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Benfekir A.,Oran University of Science and Technology - Mohamed Boudiaf | Hamaci S.,EPMI | Darcherif A.-M.,EPMI | Laval L.,ECS Laboratory | Bouhamida M.,Oran University of Science and Technology - Mohamed Boudiaf
2013 18th International Conference on Methods and Models in Automation and Robotics, MMAR 2013 | Year: 2013

This paper deals with the analysis of dynamic behavior of Timed Event Graphs with Multipliers. These graphs are an extension of weighted T-systems studied in the Petri net literature. The purpose of this analyse is to extract the performances of a system by analyzing the dynamic of state associated of each transition of graph. For that, we determine the mathematical model governing the dynamic evolution of this type of graph, in a dioid of formal power series based on operators. © 2013 West Pomeranian University of Technology. Source

Maiga M.,University of Orleans | Combastel C.,ECS Laboratory | Ramdani N.,University of Orleans | Trave-Massuyes L.,CNRS Laboratory for Analysis and Architecture of Systems
2014 European Control Conference, ECC 2014 | Year: 2014

The computation of reachable sets for hybrid systems with nonlinear continuous dynamics is addressed. In this context, the computation of the intersection of the reachable set with the guard set is a challenging problem. In a previous work, we have proposed a guaranteed relaxation method expressed as a constraint satisfaction problem to solve the event detection and localization problems underlying flow/guard intersection. The algorithm also relies on bisection operations which may generate a large number of boxes. The main contribution of this paper is to merge the solution domains related to these boxes and corresponding to the reachable set at a given time. An algorithm minimizing the conservatism of a convex enclosure obtained by aggregating several solution domains into one domain is proposed: it relies on a zonotopic representation which is consistent with our continuous reachability approach. The combination of constraint propagation, bisection and merging makes it possible to achieve good algorithm performance, which will be illustrated through a numerical example involving a typical hybrid dynamical system: a bouncing ball with continuous state dimensions up to 4. Our evaluation shows very promising results. © 2014 EUCA. Source

Maiga M.,University of Orleans | Ramdani N.,University of Orleans | Trave-Massuyes L.,CNRS Laboratory for Analysis and Architecture of Systems | Combastel C.,ECS Laboratory
Mathematics in Computer Science | Year: 2014

Computing the reachable set of hybrid dynamical systems in a reliable and verified way is an important step when addressing verification or synthesis tasks. This issue is still challenging for uncertain nonlinear hybrid dynamical systems. We show in this paper how to combine a method for computing continuous transitions via interval Taylor methods and a method for computing the geometrical intersection of a flowpipe with guard sets, to build an interval method for reachability computation that can be used with truly nonlinear hybrid systems. Our method for flowpipe guard set intersection has two variants. The first one relies on interval constraint propagation for solving a constraint satisfaction problem and applies in the general case. The second one computes the intersection of a zonotope and a hyperplane and applies only when the guard sets are linear. The performance of our method is illustrated on examples involving typical hybrid systems. © 2014, Springer Basel. Source

Labadi K.,ECS Laboratory | Benarbia T.,Oran University of Science and Technology - Mohamed Boudiaf | Barbot J.-P.,ECS Laboratory | Hamaci S.,ECS Laboratory | Omari A.,University of Science and Technology of Oran
IEEE Transactions on Automation Science and Engineering | Year: 2015

Public Bicycle-Sharing Systems (PBSS) have been appearing in more and more cities around the world in the last few years. Although their apparent success as an alternative form of public transportation mode, there are major challenges confronting the operators while few scientific works are available to support such complex dynamical systems to influence their economic viability and operational efficiency. One of the most crucial factors for the success of a PBS system is its ability to ensure that bicycles are available for pick up and vacant berths available for bicycle drop off at every station. In this paper, we develop an original discrete event approach for modelling and performance evaluation of public bicycle-sharing systems by using Petri nets with time, inhibitor arcs and variable arc weights. © 2014 IEEE. Source

Deza J.,Alcatel - Lucent | Ouslimani A.,ECS Laboratory | Konczykowska A.,Alcatel - Lucent | Kasbari A.,ECS Laboratory | And 2 more authors.
Electronics Letters | Year: 2012

Performances of two switched emitter follower structures for large bandwidth applications have been optimised, compared, implemented and measured. These circuits have been fabricated with a 320GHz-F T InP double heterojunction bipolar transistor process. Measurements in track mode show a small-signal bandwidth over 65GHz for one structure and over 50GHz for the other. Track mode SFDR measured for 500mV PP up to 15GHz signal input is greater than 45 dBc. © 2012 The Institution of Engineering and Technology. Source

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