Continuity as a computational effect

The original purpose of component-based development was to provide techniques to master complex software, through composition, reuse and parametrisation. However, such systems are rapidly moving towards a level in which software becomes prevalently intertwined with (continuous) physical processes. A possible way to accommodate the latter in component calculi relies on a suitable encoding of continuous behaviour as (yet another) computational effect. This paper introduces such an encoding through a monad which, in the compositional development of hybrid systems, may play a role similar to the one played by 1+, powerset, and distribution monads in the characterisation of partial, nondeterministic and probabilistic components, respectively. This monad and its Kleisli category provide a universe in which the effects of continuity over (different forms of) composition can be suitably studied.This work is financed by the ERDF - European Regional Development Fund through the Operational Programme for Competitiveness and Internationalisation - COMPETE 2020 Programme and by National Funds through the Portuguese funding agency, FCT - Fundacao para a Ciencia e a Tecnologia within project POCI-01-0145-FEDER-016692.The first author is also sponsored by FCT grant SFRH/BD/52234/2013, and the second one by FCT grant SFRH/BSAB/113890/2015. Moreover, D. Hofmann and M. Martins are supported by the EU FP7 Marie Curie PIRSES-GA-2012-318986 project GeTFun: Generalizing Truth-Functionality and FCT project UID/MAT/04106/2013 through CIDMA

Ein Framework für die automatische Verifikation von zeitdiskreten MATLAB Simulink Modellen mit Boogie

MATLAB/Simulink ist ein weit verbreitetes Werkzeug für die Entwicklung von eingebetteten Systemen, welches vor allem in der Automobilindustrie zur Entwicklung von Steuerungssystemen benutzt wird. Da solche Systeme häufig in sicherheitskritischen Umgebungen eingesetzt werden, wo eine Fehlfunktion zu schweren Verletzungen und Todesfällen führen kann, werden umfangreiche und vollständige Qualitätssicherungsmaßnahmen benötigt um die Korrektheit der Systeme für alle möglichen Ausführungen sicher zu stellen. Trotzdem werden unvollständige Techniken wie Testen in der Praxis gegenüber den sicheren formalen Methoden bevorzugt. Obwohl es einige formale Verifikationstechniken für MATLAB/Simulink gibt, sind diese entweder kaum automatisiert oder skalieren schlecht. Um dieses Problem zu lösen stellen wir in dieser Arbeit einen Ansatz für eine hochautomatisierte Verifikationsumgebung für MATLAB/Simulink Modelle vor, mit der zeitdiskrete Modelle für Steuerungen formal verifiziert werden können. Die Kernidee in unserem Ansatz ist hierbei eine Kombination aus induktiven Verifikationstechniken und dem automatischen Extrahieren von Verifikationszielen für bestimmte Laufzeitfehler verwenden, um einen automatisierten Verifikationsfluss zu erreichen. Außerdem stellen wir einen Ansatz für das Slicing von MATLAB/Simulink Modellen vor, der als automatisches Verfahren zur Reduzierung der Modellkomplexität verwendet wird. Mit diesem erreichen wir eine bessere Skalierbarkeit, da wir eine komplexe Verifikationsaufgabe in eine Anzahl von weniger komplexen Teilaufgaben aufspalten können. Um die automatische Verifikation von MATLAB/Simulink Modellen zu ermöglichen, stellen wir eine formale Semantik für zeitdiskrete Modelle vor, die auf einer Abbildung der informellen, sequenziellen Simulationssemantik in die formale Verifikationszwischensprache Boogie2 basiert. Zusammen mit automatisch erzeugten und in das formale Modell eingewobenen Invarianten und Verifikationszielen, erlaubt dies die Verifikation der Modelle mit dem Boogie-Framework und induktiven Verifikationstechniken. Um einen hohen Grad der Automatisierung zu erreichen, unterstützen wir auch induktive Verifikationstechniken über mehr als einen Simulationsschritt (k-Induktion), was zwar die Verwendung von schwächeren, automatisch generierten Invarianten erlaubt, aber gleichzeitig die Skalierbarkeit reduziert. Um dem entgegenzuwirken, nutzen wir unser neuartiges Slicing-Verfahren für MATLAB/Simulink Modelle um diese automatisch auf genau die Blöcke zu reduzieren, die für einen (möglichen) Fehler an einem bestimmten Block relevant sind. Darüber hinaus schlagen wir einen Prozess für die effiziente Benutzung unserer Verifikations- und Slicing-Techniken vor. Um die praktische Anwendbarkeit unserer Verifikationsumgebung zu zeigen, haben wir diese in unserem MeMo-Werkzeug implementiert und unseren Prozess auf zwei industrielle Fallbeispiele angewendet. Damit haben wir die Performanz und die Fähigkeit, die Abwesenheit von wichtigen Laufzeitfehlern in einem gegebenen Modell automatisch zu verifizieren, nachgewiesen.MATLAB/Simulink is a widely used industrial tool for the development of embedded systems, especially for the development of embedded controller software in automotive industries. Since such embedded systems are often deployed in safety critical areas where an error may lead to severe injuries and even to death of persons, comprehensive and complete quality assurance measures are required for ensuring their correctness in all possible cases. Still, incomplete techniques like testing are favored over safe formal techniques in practice. Although there exist some formal verification approaches for MATLAB/Simulink models that can guarantee correctness, they are either poorly automated or suffer from scalability issues. To overcome this problem, we present an approach for a highly automated verification framework for MATLAB/Simulink models that enables the formal verification of discrete-time controller models. Our main idea is to use inductive verification techniques in combination with an automatic extraction of verification goals for a number of important run-time error classes to provide an automatic verification flow. Furthermore, as automatic model reduction technique, we present a slicing approach for MATLAB/Simulink. With that, we increase the scalability by dividing a possibly complex verification task into a number of less complex subtasks. To enable the automatic verification of MATLAB/Simulink models, we present a formal semantics for discrete-time models based on a mapping of the informally defined sequential simulation semantic into the formally well defined intermediate verification language Boogie2. Together with automatically generated invariants and verification goals that are automatically weaved into the formal model, this mapping enables the verification of the models using the Boogie verification framework and inductive verification techniques. To achieve a high degree of automation, we also support inductive verification over more than one simulation step (k-induction), which allows for weaker invariants that can be generated automatically at the price of decreased scalability. To overcome scalability issues for k-induction, we use our novel slicing technique for MATLAB/Simulink models to automatically reduce a model to those blocks that are relevant for a (possible) error at a particular block. Furthermore, we propose a process for the efficient use of our verification and slicing techniques. To show the practical applicability of our framework, we have implemented our approach as the MeMo tool suite and applied our verification process to two industrial case studies. With that, we demonstrate the performance and the capability to automatically verify a given model for the absence of important run-time errors with our verification framework for discrete-time MATLAB/Simulink models

Missão de avaliação e levantamento do sítio submarino do "clipper Thermopylae"

O presente artigo diz respeito aos vestígios submarinos do grande veleiro comercial Thermopylae, construído na Escócia em 1868 e afundado em manobras navais ao largo de Cascais em 1907, já sob a forma do pontão Pedro Nunes. Reduzidos ao estatuto de pesqueiro anónimo frequentado pelos pescadores locais, os vestígios submersos foram formalmente identificados quase um século após o afundamento e pouco depois integrados no tecido patrimonial da região. Uma missão da Câmara Municipal de Cascais realizada no decurso do Verão de 2009 pôs em destaque os parâmetros técnicos, físicos e culturais associados a este naufrágio que se cruza com a história da oceanografia e da gestão das pescarias em Portugal. Este particularismo do arqueosítio de hoje conduz a uma abordagem transdisciplinar na qual a arqueologia dos destroços físicos do navio de 1868 se molda no espaço identitário, físico e cultural, da região estuarina

eFMI: An open standard for physical models in embedded software

This paper summarizes the final research results of the ITEA3 project EMPHYSIS (embedded systems with physical models in the production code software). Its core achievement is the new open eFMI Standard enabling automated workflows from high-level mathematical models of physical systems (referred to as physical models) to automotive compliant embedded software. eFMI (FMI for embedded systems) defines a container architecture for model exchange and testing. Multiple representations from an intermediate representation of sampled algorithms (GALEC) to production and binary code for specific embedded targets are maintained in a traceable workspace. The successful integration of the developed eFMI tooling is demonstrated by a comprehensive open source Modelica test cases library and industrial demonstrators. The readiness of the proposed approach is proven by compliance checks according to common automotive code quality standards like MISRA C:2012 and a performance benchmark in terms of runtime and resource demand in comparison with state-of-the-art hand coded solutions

Project cluster FAST- fast actuators sensors and transceivers - technological breakthrough by real-time capability

This abstract gives an overview of the German research and development initiative FAST, a project cluster aiming at a technological and economic breakthrough by means of real-time capabilities. The FAST project cluster consists of around 80 partners from industry and academia, with a strong participation of small innovative companies. FAST comprises around 20 projects and is scheduled from 2014 to 2020