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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

Le problème de job-shop avec transport : modélisation et optimisation / Job-shop with transport : its modelling and optimisation

Larabi, Mohand 15 December 2010 (has links)
Dans cette thèse nous nous sommes intéressés à l’extension du problème job-shop en ajoutant la contrainte du transport des jobs entre les différentes machines. Dans cette étude nous avons retenu l’existence de deux types de robots, les robots de capacité de chargement unitaire (capacité=1 veut dire qu’un robot ne peut transporter qu’un seul job à la fois) et les robots de capacité de chargement non unitaire (capacité>1 veut dire qu’un robot peut transporter plusieurs job à la fois). Nous avons traité cette extension en deux étapes. Ainsi, la première étape est consacrée au problème du job-shop avec plusieurs robots de capacité de chargement unitaire et en seconde étape en ajoutant la capacité de chargement non unitaire aux robots. Pour les deux problèmes étudiés nous avons proposé :• Une modélisation linéaire ;• Une modélisation sous forme de graphe disjonctif ;• Plusieurs heuristiques de construction de solutions ;• Plusieurs recherches locales qui améliorent les solutions obtenues ;• Utilisation des algorithmes génétiques / mémétiques comme schéma global d’optimisation ;• De nouveaux benchmarks, des résultats de test de nos approches sur nos benchmarks et ceux de la littérature et ces résultats sont commentés et comparés à ceux de la littérature. Les résultats obtenus montrent la pertinence de notre modélisation ainsi que sa qualité. / In this thesis we are interested in the extension of the job-shop problem by adding the constraint of transport of jobs between different machines. In this study we used two types of robots, robots with unary loading capacity (capacity =1 means that each robot can carry only one job at a time,) and robots with non unary loading capacities (robot with capacity >1 can carry more than one job at time). Thus, the first step is devoted to the problem of job-shop with several robots with unary loading capacity. In the second step we extend the problem by adding the non-unary loading capacities to the robots. For both problems studied we have proposed :• A linear modeling ;• A Disjunctive graph Model ;• Several constructive heuristics ;• Several local searches methods that improve the obtained solutions ;• Use of genetic / memetic algorithms as a global optimization schema ;• New benchmarks, test results of our approaches on our benchmarks and those present in the literature and these results are commented and compared with those of literature. The results show the relevance of our model and its quality.
42

Le problème de job-shop avec transport : modélisation et optimisation

Larabi, Mohand 15 December 2010 (has links) (PDF)
Dans cette thèse nous nous sommes intéressés à l'extension du problème job-shop en ajoutant la contrainte du transport des jobs entre les différentes machines. Dans cette étude nous avons retenu l'existence de deux types de robots, les robots de capacité de chargement unitaire (capacité=1 veut dire qu'un robot ne peut transporter qu'un seul job à la fois) et les robots de capacité de chargement non unitaire (capacité>1 veut dire qu'un robot peut transporter plusieurs job à la fois). Nous avons traité cette extension en deux étapes. Ainsi, la première étape est consacrée au problème du job-shop avec plusieurs robots de capacité de chargement unitaire et en seconde étape en ajoutant la capacité de chargement non unitaire aux robots. Pour les deux problèmes étudiés nous avons proposé :* Une modélisation linéaire ;* Une modélisation sous forme de graphe disjonctif ;* Plusieurs heuristiques de construction de solutions ;* Plusieurs recherches locales qui améliorent les solutions obtenues ;* Utilisation des algorithmes génétiques / mémétiques comme schéma global d'optimisation ;* De nouveaux benchmarks, des résultats de test de nos approches sur nos benchmarks et ceux de la littérature et ces résultats sont commentés et comparés à ceux de la littérature. Les résultats obtenus montrent la pertinence de notre modélisation ainsi que sa qualité.
43

Técnicas de pesquisa operacional aplicadas ao problema de programação de cirurgias eletivas. / Operational research techniques applied to the elective surgeries scheduling problem.

Hortencio, Hanna Pamplona 20 May 2019 (has links)
Atualmente, os hospitais se veem obrigados a melhorar sua produtividade. Os centros cirúrgicos, além de ser um dos setores com maiores custos, também é o que mais gera receita dentro de um hospital, dessa forma torna-se extremamente importante o gerenciamento eficiente desse setor. Os métodos de otimização para programação de cirurgias podem ser usados como ferramentas para reduzir filas e ociosidade nos centros cirúrgicos, aumentando sua produtividade. O Problema de Programação de Cirurgias Eletivas com Múltiplos Recursos e Múltiplas Etapas consiste em alocar os recursos às etapas do processo cirúrgico dos pacientes, considerando as diferentes necessidades e rotas de cada paciente e, então, programar essas etapas no tempo respeitando a disponibilidade dos recursos e a sequência das etapas do processo cirúrgico dos pacientes. Esse problema é classificado na literatura como NP-hard e pode ser descrito como um Job Shop Flexível com blocking e função objetivo de minimização do número de pacientes não atendidos e do instante de término da última etapa, o makespan. O Objetivo desse trabalho é propor um modelo matemático e uma heurística construtiva para a resolução desse problema. O modelo matemático Multi-Mode Blocking Job Shop (MMBJS) apresentado em Pham e Klikert (2008) é explorado e algumas melhorias são apontadas neste trabalho. Um modelo matemático de Programação Linear Inteira Mista alternativo é proposto, a fim de reduzir o esforço computacional, ajustar o cálculo do makespan e sugerir uma estratégia de priorização de pacientes. Testes computacionais foram realizados, afim de comparar o modelo MMJBS e o modelo proposto. Para instâncias em que todos os pacientes são atendidos, as soluções encontradas pelo CPLEX para ambos modelos são iguais, porém o tempo computacional necessário para encontrar uma solução ótima é em média 45% menor no modelo proposto. Também foram realizados testes computacionais com objetivo de observar o comportamento do modelo com diferentes configurações de recursos. Para instâncias com 15 pacientes, os testes apontam que o tempo computacional para encontrar a solução ótima é superior a 2h de processamento. Dessa forma, uma heurística construtiva é proposta, com objetivo de gerar soluções factíveis com pouco esforço computacional. A heurística proposta aloca cada etapa do tratamento de cada paciente aos recursos necessários, respeitando as janelas de disponibilidade dos recursos e buscando reduzir a folga no sistema. Um exemplo de aplicação da heurística construtiva é apresentado. As propostas para trabalhos futuros são apresentadas no capítulo final desta dissertação. / For the past few years, hospitals have been forced to improve their productivity, with surgical centers being one of the sectors with higher costs within such organizations, but also the ones that generate the most revenue. Thus, optimization methods for surgical programming are tools that can be used to reduce queues and idleness in these sectors and consequently achieve the aforementioned goals. The \"Problem of Programming Multiple Surgical Resources with Multiple Steps\"consists in allocating the existing resources to each surgery stage that a patient will need to go through, considering the different needs, sequence and specificities of each of them, and then scheduling these steps in time. This type of problem is classified in the current literature as an NP-hard problem, being described as a Flexible Job Shop with blocking and an objective function that seeks to minimize the number of patients not served and the total makespan. The general purpose of this research is to propose a mathematical model and a constructive heuristic for this type problem. The proposed model explores the mathematical model Multi-Mode Blocking Job Shop (MMBJS) presented in Pham and Klikert (2008) suggesting improvements through the use of an alternative Mixed Integer Linear Programming that aims to: reduce the computational effort, adjust the makespan calculation and suggest a strategy of patients prioritization. In order to prove the benefits of the proposed enhancements, computational tests were performed to compare the MMJBS model and the proposed model, identifying that for instances where in which all patients are attended, the solutions found by CPLEX for both models are the same, but with a lower computational time the proposed model (45% average reduction). Also, other computational tests were performed to observe the behavior of the model with different configurations of resources. For instances with 15 patients, the tests indicate that the computational time to find the optimal solution is greater than 2 hours of processing. Thus a constructive heuristic is proposed, it aims to generate feasible solutions with little computational effort. The proposed heuristic allocates each surgery stage of a patient to the necessary resources, respecting the available windows and seeking to reduce the total slack in the system. An example of the application of the constructive heuristic is also presented. At last, future works proposals are presented in the final chapter of this dissertation.
44

Optimizing Cloudlet Scheduling and Wireless Sensor Localization using Computational Intelligence Techniques

Al-Olimat, Hussein S. 19 December 2014 (has links)
No description available.
45

Family Formation, Loading and Batch-Cyclic Flowshop Scheduling in Cellular Manufacturing Systems

Almasarwah, Najat E. January 2017 (has links)
No description available.
46

Energy-aware scheduling : complexity and algorithms

Renaud-Goud, Paul 05 July 2012 (has links) (PDF)
In this thesis we have tackled a few scheduling problems under energy constraint, since the energy issue is becoming crucial, for both economical and environmental reasons. In the first chapter, we exhibit tight bounds on the energy metric of a classical algorithm that minimizes the makespan of independent tasks. In the second chapter, we schedule several independent but concurrent pipelined applications and address problems combining multiple criteria, which are period, latency and energy. We perform an exhaustive complexity study and describe the performance of new heuristics. In the third chapter, we study the replica placement problem in a tree network. We try to minimize the energy consumption in a dynamic frame. After a complexity study, we confirm the quality of our heuristics through a complete set of simulations. In the fourth chapter, we come back to streaming applications, but in the form of series-parallel graphs, and try to map them onto a chip multiprocessor. The design of a polynomial algorithm on a simple problem allows us to derive heuristics on the most general problem, whose NP-completeness has been proven. In the fifth chapter, we study energy bounds of different routing policies in chip multiprocessors, compared to the classical XY routing, and develop new routing heuristics. In the last chapter, we compare the performance of different algorithms of the literature that tackle the problem of mapping DAG applications to minimize the energy consumption.
47

Využití optimalizace v řízení výroby / The use of optimization in production planning

Pokorný, Pavel January 2008 (has links)
The Master’s thesis deals with production scheduling in an industrial company. It uses the means of artificial intelligence to develop an appropriate production schedule in a generalized Flow-shop Programming problem. This problem can be solved by application which is a result of this thesis and was prepaired with use of the software Matlab 7.1 and its Genetic Algorithm and Direct Search toolbox. There is a part devoted to the use of advanced production systems (APS) and the concept of the operative production planning in praxis as well. The thesis pays attention to various optimization models in production scheduling and supply chain management too.
48

Integrating Combinatorial Scheduling with Inventory Management and Queueing Theory

Terekhov, Daria 13 August 2013 (has links)
The central thesis of this dissertation is that by combining classical scheduling methodologies with those of inventory management and queueing theory we can better model, understand and solve complex real-world scheduling problems. In part II of this dissertation, we provide models of a realistic supply chain scheduling problem that capture both its combinatorial nature and its dependence on inventory availability. We present an extensive empirical evaluation of how well implementations of these models in commercially available software solve the problem. We are therefore able to address, within a specific problem, the need for scheduling to take into account related decision-making processes. In order to simultaneously deal with combinatorial and dynamic properties of real scheduling problems, in part III we propose to integrate queueing theory and deterministic scheduling. Firstly, by reviewing the queueing theory literature that deals with dynamic resource allocation and sequencing and outlining numerous future work directions, we build a strong foundation for the investigation of the integration of queueing theory and scheduling. Subsequently, we demonstrate that integration can take place on three levels: conceptual, theoretical and algorithmic. At the conceptual level, we combine concepts, ideas and problem settings from the two areas, showing that such combinations provide insights into the trade-off between long-run and short-run objectives. Next, we show that theoretical integration of queueing and scheduling can lead to long-run performance guarantees for scheduling algorithms that have previously been proved only for queueing policies. In particular, we are the first to prove, in two flow shop environments, the stability of a scheduling method that is based on the traditional scheduling literature and utilizes processing time information to make sequencing decisions. Finally, to address the algorithmic level of integration, we present, in an extensive future work chapter, one general approach for creating hybrid queueing/scheduling algorithms. To our knowledge, this dissertation is the first work that builds a framework for integrating queueing theory and scheduling. Motivated by characteristics of real problems, this dissertation takes a step toward extending scheduling research beyond traditional assumptions and addressing more realistic scheduling problems.
49

Integrating Combinatorial Scheduling with Inventory Management and Queueing Theory

Terekhov, Daria 13 August 2013 (has links)
The central thesis of this dissertation is that by combining classical scheduling methodologies with those of inventory management and queueing theory we can better model, understand and solve complex real-world scheduling problems. In part II of this dissertation, we provide models of a realistic supply chain scheduling problem that capture both its combinatorial nature and its dependence on inventory availability. We present an extensive empirical evaluation of how well implementations of these models in commercially available software solve the problem. We are therefore able to address, within a specific problem, the need for scheduling to take into account related decision-making processes. In order to simultaneously deal with combinatorial and dynamic properties of real scheduling problems, in part III we propose to integrate queueing theory and deterministic scheduling. Firstly, by reviewing the queueing theory literature that deals with dynamic resource allocation and sequencing and outlining numerous future work directions, we build a strong foundation for the investigation of the integration of queueing theory and scheduling. Subsequently, we demonstrate that integration can take place on three levels: conceptual, theoretical and algorithmic. At the conceptual level, we combine concepts, ideas and problem settings from the two areas, showing that such combinations provide insights into the trade-off between long-run and short-run objectives. Next, we show that theoretical integration of queueing and scheduling can lead to long-run performance guarantees for scheduling algorithms that have previously been proved only for queueing policies. In particular, we are the first to prove, in two flow shop environments, the stability of a scheduling method that is based on the traditional scheduling literature and utilizes processing time information to make sequencing decisions. Finally, to address the algorithmic level of integration, we present, in an extensive future work chapter, one general approach for creating hybrid queueing/scheduling algorithms. To our knowledge, this dissertation is the first work that builds a framework for integrating queueing theory and scheduling. Motivated by characteristics of real problems, this dissertation takes a step toward extending scheduling research beyond traditional assumptions and addressing more realistic scheduling problems.
50

Energy-aware scheduling : complexity and algorithms / Ordonnancement sous contrainte d'énergie : complexité et algorithmes

Renaud-Goud, Paul 05 July 2012 (has links)
Dans cette thèse, nous nous sommes intéressés à des problèmes d'ordonnancement sous contrainte d'énergie, puisque la réduction de l'énergie est devenue une nécessité, tant sur le plan économique qu'écologique. Dans le premier chapitre, nous exhibons des bornes strictes sur l'énergie d'un algorithme classique qui minimise le temps d'exécution de tâches indépendantes. Dans le second chapitre, nous ordonnançons plusieurs applications chaînées de type « streaming », et nous étudions des problèmes contraignant l'énergie, la période et la latence. Nous effectuons une étude de complexité exhaustive, et décrivons les performances de nouvelles heuristiques. Dans le troisième chapitre, nous étudions le problème de placement de répliques dans un réseau arborescent. Nous nous plaçons dans un cadre dynamique, et nous bornons à minimiser l'énergie. Après une étude de complexité, nous confirmons la qualité de nos heuristiques grâce à un jeu complet de simulations. Dans le quatrième chapitre, nous revenons aux applications « streaming », mais sous forme de graphes série-parallèles, et nous tentons de les placer sur un processeur multi-cœur. La découverte d'un algorithme polynomial sur un problème simple nous permet la conception d'heuristiques sur le problème le plus général dont nous avons établi la NP-complétude. Dans le cinquième chapitre, nous étudions des bornes énergétiques de politiques de routage dans des processeurs multi-cœurs, en comparaison avec le routage classique XY, et développons de nouvheuristiques de routage. Dans le dernier chapitre, nous étudions expérimentalement le placement d'applications sous forme de DAG sur des machines réelles. / In this thesis we have tackled a few scheduling problems under energy constraint, since the energy issue is becoming crucial, for both economical and environmental reasons. In the first chapter, we exhibit tight bounds on the energy metric of a classical algorithm that minimizes the makespan of independent tasks. In the second chapter, we schedule several independent but concurrent pipelined applications and address problems combining multiple criteria, which are period, latency and energy. We perform an exhaustive complexity study and describe the performance of new heuristics. In the third chapter, we study the replica placement problem in a tree network. We try to minimize the energy consumption in a dynamic frame. After a complexity study, we confirm the quality of our heuristics through a complete set of simulations. In the fourth chapter, we come back to streaming applications, but in the form of series-parallel graphs, and try to map them onto a chip multiprocessor. The design of a polynomial algorithm on a simple problem allows us to derive heuristics on the most general problem, whose NP-completeness has been proven. In the fifth chapter, we study energy bounds of different routing policies in chip multiprocessors, compared to the classical XY routing, and develop new routing heuristics. In the last chapter, we compare the performance of different algorithms of the literature that tackle the problem of mapping DAG applications to minimize the energy consumption.

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