CPAL: High-Level Abstractions for Safe Embedded Systems

Innovation in the field of embedded systems, and more broadly in cyber-physical systems, increasingly relies on software. The productivity gain in software development can hardly keep up with the demand for software despite the increasing adoption of Model-Driven Development (MDD). In this context, we believe that major productivity and quality improvements are still ahead of us through better programming languages and environments. CPAL, the Cyber-Physical Action Language, is a contribution in that direction with the objective to speed-up the development of embedded systems with dependability constraints. The objective of this paper is to present and illustrate the use-cases of the high-level abstractions offered to the developer in CPAL with respect to real-time scheduling, introspection mechanisms, native support of Finite State Machines (FSMs), abstracting the hardware and decoupling functional concerns from non-functional concerns

From FMTV to WATERS: Lessons Learned from the First Verification Challenge at ECRTS (Artifact)

We propose here solutions to the FMTV 2015 challenge of a distributed video processing system using four different formalisms, as well as the description of the challenge itself. This artifact contains several solutions to various subchallenges, and instructions and scripts to reproduce these results smoothly

From FMTV to WATERS: Lessons Learned from the First Verification Challenge at ECRTS

We present here the main features and lessons learned from the first edition of what has now become the ECRTS industrial challenge, together with the final description of the challenge and a comparative overview of the proposed solutions. This verification challenge, proposed by Thales, was first discussed in 2014 as part of a dedicated workshop (FMTV, a satellite event of the FM 2014 conference), and solutions were discussed for the first time at the WATERS 2015 workshop. The use case for the verification challenge is an aerial video tracking system. A specificity of this system lies in the fact that periods are constant but known with a limited precision only. The first part of the challenge focuses on the video frame processing system. It consists in computing maximum values of the end-to-end latency of the frames sent by the camera to the display, for two different buffer sizes, and then the minimum duration between two consecutive frame losses. The second challenge is about computing end-to-end latencies on the tracking and camera control for two different values of jitter. Solutions based on five different tools - Fiacre/Tina, CPAL (simulation and analysis), IMITATOR, UPPAAL and MAST - were submitted for discussion at WATERS 2015. While none of these solutions provided a full answer to the challenge, a combination of several of them did allow to draw some conclusions

From FMTV to WATERS: Lessons Learned from the First Verification Challenge at ECRTS

We present here the main features and lessons learned from the first edition of what has now become the ECRTS industrial challenge, together with the final description of the challenge and a comparative overview of the proposed solutions. This verification challenge, proposed by Thales, was first discussed in 2014 as part of a dedicated workshop (FMTV, a satellite event of the FM 2014 conference), and solutions were discussed for the first time at the WATERS 2015 workshop. The use case for the verification challenge is an aerial video tracking system. A specificity of this system lies in the fact that periods are constant but known with a limited precision only. The first part of the challenge focuses on the video frame processing system. It consists in computing maximum values of the end-to-end latency of the frames sent by the camera to the display, for two different buffer sizes, and then the minimum duration between two consecutive frame losses. The second challenge is about computing end-to-end latencies on the tracking and camera control for two different values of jitter. Solutions based on five different tools - Fiacre/Tina, CPAL (simulation and analysis), IMITATOR, UPPAAL and MAST - were submitted for discussion at WATERS 2015. While none of these solutions provided a full answer to the challenge, a combination of several of them did allow to draw some conclusions

« Virial » pressure of the classical one-component plasma

Application of the virial theorem to a Coulomb system of N particles neutralized by a continuous background, leads quite naturally to the definition of a « virial » kinetic pressure for the system of particles, which is fundamentally positive. This definition is related, in a particular case, to the thermodynamic one used in previous works, which has the drawback to give negative values for sufficiently strong coupling.En appliquant le théorème du viriel à un système coulombien de N particules neutralisées par un fond continu, on définit très naturellement une pression cinétique « virielle » du système de particules, qui est une quantité essentiellement positive. Le lien est fait, dans un cas particulier, avec la définition thermodynamique de la pression utilisée dans les travaux précédents, qui a l'inconvénient de donner des valeurs négatives quand le paramètre de couplage est suffisamment grand

Uncoupling protein and alternative oxidase of Dictyostelium discoideum: occurrence, properties and protein expression during vegetative life and starvation-induced early development.

In this study we show that mitochondria of Dictyostelium discoideum contain both alternative oxidase (AOX) and uncoupling protein (UCP). AOX was stimulated by purine mononucleoside and was monomeric. UCP was stimulated by free fatty acids and was poorly sensitive to GTP. Both proteins collaborated in energy dissipation when activated together. AOX expression in free-living ameboid cells decreased strongly from exponential to stationary phase of growth but much less during starvation-induced aggregation. In contrast, UCP expression was constant in all conditions indicating permanent need. Our results suggest that AOX could play a role in cell differentiation, mainly by protecting prespore cells from programmed cell death