Model-Based Engineering for the support of Models of Computation: The Cometa Approach

The development of Real-Time Embedded Systems (RTES) increasingly requires the integration of several parts with different purposes. Consequently, the heterogeneous appearance of such systems creates a need to manage their growing complexity mainly due to the difficulty to interconnect the different parts composing them. Model-Based Engineering (MBE) has significantly participated in recent decades to find solutions in terms of methodologies and technical support tailored to the design of RTES. Indeed, several models are used to represent different aspects of the system. However, the interconnection of different modeling paradigms is still a difficult challenge. The handling of such problems requires a clear definition of the execution and interconnection semantics of the different models composing the system. Indeed, the abstraction of the execution semantics of machines or Models of Computation (MoC) can highlight properties for the whole system’s execution. In this paper, we propose an approach that captures these semantics at the earliest modeling phases with the aim of exhibiting properties that ease the design space exploration and performance analysis of systems. Our approach extends the Modeling and Analysis of Real-Time Embedded Systems profile (MARTE) by providing means to express communication semantics of models. We also review existing approaches for defining such execution semantics

Model Federation in toolchains

In this paper we introduce the toolchain topic as a federation of models based on an abstraction of dif ferents tool definitions. We consider the toolchain in the context of embedded systems, in particular the co-design which implies a co-engineering approach with many tools. Our main goal is to define a tool integration model to carry out an abstraction of several data formats and for a do main model as a reference vocabulary. This model gathers the concepts for managing the development process artif acts and the roles attributed to these artifacts over th e process. We have experimented this approach during the europ een ARTEMIS iFEST project over the OSLC layer (Open Services for Lifecycle Collaboration)

Towards a Meta-Language for the Concurrency Concern in DSLs

International audienceAbstract—Concurrency is of primary interest in the development of complex software-intensive systems, as well as thedeployment on modern platforms. Furthermore, Domain-Specific Languages (DSLs) are increasingly used in industrial processes toseparate and abstract the various concerns of complex systems.However, reifying the definition of the DSL concurrency remainsa challenge. This not only prevents leveraging the concurrencyconcern of a particular domain or platform, but it also hinders:a) the development of a complete understanding of the DSLsemantics; b) the effectiveness of concurrency-aware analysistechniques; c) the analysis of the deployment on parallelarchitectures. In this paper, we present M oCCML, a dedicatedmeta-language for formally specifying the concurrency concernwithin the definition of a DSL. The concurrency constraintscan reflect the knowledge in a particular domain, but also theconstraints of a particular platform. MoCCML comes with acomplete language workbench to help a DSL designer in thedefinition of the concurrency directly within the concepts of theDSL itself, and a generic workbench to simulate and analyzeany model conforming to this DSL. Mo CCML is illustrated onthe definition of an lightweight extension of SDF (SynchronousData Flow)

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Un cadre de définition de la sémantique basée MoC des modèles de systèmes dans le contexte de l'intégration d'outils

Embedded systems (EmS) are increasingly used in various areas such as telephony, automotive and avionics industries. In these different areas, the growth of functionality requirements causes an explosion of the size and complexity of the systems.In this context, system design flows are becoming more complex and require the use of tools from different engineering domains. The heterogeneous paradigms on which the tools rely on pose as well many reliability problems when it comes to consistent data exchanges between tools. For example, nowadays, the high-level modeling (e.g. Model-Driven Engineering) tools are unaccepted by research communities for the formal design of systems that require solid grounds on the execution semantics to carry out analysis, validation and synthesis of embedded systems activities. Indeed, the Model-Driven Engineering tools dedicated to EmS design are not yet sufficiently mature on aspects involving expression of the formal execution semantics reflecting the concurrency model of system modules. Besides, the theory of computation is identified as the field to describe formally the concurrency models that are used for the description of embedded systems.Our motivation is to use this theory to reduce the gap between different design tools that have different semantics for executing models in a design flow. We propose a methodology for the identification and comparison of the concurrency model of systems based on the theory of the Models of Computation (MoCs) and their existing classifications; we also propose a language to capture MoC-based semantics which is used to enrich system models and preserve their se- mantics through a tool chain. To prove the effectiveness of our approach, we defined a design flow connecting three tools that are involved in various activities of the Design & Implementation process (Specification, Analysis, Design Space Exploration). The tool chain highlights the con- nection of the UML modeling tool (IBM Rhapsody) (for specification and analysis), Forsyde (for multi-MoC simulation and synthesis) and Spear (Design Space Exploration and analysis). The chain is applied on a simplified version of a Radar Streaming application provided as use case in the context of the iFEST project.L’utilisation des systèmes embarqués (EmS) connait un essor conséquent dans plusieurs domaines actuels tels que la téléphonie, l’industrie automobile et l’avionique. Dans ces différents domaines, la croissance des besoins en termes de fonctionnalités a pour conséquence l’augmentation de la taille et de la complexité des systèmes conçus. Dans ce contexte, les chaînes de conception des systèmes deviennent de plus en plus complexes et requièrent l’utilisation d’outils provenant de différents domaines d’ingénieries. L’intégration des paradigmes hétérogènes associés aux outils posent beaucoup de problèmes de fiabilité à l’échange des modèles entre outils d’une même chaîne de conception. Par exemple, dans le cadre des EmS, les outils d’ingénierie dirigés par les modèles (IDM) ne sont pas acceptés par les communautés de recherches pour la conception formelle d’EmS qui requièrent des bases solides et formelles de définition des sémantiques d’exécution pour réaliser les activités d’analyses, de validation et de synthèse des systèmes embarqués. En effet, les outils IDM dédiés aux EmS ne sont à ce jour pas encore suffisamment matures concernant l’expression et la prise en compte de la sémantique d’exécution formelle mettant explicitement en avant les modèles de concurrence des systèmes. Par ailleurs, la théorie du calcul est identifiée comme le domaine permettant de décrire de manière formelle les modèles de concurrences qui sont utilisés pour la description de systèmes embarqués. La motivation de cette thèse est de mettre en œuvre cette théorie du calcul pour réduire l’écart existant entre différents outils de conception qui possèdent des sémantiques d’exécution de modèles différentes dans une chaîne de conception. La thèse propose une méthodologie d’identification et de comparaison des sémantiques d’exécution de modèles qui se base sur la théorie des Modèles de Calcul (MoCs) et leur classification existante, ainsi qu’un langage de capture des sémantiques basées MoC. Ces dernières sont utilisées pour enrichir les modèles et préserver leur sémantique entre les outils d’une chaîne de conception. Pour illustrer l’utilisation de l’approche, nous avons défini un flot de conception permettant de connecter trois outils impliqués dans diverses activités du processus “Design & Implementation” (Spécification, Analyse, Exploration de l’espace des choix de Conception). La chaîne d’outils présentée adresse la connexion de l’outil UML Modeler (IBM Rhapsody) (pour la spécification et l’analyse), Forsyde (cadre de simulation multi-MoC et de synthèse) et Spear (pour l’exploration de l’espace des choix de Conception et l’analyse). La chaîne est appliquée sur un modèle de Radar simplifié fourni comme cas d’utilisation dans le cadre du projet iFEST

A framework for the definition of a system model MoC-based semantics in the context of tool integration

L’utilisation des systèmes embarqués (EmS) connait un essor conséquent dans plusieurs domaines actuels tels que la téléphonie, l’industrie automobile et l’avionique. Dans ces différents domaines, la croissance des besoins en termes de fonctionnalités a pour conséquence l’augmentation de la taille et de la complexité des systèmes conçus. Dans ce contexte, les chaînes de conception des systèmes deviennent de plus en plus complexes et requièrent l’utilisation d’outils provenant de différents domaines d’ingénieries. L’intégration des paradigmes hétérogènes associés aux outils posent beaucoup de problèmes de fiabilité à l’échange des modèles entre outils d’une même chaîne de conception. Par exemple, dans le cadre des EmS, les outils d’ingénierie dirigés par les modèles (IDM) ne sont pas acceptés par les communautés de recherches pour la conception formelle d’EmS qui requièrent des bases solides et formelles de définition des sémantiques d’exécution pour réaliser les activités d’analyses, de validation et de synthèse des systèmes embarqués. En effet, les outils IDM dédiés aux EmS ne sont à ce jour pas encore suffisamment matures concernant l’expression et la prise en compte de la sémantique d’exécution formelle mettant explicitement en avant les modèles de concurrence des systèmes. Par ailleurs, la théorie du calcul est identifiée comme le domaine permettant de décrire de manière formelle les modèles de concurrences qui sont utilisés pour la description de systèmes embarqués. La motivation de cette thèse est de mettre en œuvre cette théorie du calcul pour réduire l’écart existant entre différents outils de conception qui possèdent des sémantiques d’exécution de modèles différentes dans une chaîne de conception. La thèse propose une méthodologie d’identification et de comparaison des sémantiques d’exécution de modèles qui se base sur la théorie des Modèles de Calcul (MoCs) et leur classification existante, ainsi qu’un langage de capture des sémantiques basées MoC. Ces dernières sont utilisées pour enrichir les modèles et préserver leur sémantique entre les outils d’une chaîne de conception. Pour illustrer l’utilisation de l’approche, nous avons défini un flot de conception permettant de connecter trois outils impliqués dans diverses activités du processus “Design & Implementation” (Spécification, Analyse, Exploration de l’espace des choix de Conception). La chaîne d’outils présentée adresse la connexion de l’outil UML Modeler (IBM Rhapsody) (pour la spécification et l’analyse), Forsyde (cadre de simulation multi-MoC et de synthèse) et Spear (pour l’exploration de l’espace des choix de Conception et l’analyse). La chaîne est appliquée sur un modèle de Radar simplifié fourni comme cas d’utilisation dans le cadre du projet iFEST.Embedded systems (EmS) are increasingly used in various areas such as telephony, automotive and avionics industries. In these different areas, the growth of functionality requirements causes an explosion of the size and complexity of the systems.In this context, system design flows are becoming more complex and require the use of tools from different engineering domains. The heterogeneous paradigms on which the tools rely on pose as well many reliability problems when it comes to consistent data exchanges between tools. For example, nowadays, the high-level modeling (e.g. Model-Driven Engineering) tools are unaccepted by research communities for the formal design of systems that require solid grounds on the execution semantics to carry out analysis, validation and synthesis of embedded systems activities. Indeed, the Model-Driven Engineering tools dedicated to EmS design are not yet sufficiently mature on aspects involving expression of the formal execution semantics reflecting the concurrency model of system modules. Besides, the theory of computation is identified as the field to describe formally the concurrency models that are used for the description of embedded systems.Our motivation is to use this theory to reduce the gap between different design tools that have different semantics for executing models in a design flow. We propose a methodology for the identification and comparison of the concurrency model of systems based on the theory of the Models of Computation (MoCs) and their existing classifications; we also propose a language to capture MoC-based semantics which is used to enrich system models and preserve their se- mantics through a tool chain. To prove the effectiveness of our approach, we defined a design flow connecting three tools that are involved in various activities of the Design & Implementation process (Specification, Analysis, Design Space Exploration). The tool chain highlights the con- nection of the UML modeling tool (IBM Rhapsody) (for specification and analysis), Forsyde (for multi-MoC simulation and synthesis) and Spear (Design Space Exploration and analysis). The chain is applied on a simplified version of a Radar Streaming application provided as use case in the context of the iFEST project

Model Based Engineering for the support of Models of Computation: The Cometa Approach

International audienceThe development of Real Time Embedded Systems increasingly requires the integration of several parts with different purposes. Consequently, the heterogeneous appearance of such system creates a need to manage their growing complexity mainly due to the difficulty to interconnect the different parts composing them. Model Based Engineering has significantly participated in recent decades to find solutions in terms of methodologies and technical supports tailored to design RTES. Indeed, several models are used to represent different aspects of the system. However, the interconnection of different models paradigm is still a difficult challenge. The handling of such problems requires a clear definition of the execution and interconnection semantics of the different models composing the system. Indeed, the abstraction of the execution semantics of machines (Models of Computation) can highlight properties for the whole systems execution. In this paper, we propose an approach that captures these semantics the earliest possible in the modeling phases with the aim of exhibiting properties that ease the design space exploration and performance analysis of systems. We also review existing approaches for defining such execution semantics

A Model-Driven Approach to Enhance Tool Interoperability using the Theory of Models of Computation

International audienceIn the context of embedded systems design, the growing het erogeneity of systems leads to increasingly complex and unreliable tool chains. The Model Driven Engineering (MDE) community has been mak-ing considerable eff orts to abstract tool languages in meta-models, and to o ffer model transformation mechanisms for models exchanges. However, the interoperability problems are recurring and still not consistently addressed. For instance, when it comes to executable models exchanges, it is very di fficult to ensure the preservation of the models behavior from one tool to another. This is mainly due to a lack of understanding of the Models of Computation (MoC) and execution semantics behind the models within di erent environments. In this paper, we introduce a methodology and a framework to: make explicit the execution semantics of models (based on the theory of MoC); provide semantics enrichment mechanisms to ensure the preservation of the execution semantics of models between tools. Our case study is an integration between a UML speci cation tool and an industrial Intensive Data Flow processing tool. This contribution helps to highlight execution semantics concerns within tool integration context

An approach for describing concurrency and communication of heterogeneous systems

International audienceThe fast development of technology and the time-to-market constraints need well-adapted technical support and development processes to ease design space exploration and the reduction of the productivity gap. Model Based Engineering (MBE) overcomes the increasing complexity of system being highly heterogeneous and integrating concurrent sub-systems. Elsewhere, Models of Computation (MoC) help enforcing MBE with aspects related to the execution semantics of models. In a previous paper, we introduced a language called Cometa providing more expressiveness for these aspects. It allows the capture and analysis of several MoCs at high level of abstraction, highlighting communication and synchronization among parts of a heterogeneous system. The language was tooled in Rhapsody and tested on an industrial case. In this paper, we present the key concepts of the Cometa language and the tooling experiments of Cometa in an open source environment. The objective of this approach is being able to model heterogeneous systems, but also to broaden the scope of the language tooling, by taking benefits from an open source environment