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Concurrent Constraint Programming (CCP) is a simple and powerful model for concurrency where agents interact by telling and asking constraints. Since their inception, CCP-languages have been designed for having a strong connection to logic. In fact, the underlying constraint system can be built from a suitable fragment of intuitionistic (linear) logic -ILL- and processes can be interpreted as formulas in ILL. Constraints as ILL formulas fail to represent accurately situations where “preferences” (called soft constraints) such as probabilities, uncertainty or fuzziness are present. In order to circumvent this problem, c-semirings have been proposed as algebraic structures for defining constraint systems where agents are allowed to tell and ask soft constraints. Nevertheless, in this case, the tight connection to logic and proof theory is lost. In this work, we give a proof theoretical meaning to soft constraints: they can be defined as formulas in a suitable fragment of ILL with subexponentials (SELL) where subexponentials, ordered in a c-semiring structure, are interpreted as preferences. We hence achieve two goals: (1) obtain a CCP language where agents can tell and ask soft constraints and (2) prove that the language in (1) has a strong connection with logic. Hence we keep a declarative reading of processes as formulas while providing a logical framework for soft-CCP based systems. An interesting side effect of (1) is that one is also able to handle probabilities (and other modalities) in SELL, by restricting the use of the promotion rule for non-idempotent c-semirings.This finer way of controlling subexponentials allows for considering more interesting spaces and restrictions, and it opens the possibility of specifying more challenging computational systems.

International audience; The aim of this study was to determine 1) the relevance of using the Pacific oyster Crassostrea gigas as a sentinel organism, at a juvenile stage, for polycyclic aromatic hydrocarbon (PAH) and persistent organic pollutant (polychlorobiphenyls, PCBs, polybromodimethylethers, PBDEs, and organochlorine pesticides, OCPs) contamination, 2) the potential levels of chemical organic contamination in the Marennes-Oleron Bay, and their potential sources 3) the potential influence of physiological or environmental factors on contaminant body burdens in oysters. To this end, juvenile oysters purchased from a oyster hatchery were transplanted to a reference site, in Bouin, and to different transplantation sites in the Marennes-Oléron Bay, the first oyster production area in France, and in the Gironde Estuary, the biggest estuary in Occidental Europe. Transplantations were done during summer and winter. Whole oyster soft tissues from each site were analyzed for PAHs, PCBs, PBDEs and OCPs. Results obtained with a transplantation period of 3 months suggest that the C. gigas, at the juvenile stage, is a relevant sentinel organism for short-term contamination for these contaminants. In addition, no significant effects of physiological factors on contaminant body burdens were observed. A principal component analysis performed with chemical body burdens allowed them to be separated into three groups: 1) the reference site, 2) Les Palles (LP) and Boyard (BOY) in winter and 3) all the other sites. The group of LP and BOY was clearly defined by the levels of PAHs and OCPs, suggesting higher levels of contamination of these chemical compounds on these sites, potentially due to local contamination sources. In addition, no relevant effects of physiological or environmental factors on contaminant body burdens were observed. Results suggest also a predominance of contaminants related to agricultural activities along the Marennes-Oléron Bay, and therefore, further studies on the presence of pesticides in this region should be considered.

Efficient and reliable extraction of coronary artery centerline from computed tomography angiography data is a prerequisite for a variety of medical imaging applications. Many authors have combined minimum-cost path algorithms and vesselness measures to extract coronary centerlines. We propose a modular decomposition of this extraction process, in order to facilitate the implementation and comparison of different minimum-cost path strategies allowing users (radiologists and developers) to focus on subsequent image analysis tasks. Evaluation results show a good overlap (> 84%), and small distances with regard to reference centerlines (on average, not larger than the voxel size) in multi-vendor datasets, for two combinations of algorithms that follow this framework. Therefore, it can serve as a starting point to subsequent image analysis stages that require coronary centerlines.

We propose a method to compute local scene flow by tracking in intensity and depth.We propose a pixel motion model to constrain the 3D motion vector on 2D.We extend the Lucas-Kanade framework to work with intensity and depth data.Throughout some experiments we demonstrated the validity of our method.We simultaneously solve for the 2D tracking and for the local scene flow. The scene flow describes the motion of each 3D point between two time steps. With the arrival of new depth sensors, as the Microsoft Kinect, it is now possible to compute scene flow with a single camera, with promising repercussion in a wide range of computer vision scenarios. We propose a novel method to compute a local scene flow by tracking in a Lucas-Kanade framework. Scene flow is estimated using a pair of aligned intensity and depth images but rather than computing a dense scene flow as in most previous methods, we get a set of 3D motion vectors by tracking surface patches. Assuming a 3D local rigidity of the scene, we propose a rigid translation flow model that allows solving directly for the scene flow by constraining the 3D motion field both in intensity and depth data. In our experimentation we achieve very encouraging results. Since this approach solves simultaneously for the 2D tracking and for the scene flow, it can be used for motion analysis in existing 2D tracking based methods or to define scene flow descriptors.

Este artículo surgió de un diálogo realizado con el profesor mexicano Abraham Nosnik Ostrowiak, en el que plantea las diferencias entre los conceptos de comunicación organizacional y estratégica y su propuesta sobre comunicación productiva. El profesor Nosnik destaca los vacíos y temas pendientes de la investigación en comunicación organizacional, entre ellos, un mayor conocimiento de la comunicación en las organizaciones sociales y un mayor enfoque hacia los problemas sociales. Así mismo, menciona algunas competencias del comunicador organizacional de cara a su realidad y contexto y al final propone pensar la creatividad como uno de los principales intangibles que deben desarrollar las organizaciones hoy., This article arose from a dialog with Mexican Professor Abraham Nosnik Ostrowiak, in which he raises the differences between organizational and strategic communication concepts and his proposal about productive communication. Prof. Nosnik emphasizes the empty and topics pending in organizational communication research, between them, a major knowledge of communication in social organizations and a major approach towards social problems. Likewise, it mentions some skills for organizational communicator with a view to his reality and context and finally, he proposes to think the creativity as one of the principal intangibles that organizations must develop today.

International audience; Contaminant effects on defence responses of ecologically and economically important organisms, such as the Pacific oyster Crassostrea gigas, are likely to influence their ability to resist infectious diseases, particularly at the young stages. The aim of this study was to explore the potential relationships between organic contaminants accumulated in the soft tissues of juvenile oysters, defence responses and physiological condition. Oysters were transplanted during summer and winter periods in different sites in the Marennes-Oléron Bay, the first area of oyster production in France, and in the Gironde Estuary, the biggest estuary in Occidental Europe. Among the battery of biochemical and physiological biomarkers applied in the present work (superoxide dismutase -SOD-, catalase, glutathione peroxidase -GPx-, malondyaldehyde -MDA-, catecholase, laccase and lysozyme in gills, digestive gland, mantle and haemolymph, glycogen, proteins and lipids in the digestive gland and the condition index at the whole organism level), MDA and lysozyme in the digestive gland and SOD, GPx and laccase in plasma contibuted to significantly discriminate sites in which oysters bioaccumulated different levels of heavy polycyclic aromatic hydrocarbons (HPAHs), polychlorobiphenyls (PCBs), polybromodiphenylethers (PBDEs), dichlorodiphenyltrichloroethanes (DDTs) and lindane. These results strengthen the hypothesis that it is possible to differentiate sites depending on their contamination levels and biological effects by carrying out studies with transplanted juvenile oysters. In addition, correlations between antioxidant and immune defence responses and PAH and DDT body burdens in the first area of oyster production in France, the Marennes-Oléron Bay, and where massive oyster mortalities have been reported, suggest that the presence of organic chemical contaminants in the Marennes-Oléron Bay may influence defence responses in juveniles of C. gigas, and, therefore, could influence their ability to resist infectious diseases.

International audience; In this article, the design of a feedback control law for DC-DC power converters in continuous conduction mode based on hybrid optimal control theory is presented. The proposed technique consists in determining the singular arcs when a solution of the original optimal control problem cannot be provided. The closed loop stability analysis uses a Lyapunov function based on a port-Hamiltonian representation of the system. The proposed control law is applied to SEPIC converter and validated in simulation.

This paper presents an analysis of the consequences of using a step-up transformer in the supply of a dielectric barrier discharge (DBD) excimer lamp. A simplified transformer model is used to analyze the effects of the different parasitic elements in the operation of a current mode power supply. Mathematical expressions are found for each element and experimental validation is performed. The design of the transformer is developed on the basis of the lamp specifications and two transformer configurations are tested experimentally, analyzing the effect of the parasitic elements and evidencing the influence of grounding a lamp terminal.

Part 1: Cross-Domain Conference and Workshop on Multidisciplinary Research and Practice for Information Systems (CD-ARES 2013); International audience; The extraction of metadata used during the planning phase in mediation systems assumes the existence of a metadata repository that in most cases must be created with high human involvement. This dependency rises complexity of maintenance of the system and therefore the reliability of the metadata itself. This article presents MetaExtractor, a system which extracts structure, quality, capability and content metadata of structured data sources available on a mediation system. MetaExtractor is designed as a Multi-Agent System(MAS) where each agent specializes in the extraction of a particular type of metadata. The MAS cooperation capability allows the creation and maintenance of the metadata repository. MetaExtractor is useful to reduce the number of data sources selected during query planning in large scale mediation systems due to its ability to prioritize data sources that better contribute to answer a query. The work reported in this paper presents the general architecture of MetaExtractor and emphasizes on the extraction logic of content metadata and the strategy used to prioritize data sources accordingly to a given query.

International audience; A new generator topology, specifically studied for the supply of DBD excilamps (Xe-Cl, Kr-Cl), has been recently developed at LAPLACE Laboratory. It exhibits a controllable discontinuous current-source behavior, which allows an accurate control of the UV emission. Design rules and performances (including experiments, electrical efficiency measurements-higher than 90%) of this discontinuous resonant current inverter are presented. Under specific experimental conditions, which will be detailed, a Xe-Cl excilamp connected to this power supply exhibits an unexpected system behavior: low frequency (# 0.05 Hz) jumps are observed on the UV emission (with intense flash of a few seconds). A study of the couplings between the generator and the lamp, and of the sensitivity of the transferred power relatively to the lamp parameters [4] is proposed to analyze this behavior and will be discussed.

Colloque avec actes et comité de lecture. Internationale.; International audience

Colloque avec actes et comité de lecture. Internationale.; International audience

IF=2.368; International audience; Heterarchical control architectures are essentially founded on cooperation and full local autonomy, resulting in high reactivity, no master/slave relationships and local information retention. Consequently, these architectures experience myopic decision-making, bringing entities towards local optimality rather than the system’s overall performance. Although this issue has been identified as an important problem within heterarchical control architectures, it has not been formally studied. The aim of this paper is to identify the dimensions of myopic behavior and propose mechanisms to control this behavior. This study focuses on myopic behavior found in manufacturing control. For this particular study, we propose a holonic framework and a holonic organization that integrates specific mechanisms to control the temporal and social myopia. Our proposal was validated using simulations designed for solving the allocation problem in flexible manufacturing systems. These simulations were conducted to show the improvement by integrating the new mechanisms. These simulation results indicate that the myopic control mechanisms achieve better performance than the reactive strategies, because not only they introduce a planning horizon, but also because they balance local and global objectives, seeking a consensus.

International audience; In Dielectric Barrier Discharges (DBDs), the control of the power transfer, from the low-voltage static converter to the high voltage DBD, is strongly affected by the parasitic capacitive effects of the step-up transformer. Minimizing these capacitances is of major importance and this paper aims to establish and validate analytical expressions in order to predict the values of the parasitic capacitances of high ratio, step-up transformers, according to different windings arrangements using cylindrical conductors. Afterward, experimental validations are performed on three transformers which have been realized according to same specifications, in order to show the accuracy of the method and to understand the influence the winding arrangements on the capacitive parasitic effects.

International audience; This paper proposes an efficient modeling and an identification method for dielectric barrier discharge (DBD) systems, based on input–output (current–voltage) experimental measurements. The DBD is modeled using an equivalent electric circuit associated with a differential equation that describes the dynamics of its conductance. This equation assumes a homogeneous behavior of the gas. This paper introduces a series of polynomial terms of the current of the gas into the conductance equation. These terms, after identification, are a very useful tool to analyze the physical mechanisms that take place in the gas. The identification process also returns the numerical values of other DBD parameters, such as associated capacitances and the breakdown voltage. In addition, an asymmetric model for the gas, which considers the direction of the current, is proposed to consider the possible geometrical dissimilarity between the two electrodes of the DBD setup. Experimental measurements taken on two different DBD applications are used for validating the proposed approach.

La ponencia analiza los cambios y permanencias de las trayectorias identitarias de los y las jóvenes colombianos en migración en España desde el enfoque del construccionismo social y el interaccionismo simbólico, para plantear que las identificaciones sociales y políticas de los y las jóvenes en migración se transforman en consonancia a los contextos sociales, políticos, culturales y económicos específicos de origen y destino, en su dimensión espacial y temporal, e influyen de manera significativa en sus posicionamientos como actores sociales fundamentales en los procesos migratorios. Se destaca la configuración de una emergente identidad latinoamericana que al inicio de sus trayectorias migratorias se alimentaba principalmente de las incipientes relaciones con jóvenes de otros países latinoamericanos, y que se refuerza, se retroalimenta de y se ratifica en un contexto discriminatorio y excluyente como una identidad defensa en sus luchas por el reconocimiento. La aparición de las mal llamadas "Bandas Latinas" desde el discurso público, académico y publicado a partir del año 2003, estigmatiza a los jóvenes latinoamericanos, principalmente los varones en su transitar migratorio en España. Se pasa así de la invisivilización de los jóvenes de origen latinoamericano por su supuesta cercanía cultural e idiomática con la población autóctona a la conformación del "joven latinoamericano" como una "otredad" estigmatizada. El análisis se enmarca en los resultados de la tesis doctoral "Son diez horas de viaje y cinco años que te meten encima". Proyectos, identidades y vínculos transnacionales de los y las jóvenes colombianas en España. Investigación cualitativa, etnográfica y longitudinal desarrollada por la autora desde el año 2001 a 2007 con 65 jóvenes colombianos, hombres y mujeres que migraron por diferentes motivos -reagrupación familiar, autónomamente o por exilio-, en las regiones de Madrid y Murcia en España. Las narrativas de los y las jóvenes y otros actores claves se recogieron a través de grupos de discusión, entrevistas en profundidad y observación participante.

International audience; This paper presents the study of a series-resonant inverter for the supply of a dielectric barrier discharge (DBD) excimer lamp. Causal analysis, based on the fundamental properties of the load, is used to justify the choice of this topology. In order to correctly control the lamp power, the operating mode selected for this converter combines discontinuous current-mode and soft-commutation (ZCS), obtaining as well low electromagnetic emissions, and reducing switching losses. The model of the lamp is briefly presented and it allows a simple state plane analysis to calculate all the electric variables involved in the converter and consequently to select the components of the supply. The mathematical relationships obtained from this process are validated with simulations and experimental results. Performances for lamp operation and UV emission control are presented.

International audience; We introduce spatial and epistemic process calculi for reasoning about spatial information and knowledge distributed among the agents of a system. We introduce domain-theoretical structures to represent spatial and epistemic information. We provide operational and denotational techniques for reasoning about the potentially infinite behaviour of spatial and epistemic processes. We also give compact representations of infinite objects that can be used by processes to simulate announcements of common knowledge and global information

In this paper, we enrich the pi-calculus with an operator for confidentiality (hide), whose main effect is to restrict the access to the object of the communication, thus representing confidentiality in a natural way. The hide operator is meant for local communication, and it differs from new in that it forbids the extrusion of the name and hence has a static scope. Consequently, a communication channel in the scope of a hide can be implemented as a dedicated channel, and it is more secure than one in the scope of a new. To emphasize the difference, we introduce a spy context that represents a side-channel attack and breaks some of the standard security equations for new. To formally reason on the security guarantees provided by the hide construct, we introduce an observational theory and establish stronger equivalences by relying on a proof technique based on bisimulation semantics., Comment: In Proceedings EXPRESS/SOS 2012, arXiv:1208.2440

International audience; A recent trend in object oriented programming languages is the use Access Permissions (AP) as abstraction to control concurrent exe- cutions. AP define a protocol specifying how different references can access the mutable state of objects. Although AP simplify the task of writing concurrent code, an unsystematic use of permissions in the program can lead to subtle problems. This paper presents a Linear Concurrent Constraint (lcc) approach to verify AP an- notated programs. We model AP as constraints (i.e., formulas in logic) in an underlying constraint system, and we use entailment of constraints to faithfully model the flow of AP in the program. We verify relevant properties about programs by taking advantage of the declarative interpretation of lcc agents as formulas in lin- ear logic. Properties include deadlock detection, program correct- ness (whether programs adhere to their AP specifications or not), and the ability of methods to run concurrently. We show that those properties are decidable and we present a complexity analysis of finding such proofs. We implemented our verification and analysis approach as the Alcove tool, which is available on-line.

International audience; Organizations of all sizes are currently supporting their performance on information systems that record the real execution of their business processes in event logs. Process mining tools analyze the log to provide insight on the real problems of the process, as part of the diagnostic phase. Nonetheless, to complete the lifecycle of a process, the latter has to be redesigned, a task for which simulation techniques can be used in combination with process mining, in order to evaluate different improvement alternatives before they are put in practice. In this context, the current work presents a methodological approach to the integration of process mining and simulation techniques in a process redesign project.

Concurrent constraint programming (ccp) is a well-established model for concurrency that singles out the fundamental aspects of asynchronous systems whose agents (or processes) evolve by posting and querying (partial) information in a global medium. Bisimilarity is a standard behavioural equivalence in concurrency theory. However, only recently a well-behaved notion of bisimilarity for ccp, and a ccp partition refinement algorithm for deciding the strong version of this equivalence have been proposed. Weak bisimiliarity is a central behavioural equivalence in process calculi and it is obtained from the strong case by taking into account only the actions that are observable in the system. Typically, the standard partition refinement can also be used for deciding weak bisimilarity simply by using Milner's reduction from weak to strong bisimilarity; a technique referred to as saturation. In this paper we demonstrate that, because of its involved labeled transitions, the above-mentioned saturation technique does not work for ccp. We give an alternative reduction from weak ccp bisimilarity to the strong one that allows us to use the ccp partition refinement algorithm for deciding this equivalence., In Proceedings ICE 2012, arXiv:1212.3458. arXiv admin note: text overlap with arXiv:1212.1548

International audience; Concurrent constraint programming (ccp) is a mature formalism for reasoning about concurrent systems that exhibit a constrained behavior. Spatial ccp and epistemic ccp are two novel variants of ccp currently being developed by Knight and Valencia. These variants model systems with spatial hierarchies of group information and knowledge. These systems are ubiquitous due to the advent of social networks and cloud computing where agents may share certain information with certain groups. This paper introduces an interpreter for these extensions we call k-stores. The interpreter is a Prolog implementation of the operational semantics of the languages allowing the programmer to simulate distributed information systems. The main feature consists of an implementation of a spatial (distributed) store that allows epistemic information in it. The system supports the specification of (named) processes along with the ccp classic primitives, namely, ask and tell operations. The declarative view of processes is inherited from the ccp extensions. The orthogonal implementation of the local space abstraction and the epistemic constraint system makes further extensions possible. Special attention is paid to the representation of distributed knowledge and common knowledge

International audience; Based on causality analysis relying on the capacitive nature of the Dielectric Barrier Discharge (DBD) excimer lamps, a converter that allows the variation of the electrical power injected to a KrCl excimer lamp is designed and implemented. This converter is capable of controlling the lamp current by means of the three degrees of freedom (D.O.F.) of a square shape: amplitude, duty cycle and frequency. It has been conceived for the study of the UV radiation of DBD lamps; consequently, the UV power measurements for the DBD excilamp under different combinations of these three D.O.F., are presented and analyzed.

International audience; Dielectric barrier discharge (DBD) lamps, being capacitive loads, must be associated with bidirectional current sources for an appropriate control of the transferred power. Pulsed current source supplies, which are known to offer very interesting performances, require specific power switches that are able to manage bidirectional voltage and unidirectional current at much higher frequencies (several hundreds of kilohertz) than commercial thyristors. This paper proposes the detailed design of such a high-speed synthesized thyristor, using discrete components: a MOSFET in series with a high-voltage (HV) diode and a logic circuit that controls its gate. This switch is associated with an optimized self-powered driver, which is a very efficient solution to handle the perturbations associated with the HV and high-frequency operation. Experimental application of this device for DBD excimer lamp supply is proposed.

Saraswat's concurrent constraint programming (ccp) is a mature formalism for modeling processes (or programs) that interact by telling and asking constraints in a global medium, called the store. Bisimilarity is a standard behavioural equivalence in concurrency theory, but a well-behaved notion of bisimilarity for ccp has been proposed only recently. When the state space of a system is finite, the ordinary notion of bisimilarity can be computed via the well-known partition refinement algorithm, but unfortunately, this algorithm does not work for ccp bisimilarity. In this paper, we propose a variation of the partition refinement algorithm for verifying ccp bisimilarity. To the best of our knowledge this is the first work providing for the automatic verification of program equivalence for ccp, 27th ACM Symposium On Applied Computing, Trento : Italy (2012)

International audience; The efficiency of the electrical power transfer to the gas mixture of a XeCl dielectric barrier discharge (DBD) exciplex lamp is analysed. An equivalent circuit model of the DBD is considered. It is shown that the excilamp power can be controlled by applying current to the lamp. This highly desired property is ensured by means of a specific power supply topology, whose concepts and design are discussed. The experimental prototype of a current-mode converter operating in the pulsed regime at pulse repetition rate of 50 kHz is presented and its capability to control the amount of energy transferred during each current pulse is demonstrated. The capability of this power supply to maintain specific operating conditions for the DBD lamp, with a very stable behaviour (even at a very low current, in the regime of a single discharge channel), is illustrated. The experimental results of a combined use of this converter and a XeCl excilamp are presented. The influence of the supply parameters on the 308-nm XeCl excilamp is analysed. The shape of the UV pulse of the lamp is experimentally shown to be similar to that of the current, which actually flows into the gas mixture. The UV radiation power is demonstrated to be tightly correlated to the current injected into the gas and controlled by the available degrees of freedom offered by the power supply. The measured UV output characteristics and performance of the system are discussed. Time resolved UV imaging of a XeCl DBD excilamp is used to analyse the mechanisms involved in the production of exciplexes at various power supply regimes. It is shown that a pulsed voltage source leads to formation of short high intensity UV peaks, while current pulses lead to formation of sustained discharge filaments. Based on the results of modelling of the above-mentioned operation conditions, the two power supply regimes are compared and analysed from the point of view of the UV power and radiative control.

International audience; A pulsed current-mode converter specifically designed for the supply of dielectric barrier discharge excimer lamps is proposed in this paper. The power supply structure is defined on the basis of causality criteria that are justified by the structure of the lamp model. The converter operation is studied, and its design criteria are established using state-plane analysis. This converter, operating in discontinuous conduction mode, controls directly both the amplitude and the duration of the emitted ultraviolet (UV) pulses. Experimentally, the UV radiation is demonstrated to be proportional to the current injected into the gas, and the degrees of freedom offered by the control of the supply are shown to be very efficient for the active control of the UV power.

Negative density dependence (NDD) and environmental filtering (EF) shape community assembly, but their relative importance is poorly understood. Recent studies have shown that seedlings mortality risk is positively related to the phylogenetic relatedness of neighbours. However, natural enemies, whose depredations often cause NDD, respond to functional traits of hosts rather than phylogenetic relatedness per se. To understand the roles of NDD and EF in community assembly, we assessed the effects on seedling mortality of functional similarity, phylogenetic relatedness and stem density of neighbouring seedlings and adults in a species-rich tropical forest. Mortality risks increased for common species when their functional traits departed substantially from the neighbourhood mean, and for all species when surrounded by close relatives. This indicates that NDD affects community assembly more broadly than does EF, and leads to the tentative conclusion that natural enemies respond to phylogenetically correlated traits. Our results affirm the prominence of NDD in structuring species-rich communities.

International audience; The power of the UV emission produced by Dielectric Barrier Discharge (DBD) exciplex lamps has shown to be controllable by means of the current which is injected by the supply into the bulb. A systematic analysis of the couplings between the current driven by the supply and the UV emission is proposed, according to two different investigation's directions:  1D axi symmetrical PDE model, together with an equivalent circuit modeling;  experimental approach: the bulbs are supplied with an especially designed power supply. The latter is a programmable square shape current source, which offers several degrees of freedom for the control of UV emission. The design of the power supply is presented and the obtained characteristics and performances of the system (for lamps filled with Xe-Cl and Kr-Cl gas mixtures) are discussed.

International audience; The molecular mechanisms of cell communication with the environment involve many concurrent processes governing dynamically the cell function. This concurrent behavior makes traditional methods, such as differential equations, unsatisfactory as a modeling strategy since they do not scale well when a more detailed view of the system is required. Concurrent Constraint Programming (CCP) is a declarative model of concurrency closely related to logic for specifying reactive systems, i.e., systems that continuously react with the environment. Agents in CCP interact by telling and asking information represented as constraints (e.g., x > 42). In this paper we describe a modeling strategy for cellular signaling systems based on a temporal and probabilistic extension of CCP. Starting from an abstract model, we build refinements adding further details coming from experimentation or abstract assumptions. The advantages of our approach are: due to the notion of partial information as constraints in CCP, the model can be straightforwardly extended when more information is available; qualitative and quantitative information can be represented by means of probabilistic constructs of the language; finally, the model is a runnable specification and can be executed, thus allowing for the simulation of the system. We outline the use of this methodology to model the interaction of G-protein-coupled receptors with their respective G-proteins that activates signaling pathways inside the cell. We also present simulation results obtained from an implementation of the framework

International audience; Concurrent constraint programming (ccp) is a well-established model for concurrency that builds upon operational and algebraic notions from process calculi and first-order logic. Bisimilarity is one of the central reasoning techniques in concurrency. The standard definition of bisimilarity, however, is not completely satisfactory for ccp since it yields an equivalence that is too fine grained. By building upon recent foundational investigations, we introduce a labelled transition semantics and a novel notion of bisimilarity that is fully abstract w.r.t. the typical observational equivalence in ccp. This way we provide ccp with a new proof technique for ccp coherent with existing ones

Part 9: Short Papers; International audience; To facilitate collaboration in the patient-centered medical home (PCMH), our prior work extended the NIST role-based access control (RBAC) model to yield a formal collaboration on duty and adaptive workflow (COD/AWF) model. The next logical step is to place this work into the context of an integrated software process for security engineering from design through enforcement. Towards this goal, we promote a secure software engineering process that leverages an extended unified modeling language (UML) to visualize COD/AWF policies to achieve a solution that separates concerns while still providing the means to securely engineer dynamic collaborations for applications such as the PCMH. Once defined, these collaboration UML diagrams can be utilized to generate the corresponding aspect oriented policy code upon which the enforcement mechanism can be applied to at runtime.

International audience; In this chapter we follow this "economy of means" way to present several vari- eties of CCP calculi, starting from a very basic one and building from it by adding new features. A fundamental one for music applications is the ability to represent temporal behavior. This can be introduced within the context of determinate (tcc, utcc) or non-determinate (ntcc) computation. For the determinate case, we show how the addition of a process abstraction feature (utcc) allows to model dynamic musical structures in a very simple way. In particular, we model a dynamic version of interactive scores ([ALL 07]). For the nondeterminate case, we use the possibility of defining many alternative computational paths to model an agent following different rhythmic patterns constructed from a given basic one. We then go on to consider a more "metrical" notion of time (rtcc) based on uniform ticks used by processes to define their time of execution in a more fine-grained way, or to cause preemption of other processes at more precisely defined points in time. We use these new "real-time" features to describe a simple model of a basic form of musical dissonances.

This paper concerns querying in large scale virtual organizations. Such organizations are characterized by a challenging data context involving a large number of distributed data sources with strong heterogeneity and uncontrolled data overlapping. In that context, data source selection during query evaluation is particularly important and complex. To cope with this task, we propose OptiSource, an original strategy for source selection using combinatorial optimization techniques combined to organizational knowledge of the virtual organization. Experiment numerical results show that OptiSource is a robust strategy that improves the precision and the recall of the source selection process. This paper presents the data and knowledge models, the definition of OptiSource, the related mathematical model, the prototype and an extensive experimental study.

The arterial lumen is modeled by a spatially continuous right generalized cylinder with piece-wise constant parameters. The method is the identifies the parameters of each cylinder piece from a series of planar contours extracted along an approximate axis of the artery. This curve is defined by a minimal path between the artery end-points. The contours are extracted by use of a 2D Fast Marching algorithm. The identification of the axial parameters is based on a geometrical analogy with piece-wise helical curves, while the identification of the surface parameters uses the Fourier series decomposition of the contours. Thus identified parameters are used as observations in a Kalman optimal estimation scheme that manages the spatial consistency from each piece to another. The method was was evaluated on 15 training and 31 testing datasets from the MICCAI 3D Segmentation in the Clinic Grand Challenge: Carotid Bifurcation Lumen Segmentation and Stenosis Grading (http://cls2009.bigr.nl/).

International audience; This paper presents OptiSource, a novel approach of source selection that reduces the number of data sources accessed during query evaluation in complex large scale distributed data contexts in virtual organizations (VO). In these contexts autonomous organizations share data about a group of domain concepts (e.g. patient, client, gene). The instances of such concepts are constructed from non-disjointed fragments provided by several local data sources. This fact, in addition to the absence of reliable statistics on source contents and the large number of sources, make current proposals unsuitable in terms of response quality and/or response time. OptiSource optimizes data source selection in query evaluation using a combinatorial optimization model to distinguish the sets of sources that maximize benefits and minimize the number of sources to contact to while satisfying resource constraints. The precision and recall of source selection during query planning is highly improved as demonstrated by the tests performed with the OptiSource prototype. Furthermore, tests with the optimization model confirmed that the approach can handle different levels of precision on the benefit prediction.

This work proposes the development of a power supply for Dielectric Barrier Discharge (DBD) lamps, intended for the evaluation of a water treatment system based on UV radiation. The DBD excimer lamp is an attractive source of UV because of its cost and radiation power. The proposed converter is conceived to control the UV radiation by programming different lamp current intensities, duty cycles and frequencies. For the converter synthesis, a capacitive electric equivalent model of the DBD is used. A simulation of the converter and its control analysis is presented.

International audience; Model-Driven SPL approaches use metamodels and transformation rules to obtain concrete software artifacts departing from models. Most of such approaches use also feature models to express variability. Because of the variability, to derive products, they have to adapt the transformation rules according to user choices captured in feature configurations. In this paper we propose an approach based on Constraint Programming to derive Model-Driven SPLs. Our contribution is twofold. First, we assist product line architects when relating transformation rules and features in order to derive prod- ucts based on feature configurations; the novelty is that we facilitate the management of feature interactions to architects. Second, current approaches to reason on feature models in SPL Engineering only deal with problems related to product configuration. We improve such approaches adding facilities for product derivation.

International audience; This paper presents OptiSource, a novel approach of source selection that reduces the number of data sources accessed during query evaluation in large scale distributed data contexts. These contexts are typical of large scale Virtual Organizations (VO) where autonomous organizations share data about a group of domain concepts (e.g. patient, gene). The instances of such concepts are constructed from nondisjointed fragments provided by several local data sources. Such sources overlap in a non mastered way making data location uncertain. This fact, in addition to the absence of reliable statistics on source contents and the large number of sources, make current proposals unsuitable in terms of response quality and/or response time. OptiSource optimizes source selection by taking advantage of organizational aspects of VOs to predict the benefit of using a source. It uses an optimization model to distinguish the sets of sources that maximize benefits and minimize the number of sources to contact to while satisfying resource constraints. The precision and recall of source selection is highly improved as demonstrated by the tests performed with the OptiSource prototype.

International audience; The biological data regarding the signalling pathways often consider single pathways or a small number of them. We propose a methodology for composing this kind of data in a coherent framework, in order to be able to investigate a bigger number of signalling pathways. We specify a biological system by means of a set of stoichiometric-like equations resembling the essential features of molecular interactions. We represent these equations by a timed concurrent constraint (ntcc) language, which can deal with partial information and the time for a reaction to occur. We describe a freely available prototypical implementation of our framework.

International audience; Dielectric barrier discharge excimer lamps (excilamps) are well known powerful and efficient sources of UV emission. The UV emission is tightly related to the electric power transferred to the lamp and very different performances are obtained, depending upon the characteristics of the power supply which is used. This paper proposes a review of power topologies, which have been used by the authors for various purposes (laboratory physic domain investigations and UV emission process oriented studies). For each of them, the topology and its operating principle, as well as a discussion of the merits concerning the performances (UV emission, design pitfalls, efficiency, reliability, waveforms …) are proposed.

International audience; In this paper, using a generalization of a Richter and Sundberg representation theorem, we give a new characterization of Carleson measures for the Dirichlet-type space $\mathcal D(\mu)$ when $\mu$ is a finite sum of point masses. A reproducing kernel thesis result is also established in this case.

International audience; La posición filogenética de los monos ardilla (género Saimiri) dentro del infraorden Platyrrhini es aún debatida. De hecho, hay un gran número de especies y subespecies de este género que tienen mucha plasticidad fenotípica. La taxonomía subgenérica y sistemática de los micos ardilla, basada en varias bases de datos con caracteres morfológicos, de comportamiento, citología y origen geográfico, ha resultado en una clasificación confusa. Revisiones sucesivas llevaron a inferencias disímiles, identificando de una hasta siete especies y 16 subespecies diferentes. Recientemente, los caracteres moleculares han aportado un marco coherente para entender la sistemática de los micos ardilla en el Neotrópico, indicando 4 clados distintos (Saimiri oerstedii, Saimiri sciureus, Saimiri boliviensis y Saimiri ustus). Dependiendo del gen de interés (mitocondrial o nuclear), la divergencia entre S. sciureus y S. boliviensis fue datada en 1.2 a 6.4 millones de años. Nosotros enfocamos nuestro análisis en Individuos de Saimiri principalmente de la cuenca amazónica. Sus relaciones filogenéticas fueron inferidas a partir de secuencias de nucleótidos del gen del Citocromo B. Estudiamos 38 micos ardilla salvajes y con un origen geográfico bien definido. Un total de 20 haplotipos diferentes de ADN mitocondrial fueron encontrados, con una divergencia máxima de secuencias del 4.6%, observada entre los individuos bolivianos y de la Guyana. Los diferentes clados descritos por Cropp y Boinski (2000a) fueron confirmados y nuevos grupos fueron evidenciados, correspondiendo a S. s. macrodon, S. s. albigena, S. s. cassiquiarensis, y S. s. collinsi. Nuestros datos concuerdan con la taxonomía propuesta por Hershkovitz (1984) y revela una gran cantidad de diversidad genética dentro del género. Basados en estos análisis moleculares, investigamos hipótesis concernientes a la diversificación y dispersión de los micos ardilla en Sur América. Los resultados sugieren que los ríos (como barreras) y los refugios pueden haber contribuido en la estructuración de estas poblaciones. Futuros análisis moleculares, comportamentales y morfológicos son necesarios para afinar el estatus taxonómico de este género.

The Italian Logic Programming community has given several contributions to the theory of Concurrent Constraint Programming. In particular, in the topics of semantics, verification, and timed extensions. In this paper we review the main lines of research and contributions of the community in this field.

International audience; UV excimer lamps are efficient narrowband sources of UV radiation with applications in various domains. The issue of controlling the UV emission by means of the power supply associated with such lamps favors pulsed current-controlled generators. After having established the previous statements, we propose a dedicated power converter topology which implements the needed performances. The analysis of the degrees of freedom of this structure shows the capability of this pulsed supply to realize the control of both the pulses’ current energy and of the mean power transferred to the lamp. Actual experimental realizations and measurement are presented and the feasibility and the performances of the proposed solutions are established.

International audience; In this paper we discuss the design of a generator of musical sequences for the purpose of aiding musicians in their compositional work. A series of steps were abstracted to reflect composition as a sequential flow of data refination; also each step involved in this process was modeled to gain each one of their functions. Specifically, in the case of the main structure of the suggestion a stochastic context-free grammar was developed to generate harmonic progressions, in the case of rhythms a probabilistic model based on accents was also developed, and finally, to state individual notes of the suggestion another probabilistic model based in the dissonance of intervals was used. Each one of these models were structured upon J.S. Bach's rules of homophonic composition as this was the target musical genre of the work

International audience; Dissonances in music have had a long evolution history dating back to days of strictly prohibition to times of en-richeness of musical motives and forms. Nowadays, dis-sonances account for most of the musical expressiveness and contain a full application theory supporting their use making them a frequently adopted resource of composition. This work partially describes their theoretical background as well as their evolution in music and finally proposing a new model for their computational use

The authors of this chapter present a two-fold approach for adapting content information delivered to a group of mobile users. This approach is based on a filtering process which considers both the user’s current context and her/his preferences for this context. The authors propose an object-based context representation, which takes into account the user’s physical and collaborative contexts, including elements related to collaboration tasks and group work in which the user is involved. They define the notion of preference for an individual or a group of people that develops a collaborative task and give a typology of preferences before proposing a formalism to represent them. This representation is exploited by a context matching algorithm in order to select only user preferences which can be applied according to the context of use. This chapter also presents the framework PUMAS which adopts a Multi-Agent System approach to support our propositions.

International audience; The UV power, emitted by a XeCl Dielectric Barrier Discharge exciplex lamp, is shown, on the basis of causality analysis, to be controllable by the current supplied to the lamp. Experimentally, the UV radiation is demonstrated to be proportional to the current injected into the gas. A current-mode converter operating in discontinuous current mode controls in a direct form the amplitude and duration of the pulsed UV power radiated by the lamp.