WorldCat Identities

Lopez, Pierre

Overview
Works: 24 works in 52 publications in 2 languages and 537 library holdings
Genres: History 
Roles: Director, Thesis advisor, Editor, Opponent, Author, Other, Publishing director
Classifications: TS157.5, 658.53
Publication Timeline
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Most widely held works by Pierre Lopez
Production scheduling by Pierre Lopez( )

17 editions published between 2001 and 2013 in English and French and held by 498 WorldCat member libraries worldwide

"This title presents recently developed methods for resolving scheduling issues. The basic concepts and the methods of production scheduling are introduced and advanced techniques are discussed, providing readers with a comprehensive and accessible guide to employing this process."--Jacket
Approche énergétique pour l'ordonnancement de tâches sous contraintes de temps et des ressources by Pierre Lopez( Book )

3 editions published between 1991 and 2005 in French and held by 5 WorldCat member libraries worldwide

Ce travail concerne l'ordonnancement de tâches interdépendantes sous contraintes de temps et de ressources. Les méthodes et techniques développées s'inscrivent dans la problématique de l'analyse sous contraintes des problèmes d'ordonnancement. Celle-ci vise à caractériser les ordonnancements admissibles de manière a proposer au décideur un choix d'actions cohérentes vis-à-vis des contraintes. L'analyse est décrite comme un processus d'inférence mettant en interaction une base de règles et une base de faits temporels et séquentiels représentant les caractéristiques des ordonnancements admissibles. Des travaux antérieurs ont ainsi permis la réalisation du logiciel Mascot écrit en Prolog. Ils sont ici enrichis par une nouvelle approche dont l'originalité réside essentiellement dans l'utilisation du concept d'énergie issu du couplage du temps et des ressources. Le concept d'intervalle temps-ressource est introduit; il permet de représenter simultanément des caractéristiques temporelles et de ressource. On distingue les intervalles consommateurs (ou tâches) et les intervalles fournisseurs. Le type de déduction mis en jeu dans Mascot a été amélioré par la prise en compte des interactions entre intervalles consommateurs et fournisseurs. De nouvelles règles de déduction ont été écrites et intégrées dans Mascot, donnant lieu au logiciel Mascot2. D'autre part, un processus de déduction, basé sur un raisonnement purement énergétique, a été élaboré et implémenté en Prolog (logiciel report). Il met en jeu des instants remarquables, points de cassure des courbes d'énergie associées aux tâches. L'outil de modélisation utilisé est le graphe potentiels-bornes; il permet de représenter des contraintes numériques et des contraintes symboliques entre intervalles. Il sert de support a un processus d'inférence par propagation numérique des contraintes
Entre politique, éthique et esthétique : interroger la mémoire en Amérique latine : 1980 à nos jour by Centre aixois d'études romanes( Book )

3 editions published in 2020 in French and held by 4 WorldCat member libraries worldwide

Nouvelles approches pour la résolution du problème d'ordonnancement de projet à moyens limités by Oumar Koné( Book )

2 editions published in 2009 in French and held by 3 WorldCat member libraries worldwide

Dans ce travail de thèse, nous avons étudié deux types de problèmes d'ordonnancement. La majeure partie concerne le problème d'ordonnancement de projet à moyens limités (RCPSP). Le problème d'ordonnancement des opérations de manutention dans un entrepôt de transbordement ("crossdocking") est également traité avec une moindre importance. Dans une première partie (la plus étendue), nous abordons le RCPSP. À partir de modélisations utilisant la programmation linéaire en nombres entiers, nous avons proposé deux nouvelles formulations de ce problème, utilisant des variables indicées par des événements. Dans l'une d'entre elles, on utilise une variable binaire pour marquer le début de l'exécution de chaque activité et une autre variable pour marquer sa fin. Dans la seconde proposition, une seule variable est utilisée. Elle identifie les événements après lesquels l'activité reste en cours ou débute son exécution. De façon générale, comparées à d'autres modèles de la littérature sur divers types d'instances, nos propositions affichent des résultats plus intéressants sur les instances contenant des activités aux durées disparates et associées à de longs horizons d'ordonnancement. En particulier, sur ces mêmes types d'instances mais hautement cumulatives (caractéristiques de base du RCPSP), elles sont également les plus performantes. Nous avons également abordé la résolution d'une extension du RCPSP consistant à prendre en compte des ressources particulières, qui peuvent être consommées en début d'exécution de chaque activité, mais aussi produites à leur fin : il s'agit du RCPSP avec consommation et production de ressources. Afin d'effectuer une comparaison expérimentale entre différents modèles, nous avons proposé une adaptation de nos formulations basées événements, des formulations à temps discret de Pritsker et de Christofides, et de la formulation à temps continu basée sur les flots (proposé par Artigues sur la base des travaux de Balas). Globalement, les résultats montrent que nos formulations basées événements obtiennent les meilleurs résultats sur bon nombre de types d'instances
Une approche interdisciplinaire pour l'ordonnancement des transports by Bernat Gacias Pastor( Book )

2 editions published in 2010 in French and held by 2 WorldCat member libraries worldwide

An interdisciplinary approach has been proposed for the vehicle routing problem. The idea is to consider human factors and dynamic aspects for the decision support system (DSS) design. In our approach, a link is done between methods of operations research and an ecological interface design coming from engineering cognitive. A work domain analysis for the vehicle routing problem has been done. The analysis is realized through an abstraction hierarchy, which facilitates the identification of the problem constraints. We have proposed a DSS architecture based on this analysis and on constraint programming. Specific algorithms and solving mechanisms based on model inversion have been proposed and integrated in the system. Finally, we have design a set of human-machine interfaces in order to facilitate the problem solving to the human planning. The interdisciplinary study has been preceded by an analysis of the parallel machine scheduling problem with precedence constraints and setup times. Tree searches and local searches based on limited discrepancy search have been proposed to solve the problem
Les processus cognitifs dans les activités d'ordonnancement en environnement incertain by Koosha Khademi( )

2 editions published in 2016 in French and held by 2 WorldCat member libraries worldwide

Planning processes, especially, scheduling play a major role in work systems stability and efficiency. Scheduling is regarded as a complex problem; among complexity factors, uncertainty represent a central dimension. Although numerous automated tools or decision support systems have already been designed to help operators schedule their activities. The part played by said operators remains primordial. Paradoxically, few researches were concerned by the cognitive activity of the scheduler. This PhD thesis in human factors aims at studying those cognitive processes, with a specific interest in uncertainty management strategies.After exposing a scheduling situations typology and a method for activity analysis, we presented two scheduling situations with high uncertainty factors to study: organization of rounds in Road Freight Transports (RFT) and scheduling in Visiting Nurse Agencies (VNAs). This ecological approach allowed for a better understanding of the human aspects of scheduling and the detection of uncertainty management strategies. This work contributes to widen the debate around the optimisation of Man-Machine collaboration
Ordonnancement sous contraintes d'énergie by Margaux Nattaf( Book )

2 editions published in 2016 in French and held by 2 WorldCat member libraries worldwide

Resource-constrained scheduling problems have been widely studied in the literature. However, in most cases, it is assumed that the activities have a fixed duration and require a constant amount of the resource throughout their execution. In this thesis, we propose to treat a scheduling problem in wich tasks have a variable duration and a variable resource consumption profile. This profile, which may vary over time, is a decision variable of the problem on wich depends the ruration of the associated task. Furthermore, we consider linear and nonlinear efficiency functions to represent resource usage, which makes more complex the problem and permits the modeling of energy transfers. For this NP-complete problem, we present several properties allowing us to derive models and solution methods. These solution methods are divided into two parts. The first part studies the problem from the perspective of Constraint Programmming and several methods derived from this paradigm are detailed, among which new developments on energetic reasoning for the considered problem. The second part of the thesis, dedicated to Mixed Integer Linear Programming approches, presents several models, including a novel continuous time model based on events as well theoretical analysis of the models and improvement of theses techniques. Finally, experiments show the relative effectiveness of the results presented in this thesis
Multi-objective optimization of earth observing satellite missions by Panwadee Tangpattanakul( Book )

2 editions published in 2013 in English and held by 2 WorldCat member libraries worldwide

This thesis considers the selection and scheduling problem of observations for agile Earth observing satellites. The mission of Earth observing satellites is to obtain photographs of the Earth surface to satisfy user requirements. Requests from several users have to be managed before transmitting an order, which is a sequence of selected acquisitions, to the satellite. The obtained sequence must optimize two objectives under operation constraints. The first objective is to maximize the total profit of the selected acquisitions. The second one is to ensure the fairness of resource sharing by minimizing the maximum profit difference between users. Two metaheuristic algorithms, consisting of a biased random key genetic algorithm (BRKGA) and an indicator-based multi-objective local search (IBMOLS), are proposed to solve the problem. For BRKGA, three selection methods, borrowed from NSGA-II, SMS-EMOA, and IBEA, are proposed to select a set of preferred chromosomes to be the elite set. Three decoding strategies, which are two single decoding and a hybrid decoding, are applied to decode chromosomes to become solutions. For IBMOLS, several methods for generating the initial population are tested and the neighborhood structure according to the problem is also proposed. Experiments are conducted on realistic instances based on ROADEF 2003 challenge instances. Hypervolumes of the approximate Pareto fronts are computed and the results from the two algorithms are compared
Modélisation et résolution de problèmes d'optimisation combinatoire issus d'applications spatiales by Catherine Mancel( Book )

2 editions published in 2004 in French and held by 2 WorldCat member libraries worldwide

Nos travaux portent sur la modélisation et la résolution de problèmes d'optimisation combinatoire émergeant dans le cadre de la planification de missions spatiales. Ces problèmes de grande taille présentent des caractéristiques communes en termes de types de données, de contraintes et de critères à optimiser. Nous nous focalisons sur l'apport de la programmation linéaire pour ces problèmes, associée à des méthodes de simplification de l'espace de recherche, par décomposition ou grâce à des techniques de propagation de contraintes. Nous avons plus particulièrement étudié deux problèmes. Le premier concerne la planification de communications sonde/satellite et d'expériences dans un projet d'exploration martienne. Une décomposition de ce problème permet de le formuler comme deux problèmes indépendants : un problème de planification des communications que nous modélisons par un programme linéaire en nombres entiers et que nous résolvons de façon exacte par un algorithme classique, et un problème d'aide à la décision pour la planification des expériences, pour lequel nous établissons des courbes d'évaluation de la charge des ressources, déduites de l'application de techniques de propagation de contraintes basées sur un raisonnement énergétique. Le second problème étudié est celui de la planifiacation de prises de vue d'un satellite d'observation de la Terre. Nous proposons un modèle linéaire en variables mixtes et nous développons une approche de résolution par génération de colonnes, qui est une adaptation de la programmation linéaire au traitement de problèmes de grande taille, faisant appel à certaines techniques de décomposition des modèles
Operational research approach for optimising the operations of a nuclear research laboratory by Oliver Javier Polo Mejia( Book )

2 editions published in 2019 in English and held by 2 WorldCat member libraries worldwide

Cette thèse présente les résultats d'un projet de recherche visant l'optimisation du processus d'ordonnancement d'activités au sein d'un laboratoire de recherche du Commissariat à l'Énergie Atomique et aux Énergies Alternatives (CEA). Pour aborder ce problème, nous décomposons chaque activité en un ensemble de tâches élémentaires pour appliquer des méthodes classiques d'ordonnancement. Nous modélisons le problème d'ordonnancement du laboratoire comme une version étendue du problème de gestion de projet multi-compétences (Multi-Skill Project Scheduling Problem ou MSPSP). En première approche, nous proposons un MSPSP avec pénalité par préemption, ainsi que sa formulation en Programmation Linéaire en Nombres Entiers (PLNE). Dans cette version du problème, la préemption est autorisée et une pénalité est appliquée chaque fois qu'une activité est interrompue. Cette approche précédente ne prend cependant pas en compte toutes les contraintes de sûreté et sécurité de l'installation et une variante plus précise du problème est nécessaire. Ainsi, nous proposons ensuite d'intégrer le concept de préemption partielle au MSPSP. Ce concept, qui n'a pas encore été étudié dans la littérature scientifique, implique que seul un sous-ensemble de ressources est libéré pendant les périodes de préemption. Le problème qui en découle (MSPSP avec préemption partielle ou MSPSP-PP) est modélisé à l'aide de deux méthodologies : la PLNE et la programmation par contraintes. Compte tenu du besoin industriel de disposer de bonnes solutions dans un délai très court, nous présentons également une série d'algorithmes heuristiques pour MSPSP-PP. Tout d'abord, nous présentons un algorithme glouton qui utilise des règles de priorité et un problème de flot pour l'affectation des techniciens. Pour améliorer les solutions de l'algorithme glouton, nous présentons un algorithme de recherche locale basée sur une arborescence binaire et une procédure de recherche adaptative aléatoire gloutonne. Enfin, nous présentons un algorithme de recherche locale à grand voisinage, une procédure hybride combinant des méthodes exactes et heuristiques. Une maquette d'interface graphique, permettant l'exploitation simple des algorithmes d'ordonnancement par l'équipe de planification de l'installation, est aussi présentée
Méthodes arborescentes pour la résolution de problèmes d'ordonnancement flexible by Abir Ben Hmida( Book )

2 editions published in 2009 in French and held by 2 WorldCat member libraries worldwide

Nowadays, the flexible scheduling problems drew attention of researchers in the field of operational research. These problems introduce an additional difficulty due to the fact that an operation can be carried out by one or several machines to be chosen among other candidates. The objective is to assign and to sequence the operations on the resources so that the total duration of the schedule is minimized. In this study, we offer to solve three flexible problems: the hybrid flow shop on several stages, the two-stage hybrid flow shop, and the flexible job shop problem, by using tree methods based on discrepancies. An exhaustive experimental study proved the efficiency of the different approaches developed for considered problems
Méthodes arborescentes pour la résolution de problèmes d'ordonnancement flexible by Abir Ben Hmida( )

1 edition published in 2009 in French and held by 1 WorldCat member library worldwide

Nowadays, the flexible scheduling problems drew attention of researchers in the field of operational research. These problems introduce an additional difficulty due to the fact that an operation can be carried out by one or several machines to be chosen among other candidates. The objective is to assign and to sequence the operations on the resources so that the total duration of the schedule is minimized. In this study, we offer to solve three flexible problems: the hybrid flow shop on several stages, the two-stage hybrid flow shop, and the flexible job shop problem, by using tree methods based on discrepancies. An exhaustive experimental study proved the efficiency of the different approaches developed for considered problems
Une approche interdisciplinaire pour l'ordonnancement des transports by Bernat Gacias Pastor( )

1 edition published in 2011 in French and held by 1 WorldCat member library worldwide

Dans cette thèse, nous proposons d'aborder l'ordonnancement des transports par une approche interdisciplinaire. L'idée est d'intégrer les facteurs humains dans le système d'aide à la décision réalisé, de façon à ce que l'homme puisse agir sur la modélisation et la résolution du problème. Le système proposé doit offrir de la flexibilité, afin d'être capable de s'adapter aux nouvelles situations et aux changements, même si ceux-ci n'ont pas été prévus initialement par le concepteur du système. Pour atteindre l'objectif fixé, nous nous sommes notamment appuyé sur une analyse du domaine de travail (« Work Domain Analysis ») basée sur une hiérarchie d'abstraction des entités (physiques ou plus abstraites) manipulées dans ce type de problèmes. Nous avons proposé une architecture pour le système d'aide à la décision basée sur cette analyse du domaine et la programmation par contraintes. Nous avons également conçu, et intégré dans le système, des algorithmes dédiés et des méthodes de résolution basés sur le principe d'inversion de modèle. Enfin, nous avons proposé une architecture d'interfaces avec l'objectif d'assister efficacement l'opérateur humain dans la réalisation des différentes sous-tâches nécessaires à la résolution globale du problème. L'étude du sujet interdisciplinaire a été précédée d'une analyse focalisée sur la résolution de problèmes théoriques d'ordonnancement à machines parallèles avec contraintes de précédence et temps de préparation des machines entre opérations, utilisant des méthodes de recherche arborescente basée sur les divergences
Méthodes à divergences pour la résolution de problèmes de satisfaction de contraintes et d'optimisation combinatoire by Wafa Karoui( Book )

1 edition published in 2010 in French and held by 1 WorldCat member library worldwide

The CSP (Constraint Satisfaction Problem) formalism can be considered as a simple example of a formal representation language covering all problems including constraints. The advantage of this formalism consists in the fact that it allows powerful general-purpose algorithms as much as useful specific algorithms. In this PhD thesis, we study several tree search methods for solving CSPs and focus on ones based on the discrepancy concept (a discrepancy is a deviation from the first choice of the heuristic). In this context, we propose improving mechanisms for general methods. These mechanisms take benefits from conflicts and guide the search by weighting the variables and the values. We propose also special mechanisms for methods based on discrepancies as the discrepancies restriction, the discrepancies counting, and the discrepancies positions. All propositions are validated by experiments done on real and random CSPs. We compare variants of methods based on discrepancies integrating several combinations of improvements and other methods known for their efficiency. In a second part, we extend our propositions to an optimisation context considering scheduling problems with time lags. In this purpose, we adapt a discrepancy-based method, Climbing Discrepancy Search, to solve these problems. Efficiency of some improved variants of this method is tested on known benchmarks
Gestion de contraintes et expertise dans les stratégies d'ordonnancement by Clément Guérin( )

1 edition published in 2012 in French and held by 1 WorldCat member library worldwide

Only a few research works in psychology are devoted to scheduling, for example about planning tasks, workers and machines occupation in the shop. In the literature, schedulers are mainly described from the procedural viewpoint. For describing scheduling activity, we adopted the complementary representational viewpoints in terms of constraints management. Two scheduling situations have been studied: timetabling and industrial scheduling. By comparing novices and experts, we observed that the latter used constraints visible on the timetable or on the Gantt chart, to solve the scheduling problem. Moreover, experts used a higher level of abstraction than novices in the control of processing. Finally, we highlighted the similarities and differences between industrial scheduling and timetabling. In addition, we conducted a multidisciplinary study from a previous work in the field of operational research by evaluating a scheduling tool. We investigated the effect of the mutual control modality on human scheduling decisions, and the management of breakdowns risks in a shop by schedulers
Schedule generation schemes for the job-shop problem with sequence-dependent setup times dominance properties and computational analysis by Christian Artigues( )

1 edition published in 2006 in English and held by 1 WorldCat member library worldwide

We consider the job-shop problem with sequence-dependent setup times. We focus on the formal definition of schedule generation schemes (SGSs) based on the semi-active, active, and non-delay schedule categories. We study dominance properties of the sets of schedules obtainable with each SGS. We show how the proposed SGSs can be used within single-pass and multi-pass priority rule based heuristics. We study several priority rules for the problem and provide a comparative computational analysis of the different SGSs on sets of instances taken from the literature. The proposed SGSs significantly improve previously best-known results on a set of hard benchmark instances
New single machine scheduling problems with deadline for the characterization of optimal solutions by Thanh Thuy Tien Ta( )

1 edition published in 2018 in English and held by 1 WorldCat member library worldwide

We consider a single machine scheduling problem with deadlines and we want to characterise the set of optimal solutions, without enumerating them. We assume that jobs are numbered in EDD order and that this sequence is feasible. The key idea is to use the lattice of permutations and to associate to the supremum permutation the EDD sequence. In order to characterize a lot of solutions, we search for a feasible sequence, as far as possible to the supremum. The distance is the level of the sequence in the lattice, which has to be minimum. This new objective function is investigated. Some polynomially particular cases are identified, but the complexity of the general case problem remains open. Some resolution methods, polynomial and exponential, are proposed and evaluated. The level of the sequence being related to the positions of jobs in the sequence, new objective functions related to the jobs positions are identified and studied. The problem of minimizing the total weighted positions of jobs is proved to be strongly NP-hard. Some particular cases are investigated, resolution methods are also proposed and evaluated
Nouvelles approches pour la résolution du problème d'ordonnancement de projet à moyens limités by Oumar Koné( )

1 edition published in 2010 in French and held by 1 WorldCat member library worldwide

In this thesis, we studied two types of scheduling problems. The major part concerns the Resource-Constrained Project Scheduling Problem (RCPSP). The scheduling problem of handling operations in a warehouse of Crossdocking is also dealt. First, from models using mixed integer linear programming, we proposed two new formulations of this problem, using variables indexed by events. In one of them, we use a binary variable to mark the beginning of the performing of each activity and another variable to mark its end. In the second proposal, a single variable is used. It identifies events in which the activity starts or continues its performing. Overall, compared to other models in the literature on various types of instances, our proposals show more interesting results on the instances with long scheduling horizons containing activities with disparate durations. In particular, on the highly cumulative instances (basic characteristics of RCPSP) of these types of instances, they are the most efficient. We also treat the resolution of the extension of the RCPSP which consists in taking into account specific resources that can be consumed during the performing of each activity, but also produced in another quantity at the end of performing of each activity: it is the RCPSP with consumption and production of resources. To make a comparison between different experimental models, we proposed an adaptation of our event-based formulations, the discrete-time formulations of Pritsker and Christofides, and the flow-based continuous-time formulation (proposed by Artigues on basis of the work of Balas). Overall, the results show that our event-based formulations are most successful on many types of instances. Second, in one less extensive part, we proposed a branch-and-bound using some cuts based on the Pareto frontier for the resolution of the scheduling problem of handling operations in a warehouse of Crossdocking. The excellent results obtained, which had strengthened our questions about the non-proved complexity of this problem, have contributed to establish later that this problem is of polynomial complexity
ORCA : architecture hybride pour le contrôle de la myopie dans le cadre du pilotage des systèmes flexibles de production by Cyrille Pach( )

1 edition published in 2013 in French and held by 1 WorldCat member library worldwide

This thesis deals with the control of myopia in Flexible Manufacturing Systems (FMS). Myopia arises when decisional entities take local decisions using limited amount of information. This decision making targets a fast reactivity under perturbations but compromises the overall performance. Thus this phenomenon should be controlled to obtain more efficient control architectures. After a presenting the related literature in myopia in other domains, myopic behavior in FMS is defined. An analysis of state-of-the-art regarding different types of control architectures determined that hybrid control architectures, mixing hierarchy and heterarchy, are the best option to control myopia. Therefore, a thorough study on hybrid control architectures is presented. Afterwards, a new architecture is proposed: ORCA. ORCA first described and then applied to FMS control (ORCA-FMS). ORCA-FMS combines two approaches: a linear model (ILP) and a potential fields approach. ORCA-FMS is then applied to the case study of the flexible cell of Valenciennes' AIP PRIMECA. First, a simulation model, as close as possible to the real case study is presented. It allows testing the architecture in the simulation environment NetLogo. Then, to validate the behaviors observed in simulation, the architecture is implemented on the real cell using the active product concept. The industrial equipment used for the implementation, the experimental protocol and the results are detailed and discussed
Planification d'une chaîne logistique : approche par satisfaction de contraintes dynamiques by Mariem Trojet( )

1 edition published in 2014 in French and held by 1 WorldCat member library worldwide

This work focuses on the supply chain operational and tactical planning problem in an uncertain environment. We propose a tactical planning model, based on a two-level decisional structure. Adopting a dynamic process, which enables data updating at each planning step, the first level performs a plan by searching for the best compromise between available decision-making levers for production costs and capacity. The second level establishes an aggregate scheduling of production tasks by minimizing the total weighted completion time. The use of an integrated decision structure involves interaction between the upper and lower decision levels constraints, implemented by constraints known as energy conservation constraints. Our approach is formulated according to a constraint satisfaction problem (CSP) and evaluated by simulation under uncertain data. For this, we have developed various experiments related to the variation of customer demand, resource capacity, and the re-planning of demand. All the experiments are carried out by two different methods : a method based on a static CSP and a method based on a dynamic CSP. The performance of a scheduling/planning solution is reported through a set of robustness and stability measurements. Results of experiments confirm the performance of the method based on a dynamic CSP
 
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