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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.
51

Proposta de modelo para priorização de investimentos em infraestrutura de transporte de cargas: abordagem multicritério para problemas de fluxos em rede. / A proposed model for prioritizing investments in freight transport infrastructure: multi-criteria approach for network flow problems.

Samir Kazan 23 September 2013 (has links)
A relevância da infraestrutura de transporte para incrementos em produtividade, induzindo ao desenvolvimento socioeconômico de determinada região é amplamente reconhecida. O Brasil, no entanto, apresenta sérias deficiências em relação à sua infraestrutura de transporte, oriundas de seu desenvolvimento histórico e da redução de níveis de investimentos públicos no setor nas últimas décadas. Estas deficiências traduzem-se em grande concentração no modal rodoviário para o transporte de cargas, menos eficiente do que os modais ferroviário e hidroviário, resultando em reduzida competitividade das organizações nacionais. Neste contexto, objetivou-se no presente trabalho a proposição de um modelo para avaliação e seleção de investimentos em infraestrutura de transporte de cargas, considerando-se seu caráter multidimensional. Para isso, foi proposta metodologia integrando os conceitos de análise de decisão multicritério e de programação matemática, representados pela teoria de utilidade multiatributo (Multi-Attribute Utility Theory - MAUT) e por problema de otimização de fluxos em rede (Minimum Cost Network Flow Problem - MCNFP), respectivamente. No desenvolvimento do modelo foram contemplados critérios de avaliação referentes às dimensões de análise financeira, operacional e ambiental. Posteriormente, foi considerada a aplicação de versões do modelo proposto com diferentes números de períodos de análise em caso ilustrativo, representativo da rede de transporte disponível e planejada da região Norte do Brasil. A aplicação das diversas versões do modelo proposto, de forma geral, apresentou resultados compatíveis com as teorias relacionadas à avaliação deste problema de decisão, incluindo indução à multimodalidade. Algumas versões do modelo apresentaram violações em algumas de suas restrições. Estes resultados adversos não foram plenamente eliminados, devido a limitações das ferramentas adotadas para aplicação. No entanto, foi possível a correção manual destas violações, resultando em soluções viáveis que, apesar de não serem consideradas ótimas, são mais completas do que soluções obtidas por meio de metodologias unidimensionais de análise. Por fim, foram apresentadas recomendações para condução de trabalhos futuros visando eliminação dos resultados adversos do modelo proposto e complementação de sua análise. / The role of transport infrastructure in productivity increases leading to regional social-economic development is widely recognized. Brazil, however, has serious deficiencies in its transport infrastructure, rooted in the country\'s historical development and in the recent decades\' reduction of public investment in the sector. These deficiencies can be observed in Brazil\'s strong focus on roads for cargo transportation, which besides being less efficient than rail and waterways, results in reduced competitiveness of national enterprises. In this context, the aim of this work was to propose a model for evaluating and selecting investments in freight\'s transportation infrastructure, considering its multidimensional character. It was proposed a methodology integrating the concepts of multi-criteria decision analysis and mathematical programming, represented by the Multi-Attribute Utility Theory (MAUT) along with the Minimum Cost Network Flow Problem (MCNFP). The developed model included financial, operational and environmental analysis evaluation criteria. Subsequently, this study applied the proposed model into a case study of the transportation network, available and planned, of the Northern region of Brazil. Overall, the application of various versions of the proposed model yielded results consistent with related evaluation and decision making theories, including induction of multimodality. Some versions of the model presented some violations of its restrictions. These adverse results were not fully eliminated due to the limitations of the application tools utilized. It was possible, however, to manually correct these violations and obtain viable solutions that, while cannot be considered optimal, are more complete than those obtained by single dimension analysis. Finally, recommendations were made for future studies aiming at eliminating the proposed model\'s adverse outcomes, and complementing its analysis.
52

Analýza nákladní železniční dopravy v Evropě / Analysis of Rail Freight Transport in Europe

Jindrová, Veronika January 2015 (has links)
The aim of the thesis is to analyse the status of the rail freight transport in Europe in the sense of its competitiveness on the transport market. The analysis is based on the identification of main barriers that characterise European rail freight and the extent of technological and legislative harmonisation across Europe. The status of the rail freight transport is also explored on the basis of the volume of goods transported by rail in European countries as well as on the comparison with road transport. In order to get the realistic idea about this issue the thesis focuses also on the main Czech rail carrier, ČD Cargo, a.s. and their realized transportations.
53

Evropské fondy a jejich využitelnost pro logistické projekty v ČR / European funds and their usage for logistics projects in Czech Republic.

Číhalová, Denisa January 2015 (has links)
The thesis discusses the issue of freight villages and the possible usage of European funds for their construction. The topic is very actual because by the current program period 2014-2020 has appeared change concerning the financial support of multimodal freight transportation. The aim of this thesis is to determine, whether from the production companies operating in the automotive industry exists demand for such a freight villages. Needed information has been obtained on the basis of in-depths inteviews of manufacturing companies located in the region Vysočina.
54

The synchronization of shared mobility flows in urban environments / La synchronisation des flux de passagers et de marchandises dans les systèmes de mobilité urbaine

Mourad, Abood 14 June 2019 (has links)
Avec l’augmentation progressive de la population dans les grandes villes, comme Paris, nous prévoyons d’ici 2050 une augmentation de 50% du trafic routier. En considérant les embouteillages et la pollution que cette augmentation va générer, on voit clairement la nécessité de nouveaux système de mobilité plus durables, comme le covoiturage, ou plus généralement toute la mobilité partagée. En parlant de mobilité partagée, ce n’est pas seulement le partage de trajets de personnes qui ont le même itinéraire au même temps, elle inclut aussi les marchandises.Cette thèse aborde le défi de la synchronisation des flux de passagers et de marchandises dans les systèmes de mobilité urbaine et elle vis à développer des méthodes d’optimisation pour que cette synchronisation dans la mobilité partagée soit faisable. Plus précisément, elle aborde les questions de recherche suivantes:*Q1: Quelles sont les variantes des systèmes de mobilité partagée et comment les optimiser?*Q2: Comment synchroniser les déplacements de personnes et quels gains cette synchronisation peut-elle générer?*Q3: Comment combiner les flux de passagers et de fret et quels sont les avantages attendus?*Q4: Quels sont les effets de l'incertitude sur la planification et l'exploitation de systèmes de mobilité partagée?Dans un premier temps, nous étudions les différentes variantes des systèmes de mobilité partagée et nous les classifions en fonction de leurs modèles, caractéristiques, approches de résolution et contexte d'application. En se basant sur cette revue de littérature, nous identifions deux problèmes de mobilité partagés, que nous considérons en détails dans cette thèse et nous développons des méthodes d'optimisation pour les résoudre.Pour synchroniser les flux de passagers, nous étudions un modèle de covoiturage en utilisant les véhicules autonomes, personnels et partagés, et des points de rencontre où la synchronisation entre passagers peut avoir lieu. Pour cela, une méthode heuristique en deux phases est proposée et une étude de cas sur la ville de New York est présentée.Ensuite, nous développons un modèle d’optimisation qui combine les flux de passagers et de marchandises dans une région urbaine. Le but de ce modèle est d’utiliser les capacités disponibles sur une ligne de transport fixe pour transporter les passagers et des robots transportant des petits colis à leurs destinations finales en considérant que la demande de passagers est stochastique. Les résultats obtenus montrent que les solutions proposées par ces deux modèles peuvent conduire à une meilleure utilisation des systèmes de transport dans les régions urbaines. / The rise of research into shared mobility systems reflects emerging challenges, such as rising urbanization rates, traffic congestion, oil prices and environmental concerns. The operations research community has turned towards more sharable and sustainable systems of transportation. Although shared mobility comes with many benefits, it has some challenges that are restricting its widespread adoption. More research is thus needed towards developing new shared mobility systems so that a better use of the available transportation assets can be obtained.This thesis aims at developing efficient models and optimization approaches for synchronizing people and freight flows in an urban environment. As such, the following research questions are addressed throughout the thesis:*Q1: What are the variants of shared mobility systems and how to optimize them?*Q2: How can people trips be synchronized and what gains can this synchronization yields?*Q3: How can people and freight flows be combined and what are the intended benefits?*Q4: What impacts uncertainty can have on planning and operating shared mobility systems?First, we review different variants of the shared mobility problem where either (i) travelers share their rides, or (ii) the transportation of passengers and freight is combined. We then classify these variants according to their models, solution approaches and application context and We provide a comprehensive overview of the recently published papers and case studies. Based on this review, we identify two shared mobility problems, which we study further in this thesis.Second, we study a ridesharing problem where individually-owned and on-demand autonomous vehicles (AVs) are used for transporting passengers and a set of meeting points is used for synchronizing their trips. We develop a two-phase method (a pre-processing algorithm and a matching optimization problem) for assessing the sharing potential of different AV ownership models, and we evaluate them on a case study for New York City.Then, we present a model that integrates freight deliveries to a scheduled line for people transportation where passengers demand, and thus the available capacity for transporting freight, is assumed to be stochastic. We model this problem as a two-stage stochastic problem and we provide a MIP formulation and a sample average approximation (SAA) method along with an Adaptive Large Neighborhood Search (ALNS) algorithm to solve it. We then analyze the proposed approach as well as the impacts of stochastic passengers demand on such integrated system on a computational study.Finally, we summarize the key findings, highlight the main challenges facing shared mobility systems, and suggest potential directions for future research.
55

Evaluating the Performance of the Freight Transportation System of the Great Lakes Region: An Intermodal Approach to Routing and Forecasting

Wang, Qifeng January 2014 (has links)
No description available.
56

PROGETTAZIONE PEDAGOGICA, "KMETRO VERDE". MOBILITA' E TRASPORTI SOSTENIBILI NEI SISTEMI AGROALIMENTARI

SANDRINI, SIMONA 18 March 2016 (has links)
L’intensità del trasporto alimentare è un trend destinato ad aumentare nella sua complessità. La ricerca attesta come sia rilevante analizzare “come il cibo viaggia”, forse più di “quanto il cibo viaggia”, nel mercato globalizzato dei prodotti agroalimentari, nelle realtà urbane che modificano le abitudini di consumo e nel “global food system” composto da cinque tipologie di sistemi agroalimentari. Gli impatti in sostenibilità sono strettamente dipendenti dall’efficienza del trasporto e della logistica, di merci agroalimentari e di persone che si spostano per l’approvvigionamento, dal campo al consumatore e viceversa. Eppure il concetto di food miles si è ampiamente diffuso tra gruppi di consumatori, attestando mutamenti culturali significativi. Si pensi all’idea tutta italiana di “km-zero”. “Può il trasporto del cibo essere economicamente, socialmente e culturalmente sostenibile, per conservare l'ecosistema?” Questa domanda, approfondita pedagogicamente, può essere riformulata: “How can consumers, economical stakeholders and policy makers become environmentally friendly about transportation of food?” Il quesito conduce all’interrogativo di quale formazione e ricerca interdisciplinare progettare per orientare gli sforzi verso questo fine. Una nuova formulazione concettuale potrebbe promuovere azioni sostenibili per la mobilità e i trasporti sulle lunghe, medie e corte distanze, per la filiera lunga e corta: il “Kmetro verde”. / The transportation of agro-alimentary products is constantly evolving. The research has been focusing on long distances, tied with the global market. But results in a lack of investigations in medium and short distances which also possess some efficiency gain. The investigation of these shorter mode of transport is paramount as they have significant impact on the triptych of sustainability. In this context, the concepts of "food miles" and of "km-zero" have spread widely among the consumers, attesting the community awareness regarding sustainability issues. However, as environmental concerns arise, such concept has showed it's limit. Therefore the question, "Can transportation of food become economically, socially and culturally sustainable, to preserve the ecosystem?", that lead to this concept, needs to be reassessed. Starting from a pedagogical standpoint, this question can be rephrased as “How can consumers, economical stakeholders and policy makers become environmentally friendly about transportation of food, to preserve the ecosystem?”. For a successful undertaking of such problematic, it is paramount to evaluate the need of novel training practises as well as the design of interdisciplinary research. A new formulation of such concept, embodied in "kmeter green", would aim to promote sustainable mobility on all the distances and chains' lengths.
57

Scheduled service network design for integrated planning of rail freight transportation

Zhu, Endong 08 1900 (has links)
Cette thèse étudie une approche intégrant la gestion de l’horaire et la conception de réseaux de services pour le transport ferroviaire de marchandises. Le transport par rail s’articule autour d’une structure à deux niveaux de consolidation où l’affectation des wagons aux blocs ainsi que des blocs aux services représentent des décisions qui complexifient grandement la gestion des opérations. Dans cette thèse, les deux processus de consolidation ainsi que l’horaire d’exploitation sont étudiés simultanément. La résolution de ce problème permet d’identifier un plan d’exploitation rentable comprenant les politiques de blocage, le routage et l’horaire des trains, de même que l’habillage ainsi que l’affectation du traffic. Afin de décrire les différentes activités ferroviaires au niveau tactique, nous étendons le réseau physique et construisons une structure de réseau espace-temps comprenant trois couches dans lequel la dimension liée au temps prend en considération les impacts temporels sur les opérations. De plus, les opérations relatives aux trains, blocs et wagons sont décrites par différentes couches. Sur la base de cette structure de réseau, nous modélisons ce problème de planification ferroviaire comme un problème de conception de réseaux de services. Le modèle proposé se formule comme un programme mathématique en variables mixtes. Ce dernie r s’avère très difficile à résoudre en raison de la grande taille des instances traitées et de sa complexité intrinsèque. Trois versions sont étudiées : le modèle simplifié (comprenant des services directs uniquement), le modèle complet (comprenant des services directs et multi-arrêts), ainsi qu’un modèle complet à très grande échelle. Plusieurs heuristiques sont développées afin d’obtenir de bonnes solutions en des temps de calcul raisonnables. Premièrement, un cas particulier avec services directs est analysé. En considérant une cara ctéristique spécifique du problème de conception de réseaux de services directs nous développons un nouvel algorithme de recherche avec tabous. Un voisinage par cycles est privilégié à cet effet. Celui-ci est basé sur la distribution du flot circulant sur les blocs selon les cycles issus du réseau résiduel. Un algorithme basé sur l’ajustement de pente est développé pour le modèle complet, et nous proposons une nouvelle méthode, appelée recherche ellipsoidale, permettant d’améliorer davantage la qualité de la solution. La recherche ellipsoidale combine les bonnes solutions admissibles générées par l’algorithme d’ajustement de pente, et regroupe les caractéristiques des bonnes solutions afin de créer un problème élite qui est résolu de facon exacte à l’aide d’un logiciel commercial. L’heuristique tire donc avantage de la vitesse de convergence de l’algorithme d’ajustement de pente et de la qualité de solution de la recherche ellipsoidale. Les tests numériques illustrent l’efficacité de l’heuristique proposée. En outre, l’algorithme représente une alternative intéressante afin de résoudre le problème simplifié. Enfin, nous étudions le modèle complet à très grande échelle. Une heuristique hybride est développée en intégrant les idées de l’algorithme précédemment décrit et la génération de colonnes. Nous proposons une nouvelle procédure d’ajustement de pente où, par rapport à l’ancienne, seule l’approximation des couts liés aux services est considérée. La nouvelle approche d’ajustement de pente sépare ainsi les décisions associées aux blocs et aux services afin de fournir une décomposition naturelle du problème. Les résultats numériques obtenus montrent que l’algorithme est en mesure d’identifier des solutions de qualité dans un contexte visant la résolution d’instances réelles. / This thesis studies a scheduled service network design problem for rail freight transportation planning. Rails follow a special two level consolidation organization, and the car-to-block, block-to-service handling procedure complicates daily operations. In this research, the two consolidation processes as well as the operation schedule are considered simultaneously, and by solving this problem, we provide an overall cost-effective operating plan, including blocking policy, train routing, scheduling, make-up policy and traffic distribution. In order to describe various rail operations at the tactical level, we extend the physical network and construct a 3-layer time-space structure, in which the time dimension takes into consideration the temporal impacts on operations. Furthermore, operations on trains, blocks, and cars are described in different layers. Based on this network structure, we model the rail planning problem to a service network design formulation. The proposed model relies on a complex mixed-integer programming formulation. The problem is very hard to solve due to the computational difficulty as well as the tremendous size of the application instances. Three versions of the problem are studied, which are the simplified model (with only non-stop services), complete model (with both non-stop and multi-stop services) and very-large-scale complete model. Heuristic algorithms are developed to provide good feasible solutions in reasonable computing efforts. A special case with non-stop services is first studied. According to a specific characteristic of the direct service network design problem, we develop a tabu search algorithm. The tabu search moves in a cycle-based neighborhood, where flows on blocks are re-distributed according to the cycles in a conceptual residual network. A slope scaling based algorithm is developed for the complete model, and we propose a new method, called ellipsoidal search, to further improve the solution quality. Ellipsoidal search combines the good feasible solutions generated from the slope scaling, and collects the features of good solutions into an elite problem, and solves it with exact solvers. The algorithm thus takes advantage of the convergence speed of slope scaling and solution quality of ellipsoidal search, and is proven effective. The algorithm also presents an alternative for solving the simplified problem. Finally, we work on the very-large-size complete model. A hybrid heuristic is developed by integrating the ideas of previous research with column generation. We propose a new slope scaling scheme where, compared with the previous scheme, only approximate service costs instead of both service and block costs are considered. The new slope scaling scheme thus separates the block decisions and service decisions, and provide a natural decomposition of the problem. Experiments show the algorithm is good to solve real-life size instances.
58

Scheduled service network design for integrated planning of rail freight transportation

Zhu, Endong 08 1900 (has links)
Cette thèse étudie une approche intégrant la gestion de l’horaire et la conception de réseaux de services pour le transport ferroviaire de marchandises. Le transport par rail s’articule autour d’une structure à deux niveaux de consolidation où l’affectation des wagons aux blocs ainsi que des blocs aux services représentent des décisions qui complexifient grandement la gestion des opérations. Dans cette thèse, les deux processus de consolidation ainsi que l’horaire d’exploitation sont étudiés simultanément. La résolution de ce problème permet d’identifier un plan d’exploitation rentable comprenant les politiques de blocage, le routage et l’horaire des trains, de même que l’habillage ainsi que l’affectation du traffic. Afin de décrire les différentes activités ferroviaires au niveau tactique, nous étendons le réseau physique et construisons une structure de réseau espace-temps comprenant trois couches dans lequel la dimension liée au temps prend en considération les impacts temporels sur les opérations. De plus, les opérations relatives aux trains, blocs et wagons sont décrites par différentes couches. Sur la base de cette structure de réseau, nous modélisons ce problème de planification ferroviaire comme un problème de conception de réseaux de services. Le modèle proposé se formule comme un programme mathématique en variables mixtes. Ce dernie r s’avère très difficile à résoudre en raison de la grande taille des instances traitées et de sa complexité intrinsèque. Trois versions sont étudiées : le modèle simplifié (comprenant des services directs uniquement), le modèle complet (comprenant des services directs et multi-arrêts), ainsi qu’un modèle complet à très grande échelle. Plusieurs heuristiques sont développées afin d’obtenir de bonnes solutions en des temps de calcul raisonnables. Premièrement, un cas particulier avec services directs est analysé. En considérant une cara ctéristique spécifique du problème de conception de réseaux de services directs nous développons un nouvel algorithme de recherche avec tabous. Un voisinage par cycles est privilégié à cet effet. Celui-ci est basé sur la distribution du flot circulant sur les blocs selon les cycles issus du réseau résiduel. Un algorithme basé sur l’ajustement de pente est développé pour le modèle complet, et nous proposons une nouvelle méthode, appelée recherche ellipsoidale, permettant d’améliorer davantage la qualité de la solution. La recherche ellipsoidale combine les bonnes solutions admissibles générées par l’algorithme d’ajustement de pente, et regroupe les caractéristiques des bonnes solutions afin de créer un problème élite qui est résolu de facon exacte à l’aide d’un logiciel commercial. L’heuristique tire donc avantage de la vitesse de convergence de l’algorithme d’ajustement de pente et de la qualité de solution de la recherche ellipsoidale. Les tests numériques illustrent l’efficacité de l’heuristique proposée. En outre, l’algorithme représente une alternative intéressante afin de résoudre le problème simplifié. Enfin, nous étudions le modèle complet à très grande échelle. Une heuristique hybride est développée en intégrant les idées de l’algorithme précédemment décrit et la génération de colonnes. Nous proposons une nouvelle procédure d’ajustement de pente où, par rapport à l’ancienne, seule l’approximation des couts liés aux services est considérée. La nouvelle approche d’ajustement de pente sépare ainsi les décisions associées aux blocs et aux services afin de fournir une décomposition naturelle du problème. Les résultats numériques obtenus montrent que l’algorithme est en mesure d’identifier des solutions de qualité dans un contexte visant la résolution d’instances réelles. / This thesis studies a scheduled service network design problem for rail freight transportation planning. Rails follow a special two level consolidation organization, and the car-to-block, block-to-service handling procedure complicates daily operations. In this research, the two consolidation processes as well as the operation schedule are considered simultaneously, and by solving this problem, we provide an overall cost-effective operating plan, including blocking policy, train routing, scheduling, make-up policy and traffic distribution. In order to describe various rail operations at the tactical level, we extend the physical network and construct a 3-layer time-space structure, in which the time dimension takes into consideration the temporal impacts on operations. Furthermore, operations on trains, blocks, and cars are described in different layers. Based on this network structure, we model the rail planning problem to a service network design formulation. The proposed model relies on a complex mixed-integer programming formulation. The problem is very hard to solve due to the computational difficulty as well as the tremendous size of the application instances. Three versions of the problem are studied, which are the simplified model (with only non-stop services), complete model (with both non-stop and multi-stop services) and very-large-scale complete model. Heuristic algorithms are developed to provide good feasible solutions in reasonable computing efforts. A special case with non-stop services is first studied. According to a specific characteristic of the direct service network design problem, we develop a tabu search algorithm. The tabu search moves in a cycle-based neighborhood, where flows on blocks are re-distributed according to the cycles in a conceptual residual network. A slope scaling based algorithm is developed for the complete model, and we propose a new method, called ellipsoidal search, to further improve the solution quality. Ellipsoidal search combines the good feasible solutions generated from the slope scaling, and collects the features of good solutions into an elite problem, and solves it with exact solvers. The algorithm thus takes advantage of the convergence speed of slope scaling and solution quality of ellipsoidal search, and is proven effective. The algorithm also presents an alternative for solving the simplified problem. Finally, we work on the very-large-size complete model. A hybrid heuristic is developed by integrating the ideas of previous research with column generation. We propose a new slope scaling scheme where, compared with the previous scheme, only approximate service costs instead of both service and block costs are considered. The new slope scaling scheme thus separates the block decisions and service decisions, and provide a natural decomposition of the problem. Experiments show the algorithm is good to solve real-life size instances.
59

Modélisation et évaluation des performances de la chaine de transport intermodal de porte à porte : le cas du corridor de la Vallée de Seine / Modeling and evaluating the performance of the intermodal freight transportation chain based on door-to-door service : case study of the corridor of the Seine Valley

Gouiza, Fairouz 08 March 2016 (has links)
Le travail présenté dans ce mémoire contribue au domaine de l’entreprise étendue et le développement des systèmes d’informations distribués. et le développement des systèmes d’informations distribués. C’est bien évidemment un sujet d’étude important pour la communauté Logistique (chaîne logistique), mais aussi pour la communauté Génie logiciel. C’est dans cette perspective que se situent les objectifs de proposer une modélisation de la chaîne logistique globale dans un environnement de transport intermodal de porte à porte en vue de résoudre les problèmes : (i) d’interfaces entre les différents acteurs intervenants le long de la chaîne et (ii) de rupture des charges engendrés par les opérations de transfert de marchandises d’un mode de transport à l’autre. Ainsi, l’amélioration de performance de la chaine logistique dépend fortement du niveau de coopération et de coordination, et surtout du partage et de la validité des informations et des connaissances, entre ces différents acteurs de la chaîne (organisateur du transport, transitaire, fournisseur, etc.). L’applicatif se situe dans le corridor de la vallée de Seine. Le travail s’inscrit dans le projet APLOG (Amélioration et Performance de la LOgistique Globale) financé par la région Haute Normandie. / The work presented in this thesis contributes to the field of the extended enterprise and the development of distributed information systems. This is obviously an important subject of study for the logistics community (supply chain), but also for the software engineering community. It is in this context that the objectives are to provide a model of global supply chain in an intermodal environment door to door service to solve the problems: (i) interfaces between the different actors involved along the chain and (ii) trans-loading operations generated by the goods transfer operations from one mode of transport to another. Thus, improved performance of the supply chain depends heavily on the level of cooperation and coordination, and especially sharing and validity of information and knowledge between the different actors in the chain (transport organizer, forwarding, Supplier, etc.). The application is located in the corridor of the Seine valley. The work is part of the project APLOG (Performance Improvement and global logistics) financed by the Haute Normandie region.
60

Abordagens de otimização para o problema de alocação dinâmica de veículos no contexto de transporte rodoviário de carga no Brasil

Alvarez Cruz, Cesar Dario 10 March 2017 (has links)
Submitted by Aelson Maciera (aelsoncm@terra.com.br) on 2017-09-26T19:15:52Z No. of bitstreams: 1 DissCDAC.pdf: 10114021 bytes, checksum: b3e4f52846924539caadab8587fe2250 (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-26T18:36:20Z (GMT) No. of bitstreams: 1 DissCDAC.pdf: 10114021 bytes, checksum: b3e4f52846924539caadab8587fe2250 (MD5) / Approved for entry into archive by Ronildo Prado (bco.producao.intelectual@gmail.com) on 2018-01-26T18:36:39Z (GMT) No. of bitstreams: 1 DissCDAC.pdf: 10114021 bytes, checksum: b3e4f52846924539caadab8587fe2250 (MD5) / Made available in DSpace on 2018-01-26T18:42:45Z (GMT). No. of bitstreams: 1 DissCDAC.pdf: 10114021 bytes, checksum: b3e4f52846924539caadab8587fe2250 (MD5) Previous issue date: 2017-03-10 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / This work aims at treating the Dynamic Vehicle Allocation Problem (DVAP) in the context of the Brazilian Freight Transportation system. The problem consists of allocating empty vehicles to different terminals so as to attend the demand of freight transport during a predetermined planning horizon while maximizing the profit from these services. These type of decisions arise in customized freight transport services and in between-terminals operations of consolidation freight services. Given the size of the resulting models of real life problems confronted by third party logistics operators are large for using exact solution methods, heuristic methods have been used for giving good quality solution at the expense of optimality guarantee. In this context, the objective of this work is to contribute with solution methods that provide optimality guarantee or quality solution certificates for treating large-scale problems in reasonable computational times. The methods utilized are lagrangean relaxation, using subgradient optimization, and DantzigWolfe decomposition together with a lagrangian heuristic and factibilization method, respectively. Computational experiments are presented and analyzed for randomly generated instances and real-world instances from a brasilian freight operator. The latter method shows great potential for treating large-scale problems. / Este trabalho aborda o problema de Alocação Dinâmica de Veículos (PADV) no contexto de Transporte Rodoviário de Carga. O problema envolve alocar veículos de carga para atender a demanda de transporte de carga prevista entre terminais durante um horizonte de tempo multiperíodos e finito. O objetivo e maximizar o lucro gerado pelos serviços completados. Este tipo de decisões surge nos serviços de transporte de carga de lotação e na parcela de transporte de transferência dos serviços de transporte de carga consolidada. Dado que o tamanho dos problemas que enfrentam as transportadoras logísticas sÃo consideravelmente grandes parase resolver com métodos exatos em tempos computacionais aceitáveis, tem-se utilizado métodos heurísticos para dar boas soluções sem garantia de otimalidade mas em tempos toleráveis a estes problemas. Neste contexto, pretende-se contribuir com métodos de solução que proporcionem garantia de otimalidade e/ou boas soluções aproximadas, acompanhadas de certificados de otimalidade ou de qualidade de solução, para tratar problemas de porte em tempos razoáveis. Os métodos propostos estao baseados em relaxação lagrangiana, utilizando o método de otimização do subgradiente, e na decomposto de Dantzig Wolfe, utilizando a técnica de geração de colunas, além de heurísticas lagrangianas e de factibilização acopladas nestes métodos. Experimentos computacionais usando instâncias geradas aleatoriamente e baseados em dados reais de transportadoras brasileiras sao apresentados e analisados, para as duas abordagens, mostrando seus potenciais de aplicação pratica, principalmente para problemas de grande porte.

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