References of "Nain, Grégory 50002716"
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See detailKevoreeJS: Enabling dynamic software reconfigurations in the Browser
Tricoire, Maxime; Barais, Olivier; Leduc, Manuel et al

in WICSA/CompArch 2016 Proceedings (2016, March)

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See detailStream my Models: Reactive Peer-to-Peer Distributed Models@run.time
Hartmann, Thomas UL; Moawad, Assaad UL; Fouquet, François UL et al

in Lethbridge, Timothy; Cabot, Jordi; Egyed, Alexander (Eds.) 2015 ACM/IEEE 18th International Conference on Model Driven Engineering Languages and Systems (MODELS) (2015, September)

The models@run.time paradigm promotes the use of models during the execution of cyber-physical systems to represent their context and to reason about their runtime behaviour. However, current modeling ... [more ▼]

The models@run.time paradigm promotes the use of models during the execution of cyber-physical systems to represent their context and to reason about their runtime behaviour. However, current modeling techniques do not allow to cope at the same time with the large-scale, distributed, and constantly changing nature of these systems. In this paper, we introduce a distributed models@run.time approach, combining ideas from reactive programming, peer-to-peer distribution, and large-scale models@run.time. We define distributed models as observable streams of chunks that are exchanged between nodes in a peer-to-peer manner. lazy loading strategy allows to transparently access the complete virtual model from every node, although chunks are actually distributed across nodes. Observers and automatic reloading of chunks enable a reactive programming style. We integrated our approach into the Kevoree Modeling Framework and demonstrate that it enables frequently changing, reactive distributed models that can scale to millions of elements and several thousand nodes. [less ▲]

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See detailBeyond Discrete Modeling: A Continuous and Efficient Model for IoT
Moawad, Assaad UL; Hartmann, Thomas UL; Fouquet, François UL et al

in Lethbridge, Timothy; Cabot, Jordi; Egyed, Alexander (Eds.) 2015 ACM/IEEE 18th International Conference on Model Driven Engineering Languages and Systems (MODELS) (2015, September)

Internet of Things applications analyze our past habits through sensor measures to anticipate future trends. To yield accurate predictions, intelligent systems not only rely on single numerical values ... [more ▼]

Internet of Things applications analyze our past habits through sensor measures to anticipate future trends. To yield accurate predictions, intelligent systems not only rely on single numerical values, but also on structured models aggregated from different sensors. Computation theory, based on the discretization of observable data into timed events, can easily lead to millions of values. Time series and similar database structures can efficiently index the mere data, but quickly reach computation and storage limits when it comes to structuring and processing IoT data. We propose a concept of continuous models that can handle high-volatile IoT data by defining a new type of meta attribute, which represents the continuous nature of IoT data. On top of traditional discrete object-oriented modeling APIs, we enable models to represent very large sequences of sensor values by using mathematical polynomials. We show on various IoT datasets that this significantly improves storage and reasoning efficiency. [less ▲]

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See detailPolymer: A Model-Driven Approach for Simpler, Safer, and Evolutive Multi-Objective Optimization Development
Moawad, Assaad UL; Hartmann, Thomas UL; Fouquet, François UL et al

in Hammoudi, Slimane; Pires, Luis Ferreira; Desfray, Philippe (Eds.) et al MODELSWARD 2015 - Proceedings of the 3rd International Conference on Model-Driven Engineering and Software Development (2015, February)

Multi-Objective Evolutionary Algorithms (MOEAs) have been successfully used to optimize various domains such as finance, science, engineering, logistics and software engineering. Nevertheless, MOEAs are ... [more ▼]

Multi-Objective Evolutionary Algorithms (MOEAs) have been successfully used to optimize various domains such as finance, science, engineering, logistics and software engineering. Nevertheless, MOEAs are still very complex to apply and require detailed knowledge about problem encoding and mutation operators to obtain an effective implementation. Software engineering paradigms such as domain-driven design aim to tackle this complexity by allowing domain experts to focus on domain logic over technical details. Similarly, in order to handle MOEA complexity, we propose an approach, using model-driven software engineering (MDE) techniques, to define fitness functions and mutation operators without MOEA encoding knowledge. Integrated into an open source modelling framework, our approach can significantly simplify development and maintenance of multi-objective optimizations. By leveraging modeling methods, our approach allows reusable optimizations and seamlessly connects MOEA and MDE paradigms. We evaluate our approach on a cloud case study and show its suitability in terms of i) complexity to implement an MOO problem, ii) complexity to adapt (maintain) this implementation caused by changes in the domain model and/or optimization goals, and iii) show that the efficiency and effectiveness of our approach remains comparable to ad-hoc implementations. [less ▲]

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See detailConviviality-driven access control policy
El Kateb, Donia UL; Zannone, N.; Moawad, Assaad UL et al

in Requirements Engineering (2015), 20(4), 363-382

Nowadays many organizations experience security incidents due to unauthorized access to information. To reduce the risk of such incidents, security policies are often employed to regulate access to ... [more ▼]

Nowadays many organizations experience security incidents due to unauthorized access to information. To reduce the risk of such incidents, security policies are often employed to regulate access to information. Such policies, however, are often too restrictive, and users do not have the rights necessary to perform assigned duties. As a consequence, access control mechanisms are perceived by users as a barrier and thus bypassed, making the system insecure. In this paper, we draw a bridge between the social concept of conviviality and access control. Conviviality has been introduced as a social science concept for ambient intelligence and multi-agent systems to highlight soft qualitative requirements like user-friendliness of systems. To bridge the gap between conviviality and security, we propose a methodological framework for updating and adapting access control policies based on conviviality recommendations. Our methodology integrates and extends existing techniques to assist system designers in the derivation of access control policies from socio-technical requirements of the system, while taking into account the conviviality of the system. We illustrate our framework using the Ambient Assisted Living use case from the HotCity of Luxembourg. © 2014, Springer-Verlag London. [less ▲]

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See detailModel-based time-distorted Contexts for efficient temporal Reasoning
Hartmann, Thomas UL; Fouquet, François UL; Nain, Grégory UL et al

Poster (2014, July 02)

Intelligent systems continuously analyze their context to autonomously take corrective actions. Building a proper knowledge representation of the context is the key to take adequate actions. This requires ... [more ▼]

Intelligent systems continuously analyze their context to autonomously take corrective actions. Building a proper knowledge representation of the context is the key to take adequate actions. This requires numerous and complex data models, for example formalized as ontologies or meta-models. As these systems evolve in a dynamic context, reasoning processes typically need to analyze and compare the current context with its history. A common approach consists in a temporal discretization, which regularly samples the context (snapshots) at specific timestamps to keep track of the history. Reasoning processes would then need to mine a huge amount of data, extract a relevant view, and finally analyze it. This would require lots of computational power and be time-consuming, conflicting with the near real-time response time requirements of intelligent systems. This paper introduces a novel temporal modeling approach together with a time-relative navigation between context concepts to overcome this limitation. Similarly to time distortion theory, our approach enables building time-distorted views of a context, composed by elements coming from different times, which speeds up the reasoning. We demonstrate the efficiency of our approach with a smart grid load prediction reasoning engine. [less ▲]

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See detailReasoning at Runtime using time-distorted Contexts: A Models@run.time based Approach
Hartmann, Thomas UL; Fouquet, François UL; Nain, Grégory UL et al

in Proceedings of the 26th International Conference on Software Engineering and Knowledge Engineering (2014, July)

Intelligent systems continuously analyze their context to autonomously take corrective actions. Building a proper knowledge representation of the context is the key to take adequate actions. This requires ... [more ▼]

Intelligent systems continuously analyze their context to autonomously take corrective actions. Building a proper knowledge representation of the context is the key to take adequate actions. This requires numerous and complex data models, for example formalized as ontologies or meta-models. As these systems evolve in a dynamic context, reasoning processes typically need to analyze and compare the current context with its history. A common approach consists in a temporal discretization, which regularly samples the context (snapshots) at specific timestamps to keep track of the history. Reasoning processes would then need to mine a huge amount of data, extract a relevant view, and finally analyze it. This would require lots of computational power and be time-consuming, conflicting with the near real-time response time requirements of intelligent systems. This paper introduces a novel temporal modeling approach together with a time-relative navigation between context concepts to overcome this limitation. Similarly to time distortion theory, our approach enables building time-distorted views of a context, composed by elements coming from different times, which speeds up the reasoning. We demonstrate the efficiency of our approach with a smart grid load prediction reasoning engine. [less ▲]

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See detailKevoree Modeling Framework (KMF): Efficient modeling techniques for runtime use
Fouquet, François UL; Nain, Grégory UL; Morin, Brice et al

Report (2014)

The creation of Domain Specific Languages(DSL) counts as one of the main goals in the field of Model-Driven Software Engineering (MDSE). The main purpose of these DSLs is to facilitate the manipulation of ... [more ▼]

The creation of Domain Specific Languages(DSL) counts as one of the main goals in the field of Model-Driven Software Engineering (MDSE). The main purpose of these DSLs is to facilitate the manipulation of domain specific concepts, by providing developers with specific tools for their domain of expertise. A natural approach to create DSLs is to reuse existing modeling standards and tools. In this area, the Eclipse Modeling Framework (EMF) has rapidly become the defacto standard in the MDSE for building Domain Specific Languages (DSL) and tools based on generative techniques. However, the use of EMF generated tools in domains like Internet of Things (IoT), Cloud Computing or Models@Runtime reaches several limitations. In this paper, we identify several properties the generated tools must comply with to be usable in other domains than desktop-based software systems. We then challenge EMF on these properties and describe our approach to overcome the limitations. Our approach, implemented in the Kevoree Modeling Framework (KMF), is finally evaluated according to the identified properties and compared to EMF. [less ▲]

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See detailReactive Security for Smart Grids Using Models@run.time-Based Simulation and Reasoning
Hartmann, Thomas UL; Fouquet, François UL; Klein, Jacques UL et al

in Proceedings of the Second Open EIT ICT Labs Workshop on Smart Grid Security (SmartGridSec14) (2014, April)

Smart grids leverage modern information and communication technology to offer new perspectives to electricity consumers, producers, and distributors. However, these new possibilities also increase the ... [more ▼]

Smart grids leverage modern information and communication technology to offer new perspectives to electricity consumers, producers, and distributors. However, these new possibilities also increase the complexity of the grid and make it more prone to failures. Moreover, new advanced features like remotely disconnecting meters create new vulnerabilities and make smart grids an attractive target for cyber attackers. We claim that, due to the nature of smart grids, unforeseen attacks and failures cannot be effectively countered relying solely on proactive security techniques. We believe that a reactive and corrective approach can offer a long-term solution and is able to both minimize the impact of attacks and to deal with unforeseen failures. In this paper we present a novel approach combining a Models@run.time-based simulation and reasoning engine with reactive security techniques to intelligently monitor and continuously adapt the smart grid to varying conditions in near real-time. [less ▲]

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See detailGeneric Cloud Platform Multi-objective Optimization Leveraging Models@run.time
El Kateb, Donia UL; Fouquet, François UL; Nain, Grégory UL et al

Scientific Conference (2014, March)

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See detailConviviality-Driven Access Control Policy
El Kateb, Donia UL; Zannone, Nicola; Moawad, Assaad UL et al

in Requirements Engineering (2014)

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See detailModularity and Dynamic Adaptation of Flexibly Secure Systems: Model-Driven Adaptive Delegation in Access Control Management
Nguyen, Phu Hong UL; Nain, Grégory UL; Klein, Jacques UL et al

in Transactions on Aspect-Oriented Software Development (2014), 11

Model-Driven Security (Mds) is a specialized Model-Driven Engineering (Mde) approach for supporting the development of secure systems. Model-Driven Security aims at improving the productivity of the ... [more ▼]

Model-Driven Security (Mds) is a specialized Model-Driven Engineering (Mde) approach for supporting the development of secure systems. Model-Driven Security aims at improving the productivity of the development process and quality of the resulting secure systems, with models as the main artifact. Among the variety of models that have been studied in a Model-Driven Security perspective, one canmention access control models that specify the access rights. So far, these models mainly focus on static definitions of access control policies, without taking into account the more complex, but essential, delegation of rights mechanism. Delegation is a meta-level mechanism for administrating access rights, which allows a user without any specific administrative privileges to delegate his/her access rights to another user. This paper gives a formalization of access control and delegation mechanisms, and analyses the main hard-points for introducing various advanced delegation semantics in Model-Driven Security. Then, we propose a modular model-driven framework for 1) specifying access control, delegation and the business logic as separate concerns; 2) dynamically enforcing/weaving access control policies with various delegation features into security-critical systems; and 3) providing a flexibly dynamic adaptation strategy.We demonstrate the feasibility and effectiveness of our proposed solution through the proof-of-concept implementations of different component-based systems running on different adaptive execution platforms, i.e. OSGi and Kevoree. [less ▲]

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See detailA Native Versioning Concept to Support Historized Models at Runtime
Hartmann, Thomas UL; Fouquet, François UL; Nain, Grégory UL et al

in Dingel, Juergen; Schulte, Wolfram; Ramos, Isidro (Eds.) et al Model-Driven Engineering Languages and Systems - 17th International Conference, MODELS 2014, Valencia, Spain, September 28 - October 3, 2014. Proceedings (2014)

Models@run.time provides semantically rich reflection layers enabling intelligent systems to reason about themselves and their surrounding context. Most reasoning processes require not only to explore the ... [more ▼]

Models@run.time provides semantically rich reflection layers enabling intelligent systems to reason about themselves and their surrounding context. Most reasoning processes require not only to explore the current state, but also the past history to take sustainable decisions e.g. to avoid oscillating between states. Models@run.time and model-driven engineering in general lack native mechanisms to efficiently support the notion of history, and current approaches usually generate redundant data when versioning models, which reasoners need to navigate. Because of this limitation, models fail in providing suitable and sustainable abstractions to deal with domains relying on history-aware reasoning. This paper tackles this issue by considering history as a native concept for modeling foundations. Integrated, in conjunction with lazy load/storage techniques, into the Kevoree Modeling Framework, we demonstrate onto a smart grid case study, that this mechanisms enable a sustainable reasoning about massive historized models. [less ▲]

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See detailA Rule-based Contextual Reasoning Platform for Ambient Intelligence environments
Moawad, Assaad UL; Bikakis, Antonis; Caire, Patrice UL et al

in Theory, Practice, and Applications of Rules on the Web (2013, July 01)

The special characteristics and requirements of intelligent environments impose several challenges to the reasoning processes of Ambient Intelligence systems. Such systems must enable heterogeneous ... [more ▼]

The special characteristics and requirements of intelligent environments impose several challenges to the reasoning processes of Ambient Intelligence systems. Such systems must enable heterogeneous entities operating in open and dynamic environments to collectively rea- son with imperfect context information. Previously we introduced Con- textual Defeasible Logic (CDL) as a contextual reasoning model that addresses most of these challenges using the concepts of context, map- pings and contextual preferences. In this paper, we present a platform integrating CDL with Kevoree, a component-based software framework for Dynamically Adaptive Systems. We explain how the capabilities of Kevoree are exploited to overcome several technical issues, such as com- munication, information exchange and detection, and explain how the reasoning methods may be further extended. We illustrate our approach with a running example from Ambient Assisted Living. [less ▲]

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See detailR-CoRe: A Rule-based Contextual Reasoning Platform for AmI
Moawad, Assaad UL; Bikakis, Antonis; Caire, Patrice UL et al

in Joint Proceedings of the 7th International Rule Challenge, the Special Track on Human Language Technology and the 3rd RuleML Doctoral Consortium hosted at the 8th International Symposium on Rules (RuleML2013) (2013, July)

In this paper we present R-CoRe; a rule-based contextual reasoning platform for Ambient Intelligence environments. R-CoRe integrates Contextual Defeasible Logic (CDL) and Kevoree, a component-based ... [more ▼]

In this paper we present R-CoRe; a rule-based contextual reasoning platform for Ambient Intelligence environments. R-CoRe integrates Contextual Defeasible Logic (CDL) and Kevoree, a component-based software platform for Dynamically Adaptive Systems. Previously, we explained how this integration enables to overcome several reasoning and technical issues that arise from the imperfect nature of context knowledge, the open and dynamic nature of Ambient Intelligence environments, and the restrictions of wireless communications. Here, we focus more on technical aspects related to the architecture of R-Core, and demonstrate its use in Ambient Assisted Living. [less ▲]

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See detailModel-Driven Adaptive Delegation
Nguyen, Phu Hong UL; Nain, Grégory UL; Klein, Jacques UL et al

in Masuhara, Hidehiko; Chiba, Sigeru; Ubayashi, Naoyasu (Eds.) Proceedings of the 12th annual international conference companion on Aspect-oriented software development (2013, March)

Model-Driven Security is a specialization of Model-Driven Engineering (MDE) that focuses on making security models productive, i.e., enforceable in the final deployment. Among the variety of models that ... [more ▼]

Model-Driven Security is a specialization of Model-Driven Engineering (MDE) that focuses on making security models productive, i.e., enforceable in the final deployment. Among the variety of models that have been studied in a MDE perspective, one can mention access control models that specify the access rights. So far, these models mainly focus on static definitions of access control policies, without taking into account the more complex, but essential, delegation of rights mechanism. User delegation is a meta-level mechanism for administrating access rights, which allows a user without any specific administrative privileges to delegate his/her access rights to another user. This paper analyses the main hard-points for introducing various delegation semantics in model-driven security and proposes a model-driven framework for 1) specifying access control, delegation and the business logic as separate concerns; 2) dynamically enforcing/weaving access control policies with various delegation features into security-critical systems; and 3) providing a flexibly dynamic adaptation strategy. We demonstrate the feasibility and effectiveness of our proposed solution through the proof-of-concept implementations of different systems. [less ▲]

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See detailAn Eclipse Modelling Framework Alternative to Meet the Models@Runtime Requirements
Fouquet, François; Nain, Grégory UL; Morin, Brice et al

in Model Driven Engineering Languages and Systems - 15th International Conference (2012, October)

Models@Runtime aims at taming the complexity of software dynamic adaptation by pushing further the idea of reflection and considering the reflection layer as a first-class modeling space. A natural ... [more ▼]

Models@Runtime aims at taming the complexity of software dynamic adaptation by pushing further the idea of reflection and considering the reflection layer as a first-class modeling space. A natural approach to Models@Runtime is to use MDE techniques, in particular those based on the Eclipse Modeling Framework. EMF provides facilities for building DSLs and tools based on a structured data model, with tight integration with the Eclipse IDE. EMF has rapidly become the defacto standard in the MDE community and has also been adopted for building Models@Runtime platforms. For example, Frascati (implementing the Service Component Architecture standard) uses EMF for the design and runtime tooling of its architecture description language. However, EMF has primarily been thought to support design-time activities. This paper highlights specific Models@Runtime requirements, discusses the benefits and limitations of EMF in this context, and presents an alternative implementation to meet these requirements. [less ▲]

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See detailIntroducing Conviviality as a New Paradigm for Interactions among IT Objects
Moawad, Assaad UL; Efthymiou, Vasileios UL; Caire, Patrice UL et al

in Proceedings of the Workshop on AI Problems and Approaches for Intelligent Environments (2012, August), 907

The Internet of Things allows people and objects to seamlessly interact, crossing the bridge between real and virtual worlds. Newly created spaces are heterogeneous; social relations naturally extend to ... [more ▼]

The Internet of Things allows people and objects to seamlessly interact, crossing the bridge between real and virtual worlds. Newly created spaces are heterogeneous; social relations naturally extend to smart objects. Conviviality has recently been introduced as a social science concept for ambient intelligent systems to highlight soft qualitative requirements like user friendliness of systems. Roughly, more opportunities to work with other people increase the conviviality. In this paper, we first propose the conviviality concept as a new interaction paradigm for social exchanges between humans and Information Technology (IT) objects, and extend it to IT objects among themselves. Second, we introduce a hierarchy for IT objects social interactions, from low-level one-way interactions to high-level complex interactions. Then, we propose a mapping of our hierarchy levels into dependence networks-based conviviality classes. In particular, low levels without cooperation among objects are mapped to lower conviviality classes, and high levels with complex cooperative IT objects are mapped to higher conviviality classes. Finally, we introduce new conviviality measures for the Internet of Things, and an iterative process to facilitate cooperation among IT objects, thereby the conviviality of the system. We use a smart home as a running example. [less ▲]

Detailed reference viewed: 105 (9 UL)