Towards a verified compiler prototype for the synchronous language SIGNAL

International audienceSIGNAL belongs to the synchronous languages family which are widely used in the design of safety-critical real-time systems such as avionics, space systems, and nuclear power plants. This paper reports a compiler prototype for SIGNAL. Compared with the existing SIGNAL compiler, we propose a new intermediate representation (named S-CGA, a variant of clocked guarded actions), to integrate more synchronous programs into our compiler prototype in the future. The front-end of the compiler, i.e., the translation from SIGNAL to S-CGA, is presented. As well, the proof of semantics preservation is mechanized in the theorem prover Coq. Moreover, we present the back-end of the compiler, including sequential code generation and multithreaded code generation with time-predictable properties. With the rising importance of multi-core processors in safety-critical embedded systems or cyber-physical systems (CPS), there is a growing need for model-driven generation of multithreaded code and thus mapping on multi-core. We propose a time-predictable multi-core architecture model in architecture analysis and design language (AADL), and map the multi-threaded code to this model

Block Library Driven Translation Validation for Dataflow Models in Safety Critical Systems

International audienceModel driven engineering is widely used in the development of complex and safety critical systems. Systems’ designs are specified and validated in domain specific modeling languages and software code is often produced by autocoding. Thus the correctness of the final systems depend on the correctness of those tools. We propose an approach for the formal verification of code generation from dataflow languages, such as Simulink, based on translation validation. It relies on the BlockLibrary DSL for the formal specification and verification of the structure, semantics and variability of the complex block libraries found in these languages. These specifications are then used here for deriving model and block-specific semantic contracts that will be woven into the generated C code. We present two different approaches for performing the block matching and weaving step. Finally, we rely on the Frama-C toolset and state-of-the-art SMT solvers for verifying the annotated code

Data consistencies of swift heavy ion induced damage creation in yttrium iron garnet analyzed by different techniques

Pronounced swelling is observed when single crystals of yttrium iron garnet Y3Fe5O12 (YIG) are irradiated in the electronic energy loss regime with various swift heavy ions. The out-of-plane swelling was measured by scanning across the border line between an irradiated and a virgin area of the sample surface with the tip of a profilometer. The step height varied between 20 and 600 nm depending on fluence, electronic energy loss and total range of the ions. The step height divided by the ion range as a function of the ion fluence exhibits a linear increase in the initial phase and saturates at high fluences leading to a density decrease of around 1.7%. With complementary channeling-Rutherford-backscattering experiments (c-RBS), the damage fraction and the corresponding damage cross section were extracted and compared to the cross section deduced from swelling measurements. Irradiation effects were also characterized by scanning force microscopy (SFM). A threshold for damage creation as deduced from all the present physical characterizations is 5.5 ± 1.0 keV/nm. The value is in full agreement with previous measurements confirming that swelling and SFM characterizations can provide information concerning the electronic energy loss threshold for track formation. In contrast, track radii deduced from swelling measurements are smaller and radii from SFM are larger than deduced from c-RBS analysis. The results of Y3Fe5O12 of this work are compared with data obtained for other crystalline oxides and for ionic crystals

Pratiques spirituelles, régimes discursifs et rapports sociaux à l’époque moderne (XVIe-XVIIIe siècles)

Pierre-Antoine Fabre, directeur d’études Le séminaire a poursuivi cette année l’exploration du champ de recherches dont il voudrait contribuer à préciser les contours : celui d’une histoire de la spiritualité moderne. On a cherché à comprendre les raisons de la particulière floraison de pratiques et d’écrits reconnus comme « spirituels » dans l’Europe du XVIIe siècle, en inscrivant leur espace dans un double écart par rapport au discours de la théologie, d’une part, que la philosophie comme m..

Abstracts of 1st International Conference on Computational & Applied Physics

This book contains the abstracts of the papers presented at the International Conference on Computational & Applied Physics (ICCAP’2021) Organized by the Surfaces, Interfaces and Thin Films Laboratory (LASICOM), Department of Physics, Faculty of Science, University Saad Dahleb Blida 1, Algeria, held on 26–28 September 2021. The Conference had a variety of Plenary Lectures, Oral sessions, and E-Poster Presentations. Conference Title: 1st International Conference on Computational & Applied PhysicsConference Acronym: ICCAP’2021Conference Date: 26–28 September 2021Conference Location: Online (Virtual Conference)Conference Organizer: Surfaces, Interfaces, and Thin Films Laboratory (LASICOM), Department of Physics, Faculty of Science, University Saad Dahleb Blida 1, Algeria