A situation-based multi-agent architecture for handling misunderstandings in interactions

During interactions, system actors may face up misunderstandings when their local states contain inconsistent data about the same fact. Misunderstandings in interactions are likely to reduce interactivity performances (deviation or deadlock) or even affect overall system behavior. In this paper, we characterize misunderstandings in interactions between system actors (that may be human users or system agents) in interactive adaptive systems. To deal with such misunderstandings and ensure state consistency, we present an agent-based architecture and a scenario structuring approach. The system includes several agents devoted to scenario unfolding, plot adaptation and consistency management. Scenario structuring is based on the notion of a situation that is an elementary building block dividing the interactions between systems’ actors into contextual scenes. This pattern supports not only scenario execution but consistency management as well. In order to organize and control interactions, the situation contextualizes interactions and activity of the system’s actors. It also includes prevention and tolerance agent-based mechanisms to deal with the misunderstandings and their causes. We validate our consistency management mechanisms using Uppaal simulation and provide some experimental results to show the effectiveness of our approach on an online distance learning case study

A Component-based Framework for the Specification, Verification and Validation of Open Distributed Systems

Open distributed systems have inherent complexity related to their control that makes it necessary to have a component-based approach to each of the activities undertaken along their life-cycle. Such an approach allows to apply the divide and conquer principles. In this paper, we propose a framework to undertake the specification, the verification and the validation (V&V) of distributed systems based on those composition principles. The approach herein uses a specification model which allows to describe the components of a distributed system. This model focuses also on the description of the interactions between the components in order to compose them into (sub- )systems. The properties expected are described and verified in a compositional way from the components to the (sub-)systems. The specification model is automatically transformed into a V&V model which is a modular Petri net standing with an object-based semantics. The verification of the properties is performed by model-checki..

Approach to Design Behavioural Models for Traffic Network Users - Choice of transport mode

Our research work concerns the development of a multimodal urban traffic simulator designed to be a tool of decision-making aid similar to a game where in the user-player can test different scenarios by immersion in a 3D virtual city. Our approach is based on the activity-based model and the multi-agent technology. The implemented result is a hybrid simulator connecting numerical simulation and behavioural aspects coming from real data. This paper is focused on two points: firstly, we introduce how a final user (the traffic regulator) instantiates and assembles components so as to model a city and its urban traffic network, secondly, we present the use of Dempster-Shafer theory in the context of discrete choice modelling. Our approach manipulates input variables in order to test realistic representations of behaviours of agent categories in a decision-making process. The traffic modelling is based on a questionnaire elaborated from standard arrays of Taguchi. The significant variables and interactions are determined with the analysis of variance which suggests a reduced model describing the behaviour of a particular social category. The belief theory is used to take into account the doubt of some respondents as well as for the preferences redistribution if the number of alternatives changes. The effects of external traffic conditions are also quantified to choose a'robust'alternative and to use the agents'memory

Driving stories, benefits of properties analysis

Emergent narrative means that it is the player that unfolds the narrative and then creates its own story. But game should control the drama in order to modify the player emotion through the game by enabling or disabling actions. In the framework of an adaptative system that manages player actions, this paper defines a formal model for interactive narration based on Linear Logic. We introduce a new kind of properties of a narration. The verification of those properties allows ensuring the quality of a game scenario. They concern the design of games as well as game execution. For each property prospects for validation are discussed

Output pulse and energy capabilities of the PHEBUS laser facility

Available at INIST (FR), Document Supply Service, under shelf-number : RM 1029 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueSIGLEFRFranc