Svalabard: Une table à dessin virtuelle pour la modélisation 3D

International audienceThis paper introduces a perspective sketching interface for creative 3D modeling: Svalabard. To close the gap between designers' abilities and 3D modeling tools, our proposal is a freehand sketching tool, metaphor of a drawing desk. Interactions and tools take advantage of designers work habits (multilayer drawing, association of interactions with input devices). Svalabard includes background drawing filters, developed from a user study in the architectural domain. Those filters detect the current drawing context in real-time to adapt the interface and clean the sketch. Finally, the result of the filters is a structured representation of drawn 3D volumes.Cet article présente une interface de dessin en perspective pour la modélisation 3D créative : Svalabard. Partant du constat d'inadéquation entre le savoir-faire des créateurs et les outils actuels, nous proposons un système de dessin libre, métaphore d'une table à dessin. L'interaction et les outils proposés sont dérivés des habitudes de travail des concepteurs (dessin multi calques, association des interactions avec des périphériques spécifiques). Svalabard intègre en particulier des filtres d'analyse sous-jacents, issus d'une étude utilisateur dans le domaine architectu- ral. Ils permettent de détecter en temps réel le contexte courant du dessin afin d'adapter l'interaction et d'épurer le dessin. Ils produisent finalement une représentation structurée des volumes 3D dessinés

Model-free based water level control for hydroelectric power plants

International audienceAutomatic water level control methods for open channels have difficulties to keep good performances for a large range of flow and significant unknown disturbances. A new concept called "model-free control" is applied in this paper for hydroelectric run-of-the river power plants. To modulate power generation, a level trajectory is planned for cascaded power plants. Numerous dynamic simulations show that with a simple and robust control algorithm, the set-point is followed even in severe operating conditions

Vers une commande sans mod\`ele pour am\'enagements hydro\'electriques en cascade

A new concept called "Model-Free Control" is applied to hydroelectric run-of-the river power plants, with severe constraints and operating conditions. Numerous computer simulations display excellent results, which are obtained thanks to simple and robust algorithms

Une "commande sans modèle" pour aménagements hydroélectriques en cascade

International audienceOn aborde, par la "commande sans modèle", la régulation du niveau d'eau dans un aménagement hydraulique, soumis à de fortes contraintes, pour produire de l'électricité. Les nombreuses simulations numériques fournissent d'excellents résultats, obtenus grâce à des algorithmes robustes et simples

The Receptive Distributed π\pi-Calculus

In this paper we study an asynchronous distributed $\pi$-calculus, with constructs for localities and migration. We show that a simple static analysis ensures the receptiveness of channel names, which, together with a simple type system, guarantees a local deadlock-freedom property, that we call message deliverability. This property states that any migrating message will find an appropriate receiver at its destination locality. We argue that this distributed, receptive calculus is still expressive enough, by giving a series of examples illustrating the «receptive style» of programming we have. Finally we show that our calculus contains the $\pi_1$-calculus, up to weak asynchronous bisimulation

Black branes on the linear dilaton background

We show that the complete static black p-brane supergravity solution with a single charge contains two and only two branches with respect to behavior at infinity in the transverse space. One branch is the standard family of asymptotically flat black branes, and another is the family of black branes which asymptotically approach the linear dilaton background with antisymmetric form flux (LDB). Such configurations were previously obtained in the near-horizon near-extreme limit of the dilatonic asymptotically flat p-branes, and used to describe the thermal phase of field theories involved in the DW/QFT dualities and the thermodynamics of little string theory in the case of the NS5-brane. Here we show by direct integration of the Einstein equations that the asymptotically LDB p-branes are indeed exact supergravity solutions, and we prove a new uniqueness theorem for static p-brane solutions satisfying cosmic censorship. In the non-dilatonic case, our general non-asymptotically flat p-branes are uncharged black branes on the background $AdS_{p+2}\times S^{D-p-2}$ supported by the form flux. We develop the general formalism of quasilocal quantities for non-asymptotically flat supergravity solutions with antisymmetric form fields, and show that our solutions satisfy the first law of theormodynamics. We also suggest a constructive procedure to derive rotating asymptotically LDB brane solutions.Comment: 16 pages, revtex4, v2 - references added, "authors" metatag correcte

Faisabilité économique du parquet massif de Chêne vert

La faisabilité économique de la fabrication de parquet en chêne vert, essence très abondante sur le pourtour méditerranéen, a été analysée par le Cirad-Forêt à la demande du Conseil Général de l’Hérault. Le prix de revient global de la transformation a été calculé en se référant à une opération expérimentale de production et fabrication avec mise en oeuvre en conditions réelles d’utilisation. La rentabilité de l’opération a été analysée en cohérence avec des marchés déjà existants. Une analyse de sensibilité des paramètres qui caractérisent la faisabilité économique de la fabrication a mis en évidence le rôle essentiel du prix de vente du produit fini, du rendement matière au sciage, et du prix d’achat de la matière première. Une variation de 1 % de chacun de ces trois paramètres peut induire une variation de plus de 35 % de la marge d’exploitation. La rentabilité de la fabrication de parquet en chêne vert est directement dépendante de la construction d’un réseau de fournisseurs réguliers pour sécuriser l’approvisionnement.

The MaggLite Post-WIMP Toolkit: Draw It, Connect It and Run It

International audienceThis article presents MaggLite, a toolkit and sketch-based interface builder allowing fast and interactive design of post-WIMP user interfaces. MaggLite improves design of advanced UIs thanks to its novel mixed-graph architecture that dynamically combines scene-graphs with interaction- graphs. Scene-graphs provide mechanisms to describe and produce rich graphical effects, whereas interaction-graphs allow expressive and fine-grained description of advanced interaction techniques and behaviors such as multiple pointers management, toolglasses, bimanual interaction, gesture, and speech recognition. Both graphs can be built interactively by sketching the UI and specifying the interaction using a dataflow visual language. Communication between the two graphs is managed at runtime by components we call Interaction Access Points. While developers can extend the toolkit by refining built-in generic mechanisms, UI designers can quickly and interactively design, prototype and test advanced user interfaces by applying the MaggLite principle: "draw it, connect it and run it"

End-User-Development for Smart Homes: Relevance and Challenges

International audienceUbiquitous computing is now mature enough to unleash the potential of Smart Homes. The obstacle is no more about hardware concerns but lies in how inhabitants can build, configure and control their Smart Home. In this paper, we defend the idea that End-User-Development (EUD), which considers inhabitants as makers rather than mere consumers, is an effective approach for tackling this obstacle. We reflect on the lifecycle of devices and services to discuss challenges that EUD system will have to address in the Smart Home context: installation and maintenance, designation, control, development (including programming, testing, and reusing), and sharing

From infinite dimensional modelling to parametric reduced-order approximation: Application to open-channel flow for hydroelectricity

International audienceIn this paper, it will be shown that open-channel hydraulic systems can be suitably represented for control purposes by using input delay linear parameter-varying (LPV) models. The physical equations on which this work is done are Saint-Venant equations applied to a non-rectangular cross section channel. These later are two coupled non-linear hyper-bolic partial differential equations which are linearized and transformed into irrational transfer functions. An accurate model approximation procedure, denoted IPTFA (Irrational Proper Transfer Function Algorithm) is developed in order to obtain a rational transfer function plus input delays which is then parameterized by one single parameter: the initial steady-state discharge. Frequency domain responses of the irrational and reduced-order transfer functions are shown to match for a large range of discharge