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See detailModel-Driven Security based on A Unified System of Security Design Patterns
Nguyen, Phu Hong UL

Report (2015)

Model-Driven Security (MDS) for secure systems development still has limitations to be more applicable in practice. A recent systematic review of MDS shows that current MDS approaches have not dealt with ... [more ▼]

Model-Driven Security (MDS) for secure systems development still has limitations to be more applicable in practice. A recent systematic review of MDS shows that current MDS approaches have not dealt with multiple security concerns system- atically. Besides, catalogs of security patterns which can address multiple security concerns have not been applied efficiently. This paper presents an MDS approach based on a unified System of Security design Patterns (SoSPa). In SoSPa, security design patterns are collected, specified as reusable aspect models to form a coherent system of them that guides developers in systematically addressing multiple security concerns. SoSPa consists of not only interrelated security design patterns but also a refinement process towards their application. We applied SoSPa to design the security of crisis management systems. The result shows that multiple security concerns in the case study have been addressed by systematically integrating different security solutions. [less ▲]

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See detailModel-Driven Security with A System of Aspect-Oriented Security Design Patterns
Nguyen, Phu Hong UL; Klein, Jacques UL; Le Traon, Yves UL

in 2nd Workshop on View-Based, Aspect-Oriented and Orthographic Software Modelling (2014, July 22)

Model-Driven Security (MDS) has emerged for more than a decade, as a specialization of Model-Driven Engineering (MDE), to propose sound MD methodologies for supporting secure systems development. Yet ... [more ▼]

Model-Driven Security (MDS) has emerged for more than a decade, as a specialization of Model-Driven Engineering (MDE), to propose sound MD methodologies for supporting secure systems development. Yet, there is still a big gap before making MDS approaches more easily applicable and adoptable by industry. Most current MDS approaches only deal with a specific security concern, e.g. Authorization, and have not taken into account multiple security concerns. Besides, security patterns which are based on domain-independent, time-proven security knowledge and expertise, can be considered as reusable security bricks upon which sound and secure systems can be built. But they are not applied as much as they could be, because developers have problems in selecting them and applying them in the right places, especially at the design phase. In this position paper, we propose an exploratory MDS approach based on a System of aspect-oriented Security design Patterns (SoSPa) in which security design patterns are collected, specified as reusable aspect models to form a coherent system of them that guides developers in systematically selecting the right security design patterns for the job. Our MDS approach allows the selected security design patterns to be automatically composed with the target system model. The woven secure system model can then be used for code generation, including configured security infrastructures. [less ▲]

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See detailModel-Driven Security With Modularity and Reusability For Engineering Secure Software Systems
Nguyen, Phu UL

Doctoral thesis (2015)

Context: The more human beings depend on software systems, the more important role that software security engineering must play to build secure software systems. Model-Driven Security (MDS) emerged more ... [more ▼]

Context: The more human beings depend on software systems, the more important role that software security engineering must play to build secure software systems. Model-Driven Security (MDS) emerged more than a decade ago as a specialised Model-Driven Engineering (MDE) research area for engineering secure software systems. MDS is promising but not mature yet. Our recent systematic literature review (SLR) has revealed several current limitations and open issues in the state of the art of MDS research. Objectives: This PhD work aims at addressing three of the main open issues in the current state of the art of MDS research that are pointed out by the SLR. First, our SLR shows that multiple security concerns need to be handled together more systematically. Second, true Aspect-Oriented Modelling techniques for better ensuring the separation- of-concern in MDS approaches could have been leveraged more extensively. Third, complete tool chains based on integrated MDE techniques covering all the main stages of the development cycle are emerging, but still very rare. Methods: On one hand, we develop a full MDS framework with modularity based on domain-specific modelling, model transformations, and model-based security testing. This MDS framework can help us to deal with complex delegation mechanisms in access control administration, from modelling till testing. On the other hand, we propose a highly modular, reusable MDS solution based on a System of Security design Patterns (SoSPa) and reusable aspect models to tackle multiple security concerns systematically. Results: First, an extensive SLR has been conducted for revealing and analysing the current state of the art of MDS research. Second, a full MDS framework focusing on modularity has been proposed that integrates domain-specific modelling, model transformations, and model-based security testing to support all the main stages of an MDS development cycle. Third, we have developed a highly reusable, modular MDS approach based on a System of Security design Patterns for handling multiple security concerns together systematically. Finally, we have showed how our MDS approaches can be integrated in a full MDS framework, called MDS-MoRe, which could be the basis of a complete tool chain for MDS development of secure systems. Conclusion: In this thesis, integrated MDS methodologies with modularity and reusability have been proposed for engineering secure software systems. This work has tackled three main current open issues in MDS research revealed from an extensive SLR. [less ▲]

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See detailModel-Driven Security with Modularity and Reusability for Secure Systems Development
Nguyen, Phu Hong UL

in STAF-DS 2014 (2014)

Model-Driven Security (MDS) has emerged as a promising sound methodology for modern secure systems development. Following the advances in MDS, this paper describes the late-PhD work that has proposed a ... [more ▼]

Model-Driven Security (MDS) has emerged as a promising sound methodology for modern secure systems development. Following the advances in MDS, this paper describes the late-PhD work that has proposed a solution to better support secure systems development, and further strengthens MDS. Our MDS solution focuses on modularity and reusability in secure systems development. On one hand, we have pro- posed a modular approach for modularity and dynamic adaptation of flexibly secure systems. On the other hand, we have been working on MDS based on a library-like System of generic Security design Patterns in which security design patterns are collected, specified as reusable aspect models to form a coherent system of them that guides developers in systematically selecting the right security design patterns for the right job. Either way, security (design pattern) models can be automatically woven into the target system model. The woven secure system model can then be used for code generation, including configured security infrastructures. We have been also working on using model-based security testing techniques to validate the resulting secure systems. [less ▲]

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See detailModel-driven situational awareness for moving target defense
Jhawar, Ravi UL; Mauw, Sjouke UL

in Scanlon, Marc; Le-Khac, Nhien-An (Eds.) Proc. 16th European Conference on Cyber Warfare and Security (2017)

Moving Target Defense (MTD) presents dynamically changing attack surfaces and system configurations to attackers. This approach decreases the success probabilities of attacks and increases attacker's ... [more ▼]

Moving Target Defense (MTD) presents dynamically changing attack surfaces and system configurations to attackers. This approach decreases the success probabilities of attacks and increases attacker's workload since she must continually re-assess, re-engineer and re-launch her attacks. Existing research has provided a number of MTD techniques but approaches for gaining situational awareness and deciding when/how to apply these techniques are not well studied. In this paper, we present a conceptual framework that closely integrates a set of models with the system and obtains up-to-date situational awareness following the OODA loop methodology. To realize the framework, as the first step, we propose a modelling approach that provides insights about the dynamics between potential attacks and defenses, impact of attacks and adaptations on the system, and the state of the system. Based on these models, we demonstrate techniques to quantitatively assess the effectiveness of MTD and show how to formulate decision-making problems. [less ▲]

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See detailModel-Driven Trace Diagnostics for Pattern-based Temporal Specifications
Dou, Wei UL; Bianculli, Domenico UL; Briand, Lionel UL

in Proceedings of the 2018 ACM/IEEE 21st International Conference on Model Driven Engineering Languages and Systems (MODELS 2018) (2018, October)

Offline trace checking tools check whether a specification holds on a log of events recorded at run time; they yield a verification verdict (typically a boolean value) when the checking process ends. When ... [more ▼]

Offline trace checking tools check whether a specification holds on a log of events recorded at run time; they yield a verification verdict (typically a boolean value) when the checking process ends. When the verdict is false, a software engineer needs to diagnose the property violations found in the trace in order to understand their cause and, if needed, decide for corrective actions to be performed on the system. However, a boolean verdict may not be informative enough to perform trace diagnostics, since it does not provide any useful information about the cause of the violation and because a property can be violated for multiple reasons. The goal of this paper is to provide a practical and scalable so- lution to solve the trace diagnostics problem, in the settings of model-driven trace checking of temporal properties expressed in TemPsy, a pattern-based specification language. The main contributions of the paper are: a model-driven approach for trace diagnostics of pattern-based temporal properties expressed in TemPsy, which relies on the evaluation of OCL queries on an instance of a trace meta-model; the implementation of this trace diagnostics procedure in the TemPsy-Report tool; the evaluation of the scalability of TemPsy-Report, when used for the diagnostics of violations of real properties derived from a case study of our industrial partner. The results show that TemPsy-Report is able to collect diagnostic information from large traces (with one million events) in less than ten seconds; TemPsy-Report scales linearly with respect to the length of the trace and keeps approximately constant performance as the number of violations increases. [less ▲]

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See detailModel-free reinforcement learning as mixture learning
Vlassis, Nikos UL; Toussaint, M.

in Proceedings of the 26th International Conference on Machine Learning (2009)

We cast model-free reinforcement learning as the problem of maximizing the likelihood of a probabilistic mixture model via sampling, addressing both the infinite and finite horizon cases. We describe a ... [more ▼]

We cast model-free reinforcement learning as the problem of maximizing the likelihood of a probabilistic mixture model via sampling, addressing both the infinite and finite horizon cases. We describe a Stochastic Approximation EM algorithm for likelihood maximization that, in the tabular case, is equivalent to a non-bootstrapping optimistic policy iteration algorithm like Sarsa(1) that can be applied both in MDPs and POMDPs. On the theoretical side, by relating the proposed stochastic EM algorithm to the family of optimistic policy iteration algorithms, we provide new tools that permit the design and analysis of algorithms in that family. On the practical side, preliminary experiments on a POMDP problem demonstrated encouraging results. [less ▲]

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See detailModel-Free Robust Adaptive Control for Flexible Rubber Objects Manipulation
Jasim, Ibrahim UL; Plapper, Peter UL; Voos, Holger UL

in 20th IEEE International Conference on Emerging Technologies and Factory Automation (ETFA 2015), Luxembourg 8-11 September 2015 (2015, September 08)

This article addresses the control problem of robots with unknown dynamics and manipulating flexible rubber objects of unknown elasticity. The manipulated rubber object is considered to be interacting ... [more ▼]

This article addresses the control problem of robots with unknown dynamics and manipulating flexible rubber objects of unknown elasticity. The manipulated rubber object is considered to be interacting with arbitrarily-switched constraints. Such a kind of robot system is shown to have switched impedance parameters during a task execution that results in an unknown hybrid nonlinear system with arbitrarily switched signal. A Model-Free Robust Adaptive Control (MFRAC) strategy is proposed for such a robot system that is proved to guarantee global stable performance with all closed loop signals are assured to be bounded. The suggested MFRAC strategy relies on the synergy of the Adaptive Fuzzy System (AFS), the Sliding Mode Control (SMC), and the notion of Common Lyapunov Functions (CLF). The AFS relaxes the need for knowing the precise robot dynamics, the SMC adds robustness against the drift of the dynamics parameters, and the CLF accommodates the arbitrary switching of the impedance parameters. The bounds of the impedance parameters are adapted online and incorporated in the MFRAC design such that a convergent performance is achieved. Experiment is conducted on a KUKA Lightweight Robot (LWR) doing flexible rubber peg-in-hole assembly process that falls in the category of systems considered in this article. From the experimental results, excellent tracking performance is reported when using the proposed MFRAC strategy for the considered robotic system despite the dynamics anonymity and the unknown impedance parameters arbitrary switching. [less ▲]

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See detailUn modèle cellulaire et dynamique de dispersion et ségrégation spatiale périurbaine
Caruso, Geoffrey UL

in XXXIX ème Colloque de l’Association de Science Régionale de Langue Française (2003)

Cette contribution propose d’explorer les processus de dispersion des ménages et de ségrégation par le revenu au sein d’un espace périurbain. La méthode consiste à simuler un modèle économique ... [more ▼]

Cette contribution propose d’explorer les processus de dispersion des ménages et de ségrégation par le revenu au sein d’un espace périurbain. La méthode consiste à simuler un modèle économique urbain avec deux types d’externalités de voisinage sur un espace cellulaire. Il permet la mise en place de processus dynamiques locaux endogènes et offre un éclairage sur la relation qui unit la morphologie des espaces périurbains et les caractéristiques des agents économiques qui s’y localisent. Des structures spatiales diverses sont générées sur deux configurations données des lots fonciers. Les équilibres présentent des structures concentriques constituées de multiples anneaux mais aussi, au cours des étapes de la croissance de la ville, des processus de dégradation cumulée ou des structures plus indépendantes de la distance. [less ▲]

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See detailUn modèle cellulaire et dynamique de dispersion et ségrégation spatiale périurbaine
Caruso, Geoffrey UL

in Buisson, Marie-Andrée; Mignot, Dominique (Eds.) Concentration économique et ségréegation spatiale (2005)

Cette contribution propose d’explorer les processus de dispersion des ménages et de ségrégation par le revenu au sein d’un espace périurbain. La méthode consiste à simuler un modèle économique urbain avec ... [more ▼]

Cette contribution propose d’explorer les processus de dispersion des ménages et de ségrégation par le revenu au sein d’un espace périurbain. La méthode consiste à simuler un modèle économique urbain avec deux types d’externalités de voisinage sur un espace cellulaire. Il permet la mise en place de processus dynamiques locaux endogènes et offre un éclairage sur la relation qui unit la morphologie des espaces périurbains et les caractéristiques des agents économiques qui s’y localisent. Des structures spatiales diverses sont générées sur deux configurations données des lots fonciers. Les équilibres présentent des structures concentriques constituées de multiples anneaux mais aussi, au cours des étapes de la croissance de la ville, des processus de dégradation cumulée ou des structures plus indépendantes de la distance. [less ▲]

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See detailUn modèle en pistes causales pour appréhender la complexité du phénomène d’accrochage scolaire lors de la transition primaire-secondaire
Poncelet, Débora UL; Lafontaine, Dominique

in Mesure et Evaluation en Education [=MEE] (2011), 34(1), 55-95

Detailed reference viewed: 52 (0 UL)
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See detail« Le modèle Internet en question (années 1970-2010) »
Musiani, Francesca; Schafer, Valerie UL

in Flux : Cahiers Scientifiques Internationaux Réseaux et Territoires = International Scientific Quarterly on Networks and Territories (2011), 3

Cet article se propose de montrer comment le « modèle Internet » – entendu comme un écosystème en évolution constante, sous l’effet du développement du Web, de ses usages commerciaux et grand public, des ... [more ▼]

Cet article se propose de montrer comment le « modèle Internet » – entendu comme un écosystème en évolution constante, sous l’effet du développement du Web, de ses usages commerciaux et grand public, des (re)compositions de la chaî- ne de valeur Internet – pose, depuis le développement d’Arpanet à la fin des années 1960, des questions de modélisa- tion et de gestion des flux. [less ▲]

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See detailUn modèle multi-agents de structuration sociale de la ville
Lemoy, Rémi UL; Raux, Charles; Jensen, Pablo

in Antoni, Jean-Philippe (Ed.) Modéliser la ville. Forme urbaine et politiques de transport (2010)

Detailed reference viewed: 24 (0 UL)
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See detailModèles de comportements collectifs et coopératifs
Provitolo, Damienne; Frankhauser, Pierre; Morer, Myriam et al

in Dominique, Frankhauser Pierre Et Ansel (Ed.) La Décision d'Habiter Ici ou Ailleurs (2012)

Le choix résidentiel est considéré comme un acte individuel ou celui d'un " mini-groupe " (famille) qui est conditionné par des références collectives. De ce fait, il s'appuie sur des informations ... [more ▼]

Le choix résidentiel est considéré comme un acte individuel ou celui d'un " mini-groupe " (famille) qui est conditionné par des références collectives. De ce fait, il s'appuie sur des informations (renommée de quartiers, d'une école, accessibilité à des services, commerces ...) mais il contribue également à l'émergence de tendances (préférence de certains modes de vie et de quartiers ...) qui peuvent \^etre à l'origine de flux migratoires. Ces derniers participent à l'émergence de nouvelles configurations spatiales à l'échelle d'une ville, donc de phénomènes macroscopiques. De telles tendances sont donc le résultat d'interactions entre individus et groupe sociaux, entre individus et société, ce qui nous amène à considérer les phénomènes émergents dans ce chapitre d'ouvrage. Afin d'aborder les comportements émergents dans le domaine de la mobilité quotidienne et résidentielle, quatre théories, qui constituent l'ossature de ce chapitre, sont présentées : deux d'entre elles s'inscrivent dans des champs disciplinaires, à savoir la physique et la psychologie sociale, tandis que les deux autres sont du domaine des systèmes complexes. Il s'agit respectivement des théories de la synergétique (issue de la physique des lasers) et de la dissonance cognitive (issue de la psychologie sociale) et des théories de l'auto-organisation critique (Bak (1996)) et des jeux (von Neumann (1944)). Le choix de ces quatre cadres théoriques n'est pas anodin. Ces derniers permettent, du point de vue du théoricien et du modélisateur, de centrer l'analyse des phénomènes émergents autour des interactions et des jeux d'échelles, autour de l'étude des phénomènes critiques et des points de rupture (synergétique, auto-organisation critique) ou des équilibres (usage de la théorie des jeux coopératifs et non coopératifs en économie), et autour des dynamiques lentes et rapides des systèmes. Les auteurs ont pris le parti d'associer à chacune de ces présentations théoriques des modèles, certains con cus spécifiquement dans le cadre de du projet ECDESUP, d'autres construits par nos prédécesseurs. [less ▲]

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See detailModèles de mesure et évaluation des compétences complexes
Burton, Réginald UL; Dierendonck, Christophe UL

in Actes du 16e congrès de l’Association Mondiale des Sciences de l’Education (AMSE). (2010)

Detailed reference viewed: 36 (9 UL)
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See detailModèles pour le contenu des tâches d’assemblage de faces géométriques et difficulté des items
Dickes, Paul; Houssemand, Claude UL; Reuter, Monique

in Psychologie Française (1996), 41

Deux modèles théoriques pour décrire l'univers des configurations à quatre faces et deux couleurs dans une tâche d'assemblage de type Kohs sont proposés. Le premier se base sur les relations qui existent ... [more ▼]

Deux modèles théoriques pour décrire l'univers des configurations à quatre faces et deux couleurs dans une tâche d'assemblage de type Kohs sont proposés. Le premier se base sur les relations qui existent entre les faces et le second sur les caractéristiques distinctives entre les items. L'isomorphisme entre les deux modèles est souligné. Le modèle relationnel explique 49% et le modèle en saillance 42% de la variance de la difficulté des 1296 items de l'univers, déterminée par une recherche empirique avec des enfants et des étudiants. L'utilité des deux modèles est discutée. [less ▲]

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See detailModeling a BSG-E automotive system with the Timing augmented description language
Peraldi-Frati, M.-A.; Goknil, A.; Adedjouma, Morayo UL et al

in Proceedings of 5th International Symposium of Leveraging Applications of Formal Methods, Verification and Validation. Applications and Case Studies (2012)

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See detailModeling Adsorption and Reactions of Organic Molecules at Metal Surfaces
Liu, Wei; Tkatchenko, Alexandre UL; Scheffler, Matthias

in ACCOUNTS OF CHEMICAL RESEARCH (2014), 47(11, SI), 3369-3377

CONSPECTUS: The understanding of adsorption and reactions of (large) organic molecules at metal surfaces plays an increasingly important role in modern surface science and technology. Such hybrid ... [more ▼]

CONSPECTUS: The understanding of adsorption and reactions of (large) organic molecules at metal surfaces plays an increasingly important role in modern surface science and technology. Such hybrid inorganic/organic systems (HIOS) are relevant for many applications in catalysis, light emitting diodes, single-molecule junctions, molecular sensors and switches, and photovoltaics. Obviously, the predictive modeling and understanding of the structure and stability of such hybrid systems is an essential prerequisite for tuning their electronic properties and functions. At present, density-functional theory (DFT) is the most promising approach to study the structure, stability, and electronic properties of complex systems, because it can be applied to both molecules and solids comprising thousands of atoms. However state-of-the-art approximations to DFT do not provide a consistent and reliable description for HIOS, which is largely due to two issues: (i) the self-interaction of the electrons with themselves arising from the Hartree term of the total energy that is not fully compensated in approximate exchange-correlation functionals, and (ii) the lack of long-range part of the ubiquitous van der Waals (vdW) interactions. The self-interaction errors sometimes lead to incorrect description of charge transfer and electronic level alignment in HIOS, although for molecules adsorbed on metals these effects will often cancel out in total energy differences. Regarding vdW interactions, several promising vdW-inclusive DFT-based methods have been recently demonstrated to yield remarkable accuracy for intermolecular interactions in the gas phase. However, the majority of these approaches neglect the nonlocal collective electron response in the vdW energy tail, an effect that is particularly strong in condensed phases and at interfaces between different materials. Here we show that the recently developed DFT+vdW(surf) method that accurately accounts for the collective electronic response effects enables reliable modeling of structure and stability for a broad class of organic molecules adsorbed on metal surfaces. This method was demonstrated to achieve quantitative accuracy for aromatic hydrocarbons (benzene, naphthalene, anthracene, and diindenoperylene), C-60, and sulfur/oxygen-containing molecules (thiophene, NTCDA, and PTCDA) on dose-packed and stepped metal surfaces, leading to an overall accuracy of 0.1 angstrom in adsorption heights and 0.1 eV in binding energies with respect to state-of-the-art experiments. An unexpected finding is that vdW interactions contribute more to the binding of strongly bound molecules on transition-metal surfaces than for molecules physisorbed on coinage metals. The accurate inclusion of vdW interactions also significantly improves tilting angles and adsorption heights for all the studied molecules, and can qualitatively change the potential-energy surface for adsorbed molecules with flexible functional groups. Activation barriers for molecular switches and reaction precursors are modified as well. [less ▲]

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