University Of Toulouse Irit

Toulouse, France

University Of Toulouse Irit

Toulouse, France
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Forgione T.,University Of Toulouse Irit | Carlier A.,University Of Toulouse Irit | Morin G.,University Of Toulouse Irit | Ooi W.T.,National University of Singapore | Charvillat V.,University Of Toulouse Irit
Proceedings of the 7th International Conference on Multimedia Systems, MMSys 2016 | Year: 2016

A 3D bookmark in a networked virtual environment (NVE) provides a navigation aid, allowing the user to move quickly from its current viewpoint to a bookmarked viewpoint by simply clicking on the bookmark. In this paper, we first validate the positive impact that 3D bookmarks have in easing navigation in a 3D scene. Then, we show that, in the context of a NVE that streams content on demand from server to client, navigating with bookmarks leads to lower rendering quality at the bookmarked viewpoint, due to lower locality of data. We then investigate into how prefetching the 3D data at the bookmarks and precomputation of visible faces at the bookmarks help to improve the rendering quality. © 2016 ACM.

Chaabani M.,University of Boumerdès | Echahed R.,Laboratoire Dinformatique Of Grenoble | Strecker M.,University Of Toulouse Irit
CEUR Workshop Proceedings | Year: 2013

This paper is about transformations of knowledge bases with the aid of an imperative programming language which is non-standard in the sense that it features conditions (in loops and selection statements) that are description logic (DL) formulas, and a non-deterministic assignment statement (a choice operator given by a DL formula). We sketch an operational semantics of the proposed programming language and then develop a matching Hoare calculus whose pre- and post-conditions are again DL formulas. A major diffculty resides in showing that the formulas generated when calculating weakest preconditions remain within the chosen DL fragment. In particular, this concerns substitutions whose result is not directly representable. We therefore explicitly add substitution as a constructor of the logic and show how it can be eliminated by an interleaving with the rules of a traditional tableau calculus.

Faure L.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Battaia G.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Marques G.,Ecole Nationale Superieure des Mines de Saint - Etienne CMP | Guillaume R.,University Of Toulouse Irit | And 5 more authors.
IEEE International Conference on Digital Ecosystems and Technologies | Year: 2013

In this paper, we elaborate a methodology to study a particular case of collaborative network: city logistics. We identify that many solutions for urban logistics are, most of time, badly evaluated. Indeed, the theory often predicts a positive effect but the reality is most of time counterbalanced. We tried to fill this gap by making use of innovative methods. To do so, we mobilize several domains of knowledge: operational research, game theory and transportation studies on real cases. We suggest a solution to anticipate the level of activity of an Urban Consolidation Center and determine the condition under which it generates benefit for a carrier using or not, the collaborative network. We present the result obtained by application of our method on the real case of the city of Saint-Etienne. © 2013 IEEE.

Baklanova N.,University Of Toulouse Irit | Brenas J.H.,French National Center for Scientific Research | Echahed R.,French National Center for Scientific Research | Percebois C.,University Of Toulouse Irit | And 2 more authors.
CEUR Workshop Proceedings | Year: 2015

We present a prototype for executing and verifying graph transformations. The transformations are written in a simple imperative programming language, and pre-and post-conditions as well as loop invariants are specified in the Description Logic ALC (whence the name of the tool). The programming language has a precisely defined operational semantics and a sound Hoare-style calculus. The tool consists of the following sub-components: a compiler to Java for executing the transformations; a verification condition generator; and a tableau prover for an extension of ALC capable of deciding the generated verification conditions. A description of these components and their interaction is the main purpose of this paper.

Ammar O.B.,University Of Toulouse Irit | Guillaume R.,University Of Toulouse Irit | Thierry C.,University Of Toulouse Irit
IFAC-PapersOnLine | Year: 2016

One of the main problems in supply chains is the supply planning of an actor (customer) in function of others network actors (suppliers). In this context, the knowledge of the supplier lead times uncertainty is essential in the client's risk management process. In this article we are particularly interested in the management of risks by an actor responsible of assembly activity. We suppose that each supplier is able to give his uncertain lead time by the meaning of intervals. In this collaborative context, we search to determine robust assembly process. In this study, we treat the case of a single-product and regular launches of the assembly. For this, we will propose a method based on MIP formulation and relaxation constraints approach to determine robust optimal suppliers’ lead times which minimize the both risk of assembly delay and storage of components. © 2016

Ober I.,University Of Toulouse Irit | Dragomir I.,University Of Toulouse Irit
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2011

Starting from version 2.0, UML introduced hierarchical composite structures, which are a very expressive way of defining complex software architectures, but which have a very loosely defined semantics in the standard. In this paper we propose a set of consistency rules that ensure UML composite structures are unambiguous and can be given a precise semantics. Our primary application of the static consistency rules defined in this paper is within the OMEGA UML profile [6], but these rules are general and applicable to other hierarchical component models based on the same concepts, such as MARTE GCM or SysML. The rule set has been formalized in OCL and is currently used in the OMEGA UML compiler. © 2011 Springer-Verlag Berlin Heidelberg.

Guillaume R.,University Of Toulouse Irit | Kobylanski P.,Wroclaw University of Technology | Zielinski P.,Wroclaw University of Technology
Fuzzy Sets and Systems | Year: 2012

The paper deals with a lot sizing problem with ill-known demands modeled by fuzzy intervals whose membership functions are possibility distributions for the values of the uncertain demands. Optimization criteria, in the setting of possibility theory, that lead to choose robust production plans under fuzzy demands are given. Some algorithms for determining optimal robust production plans with respect to the proposed criteria, and for evaluating production plans are provided. Some computational experiments are presented. © 2012 Elsevier B.V.

Guillaume R.,University Of Toulouse Irit | Thierry C.,University Of Toulouse Irit | Zielinski P.,Wroclaw University of Technology
2013 10th IEEE International Conference on Networking, Sensing and Control, ICNSC 2013 | Year: 2013

In this paper, we are interested in a production planning process in collaborative supply chains. More precisely, we consider supply chains, where actors use Manufacturing Resource Planning process (MRPII). Moreover, these actors collaborate by sharing procurement plans.We focus on a supplier, who applies the Periodic Order Quantity (POQ) rule to plan a production integrating the uncertain procurement plan sent by her/his customer. The uncertainty of the procurement plan is expressed by closed intervals on the cumulative demands. In order to choose a robust production plan, under the interval uncertainty representation, the min-max criterion is applied. We propose algorithms for determining the set of possible costs of a given production plan - due to the uncertainty on the cumulative demands.We then construct algorithms for computing a robust production plan with respect to the min-max criterion: the algorithm based on iterative adding constraints and the polynomial algorithms under certain realistic assumptions. © 2013 IEEE.

Guillaume R.,University Of Toulouse Irit | Zielinski P.,Wroclaw University of Technology
Communications in Computer and Information Science | Year: 2012

The paper deals with a collaborative supply chain, where actors use Material Requirement Planning (MRP) with uncertain demands. The demand uncertainty is modeled by a scenario set containing all possible demand realizations. Three scenario based uncertainty representations are examined. The min-max and the Hurwicz criterion and the ordered weighted averaging aggregation(OWA) are adopted to choose a best production or procurement plan under the assumed uncertainty models. Efficient solution methods for finding optimal plans with respect to each optimization criterion are provided. © 2012 Springer-Verlag.

Dragomir I.,University Of Toulouse Irit | Ober I.,University Of Toulouse Irit | Percebois C.,University Of Toulouse Irit
CEUR Workshop Proceedings | Year: 2013

The compositional approach based on components and driven by requirements is a common method used in the development of critical realtime embedded systems. Since the satisfaction of a requirement is subject to the composition of several components, defining abstract and partial behaviors for components with respect to the point of view of the requirement allows for a manageable design of systems. In this paper we consider such specifications in the form of contracts. A contract for a component is a pair (assumption, guarantee) where the assumption is an abstraction of the component's environment behavior and the guarantee is an abstraction of the component's behavior given that the environment behaves like the assumption. In previous work we have defined a formal contract-based theory for Timed Input/Output Automata with the aim of using it to express the semantics of UML/SysML models. In this paper we propose an extension of the UML/SysML language with a syntax and semantics for contracts and for the relations they must satisfy. Besides the important role that contracts have in design, they can also be used for the verification of requirement satisfaction and for their traceability.

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