Semantical Correctness of Simulation-to-Animation Model and Rule Transformation

In the framework of graph transformation, simulation rules are well-known to define the operational behavior of visual models. Moreover, it has been shown already how to construct animation rules in a domain specific layout from simulation rules. An important requirement of this construction is the semantical correctness which has not yet been considered. In this paper we give a precise definition for simulation-to-animation (S2A) model and rule transformations. Our main results show under which conditions semantical correctness can be obtained. The results are applied to analyze the S2A transformation of a Radio Clock model. Keywords: graph transformation, model and rule transformation, semantical correctness, simulation, animatio

Dynamic aspects of visual modelling languages

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Visualisierung komplexer reaktiver Systeme: Annotierte Bibliographie

Reaktive Systeme müssen kontinuierlich auf ihre Umwelt reagieren; die meisten eingebetteten Echtzeitsysteme sind reaktive Systeme. Ein wesentliches Hilfsmittel für die Entwicklung reaktiver Systeme ist die Visualisierung des Systemverhaltens. Der modellbasierte Entwurf unterstützt diese Verhaltensvisualisierung; bisherige Visualisierungsmechanismen sind jedoch nur für Systeme bis zu einer gewissen Größe effektiv einsetzbar. Dieser Bericht untersucht Ursachen hierfür, und fasst bisherige Ergebnisse auf verschiedenen hierfür relevanten Gebieten der Informatik zusammen

Animation-based validation of reactive software systems using behavioural models

Tese de doutoramento em InformáticaDuring the development of software systems, validation is a crucial activity to guarantee that the software system ful lls the users' needs and expectations. A key issue to have a successful validation consists in adopting a process where users and clients can actively discuss the requirements of the system under development. A reactive system is expected to continuously interact with its environment. Usually, the interaction of a reactive system with its environment is supported by a set of nonterminating processes that operate in parallel. During the interaction, the reactive system must answer to high-priority events, even when the system is executing something else. Due to above characteristics, the behaviour of reactive systems can be very complex. The approach suggested in this thesis assumes that the requirements of reactive software systems are partially described by use case diagrams, and each use case is detailed by a collection of scenario descriptions. Within this approach, one can obtain, from a set of behavioural scenarios of a given system, an executable behavioural model that can support, when complemented with animation- and domain-speci c elements, a graphical animation for reproducing that set of scenarios for validation purposes. Animating the scenarios using graphical elements from the application domain ensures an e ective involvement of the users in the system's validation. The Coloured Petri nets (CPNs) modelling language is used as the notation to obtain the behavioural models, due to its natural support for mechanisms like concurrency, synchronisation, and resource sharing and its tool support. The obtained CPN model is guaranteed to be (1) parametric, allowing an easy modi cation of the initial conditions of the scenarios, (2) environment-descriptive, meaning that it includes the state of the relevant elements of the environment, and (3) animation-separated, implying that the elements related to the animation are separated from the other ones. We validate our approach based on its application to three case studies of reactive systems.Durante o desenvolvimento de sistemas de software, a validação é uma actividade crucial para garantir que o sistema de software satisfaz as necessidades e expectativas do utilizador. O sucesso na validação consiste na utilização de um processo onde os utilizadores e os clientes possam discutir de uma forma activa os requisitos do sistema que está a ser desenvolvido. Um sistema reactivo está continuamente em interacção com o seu ambiente, que é geralmente suportada por um conjunto de processos intermináveis que operam em paralelo. Durante a interacção, o sistema reactivo dever a responder aos eventos com alta prioridade, mesmo quando o sistema está a executar algo diferente. Devido às características anteriores, o comportamento dos sistemas reactivos pode ser muito complexo. A abordagem sugerida nesta tese assume que os requisitos de sistemas reactivos são em parte descritos por diagramas de casos de uso e que cada caso de uso é detalhado por uma colecção de descrições de cenários. Nesta abordagem, é possível obter, a partir de um conjunto de cenários de um dado sistema, um modelo comportamental que seja executável e que suporte, quando complementado com elementos específicos, uma animação gráfica que reproduza aquele conjunto de cenários para fins de validação. A animação dos cenários utilizando elementos gráficos do domínio da aplicação garante um envolvimento efectivo dos utilizadores na validação do sistema. A linguagem de modelação redes de Petri coloridas (CPNs) é usada como a notação para obter os modelos comportamentais, devido ao seu suporte natural a mecanismos como a concorrência, sincronização e partilha de recursos, e às suas ferramentas de suporte. Se as recomendações da abordagem proposta foram seguidas, temos a garantia que o modelo CPN: (1) parametriza as condições iniciais dos cenários, (2) contém uma descrição do ambiente, incluindo o estado dos seus elementos, e (3) separa os elementos relacionados com a animação dos outros elementos do modelo. A validação da nossa abordagem tem por base a sua aplicação a três casos de estudo de sistemas reactivos.Fundação para a Ciência e a Tecnologia (FCT) SFRH/BD/19718/200

A cognitive exploration of the “non-visual” nature of geometric proofs

Why are Geometric Proofs (Usually) “Non-Visual”? We asked this question as a way to explore the similarities and differences between diagrams and text (visual thinking versus language thinking). Traditional text-based proofs are considered (by many to be) more rigorous than diagrams alone. In this paper we focus on human perceptual-cognitive characteristics that may encourage textual modes for proofs because of the ergonomic affordances of text relative to diagrams. We suggest that visual-spatial perception of physical objects, where an object is perceived with greater acuity through foveal vision rather than peripheral vision, is similar to attention navigating a conceptual visual-spatial structure. We suggest that attention has foveal-like and peripheral-like characteristics and that textual modes appeal to what we refer to here as foveal-focal attention, an extension of prior work in focused attention

Knowledge-based inspection

Increased level of complexity in almost every discipline and operation today raises the demand for knowledge in order to successfully run an organization whether to generate profit or to attain a non-profit mission. Traditional way of transferring knowledge to information systems rich in data structures and complex algorithms continue to hinder the ability to swiftly turnover concepts into operations. Diagrammatic modelling commonly applied in engineering in order to represent concepts or reality remains to be an excellent way of converging knowledge from domain experts. The nuclear verification domain represents ever more a matter which has great importance to the World safety and security. Demand for knowledge about nuclear processes and verification activities used to offset potential misuse of nuclear technology will intensify with the growth of the subject technology. This Doctoral thesis contributes with a model-based approach for representing complex process such as nuclear inspections. The work presented contributes to other domains characterized with knowledge intensive and complex processes. Based on characteristics of a complex process a conceptual framework was established as the theoretical basis for creating a number of modelling languages to represent the domain. The integrated Safeguards Modelling Method (iSMM) is formalized through an integrated meta-model. The diagrammatic modelling languages represent the verification domain and relevant nuclear verification aspects. Such a meta-model conceptualizes the relation between practices of process management, knowledge management and domain specific verification principles. This fusion is considered as necessary in order to create quality processes. The study also extends the formalization achieved through a meta-model by contributing with a formalization language based on Pattern Theory. Through the use of graphical and mathematical constructs of the theory, process structures are formalized enhancing the ability to analyse, compare and transform models. In the example domain all possible connections between critical nuclear processes were formalized providing also for probability-based analysis of weapons acquisition paths that will help design objective-based inspection processes.Increased level of complexity in almost every discipline and operation today raises the demand for knowledge in order to successfully run an organization whether to generate profit or to attain a non-profit mission. Traditional way of transferring knowledge to information systems rich in data structures and complex algorithms continue to hinder the ability to swiftly turnover concepts into operations. Diagrammatic modelling commonly applied in engineering in order to represent concepts or reality remains to be an excellent way of converging knowledge from domain experts. The nuclear verification domain represents ever more a matter which has great importance to the World safety and security. Demand for knowledge about nuclear processes and verification activities used to offset potential misuse of nuclear technology will intensify with the growth of the subject technology. This Doctoral thesis contributes with a model-based approach for representing complex process such as nuclear inspections. The work presented contributes to other domains characterized with knowledge intensive and complex processes. Based on characteristics of a complex process a conceptual framework was established as the theoretical basis for creating a number of modelling languages to represent the domain. The integrated Safeguards Modelling Method (iSMM) is formalized through an integrated meta-model. The diagrammatic modelling languages represent the verification domain and relevant nuclear verification aspects. Such a meta-model conceptualizes the relation between practices of process management, knowledge management and domain specific verification principles. This fusion is considered as necessary in order to create quality processes. The study also extends the formalization achieved through a meta-model by contributing with a formalization language based on Pattern Theory. Through the use of graphical and mathematical constructs of the theory, process structures are formalized enhancing the ability to analyse, compare and transform models. In the example domain all possible connections between critical nuclear processes were formalized providing also for probability-based analysis of weapons acquisition paths that will help design objective-based inspection processes

Quality assurance with dynamic meta modeling

Dynamic Meta Modeling (DMM) ist eine Semantikbeschreibungstechnik, die sich auf MOF-basierte Sprachen fokussiert und deren Verhalten durch graphische, operationale Regeln beschreibt. Der DMM-Ansatz wurde im Jahr 2000 von Engels et al. erstmals beschrieben und von Hausmann in 2006 in seiner Dissertation ausgearbeitet. Der nächste Schritt war nun, an verschiedenen Modellierungssprachen zu erproben, um die gemachten Erfahrungen in die Verbesserung von DMM und seinen Werkzeugen einfließen zu lassen. Das Ergebnis ist die DMM++-Methode, die in dieser Arbeit vorgestellt wird. Wir haben vorwiegend an drei Stellen Verbesserungen vorgenommen: Erstens haben wir basierend auf unseren Erfahrungen mit DMM neue Sprachkonzepte wie die Verfeinerung von Regeln entwickelt, und wir haben bestehende Konzepte wie die Behandlung von universell quantifizierten Strukturen oder Attributen verbessert. Zweitens haben wir einen testgetriebenen Semantikspezifizierungsprozess entwickelt: Zunächst wird eine Menge von Beispielmodellen erzeugt und deren erwartetes Verhalten formalisiert. Die DMM-Regeln werden dann inkrementell entwickelt, wobei geprüft wird, ob die Beispielmodelle tatsächlich das erwartete Verhalten erzeugen. Zudem haben wir Abdeckungskriterien für Tests von DMM-Spezifikationen entwickelt, die die Beurteilung der Qualität der Tests erlauben. Drittens haben wir gezeigt, wie funktionale und nichtfunktionale Anforderungen an Modelle und ihre DMM-Spezifikation formuliert und geprüft werden können. Für ersteres haben wir eine graphische Sprache zur Formulierung temporallogischer Eigenschaften zur Verfügung gestellt, die dann mit Model Checking geprüft werden. Für zweiteres ermöglichen wir dem Modellierer das Hinzufügen von Performanceinformationen zu den Modellen, aufgrund dessen dann z.B. der average throughput eines Modells berechnet werden kann.Dynamic Meta Modeling (DMM) is a semantics specification technique targeted at MOF-based modeling languages, where a language's behavior is defined by means of graphical operational rules which change runtime models. The DMM approach has first been suggested by Engels et al. in 2000; Hausmann has then defined the DMM language on a conceptual level within his PhD thesis in 2006. Consequently, the next step was to bring the existing DMM concepts alive, and then to apply them to different modeling languages, making use of the lessons learned to improve the DMM concepts as well as the DMM tooling. The result of this process is the DMM++ method, which is presented within this thesis. Our contributions are three-fold: First, and according to our experiences with the DMM language, we have introduced new concepts such as refinement by means of rule overriding, and we have strengthened existing concepts such as the dealing with universal quantified structures or attributes. Second, we have developed a test-driven process for semantics specification: A set of test models is created, and their expected behavior is fixed. Then, the DMM rules are created incrementally, finally resulting in a DMM ruleset realizing at least the expected behavior of the test models. Additionally, we have defined a set of coverage criteria for DMM rulesets which allow to measure the quality of a set of test models. Third, we have shown how functional as well as non-functional requirements can be formulated against models and their DMM specifications. The former is achieved by providing a visual language for formulating temporal logic properties, which are then verified with model checking techniques, and by allowing for visual debugging of models failing a requirement. For the latter, the modeler can add performance information to models and analyze their performance properties, e.g. average throughput.Tag der Verteidigung: 04.07.2013Paderborn, Univ., Diss., 201