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Angers, France

Boubaker B.B.,ESEO | Assidi M.,University of Lorraine | Ganghoffer J.F.,University of Lorraine
International Journal of Material Forming

The magnitudes of Poisson's ratios can attain some peculiar values for woven fabrics, in contrast to conventional engineering materials, leading to unusual stress-strain relationships. A mesoscopic discrete model of dry fabric has been presently developed at the scale of the armor, accounting for the yarn-yarn interactions at the yarns crossing points. From a mechanical viewpoint, yarns are modeled as elastic straight bar elements representing stretching springs connected at frictionless hinges by rotational springs. The motion of each node along the yarn is described by a lateral displacement and a local rotation. The reaction force exerted by the transverse yarns at the contact points is calculated from Timoshenko theory, and the work of the reaction forces is incorporated into the structure potential energy. The equilibrium shape of textile structures submitted to external loading is identified as configurations achieving the minimum of the potential energy; a genetic search algorithm has been implemented for the determination of the global minimum of the total potential energy. The transverse behavior of plain weave fabric is evaluated in terms of the Poisson's ratio, based on virtual simulations at the mesoscopic scale of analysis. Poisson's ratio first increases towards a maximum due to the rapid shrinkage of the sample in the transverse direction, and decreases thereafter when the crimp changes are exhausted, with yarn extension as the main deformation mechanism. The influence of the mechanical properties of both warp and weft on Poisson's coefficient is assessed. Scaling laws of the equivalent elastic properties of plain weave versus characteristic geometrical parameters (as the pick spacing) of the plain weave armor are determined. The predictions of the mesoscopic models provide a guideline for the design of woven fabrics. © 2010 Springer-Verlag France. Source

Yuan S.-Y.,Feng Chia University | Wu Y.-L.,Feng Chia University | Perdriau R.,ESEO | Liao S.-S.,Feng Chia University
IEEE Transactions on Electromagnetic Compatibility

This paper presents a combined hardware-software mechanism for the detection of electromagnetic interference of a microcontroller (μC) in daily usage. This detection mechanism is based on the instability of phase-lock loop embedded in the target μC. It can detect the presence of EMI with higher sensitivity than polling the hardware status of the μC internal registers and thus provides a better detection margin within the 10 kHz to 1 GHz EMI frequency range. Despite its relative slowness and its resource consumption, it is very robust, can be implemented in virtually any application software, and does not require any electromagnetic compatibility test equipment. © 1964-2012 IEEE. Source

Kassem R.,Beirut Arab University | Briday M.,University of Nantes | Bechennec J.-L.,University of Nantes | Savaton G.,ESEO | Trinquet Y.,University of Nantes
Journal of Systems Architecture

Validation and verification of embedded systems through simulation can be conducted at many levels, from the simulation of a high-level application model to the simulation of the actual binary code using an accurate model of the processor. However, for real-time applications, the simulated execution time must be as close as possible to the execution time on the actual platform and in this case the latter gives the closest results. The main drawback of the simulation of application's software using an accurate model of the processor resides in the development of a handwritten simulator which is a difficult and tedious task. This paper presents Harmless, a hardware architecture description language (ADL) that mainly targets real-time embedded systems. Harmless is dedicated to the generation of simulators for hardware platforms to develop and test real-time embedded applications. Compared to existing ADLs, Harmless (1) offers a more flexible description of the instruction set architecture (ISA) (2) allows to describe the microarchitecture independently of the ISA to ease its reuse and (3) compares favorably to simulators generated by the existing ADLs toolsets. © 2012 Elsevier B.V. All rights reserved. Source

Lafi L.,University of Sousse | Feki J.,University of Jeddah | Hammoudi S.,ESEO
MODELSWARD 2016 - Proceedings of the 4th International Conference on Model-Driven Engineering and Software Development

During the last two decades the theory of model transformation has been extensively studied and subject of many research. So far, several transformation languages have been developed and implemented. Recently, a metamodel matching technique has been proposed in order to find mapping models that support the deduction of transformations definitions. The model matching aims at searching semantic similarity between models elements, and therefore, facilitating semi-automatic mapping generation. However, current model matching techniques mostly focus on some comparison criteria (i.e., pre-matching effort, input model, output model, quality measures values) while ignore others; in addition these techniques are used in isolation, so that their advantages and commons are not exploited. In this paper, we tackle these issues by proposing a new technique relying on combination of metamodels matching techniques. To reach our goal, schema and ontology matching techniques can be adapted to develop a hybrid technique for metamodel matching. This technique will produce better matching results increasing the mappings quality. © Copyright 2016 by SCITEPRESS - Science and Technology Publications, Lda. All rights reserved. Source

Hammoudi S.,ESEO
ICSOFT 2011 - Proceedings of the 6th International Conference on Software and Database Technologies

Context-aware development has been an emergent subject of many research works in ubiquitous computing. Few of them propose Model Driven Development (MDD) as an approach for context-aware application development. Many focus on context capture and adaptation by the use of legacy architectures and others artefacts to bind context with application logic. This work proposes a new approach called COMODE (Context Aware Model Driven Development) which advocates Model Driven Development to promote reuse, adaptability and interoperability for context-aware application development on service platforms. In this paper we focus on the transformation issue and propose a parameterized transformation as a new approach for model driven development of context-aware services. Source

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