Thierry Vidal

École Nationale d'Ingénieurs de Tarbes | INP ENIT · Laboratoire Génie de Production

The establishment of a self-healing agent has received much interest in multiple domains such as : Web services, production supply chain, transport systems, etc. This agent has a set of actions. Its role is to respond to user request with a plan of composed actions, to on-line diagnose the status of the plan execution and to automatically repair th...

In the MARTHA project, a large number of ro-bots in a harbour are given the global task of transporting standardized containers from one area to another (ships, trains, stocking areas). The global decision-making process consisting of allocating robots to those predefined tasks can be viewed as a scheduling and resource allo-cation problem, which i...

The ability to automatically answer a request that requires the composition of a set of web services has received much interest in the last decade, as it supports B2B applications. It aims at selecting and inter-connecting services provided by different partners in response to client requests. Planning techniques are used widely in the literature t...

An important number of planning approaches have been proposed to tackle the problem of Web services composition which aims at selecting and inter-connecting services provided by different partners in response to client request. This process is beyond the human ability to analyse and generate the composition manually. Planning techniques are used wi...

The ability to automatically answer a request that requires the composition of a set of web services has received much interest in the last decade, as it supports B2B applications. Planning techniques are used widely in the literature to describe the web services composition problem but they don't scale up well. This weakness is due to the search s...

Automated composition of Web services has received much interest in the last decade, as it supports B2B applications. It aims at selecting and inter-connecting services provided by different partners in response to client requests.Planning techniques are used widely in the literature to describe Web services composition problem. However, since Web...

Based on a practical study in a local authority, this paper deals with a study on a new criterion for a weekly waste collection problem to consider the stability of proposed routes. In the problem under consideration, some parts of the network must be collected once a week (at the beginning of the week) and some parts twice a week (at the beginning...

There are many systems and techniques that address stochastic planning and scheduling problems, based on distinct and sometimes opposite approaches, especially in terms of how generation and execution of the plan, or the schedule, are combined, and if and when knowledge about the uncertainties is taken into account. In many real-life problems, it a...

Research results from industry-academic collaborative projects in service-oriented computing describe practical, achievable solutions. Service-Oriented Applications and Architectures (SOAs) have captured the interest of industry as a way to support business-to-business interaction, and the SOA market grew by $4.9 billion in 2005. SOAs and in partic...

Automated composition of Web services has received much interest in the last decade, as it supports B2B applications. It aims at selecting and inter-connecting services provided by different partners in response to client requests. Planning techniques are used widely in the literature to describe Web services composition problem. However, since Web...

WS are distributed software components that can be exposed and invoked over the Internet using standard protocols. They communicate with their clients and with other WS by sending XML based messages over the Internet. AI planning techniques can help solving the composition of WS problem. In fact, services can be modelled as actions and the business...

Artificial Intelligence is a highly creative field. Numerous research areas in Computer Science that originated over the past fifty years within AI laboratories and were discussed in AI conferences are now completely independent and mature research ...

Artificial Intelligence is a highly creative field. Numerous research areas in Computer Science that originated over the past fifty years within AI laboratories and were discussed in AI conferences are now completely independent and mature research ...

There are many systems and techniques that ad- dress stochastic scheduling problems, based on dis- tinct and sometimes opposite approaches, espe- cially in terms of how scheduling and schedule execution are combined, and if and when knowl- edge about the uncertainties are taken into ac- count. In many real-life problems, it appears that all these a...

The problem we tackle is progressive scheduling with temporal and resource uncertainty. Operation durations are imprecise and alternative resources may break down. Operation end times and resource breakdowns are observed during execution. In this paper, we assume we have a representation of uncertainty in the form of probability distributions which...

Generating off line a plan of activities before executing it on line is no longer realistic when one expects disturbances from an uncertain environment. Focusing on temporal plans and uncertain temporal constraints, we show that there are three main ways of tackling the issue: the reactive way, the proactive way and the progressive way, which are i...

In this paper we compare the performance of three distinct approaches to lexical cohesion based text segmentation. Most work in this area has focused on the discovery of textual units that discuss subtopic structure within documents. In contrast our ...

Certain planning systems that deal with quantitative time constraints have used an underlying Simple Temporal Problem solver to ensure temporal consistency of plans. However, many applications involve processes of uncertain duration whose timing cannot be controlled by the execution agent. These cases require more complex notions of temporal feasib...

The problem we tackle is on-line rescheduling with temporal uncertainty, activity durations are uncertain and activity end times must be observed during execution.

This article reports on the Sixth Robot World Cup Competition and Conference (RoboCup-2002) Fukuoka/Busan, which took place from 19 to 25 June in Fukuoka, Japan. It was the largest Robo-Cup since 1997 and held the first humanoid league competition in ...

Mots-clefs : flexibilité, incertitudes, satisfaction de contraintes, planification, ordonnancement 1 Cadre d'étude Nous voulons mettre en place un modèle générique permettant de résoudre les problèmes de gestion de projets sous incertitudes, en intégrant diverses techniques adaptées aux diverses formes d'aléas existant dans ce contexte. Notre domai...

The problem we tackle is on-line rescheduling with temporal uncertainty, activity durations are uncertain and activity end times must be observed during execu-tion. In this paper we will assume we have a represen-tation of the uncertainty of each activity duration in the form of probability distributions which are used in the simulation of schedule...

Temporal constraints pose a challenge for conditional planning, because it is necessary for a conditional planner to determine whether a candidate plan will satisfy the specified temporal constraints. This can be difficult, because temporal assignments that satisfy the constraints associated with one conditional branch may fail to satisfy the const...

. The purpose of this paper is to show that multimedia applications introduce new open problems in temporal constraint-based reasoning. In particular, we adress three issues related to scanario specification, namely the distinction of controllable and uncontrollable durations, Hierarchical structuration and Interruption-like behaviour. This paper m...

In flexible manufacturing cells, scheduling has to take into account multiple cells in charge of distinct manufacturing orders sharing common flexible machines, and frequent disturbances must be accounted for efficiently. That suggests a multiagent model distributing decisions between manufacturing order agents and machine agents. The solving proce...

In temporal planning, one needs an explicit representation of time. Our system IxTeT relies on a time-point based constraint graph, and handles symbolic as well as numerical temporal constraints (convex durations and dates). Classical CSP techniques allows to check the consistency of such a graph in polynomial-time.

Temporal Constraint Networks allow to express possible durations or delays between time-points, in the shape of intervals of values. A solution of such a network is a precise ...

Real-time monitoring calls for decision making capabilities in reaction to observed events. Associative models provide efficiency by matching the observed situation to a recorded pattern equipped with an accurate decision. We rely on a decision tree accounting for the context and temporal chronicles expressing dynamic patterns. In highly reactive d...

Applications such as aircraft combat simulation require both dynamic supervision and real-time decision-making : actions and observations interact in a reactive way, and durations between two events must be accounted for. We start from a decision-tree model, which owns strong context handling capabilities, but provides only static decision-making....

Real-time monitoring becomes highly reactive as soon as actions on the real system are as frequent as observations. This requires enhanced decision-making mechanisms, anticipating the complete recognition of typical patterns, comparing possible evolutions to decide next action. Our approach relies on a global architecture mixing a static decision-t...

In temporal planning, Temporal Constraint Networks allow to check the temporal consistency of a plan, but it has to be extended to deal with tasks which effec- tive duration is uncertain and will only be observed during execution. The Contingent TCN models it: in which Dynamic controllability has to be dmcked, i.e.: during execution, will the syste...

Temporal Constraint Networks (TCN) allow to express minimal and maximal durations between time-points. Though being used in many research areas, this model disregards the contingent nature of some constraints, whose effective duration cannot be decided by the system but is provided by the external world. We propose an extension of TCN based on the...

Applications such as aircraft combat simulation require both dynamic supervision and real-time decision-making: actions and observations interact in a reactive way, and durations between two events must be accounted for. We start from a decision-tree model, which owns strong context handling capabilities, but provides only static decision-making. W...

Temporal Constraint Networks (TCSP) allow to express minimal and maximal durations between time-points. Though being used in many research areas, this model disregards the contingent nature of some constraints, whose effective duration cannot be decided by the system but is provided by the external world. We propose an extension of TCSP in which th...

In the MARTHA project, a large number of robots in a harbour are given the global task of transporting containers from one area to another. The global decision-making process of allocating robots to those predefined tasks can be viewed as a scheduling and resource allocation problem, which is addressed here in a centralised way. Imprecision of temp...

Planning or scheduling systems that handle tasks with uncertain durations might use an extension of the Simple Temporal Network with a distinction between con-trollable and contingent variables and constraints. Temporal consistency is then re-defined in terms of Dynamic Controllability, which means the ability to decide the precise timing of tasks...

Modern systems, such as web services, need to be self- healing, which means capable of surviving autonomously the occurrence of faults, still managingto provide the desi- red functionality. Designers of such systems need tools hel- pingthemtoassess beforehandstheself-healabilityof their system, but as a first step towards such tools, one needs to b...

1 Position du problème Notre travail de recherche s'intéresse à des problèmes de collecte de déchets ménagers hebdoma-daires spécificique d'une collectivité locale. Il s'agit pour cette collectivité d'organiser deux fois par semaine (en début et en fin de semaine) les circuits de collecte de ses usagers. Une des spécificités majeures est que les ca...