Méthodes exactes et approchées pour le problème de gestion de projet à contraintes de ressources

Le problème de gestion de projet à contraintes de ressources est un des problèmesles plus étudiés dans la littérature. Il consiste à planifier des activités soumises à desrelations de précédence, et nécessitant des ressources renouvelables. L objectif est deminimiser la durée du projet, soit le makespan. Nous étudions le problème de gestion deprojet à contraintes de ressources. Nous nous sommes intéressées à la résolution exactedu problème. Dans la première partie de la thèse, nous élaborons une série de bornesinférieures basées sur le raisonnement énergétique et des formulations mathématiques.Les résultats montrent que les bornes proposées surpassent ceux de la littérature. Dansla deuxième partie, nous proposons des procédures par séparation et évaluation utilisantles bornes inférieures dévelopées dans la première partie.Resource Constrained Project Scheduling Problem is one of the most studied schedulingproblems in the literature. It consists in scheduling activities, submitted to precedencerelationship, and requiring renewable resources to be processed. The objective isto minimize the project duration, i.e., the makespan. We study the Resource ConstrainedProject Scheduling Problem. We are interested on the exact resolution of the problem.In the first part of the thesis, we develop a series of lower bounds based on energeticreasoning and mathematical formulations. The computational results show that theproposed lower bounds outperform the ones of the literature. In the second part, wepropose Branch-and-Bound procedures using the lower bounds developed on the firstpart.TOURS-Bibl.électronique (372610011) / SudocSudocFranceF

Méthodes exactes et approchées pour le problème de gestion de projet à contraintes de ressources

Le problème de gestion de projet à contraintes de ressources est un des problèmesles plus étudiés dans la littérature. Il consiste à planifier des activités soumises à desrelations de précédence, et nécessitant des ressources renouvelables. L’objectif est deminimiser la durée du projet, soit le makespan. Nous étudions le problème de gestion deprojet à contraintes de ressources. Nous nous sommes intéressées à la résolution exactedu problème. Dans la première partie de la thèse, nous élaborons une série de bornesinférieures basées sur le raisonnement énergétique et des formulations mathématiques.Les résultats montrent que les bornes proposées surpassent ceux de la littérature. Dansla deuxième partie, nous proposons des procédures par séparation et évaluation utilisantles bornes inférieures dévelopées dans la première partie.Resource Constrained Project Scheduling Problem is one of the most studied schedulingproblems in the literature. It consists in scheduling activities, submitted to precedencerelationship, and requiring renewable resources to be processed. The objective isto minimize the project duration, i.e., the makespan. We study the Resource ConstrainedProject Scheduling Problem. We are interested on the exact resolution of the problem.In the first part of the thesis, we develop a series of lower bounds based on energeticreasoning and mathematical formulations. The computational results show that theproposed lower bounds outperform the ones of the literature. In the second part, wepropose Branch-and-Bound procedures using the lower bounds developed on the firstpart

A level set method for the shape optimization problem in induction heating

International audienc

A preemptive bound for the Resource Constrained Project Scheduling Problem

The Resource Constrained Project Scheduling Problem is one of the most intensively investigated scheduling problems. It requires scheduling a set of interrelated activities, while considering precedence relationships, and limited renewable resources allocation. The objective is to minimize the project duration. We propose a new destructive lower bound for this challenging NP -hard problem. Starting from a previously suggested LP model, we propose several original valid inequalities that aim at tightening the model representation. These new inequalities are based on precedence constraints, incompatible activity subsets, and nonpreemption constraints. We present the results of an extensive computational study that was carried out on 2,040 benchmark instances of PSPLIB, with up to 120 activities, and that provide strong evidence that the new proposed lower bound exhibits an excellent performance. In particular, we report the improvement of the best known lower bounds of 5 instances.Scopu

Extension d'une borne inférieure préemptive pour le problème de gestion de projet à contraintes de ressources

National audienc

Lower bounds for an industrial multi-skill project scheduling problem

International audienceThe aim of this paper is to present lower bounds for a Multi-Skill Project Scheduling Problem, including some classical lower bounds and more enhanced ones. Starting from the lower bounds found in the literature, we focus on the particularity of our problem and on the adaptation of these lower bounds to our problem. We present preliminary results obtained with these new lower bounds. The adaptation of the time window adjustments used with energetic reasoning, shows the specificity of this problem, especially slack computation, which requires solving a max-flow with minimum cost problem

Solitary osteochondroma arising in lumbar spinous process: Case report

Solitary osteochondromas rarely occur in the axial skeleton. Those tumors mostly arise on the posterior elements of the cervical column causing various symptoms especially when developing within the spinal canal. Exophytic lumbar variety is uncommon presenting with palpable mass or spinal deformity. We report a 20-year-old man presenting with a solid painless mass at the lower lumbar region. Radiological examinations revealed an exophytic lesion arising in the third lumbar spinous process appearing to be a solitary osteochondroma. The lesion was treated by en-bloc resection; histopathological examination confirmed the diagnosis of osteochondroma with no evidence of recurrence at the end of 2-year follow up. Keywords: Osteochondroma, Lumbar spine, Spinous process, Tumor, Diagnostic imaging, Surger

Improving Classical Energetic Reasoning for the Resource Constrained Project Scheduling Problem

International audienc

A preemptive bound for the RCPSP

International audienc

Total Hip Arthroplasty Loosening Due to Mycobacterium Tuberculosis: A Case Report and Review of the Literature

Context: Prosthetic joint infection due to Mycobacterium tuberculosis with no previous history of pulmonary or extra pulmonary tuberculosis is an extremely rare complication. Aims To report the case of a patient with tuberculous mycobacterial prosthetic hip infection, 14 years after surgery for post traumatic osteoarthritis, with no previous history of tuberculosis. Methods A 46-year-old male presented an acetabular loosening of a cemented total hip arthroplasty with subnormal biologic parameters. A one stage revision surgery was planned. Intraoperative findings suggested mycobacterial tuberculous infection with presence of periacetabular yellowish rice-shaped granules. Results A one-stage prosthesis exchange was performed; Culture on Löwenstein-Jensen medium grew MTB days after inoculation and histological examination confirmed tuberculous infection. Patient was treated by antituberculous agents for 12 months with optimal clinical and biological response and no prosthetic loosening signs at eighteen months follow up. Conclusions Total hip arthroplasty loosening due to mycobacterium tuberculosis is a rare entity, which should be evoked even when no inflammatory signs are shown. Discovery of yellowish rice-shaped granules is an indicator to investigate for tuberculosis. Management of prosthetic joint infection due to M.tuberculosis must involve both medical and surgical approach