Pierre Laroche

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This paper describes the Time Warp Operating System, under development for three years at the Jet Propulsion Laboratory for the Caltech Mark III Hypercube multi-processor. Its primary goal is concurrent execution of large, irregular discrete event simulations at maximum speed. It also supports any other distributed applications that are synchronized by(More)
In this paper, we present a new tool for automatically solving Markov Decision Processes. Using a predefined partition of the MDP, a directed graph is built to decompose the global MDP into small local MDPs which are independently solved. An approximate solution for the global MDP is obtained using local solutions. Our approach has been tested on a mobile(More)
In this paper, we present a new method to localize a mobile robot in dynamic environments. This method is based on places recognition, and a match between places recognized and the sequence of places that the mobile robot is able to see during a run from an initial place to an ending place. Our method gives a coarse idea of the robot's position and(More)
In this paper, we present two state aggregation methods, used to build stochastic plans, modelling our environment with Markov Decision Processes. Classical methods used to compute stochastic plans are highly untractable for problems necessiting a large number of states, like our robotics application. The use of aggregation techniques allows to reduce the(More)
1. Introduction The main purpose of this paper is to describe a self consistent model of the bi-leader process. This model has been designed to determine the external threshold conditions for aircraft or space launcher striking, and to calculate the current and electromagnetic fields associated with the bi-leader development. Experimental studies (see part(More)