Linked Task Scheduling : Algorithms for the Single Machine Case

We consider a system made of one resource. The execution of the tasks is non-preemptive on this resource. The tasks we consider are composed of a given number of subtasks, two consecutives subtasks being separated by an idle period. These idle periods may be used for executing other subtasks. We wish to insert a new task in a given schedule. The characteristics of this task are not known before it appears, and its execution must be completed before a given deadline. The criterion is the minimization of the increase of the sum of the delays of the tasks

Insertion of a Random Task in a Schedule : a Real-Time Approach

We consider the case of a single resource. A given schedule (possibly optimal) is evaluated by means of the sum of the delays of the tasks. A taskappears in the system at a random time. The duration of this task is random, as well as its due date. The goal is to complete the task at the latest by its due date while increasing as little as possible the sum of the delays of the initial tasks. We have to find an algorithm that reduces as most as possible the amount of computation to be performed in real time at the expenses of the amount of computation to be performed off-line

The 0-1 Outcomes Feature Selection Problem : a Chi-2 Approach

This paper addresses the 0-1 outcome feature selection problem. In such a problem, a set of features leads to an outcome that is 0 or 1, depending upon the values of the features. The goal is to extract subsets of features that characterize at best outcome 1. This kind of problem arises in medical analysis, quality control and, generally, in any domain that requires series of expensive tests to evaluate the state of a system

Analysis of the Balancing Process in a Pool of Self-Service cars

In the kind of transportation system studied in this paper, cars are placed at the disposal of subscribers (customers) in stations. Customers have access to the cars using non-contact smart cards. They can use a car for a while and return it in the same or another station. At some times of the day, either an overflow or a shortage of cars may happen at one or more stations. The balancing process consists of redistributing the cars among the stations in order to avoid overflow and shortage, that is to guaranty a service ratio that is as high as possible, taking into account the number of cars available in the system. The goal of this paper is to make a systematic analysis of the balancing process and to propose an efficient balancing heuristic algorithm

Insertion of a Random Bitask in a Schedule: a Real-Time Approach

We consider a set of tasks defined by their duration and their due-date. They are performed by a single resource and scheduled in order to minimize the sum of the delays. This schedule is given. A task appears in the system at time 0. It is made of two subtasks separated by a fixed period. The duration of the two subtasks and of the period are known only when the task appears. It is also the case for the due date that cannot be violated. The goal is to insert this random task in the schedule while increasing as less as possible the criterion of the initial schedule, that is the sum of the delays. The main difficulty is to insert the task in real-time, which implies that the proposed method should manage to make most of the computation off-line

Ordonnancement en temps réel des activités des radars

The goal of this thesis, inspired by the battle radar management, is to insert in real-time a random task in the current schedule while minimizing the criterion. In our case, the criterion is the minimization of the sum of the delays of the already scheduled tasks. There is no leading rule for these delays. It is a stronger constraint than in the battle radars case, because they have to perform an amount of repetitive tasks in a given period. This may be considered as a unique due-date for all the tasks. The task we have to insert may appear at any time (For the sake of simplicity, the time at which a random task appears is time zero). Its processing time and its delay, which cannot be violated, are known only at time zero. We firstly take into consideration the case of a single random task, then we consider the case of a task made of two subtasks separated by a given period.Finally, we propose an improvement of the approach currently used to manage battle radars.L'objectif général de cette thèse, suggéré par le contrôle des radars de combat, consiste à intercaler en temps réel une tâche aléatoire dans un ordonnancement existant tout en limitant autant que possible l'augmentation de la valeur du critère. Dans notre cas, le critère que nous considérons est la somme des dépassements des délais des tâches déjà ordonnancées. Ces délais sont supposés quelconques : cette contrainte est plus dure que dans le cas des radars de combat où un certain nombre de tâches de surveillance doivent être effectuées de manière répétitive au cours d'une période donnée à l'intérieur de laquelle leur ordonnancement est libre, ce qui équivaut à un délai unique pour l'ensemble des tâches. La tâche à intercaler apparaît à un instant quelconque (c'est l'instant que nous considérons comme l'instant zéro). Sa durée n'est connue qu'au moment de son apparition. Il en est de même de son délai, qui est impératif. Nous considérons d'abord le cas d'une tâche aléatoire unique, puis le cas d'une tâche aléatoire composée de deux sous-tâches séparées par une période donnée. Enfin, nous proposons une amélioration de l'approche actuellement utilisée dans ce domaine

Ordonnancement en temps-réel des activités des radars

METZ-SCD (574632105) / SudocVILLEURBANNE-DOC'INSA LYON (692662301) / SudocSudocFranceF