Use of CCD to Detect Terrestrial Cosmic Rays at Ground Level: Altitude vs. Underground Experiments, Modeling and Numerical Monte Carlo Simulation

International audienceIn this work, we used a commercial charge-coupled device (CCD) camera to detect and monitor terrestrial cosmic rays at ground level. Multi-site characterization has been performed at sea level (Marseille), underground (Modane Underground Laboratory) and at mountain altitude (Aiguille du Midi-Chamonix Mont-Blanc at +3,780 m of altitude) to separate the atmospheric and alpha particle emitter's contributions in the CCD response. An additional experiment at avionics altitude during a long-haul flight has been also conducted. Experiment results demonstrate the importance of the alpha contamination in the CCD response at ground level and its sensitivity to charged particles. Experimental data as a function of CCD orientation also suggests an anisotropy of the particle flux for which the device is sensitive. A complete computational modeling of the CCD imager has been conducted, based on a simplified 3D CCD architecture deduced from a reverse engineering study using electron microscopy and physico-chemical analysis. Monte Carlo simulations evidence the major contribution of low energy (below a few MeV) protons and muons in the CCD response. Comparison between experiments and simulation shows a good agreement at ground level, fully validated at avionics altitudes with a much higher particle flux and a different particle cocktail composition

Marketing aspects of consumer price perception

This thesis focuses on two theoretical approaches from the marketing literature: first, the degree to which consumers tend to associate a higher product price with a higher quality (price-perceived quality relationship) and second, the assumption that odd prices (prices set just below the nearest round figure) generate higher than expected demand at that level. The thesis concludes that there seems to exist an overall positive weak correlation between product price and perceived quality, which is also product/market specific, and that the effects of odd pricing on demand have been mixed and inconclusive. Important managerial implications arise from these conclusions. On the same grounds, an empirical study examines the relation between product price and actual product quality and shows that the relation is actually very weak for products falling into the category of electronics. Lastly, a second empirical study shows that odd prices prevail in the retail sector of the Czech Republic

Soft Erreur dans les Mémoires : Nouvelles Méthodes et Pratiques pour les Tests Dynamiques et Statiques

La plupart des environnements naturels et artificiels présentent du rayonnement ionisant (RI) interagissant avec l'électronique. Les effets du RI sont étudies depuis longtemps surtout pour des applications de critiques et de sécurité dans le domaine de l'espace, nucléaire, militaire et médical. L'étude des effets de rayonnement sur les appareils électroniques est complexe et demande la combinaison d'une connaissance pluridisciplinaire allant de la physique nucléaire à l'architecture à haut niveau, l'électronique et la science de matériaux. La réduction de la taille des transistors et l'augmentation simultanée de la complexité des systèmes contribuent à rendre plus critiques les problématiques. En occupant la plus grande surface de systèmes sur puce, les mémoires électroniques représentent la source principale des fautes induits par la radiation. Par conséquent, la compréhension des effets du rayonnement ionisant sur les mémoires et leur atténuation sont essentielles. Ces travaux de thèse introduisent des nouvelles méthodes de test à niveau de simulation et expérimental. En particulier, à niveau de simulation, est proposée une méthodologie pour l'estimation du taux de soft erreurs (SER) des circuits électroniques. Cette méthode prend en compte les variations environnementales et paramétriques des circuits pendant leur exposition au rayonnement ionisant. La méthode est évaluée à travers le cas d'étude représentée par une cellule SRAM de technologie 40nm interagissant avec des neutrons atmosphériques. Au niveau expérimental, des nouvelles méthodes pour le test sous accélérateur de SRAMs sont présentées, tout en mettant l'accent sur les défaillances que le test dynamique peut révéler. Les méthodes proposées s'appuient sur les algorithmes de type March et des séquences d'adressage spécifique des mémoires. Le choix des méthodes des tests dynamiques plutôt que des tests statiques est justifié par leur capacité de sensibiliser les effets électriques et du fait qu'ils sont très représentatifs du comportement réel des mémoires de vrais systèmes électroniques. Dans ces études, sont analyses en détail des évènements de large échelle qui apparaissent pendant les tests en accélérateurs et qui menaient à des MCUs (Multiple Cell Upsets), des effets singuliers permanent SEL (Single Event Latchups) et des effets singuliers de type SEFI (Single Event Functional Interrupt). Les protons à basses menaçant les technologies le plus récentes, donc, ici, leur contribution aux effets singuliers est aussi étudiée toujours en appliquant les nouvelles méthodes des tests proposés. Avec l'expérience acquise pendant les tests accélérés, un capteur des Hadrons à Haute Energie a été proposé et par la suite testé sur le faisceau de la structure H4IRRAD du CERN. La fonction principale de ce moniteur est basée sur l'extraction de la fluence des hadrons en tant qu'une fonction des effets singuliers SEU enregistrés. En outre, sont également présentés les résultats d'un test en temps réel fait à la station Concordia en Antarctique. Dans ce cas, l'instrument de détection était une version modifié du précédent capteur. Les résultats récoltés ont démontré que cet instrument de détection peut être utilisé dans des environnements et des conditions de rayonnement diverses. Enfin, des technologies de mémoire émergeantes ont été évaluées par rapport à leur réponse au rayonnement ionisant.Most of the known natural and artificial environments present ionizing radiation interacting with electronics. The effects of ionizing radiation have been a concern for many years especially for safety and critical applications such as space, nuclear, avionics, military and medical. The study of radiation effects on electronic devices is complex and requires the combination of multidisciplinary knowledge from nuclear physics to high-level system design, electronics and science of materials. The downscaling of the transistor size and the concurrent increase of systems' complexity contributes to worsen this problematic.By occupying the largest area of Systems on Chip, electronic memories represent the biggest source of radiation induced failures. Consequently, the understanding of ionizing radiation effects on memory devices and their mitigation is crucial. This thesis introduces novel test methods for both the simulation and the experimental level. More specifically, at the simulation level a framework is proposed for the estimation of the Soft Error Rate of electronic devices. This framework considers environmental and parametric variations of the device, while subjected to ionizing radiation. The framework is evaluated by considering the case study of a 40nm SRAM cell interacting with atmospheric neutrons. At the experimental level, novel methods for the accelerated testing of SRAM devices are presented, emphasizing to the failures that dynamic mode testing is able to reveal. These proposed methods are based on March algorithms in combination with specific addressing schemes for the memories.The choice to focus on dynamic testing methods is justified by their capability to sensitize electric effects that static mode testing is not able to do, and because they are highly representative of the realistic behavior of memories in actual electronic systems. Large scale events occurring during accelerated testing as a result of Multiple Cell Upsets, Single Event Latchups and Single Event Functional Interrupts are thoroughly analyzed. With low energy protons posing a threat for latest technologies, their contribution to Soft Errors is also studied by applying the proposed testing methods. Using the experience acquired from accelerated testing, a monitor for the sensing of the High Energy Hadrons was proposed and next tested at H4IRRAD beam line (CERN). The main functionality of this monitor is based on the extraction of the hadrons fluence as a function of the recorded Single Event Upsets. Furthermore, the results from a real-time test at the Concordia station in Antarctica are also presented. This time the sensing instrument was a customized version of the previous monitor and the retrieved results proved the usability of the instrument under different radiation environments and conditions. Finally emerging memory technologies are assessed for their response under ionizing radiation

A Mixed Verification Strategy Tailored for Networks on Chip

ISBN 978-1-4673-0973-8International audienceThis paper targets the development of a verification methodology for Networks on Chip. We advocate the use of formal methods to guarantee an unambiguous expression of the specifications. A previous theorem proving based solution enables the verification of high-level properties for NoC communication algorithms, it deliberately addresses abstract NoC descriptions and ignores implementation details. We suggest here a complementary approach, oriented toward Assertion-Based Verification, that focuses on the verification of RT level implementations, also applicable to the on-line checking of robustness properties

Radiation Study of a 4Mbit Ferroelectric RAM for Space Applications

International audienceWe present a Heavy Ion radiation study for a ultra low power non volatile 4Mbit ferroelectric memory(FRAM) for space applications manufactured on a 130nm domestic CMOS technology node. The radiation summary includes SEU data from Heavy Ions static as well as dynamic stress tests. The FRAM device meets the space level upset criteria for static device stress, but requires additional system mitigation for dynamic device stress

Compositional Translation of Simulink Models into Synchronous BIP

International audienceWe present a method for the translation of a discrete-time fragment of Simulink into the synchronous subset of the BIP language. The translation is fully compositional, that is, it preserves completely the original structure and reveals the minimal control coordination structure needed to perform the correct computation within Simulink models. Additionally, this translation can be seen as providing an alternative operational semantics of Simulink models using BIP. The advantages are twofold. It allows for integration of Simulink models within heterogeneous BIP designs. It enables the use of validation and automatic implementation techniques already available for BIP on Simulink models. The translation is currently implemented in the Simulink2BIP tool. We report several experiments, in particular, we show that the executable code generated from BIP models has comparable runtime performances as the code produced by the Real-Time Workshop on several Simulink models

Investigation on the Sensitivity of a 65nm Flash-Based FPGA for CERN Applications

International audienceThe continuous need for upgrading the instrumentation and control electronics operating in various CERN experiments and along the LHC accelerator, has driven the qualification process of the new Flash-Based SmartFusion2 FPGAs; a leading candidate to be embedded in future systems. The radiation testing conditions have been chosen to fit the unique CERN environment, while the setup is carefully chosen to qualify all the subcomponents of the SoC FPGA that the engineering teams of CERN are considering for exploitation

Soft errors in commercial off-the-shelf static random access memories

International audienceThis article reviews state-of-the-art techniques for the evaluation of the effect of radiation on static random access memory (SRAM). We detailed irradiation test techniques and results from irradiation experiments with several types of particles. Two commercial SRAMs, in 90 and 65 nm technology nodes, were considered as case studies. Besides the basic static and dynamic test modes, advanced stimuli for the irradiation tests were introduced, as well as statistical post-processing techniques allowing for deeper analysis of the correlations between bit-flip cross-sections and design/architectural characteristics of the memory device. Further insight is provided on the response of irradiated stacked layer devices and on the use of characterized SRAM devices as particle detectors

Evaluating the use of APSoCs for CERN applications

All Programmable System-on-Chip (APSoC) devices can offer high performance because of the combination between high speed embedded processors and the flexibility of the programmable logic. Thus, APSoC can be attractive for the European Organization for Nuclear Research (CERN) environment, which hosts the Large Hadron Collider (LHC), due to the large amount of equipment and instrumentation electronics that has to process and analyze data. However, APSoCs may be prone to Single Event Effects (SEE). In this work, we investigate how the configuration of the processing system influences the reliability of a FLASH-based APSoC. We experimentally study the differences in the radiation-induced error rate of the processing system, under various configurations while executing an application. Furthermore, we analyze the system reliability taking into account not only the cross section, but also the execution time exposed under radiation. Preliminary results show that it is possible to double the performance and to increase the system reliability one order of magnitude by managing a various processor features such as Cache memory and Processor Exception Handlers

Investigating the Impact of Radiation-Induced Soft Errors on the Reliability of Approximate Computing Systems

Approximate Computing (AxC) is a well-known paradigm able to reduce the computational and power overheads of a multitude of applications, at the cost of a decreased accuracy. Convolutional Neural Networks (CNNs) have proven to be particularly suited for AxC because of their inherent resilience to errors. However, the implementation of AxC techniques may affect the intrinsic resilience of the application to errors induced by Single Events in a harsh environment. This work introduces an experimental study of the impact of neutron irradiation on approximate computing techniques applied on the data representation of a CNN.nonPeerReviewe