica de la Expresión Musical, Plástica y Corpora

Towards a verified transformation from AADL to the formal component-based language FIACRE

International audienceDuring the last decade, aadl  is an emerging architecture description languages addressing the modeling of embedded systems. Several research projects have shown that aadl  concepts are well suited to the design of embedded systems. Moreover, aadl  has a precise execution model which has proved to be one key feature for effective early analysis. In this paper, we are concerned with the foundational aspects of the verification support for aadl. More precisely, we propose a verification toolchain for aadl  models through its transformation to the Fiacre language which is the pivot verification language of the TOPCASED project: high level models can be transformed to Fiacre  models and then model-checked. Then, we investigate how to prove the correctness of the transformation from AADL into Fiacre and present related elementary ingredients: the semantics of aadl  and Fiacre  subsets expressed in a common framework, namely timed transition systems. We also briefly discuss experimental validation of the work

Key-recovery attacks on KIDS, a keyed anomaly detection system

Most anomaly detection systems rely on machine learning algorithms to derive a model of normality that is later used to detect suspicious events. Some works conducted over the last years have pointed out that such algorithms are generally susceptible to deception, notably in the form of attacks carefully constructed to evade detection. Various learning schemes have been proposed to overcome this weakness. One such system is Keyed IDS (KIDS), introduced at DIMVA "10. KIDS" core idea is akin to the functioning of some cryptographic primitives, namely to introduce a secret element (the key) into the scheme so that some operations are infeasible without knowing it. In KIDS the learned model and the computation of the anomaly score are both key-dependent, a fact which presumably prevents an attacker from creating evasion attacks. In this work we show that recovering the key is extremely simple provided that the attacker can interact with KIDS and get feedback about probing requests. We present realistic attacks for two different adversarial settings and show that recovering the key requires only a small amount of queries, which indicates that KIDS does not meet the claimed security properties. We finally revisit KIDS' central idea and provide heuristic arguments about its suitability and limitations

Physiological Responses at 15 Minutes of Recovery after a Session of Functional Fitness Training in Well-Trained Athletes

The aim of this study was to analyse muscle fatigue and metabolic stress at 15 min of recovery after performing two independent sessions of functional fitness training (FFT): a session of strength functional fitness training (FFTstrength) and a session of endurance functional fitness training (FFTendurance). Methods: eighteen well-trained men conducted two protocols, separated by one week of rest: FFTstrength (3 sets of 21, 15 and 9 repetitions of Thruster with bar + Pull ups) and FFTendurance (3 sets × (30 kcal rowing + 15 kcal assault air bike)). Neuromuscular fatigue and metabolic stress were measured right before, right after and at 10 and 15 min after completing the FFT workout, as well as the mean heart rate (HRmean) and the rating of perceived exertion (RPE) at the end of the FFT. Results: FFTendurance recovered the velocity loss values after 15 min of recovery. On the other hand, FFTstrength only recovered velocity in the 1 m·s−1 Tests in squat (SQ), since the velocity levels were 7% lower in the 1 m·s−1 Tests in military press exercise (MP) after 15 min. Conclusions: These data indicate that there are specific recovery patterns not only as a function of the exercise and the body regions involved, but also regarding the recovery of neuromuscular and metabolic factors, since both FFT workouts obtained high blood lactate concentrations.Sección Deptal. de Radiología, Rehabilitación y Fisioterapia (Enfermería)Fac. de Enfermería, Fisioterapia y PodologíaTRUEAlfonso X el Sabio University Foundationpu

Circulating nitrate-nitrite reduces oxygen uptake for improving resistance exercise performance after rest time in well-trained CrossFit athletes

This study aimed to determine the effects of circulating nitrate plus nitrite (NOx) concentrations on resistance exercise performance, VO2 and biomarkers of muscle damage. Eleven well-trained male CrossFit athletes (29.2 ± 3.7 years, 78.9 ± 5.4 kg, 175.1 ± 6.3 cm) carried out a resistance exercise test after drinking 140 mL of beetroot juice (BJ) or placebo. The test consisted of repeating the same resistance exercise routine twice: wall ball shots plus full back squat with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. Higher NOx plasma levels were verified after BJ than placebo in the pretest and post-test (p < 0.001). A higher number of repetitions was observed after BJ intake compared to placebo in the full back squat exercise during the first routine (p = 0.004). A significantly reduced VO2 was detected after BJ intake compared to placebo during rest and full back squat execution in the first routine (p < 0.05). Plasma myoglobin concentrations were significantly increased with BJ compared to placebo (p = 0.036). These results showed that plasma NOx levels reduced VO2 after BJ intake during rest time. These reduced VO2 was a key factor for improving full back squat performance during the first routine

Understanding the effects of beetroot juice intake on CrossFit performance by assessing hormonal, metabolic and mechanical response: a randomized, double-blind, crossover design

Background Acute beetroot juice (BJ) intake has shown to enhance aerobic and anaerobic performance. However, no studies have evaluated the effects of BJ intake on CrossFit (CF) performance by linking hormonal, metabolic, and mechanical responses. The purpose of this study was to determine the causal physiological association between hormonal, metabolic and mechanical responses, and CF workouts performance after acute BJ intake. Methods Twelve well-trained male practitioners undertook a CF workout after drinking 140 mL of BJ (~ 12.8 mmol NO3−) or placebo. The two experimental conditions (BJ or placebo) were administered using a randomized, double-blind, crossover design. The CF workout consisted of repeating the same exercise routine twice: Wall ball (WB) shots plus full back squat (FBS) with 3-min rest (1st routine) or without rest (2nd routine) between the two exercises. A 3-min rest was established between the two exercise routines. Results An interaction effect was observed in the number of repetitions performed (p = 0.04). The Bonferroni test determined a higher number of repetitions after BJ than placebo intake when a 3-min rest between WB and FBS (1st routine) was established (p = 0.007). An interaction effect was detected in cortisol response (p = 0.04). Cortisol showed a higher increase after BJ compared to placebo intake (76% vs. 36%, respectively). No interaction effect was observed in the testosterone and testosterone/cortisol ratio (p > 0.05). A significant interaction effect was found in oxygen saturation (p = 0.01). A greater oxygen saturation drop was observed in BJ compared to placebo (p <  0.05). An interaction effect was verified in muscular fatigue (p = 0.03) with a higher muscular fatigue being observed with BJ than placebo (p = 0.02). Conclusions BJ intake improved anaerobic performance only after the recovery time between exercises. This increase in performance in the first routine probably generated greater hypoxia in the muscle mass involved, possibly conditioning post-exercise performance. This was observed with a fall in oxygen saturation and in muscle fatigue measured at the end of the CF workout. The greatest perceived changes in cortisol levels after BJ intake could be attributed to the nitrate-nitrite-nitric oxide pathway

Efectos de la fatiga sobre la actividad muscular durante sucesivos test de sentadilla (30 seg).

Resumen:  Introducción: La fatiga se define como la incapacidad del Sistema neuromuscular para mantener un nivel determinado de potencia. La monitorización de la pérdida de Altura de salto ha sido utilizada como un indicador de fatiga muscular. La Electromiografía (EMG) es también una herramienta adecuada para determinar la fatiga ya que tiene una alta correlación con las unidades motoras activas (reclutamiento de fibras musculares). El objetivo del presente estudio es evaluar los efectos de la fatiga sobre la actividad muscular en las extremidades inferiores durante sucesivos test de media sentadilla (30 segundos). Métodos: 5 sujetos sanos entrenados participaron en el estudio. Realizaron 2 sesiones de test, un test de potencia máxima de media sentadilla y 4 series de un test de capacidad anaeróbica de media sentadilla (30 seg.). Resultados: Se observaron diferencias significativas (P=0.002) en la comparativa de los efectos inter-sujetos (Vasto lateral vs. Recto femoral). Observamos también diferencias significativas en la comparación por pares (P<0.001). Conclusiones: Observamos cómo la fatiga modifica la activación neuromuscular del vasto lateral y el recto femoral durante la ejecución de 4 test consecutivos de media sentadilla (30 seg.).Peer Reviewe