How to Complete Regulations in Multi-agent Systems

In this paper, we deal with regulations that may exist in multiagent systems in order to regulate agent behaviour. More precisely, we discuss two properties of regulations, consistency and ompleteness. After defining what consistency and completeness mean, we propose a way to consistently complete incomplete regulations. This contribution considers that regulations are expressed in a first order deontic logic. We will focus on particular regulations: information exchange policies

A modal logic for reasoning on consistency and completeness of regulations

In this paper, we deal with regulations that may exist in multi-agent systems in order to regulate agent behaviour and we discuss two properties of regulations, that is consistency and completeness. After defining what consistency and completeness mean, we propose a way to consistently complete incomplete regulations. In this contribution, we extend previous works and we consider that regulations are expressed in a first order modal deontic logic

Cohérences basées sur les valeurs en échec

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XML Representation of Constraint Networks: Format XCSP 2.1

We propose a new extended format to represent constraint networks using XML. This format allows us to represent constraints defined either in extension or in intension. It also allows us to reference global constraints. Any instance of the problems CSP (Constraint Satisfaction Problem), QCSP (Quantified CSP) and WCSP (Weighted CSP) can be represented using this format

Searching for Learning-Dependent Changes in the Antennal Lobe: Simultaneous Recording of Neural Activity and Aversive Olfactory Learning in Honeybees

Plasticity in the honeybee brain has been studied using the appetitive olfactory conditioning of the proboscis extension reflex, in which a bee learns the association between an odor and a sucrose reward. In this framework, coupling behavioral measurements of proboscis extension and invasive recordings of neural activity has been difficult because proboscis movements usually introduce brain movements that affect physiological preparations. Here we took advantage of a new conditioning protocol, the aversive olfactory conditioning of the sting extension reflex, which does not generate this problem. We achieved the first simultaneous recordings of conditioned sting extension responses and calcium imaging of antennal lobe activity, thus revealing on-line processing of olfactory information during conditioning trials. Based on behavioral output we distinguished learners and non-learners and analyzed possible learning-dependent changes in antennal lobe activity. We did not find differences between glomerular responses to the CS+ and the CS− in learners. Unexpectedly, we found that during conditioning trials non-learners exhibited a progressive decrease in physiological responses to odors, irrespective of their valence. This effect could neither be attributed to a fitness problem nor to abnormal dye bleaching. We discuss the absence of learning-induced changes in the antennal lobe of learners and the decrease in calcium responses found in non-learners. Further studies will have to extend the search for functional plasticity related to aversive learning to other brain areas and to look on a broader range of temporal scales

Une logique modale pour raisonner sur la cohérence et la complétude de réglementations

Nous nous intéressons dans ce papier aux réglementations qui peuvent exister dans des systèmes multi-agents pour réguler les comportements des agents. Plus précisément, nous travaillons sur deux propriétés des réglementations, la cohérence et la complétude. Après avoir donné une définition de ces deux notions, nous proposons un cadre permettant de compléter de façon cohérente une réglementation incomplète. Nous considérons dans l'article que les réglementations sont exprimées dans une logique déontique du premier ordre

A Decomposition Technique for Solving {Max-CSP}

International audienceThe objective of the Maximal Constraint Satisfaction Problem (Max-CSP) is to find an instantiation which minimizes the number of constraint violations in a constraint network. In this paper, inspired from the concept of inferred disjunctive constraints intro- duced by Freuder and Hubbe, we show that it is possible to exploit the arc-inconsistency counts, associated with each value of a net- work, in order to avoid exploring useless portions of the search space. The principle is to reason from the distance between the two best values in the domain of a variable, according to such counts. From this reasoning, we can build a decomposition technique which can be used throughout search in order to decompose the current prob- lem into easier sub-problems. Interestingly, this approach does not depend on the structure of the constraint graph, as it is usually pro- posed. Alternatively, we can dynamically post hard constraints that can be used locally to prune the search space. The practical interest of our approach is illustrated, using this alternative, with an experi- mentation based on a classical branch and bound algorithm, namely PFC-MRDAC

Cohérence et complétude des réglementations en présence de contraintes

Cet article a pour objet l'étude des réglementations qui existent dans les systèmes multi-agents et qui visent à réguler le comportement des agents. Plus précisément, nous nous intéressons à deux propriétés des réglementations : la cohérence et la complétude, et ce en présence de contraintes (lois de la nature, faits persistants) dont nous montrons l'influence. Nous montrons également comment compléter une réglementation incomplète tout en préservant sa cohérence. Ce travail considère que les réglementations sont exprimées en logique déontique du premier ordre

Substituabilité au voisinage pour le cadre WCSP

National audienceWCSP is an optimization problem for which many forms of soft local (arc) consistencies such as existential directional arc consistency (EDAC) and virtual arc consistency (VAC) have been proposed these last years. In this paper, we adopt a different perspective by revisiting the well-known property of (soft) substitutability. First, we provide a clear picture of the relationships existing between soft neighborhood substitutability (SNS) and a tractable property called $pcost$ which is based on the concept of overcost of values (through the use of so-called cost pairs). We prove that under certain assumptions, $pcost$ is equivalent to SNS but weaker than SNS in the general case since we show that SNS is coNP-hard. We also show that SNS preserves the property VAC but not the property EDAC. Finally, we introduce an optimized algorithm and we show on various series of WCSP instances, the practical interest of maintaining $pcost$ together with AC*, FDAC or EDAC, during search.WCSP est un problème d'optimisation pour lequel plusieurs formes de cohérences locales souples telles que, par exemple, la cohérence d'arc existentielle directionnelle (EDAC) et la cohérence d'arc virtuelle (VAC) ont été proposées durant ces dernières années. Dans cet article, nous adoptons une perspective différente en revisitant la propriété bien connue de la substituabilité (souple). Tout d'abord, nous précisons les relations existant entre la substituabilité de voisinage souple (SNS pour Soft Neighbourhood Substitutability) et une propriété appelée $pcost$ qui est basée sur le concept de surcoût de valeurs (par le biais de l'utilisation de paires de surcoût). Nous montrons que sous certaines hypothèses, $pcost$ est équivalent à SNS, mais que dans le cas général, elle est plus faible que SNS prouvée être coNP-difficile. Ensuite, nous montrons que SNS conserve la propriété VAC, mais pas la propriété EDAC. Enfin, nous introduisons un algorithme optimisé et nous montrons sur diverses séries d'instances WCSP l'intérêt pratique du maintien de $pcost$ avec AC*, FDAC ou EDAC, au cours de la recherche