2,652 research outputs found

    A Conceptual Framework for Adapation

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    This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

    A Conceptual Framework for Adapation

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    This paper presents a white-box conceptual framework for adaptation that promotes a neat separation of the adaptation logic from the application logic through a clear identification of control data and their role in the adaptation logic. The framework provides an original perspective from which we survey archetypal approaches to (self-)adaptation ranging from programming languages and paradigms, to computational models, to engineering solutions

    A Conceptual Framework for Adapation

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    We present a white-box conceptual framework for adaptation. We called it CODA, for COntrol Data Adaptation, since it is based on the notion of control data. CODA promotes a neat separation between application and adaptation logic through a clear identification of the set of data that is relevant for the latter. The framework provides an original perspective from which we survey a representative set of approaches to adaptation ranging from programming languages and paradigms, to computational models and architectural solutions

    Evaluating Resilience of Cyber-Physical-Social Systems

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    Nowadays, protecting the network is not the only security concern. Still, in cyber security, websites and servers are becoming more popular as targets due to the ease with which they can be accessed when compared to communication networks. Another threat in cyber physical social systems with human interactions is that they can be attacked and manipulated not only by technical hacking through networks, but also by manipulating people and stealing users’ credentials. Therefore, systems should be evaluated beyond cy- ber security, which means measuring their resilience as a piece of evidence that a system works properly under cyber-attacks or incidents. In that way, cyber resilience is increas- ingly discussed and described as the capacity of a system to maintain state awareness for detecting cyber-attacks. All the tasks for making a system resilient should proactively maintain a safe level of operational normalcy through rapid system reconfiguration to detect attacks that would impact system performance. In this work, we broadly studied a new paradigm of cyber physical social systems and defined a uniform definition of it. To overcome the complexity of evaluating cyber resilience, especially in these inhomo- geneous systems, we proposed a framework including applying Attack Tree refinements and Hierarchical Timed Coloured Petri Nets to model intruder and defender behaviors and evaluate the impact of each action on the behavior and performance of the system.Hoje em dia, proteger a rede não é a única preocupação de segurança. Ainda assim, na segurança cibernética, sites e servidores estão se tornando mais populares como alvos devido à facilidade com que podem ser acessados quando comparados às redes de comu- nicação. Outra ameaça em sistemas sociais ciberfisicos com interações humanas é que eles podem ser atacados e manipulados não apenas por hackers técnicos através de redes, mas também pela manipulação de pessoas e roubo de credenciais de utilizadores. Portanto, os sistemas devem ser avaliados para além da segurança cibernética, o que significa medir sua resiliência como uma evidência de que um sistema funciona adequadamente sob ataques ou incidentes cibernéticos. Dessa forma, a resiliência cibernética é cada vez mais discutida e descrita como a capacidade de um sistema manter a consciência do estado para detectar ataques cibernéticos. Todas as tarefas para tornar um sistema resiliente devem manter proativamente um nível seguro de normalidade operacional por meio da reconfi- guração rápida do sistema para detectar ataques que afetariam o desempenho do sistema. Neste trabalho, um novo paradigma de sistemas sociais ciberfisicos é amplamente estu- dado e uma definição uniforme é proposta. Para superar a complexidade de avaliar a resiliência cibernética, especialmente nesses sistemas não homogéneos, é proposta uma estrutura que inclui a aplicação de refinamentos de Árvores de Ataque e Redes de Petri Coloridas Temporizadas Hierárquicas para modelar comportamentos de invasores e de- fensores e avaliar o impacto de cada ação no comportamento e desempenho do sistema

    System specification and performance analysis

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    Timing verification in transaction modeling

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    Les systèmes Matériels/Logiciels deviennent indispensables dans tous les aspects de la vie quotidienne. La présence croissante de ces systèmes dans les différents produits et services incite à trouver des méthodes pour les développer efficacement. Mais une conception efficace de ces systèmes est limitée par plusieurs facteurs, certains d'entre eux sont: la complexité croissante des applications, une augmentation de la densité d'intégration, la nature hétérogène des produits et services, la diminution de temps d’accès au marché. Une modélisation transactionnelle (TLM) est considérée comme un paradigme prometteur permettant de gérer la complexité de conception et fournissant des moyens d’exploration et de validation d'alternatives de conception à des niveaux d’abstraction élevés. Cette recherche propose une méthodologie d’expression de temps dans TLM basée sur une analyse de contraintes temporelles. Nous proposons d'utiliser une combinaison de deux paradigmes de développement pour accélérer la conception: le TLM d'une part et une méthodologie d’expression de temps entre différentes transactions d’autre part. Cette synergie nous permet de combiner dans un seul environnement des méthodes de simulation performantes et des méthodes analytiques formelles. Nous avons proposé un nouvel algorithme de vérification temporelle basé sur la procédure de linéarisation des contraintes de type min/max et une technique d'optimisation afin d'améliorer l'efficacité de l'algorithme. Nous avons complété la description mathématique de tous les types de contraintes présentées dans la littérature. Nous avons développé des méthodes d'exploration et raffinement de système de communication qui nous a permis d'utiliser les algorithmes de vérification temporelle à différents niveaux TLM. Comme il existe plusieurs définitions du TLM, dans le cadre de notre recherche, nous avons défini une méthodologie de spécification et simulation pour des systèmes Matériel/Logiciel basée sur le paradigme de TLM. Dans cette méthodologie plusieurs concepts de modélisation peuvent être considérés séparément. Basée sur l'utilisation des technologies modernes de génie logiciel telles que XML, XSLT, XSD, la programmation orientée objet et plusieurs autres fournies par l’environnement .Net, la méthodologie proposée présente une approche qui rend possible une réutilisation des modèles intermédiaires afin de faire face à la contrainte de temps d’accès au marché. Elle fournit une approche générale dans la modélisation du système qui sépare les différents aspects de conception tels que des modèles de calculs utilisés pour décrire le système à des niveaux d’abstraction multiples. En conséquence, dans le modèle du système nous pouvons clairement identifier la fonctionnalité du système sans les détails reliés aux plateformes de développement et ceci mènera à améliorer la "portabilité" du modèle d'application.Hardware/Software (Hw/Sw) systems are likely to become essential in all aspects of everyday life. The increasing penetration of Hw/Sw systems in products and services creates a necessity of their efficient development. However, the productive design of these systems is limited by several factors, some of them being the increasing complexity of applications, the increasing degree of integration, the heterogeneous nature of products and services as well as the shrinking of the time-to-market delay. Transaction Level Modeling (TLM) paradigm is considered as one of the most promising simulation paradigms to break down the design complexity by allowing the exploration and validation of design alternatives at high levels of abstraction. This research proposes a timing expression methodology in TLM based on temporal constraints analysis. We propose to use a combination of two paradigms to accelerate the design process: TLM on one hand and a methodology to express timing between different transactions on the other hand. Using a timing specification model and underlining timing constraints verification algorithms can decrease the time needed for verification by simulation. Combining in one framework the simulation and analytical design exploration methods can improve the analytical power of design verification and validation. We have proposed a new timing verification algorithm based on the linearization procedure and an optimization technique to improve its efficiency. We have completed the mathematical representation of all constraint types discussed in the literature creating in this way a unified timing specification methodology that can be used in the expression of a wider class of applications than previously presented ones. We have developed the methods for communication structure exploration and refinement that permitted us to apply the timing verification algorithms in system exploration at different TLM levels. As there are many definitions of TLM and many development environments proposing TLM in their design cycle with several pro and contra, in the context of our research we define a hardware/software (Hw/Sw) specification and simulation methodology which supports TLM in such a way that several modeling concepts can be seen separately. Relying on the use of modern software engineering technologies such as XML, XSLT, XSD, object oriented programming and others supported by the .Net Framework, an approach that makes an intermediate design model reuse possible in order to cope with time-to-market constraint is presented. The proposed TLM design methodology provides a general approach in system modeling that separates various application modeling aspects from system specification: computational models, used in application modeling, supported by the language used for the functional specification and provided by simulator. As a result, in the system model we can clearly identify system functionality without details related to the development platform thereby leading to a better “portability” of the application model

    Seventh Workshop and Tutorial on Practical Use of Coloured Petri Nets and the CPN Tools, Aarhus, Denmark, October 24-26, 2006

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    This booklet contains the proceedings of the Seventh Workshop on Practical Use of Coloured Petri Nets and the CPN Tools, October 24-26, 2006. The workshop is organised by the CPN group at the Department of Computer Science, University of Aarhus, Denmark. The papers are also available in electronic form via the web pages: http://www.daimi.au.dk/CPnets/workshop0

    Modern software cybernetics: new trends

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    Software cybernetics research is to apply a variety of techniques from cybernetics research to software engineering research. For more than fifteen years since 2001, there has been a dramatic increase in work relating to software cybernetics. From cybernetics viewpoint, the work is mainly on the first-order level, namely, the software under observation and control. Beyond the first-order cybernetics, the software, developers/users, and running environments influence each other and thus create feedback to form more complicated systems. We classify software cybernetics as Software Cybernetics I based on the first-order cybernetics, and as Software Cybernetics II based on the higher order cybernetics. This paper provides a review of the literature on software cybernetics, particularly focusing on the transition from Software Cybernetics I to Software Cybernetics II. The results of the survey indicate that some new research areas such as Internet of Things, big data, cloud computing, cyber-physical systems, and even creative computing are related to Software Cybernetics II. The paper identifies the relationships between the techniques of Software Cybernetics II applied and the new research areas to which they have been applied, formulates research problems and challenges of software cybernetics with the application of principles of Phase II of software cybernetics; identifies and highlights new research trends of software cybernetic for further research

    Mathematics in Software Reliability and Quality Assurance

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    This monograph concerns the mathematical aspects of software reliability and quality assurance and consists of 11 technical papers in this emerging area. Included are the latest research results related to formal methods and design, automatic software testing, software verification and validation, coalgebra theory, automata theory, hybrid system and software reliability modeling and assessment
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