Formal Safety and Security Assessment of an Avionic Architecture with Alloy

We propose an approach based on Alloy to formally model and assess a system architecture with respect to safety and security requirements. We illustrate this approach by considering as a case study an avionic system developed by Thales, which provides guidance to aircraft. We show how to define in Alloy a metamodel of avionic architectures with a focus on failure propagations. We then express the specific architecture of the case study in Alloy. Finally, we express and check properties that refer to the robustness of the architecture to failures and attacks.Comment: In Proceedings ESSS 2014, arXiv:1405.055

Combining Model-Based Design (MBD) and Model-Based Testing (MBT) for early validation of embedded real-time systems

International audienceThis paper describes an approach combining Model-Based Engineering (MBE) and Model-Based Testing, and its application to requirements validation for an embedded Instrumentation & Control (I&C) system. Many aspects of the embedded system can thus be validated early in the lifecycle, long before an actual implementation is developed, and, most importantly, requirements can be validated before the system is implemented. A flexible integration environment makes it possible to reuse the test cases throughout the lifecycle. This approach is being implemented in the CONNEXION R&D project, using Esterel Technologies’ SCADE Suite and All4tec’s MaTeLo, with Corys’ ALICES as an integration environment

Convergence of the Latest Standards Addressing Safety and Security for Information Technology

International audienceSafety and Security have always been considered separately in most industrial process. Actually, there is a growing consensus that for many applications, Safety as well as Security demands have to be observed in a coherent manner. Risk analysis to counter malicious attacks can be also reused with appropriate modification for unplanned system failure

Random generation of finitely generated subgroups of a free group

We give an efficient algorithm to randomly generate finitely generated subgroups of a given size, in a finite rank free group. Here, the size of a subgroup is the number of vertices of its representation by a reduced graph such as can be obtained by the method of Stallings foldings. Our algorithm randomly generates a subgroup of a given size n, according to the uniform distribution over size n subgroups. In the process, we give estimates of the number of size n subgroups, of the average rank of size n subgroups, and of the proportion of such subgroups that have finite index. Our algorithm has average case complexity \O(n) in the RAM model and \O(n^2\log^2n) in the bitcost model

Disfluences dans le vieillissement "normal" et la maladie d'Alzheimer : indices segmentaux, suprasegmentaux et gestuels

International audienceThe aim of the study is to analyze and compare multimodal language productions by 10 persons with Alzheimer's disease (AD) matched to 10 controls. First, different measures at the segmental and suprasegmental levels – errors, pauses and vocalic lengthenings – have been conducted in a repetition task with or without imposed gestures to characterize a disfluency, typical of AD, and then observed in link with the production of manual gestures. Results show a significant diminution of the AD participants' fluency: more lexical errors were obtained by the patient group and at the phonetic level among patients with moderate cognitive impairment, as well as numerous silent pauses often preceding or following the production of errors at the segmental level. Moreover, a significant augmentation of suprasegmental disfluencies and phonetic errors is observed in the task with imposed gestures impacting controls and patients' fluency.L'objectif de cette étude est d'analyser et comparer les productions langagières dans leur multimodalité de 10 personnes atteintes de la maladie d'Alzheimer (MA) appariées à 10 contrôles. Différentes mesures aux niveaux segmental et suprasegmental – erreurs, pauses et allongements vocaliques – ont été réalisées dans une tâche de répétition avec ou sans gestes imposés pour caractériser une disfluence, typique de la MA, puis observées en lien avec les gestes manuels produits. Les résultats montrent la diminution significative de la fluence chez les personnes atteintes de la MA, avec davantage d'erreurs produites au niveau lexical par le groupe Patient et au niveau phonétique par les patients au stade modéré de la maladie, ainsi que de nombreuses pauses silencieuses précédant ou suivant souvent les erreurs produites au niveau segmental. De plus, dans la tâche avec gestes imposés, la répétition de ceux-ci a impacté la fluence des groupes Contrôle et Patient avec une augmentation significative des disfluences au niveau suprasegmental et des erreurs phonétiques au niveau segmental

Disfluences dans le vieillissement "normal" et la maladie d'Alzheimer : indices segmentaux, suprasegmentaux et gestuels

International audienceThe aim of the study is to analyze and compare multimodal language productions by 10 persons with Alzheimer's disease (AD) matched to 10 controls. First, different measures at the segmental and suprasegmental levels – errors, pauses and vocalic lengthenings – have been conducted in a repetition task with or without imposed gestures to characterize a disfluency, typical of AD, and then observed in link with the production of manual gestures. Results show a significant diminution of the AD participants' fluency: more lexical errors were obtained by the patient group and at the phonetic level among patients with moderate cognitive impairment, as well as numerous silent pauses often preceding or following the production of errors at the segmental level. Moreover, a significant augmentation of suprasegmental disfluencies and phonetic errors is observed in the task with imposed gestures impacting controls and patients' fluency.L'objectif de cette étude est d'analyser et comparer les productions langagières dans leur multimodalité de 10 personnes atteintes de la maladie d'Alzheimer (MA) appariées à 10 contrôles. Différentes mesures aux niveaux segmental et suprasegmental – erreurs, pauses et allongements vocaliques – ont été réalisées dans une tâche de répétition avec ou sans gestes imposés pour caractériser une disfluence, typique de la MA, puis observées en lien avec les gestes manuels produits. Les résultats montrent la diminution significative de la fluence chez les personnes atteintes de la MA, avec davantage d'erreurs produites au niveau lexical par le groupe Patient et au niveau phonétique par les patients au stade modéré de la maladie, ainsi que de nombreuses pauses silencieuses précédant ou suivant souvent les erreurs produites au niveau segmental. De plus, dans la tâche avec gestes imposés, la répétition de ceux-ci a impacté la fluence des groupes Contrôle et Patient avec une augmentation significative des disfluences au niveau suprasegmental et des erreurs phonétiques au niveau segmental

Facing ADAS validation complexity with usage oriented testing

International audienceValidating Advanced Driver Assistance Systems (ADAS) is a strategic issue, since such systems are becoming increasingly widespread in the automotive field. ADAS bring extra comfort to drivers, and this has become a selling point. But these functions, while useful, must not affect the general safety of the vehicle which is the manufacturer's responsibility. A significant number of current ADAS are based on vision systems, and applications such as obstacle detection and detection of pedestrians have become essential components of functions such as automatic emergency braking. These systems that preserve and protect road users take on even more importance with the arrival of the new Euro NCAP protocols. Therefore the robustness and reliability of ADAS functions cannot be neglected and car manufacturers need to have tools to ensure that the ADAS functions running on their vehicles operate with the utmost safety. Furthermore, the complexity of these systems in conjunction with the nearly infinite number of parameter combinations related to the usage profile of functions based on image sensors push us to think about testing optimization methods and tool standards to support the design and validation phases of ADAS systems. The resources required for the validation using current methods make them actually less and less adapted to new active safety features, which induce very strong dependability requirements. Today, to test the camera-based ADAS, test vehicles are equipped with these systems and are performing long hours of driving that can last for years. These tests are used to validate the use of the function and to verify its response to the requirements described in the specifications without considering the functional safety standard ISO26262

Disfluences dans le vieillissement "normal" et la maladie d'Alzheimer : indices segmentaux, suprasegmentaux et gestuels

International audienceThe aim of the study is to analyze and compare multimodal language productions by 10 persons with Alzheimer's disease (AD) matched to 10 controls. First, different measures at the segmental and suprasegmental levels – errors, pauses and vocalic lengthenings – have been conducted in a repetition task with or without imposed gestures to characterize a disfluency, typical of AD, and then observed in link with the production of manual gestures. Results show a significant diminution of the AD participants' fluency: more lexical errors were obtained by the patient group and at the phonetic level among patients with moderate cognitive impairment, as well as numerous silent pauses often preceding or following the production of errors at the segmental level. Moreover, a significant augmentation of suprasegmental disfluencies and phonetic errors is observed in the task with imposed gestures impacting controls and patients' fluency.L'objectif de cette étude est d'analyser et comparer les productions langagières dans leur multimodalité de 10 personnes atteintes de la maladie d'Alzheimer (MA) appariées à 10 contrôles. Différentes mesures aux niveaux segmental et suprasegmental – erreurs, pauses et allongements vocaliques – ont été réalisées dans une tâche de répétition avec ou sans gestes imposés pour caractériser une disfluence, typique de la MA, puis observées en lien avec les gestes manuels produits. Les résultats montrent la diminution significative de la fluence chez les personnes atteintes de la MA, avec davantage d'erreurs produites au niveau lexical par le groupe Patient et au niveau phonétique par les patients au stade modéré de la maladie, ainsi que de nombreuses pauses silencieuses précédant ou suivant souvent les erreurs produites au niveau segmental. De plus, dans la tâche avec gestes imposés, la répétition de ceux-ci a impacté la fluence des groupes Contrôle et Patient avec une augmentation significative des disfluences au niveau suprasegmental et des erreurs phonétiques au niveau segmental

Facing ADAS validation complexity with usage oriented testing

International audienceValidating Advanced Driver Assistance Systems (ADAS) is a strategic issue, since such systems are becoming increasingly widespread in the automotive field. ADAS bring extra comfort to drivers, and this has become a selling point. But these functions, while useful, must not affect the general safety of the vehicle which is the manufacturer's responsibility. A significant number of current ADAS are based on vision systems, and applications such as obstacle detection and detection of pedestrians have become essential components of functions such as automatic emergency braking. These systems that preserve and protect road users take on even more importance with the arrival of the new Euro NCAP protocols. Therefore the robustness and reliability of ADAS functions cannot be neglected and car manufacturers need to have tools to ensure that the ADAS functions running on their vehicles operate with the utmost safety. Furthermore, the complexity of these systems in conjunction with the nearly infinite number of parameter combinations related to the usage profile of functions based on image sensors push us to think about testing optimization methods and tool standards to support the design and validation phases of ADAS systems. The resources required for the validation using current methods make them actually less and less adapted to new active safety features, which induce very strong dependability requirements. Today, to test the camera-based ADAS, test vehicles are equipped with these systems and are performing long hours of driving that can last for years. These tests are used to validate the use of the function and to verify its response to the requirements described in the specifications without considering the functional safety standard ISO26262

ADAS Reliability and Safety

Cette communication présente une approche novatrice proposée pour valider la fiabilité et la sécurité fonctionnelle des systèmes automobiles d’aide à la conduite (ADAS) basés sur des capteurs caméra. Cette approche a été mise au point dans le cadre du projet COVADEC. La validation mise en oeuvre, conforme à la norme ISO 26262, a pour objectif de démontrer que la fonction ADAS respecte ses exigences : liées à la sécurité fonctionnelle et associées à une dégradation d’efficacité des capteurs liée aux conditions d’environnement, ou liées aux performances de fiabilité au cours d’un usage normal pour un objectif kilométrique donné.This paper presents a new approach proposed for the validation of reliability and safety of Advanced Driver Assistance Systems (ADAS) based on video camera as sensors. This approach has been developed in the context of the COVADEC project. The validation implemented, build in accordance with the ISO 26262 requirements, aims at demonstrating that the ADAS function meets its requirements: related to functional safety and associated with a degradation of sensors efficiency linked to environmental conditions or related to reliability performance during normal use for a given mileage goal