En los últimos años la Logística Inversa se ha hecho relevante no solo para el mundo académico sino también para el empresarial. Las empresas dan cada día más importancia a esta área, debido a los factores medioambientales y a los beneficios derivados del mejoramiento de su proceso de devoluciones. Así mismo, para tener unos procesos de Logística Inversa eficientes y exitosos, es necesaria la colaboración entre los miembros de la cadena de suministro. Esta tesis se concentra en ambos aspectos, Colaboración y Logística Inversa.El propósito de esta tesis es doble; primero, analizar los problemas que sufren hoy en día las empresas en esta área, partiendo de una perspectiva general, y posteriormente analizando la industria editorial española. En segundo lugar, nosotros proponemos cuatro modelos matemáticos concernientes a los problemas de planificación que presentan las empresas cuando incorporan las devoluciones, y finalmente proponemos unas metodologías para solucionarlos. / During last years Reverse Logistics has become a relevant topic not only for academics but also for the business world. Companies are giving each day more and more importance to this field, because the environmental issues and the benefits that the company can obtain by the improvement of their return's processes. To obtain a successful and efficient Reverse Logistics processes there exist the need to collaborate along the supply chain. This thesis focuses on both of these two topics, Collaboration and Reverse Logistics. The aim of this thesis is twofold; first, we try to understand the returns processes' problems that companies are facing today from the management point of view, from a general perspective and afterwards on the editorial industry. Secondly, we propose some mathematical models and solution methods related to real planning problems faced by the companies when the returns are incorporated.

From the time of the Greeks, primality testing and factoring have fascinated mathematicians, and for centuries following the Greeks primality testing and factorization were pursued by enthusiasts and professional mathematicians for their intrisic value. There was little practical application. One example application was to determine whether or not the Fermat numbers, that is, numbers of the form F;, = 2'" + 1 were prime. Fermat conjectured that for all n they were prime. For n = 1,2,3,4, the Fermat numbers are prime, but Euler showed that F; was not prime and to date no F,, n 2 5 has been found to be prime. Thus, for nearly 2000 years primality testing and factorization was largely pure mathematics. This all changed in the mid 1970's with the advent of public key cryptography. Large prime numbers are used in generating keys in many public key cryptosystems and the security of many of these cryptosystems depends on the difficulty of factoring numbers with large prime factors. Thus, the race was on to develop new algorithms to determine the primality or otherwise of a given large integer and to determine the factors of given large integers. The development of such algorithms continues today. This thesis develops both of these themes. The first part of this thesis deals with primality testing and after a brief introduction to primality testing a new probabilistic primality algorithm, ALI, is introduced. It is analysed in detail and compared to Fermat and Miller-Rabin primality tests. It is shown that the ALI algorithm is more efficient than the Miller-Rabin algorithm in some aspects. The second part of the thesis deals with factoring and after looking closely at various types of algorithms a new algorithm, RAK, is presented. It is analysed in detail and compared with Fermat factorization. The RAK algorithm is shown to be significantly more efficient than the Fermat factoring algorithm. A number of enhancements is made to the basic RAK algorithm in order to improve its performance. The RAK algorithm with its enhancements is known as IMPROVEDRAK. In conjunction with this work on factorization an improvement to Shor's factoring algorithm is presented. For many integers Shor's algorithm uses a quantum computer multiple times to factor a composite number into its prime factors. It is shown that Shor's alorithm can be modified in a way such that the use of a quantum computer is required just once. The common thread throughout this thesis is the application of factoring and primality testing techniques to integer types which commonly occur in public key cryptosystems. Thus, this thesis contributes not only in the area of pure mathematics but also in the very contemporary area of cryptology.

Abstract The removal of overlying waste rock in open pit mines to dumps is conventionally undertaken by draglines or by trucks and shovels, or by a combination of these. Waste rock dumps are the largest remnant structures of open cut mining operations and can absorb a large proportion of the mine operating costs. If the dumps are not properly developed they can be excessively expensive and can become a major safety risk and environmental hazard. There are many examples worldwide where poor design and construction of waste rock dumps have resulted in failures causing considerable loss of life and widespread damage, or have resulted in erosion and seepage that have led to severe environmental pollution. The proper design and scheduling of waste rock dumps and haul routes can significantly reduce costs, minimise the possibility of failures, and avoid harming the environment. This Thesis is limited to the consideration of trucks and shovels for waste rock haulage in open cut mining operations. It describes the development and application of a waste rock dump scheduling model using the Operations Research technique of Mixed-Integer Linear Programming, implemented in the mathematical modelling language AMPL. The model focuses on minimising the haulage cost for each block of waste rock taken from the open pit and placed in the dump. Allowance is made for the selective placement of benign and reactive waste rock, based on an open pit block model that delineates benign and reactive waste rock. The formulation requires input data including the xyz-coordinates of the block model for the open pit, information on whether the waste rock blocks are benign or reactive, the proposed time scheduling of waste rock haulage from the open pit, unit haulage costs, and the geometry of the waste rock dump, including the delineation of the zones that are benign and those that are reactive. The model was successfully tested by using both simple test data and actual mine site data. The application of the model to a simple case confirmed that it produces results that meet the Objective Function in producing an optimal haulage time and cost, and meets the various Constraints imposed. This model for scheduling the removal of waste rock from open cut mining operations with trucks and shovels will require further research and testing and, because the results are generated in a numerical format, there will also be a need to convert them to a graphical format to facilitate their interpretation. Ultimately, it will have the potential to provide a relatively low-cost scheduling tool that meets operators’ economic, safety and environmental goals.

Χωροθέτηση μονάδας επεξεργασίας ΑΣΑ σε συνδιασμό με τον απαραίτητο ΧΥΤΥ, με μικτό ακέραιο γραμμικό προγραμματισμό, για τη βελτιστοποίηση των ακολουθούμενων διαδρομών των απορριμματοφόρων προς την μονάδα επεξεργασίας και απο την μονάδα προς τον ΧΥΤΥ.Εγινε με εφαρμογή GIS στη Μεσσηνία. / The current thesis is about optimum siting of a MSW treatment plant combined with a landfill for residues based on mixed integer linear programming (MILP) and GIS methodology.

The current scenario of the Brazilian electricity sector, through the constant and recent regulatory changes imposed by ANEEL in recent years, aims to ensure continuous improvement in quality standards in the provision of electricity, significantly increased surveillance on the power quality delivered to consumers. Following this guideline, ANEEL established X Factor, which set the minimum volume of investments required to electricity distribution companies. In 2010, through the PRORET ANEEL established a new methodology for the calculation of the X Factor, including the Q component, relating to quality of service, setting a milestone in the recent regulatory history of the Brazilian electricity sector, as it allows for the first time gains the annual tariff adjustment or loss according to the performance measured in the year. In this context of regulatory innovations and increasing demands with performance standards and levels of investment made on the electrical system, the correct and efficient use of increasingly scarce resources to improve and expand the electrical system are presented as a vital challenge to financial health of companies. This paper presents a methodology for prioritizing investments in primary networks of electricity distribution, involving two consolidated methodologies aid to decision-making high complexity (AHP and PROMETHEE) and operations research methods to optimize the planning of improvement works to be held in short-term horizon, with direct reflection on regulatory issues, seeking still accommodate regional characteristics of the company and the ability to execute works of each region. / O atual cenário do setor elétrico brasileiro, através das constantes e recentes alterações regulatórias impostas pela ANEEL nos últimos anos, tem como objetivo garantir a melhoria contínua nos padrões de qualidade no fornecimento de energia elétrica, aumentado significativamente a fiscalização sobre a qualidade da energia entregue aos consumidores. Seguindo esta diretriz, a ANEEL instituiu o Fator X, que define o volume de investimentos mínimos exigidos às empresas de distribuição de energia elétrica. Em 2010, através do PRORET a ANEEL estabeleceu uma nova metodologia para o cálculo do Fator X, incluindo o componente Q, referente à qualidade do serviço prestado, configurando como um marco no recente histórico regulatório do setor elétrico brasileiro, pois permite pela primeira vez ganhos no reajuste tarifário anual ou perdas de acordo com o desempenho medido no ano. Neste contexto de inovações regulatórias e exigências cada vez maiores com os padrões de desempenho e níveis de investimentos realizados no sistema elétrico, a aplicação correta e eficiente dos cada vez mais escassos recursos disponíveis para melhoria e ampliação do sistema elétrico se apresentam como um desafio vital à saúde financeira das empresas do setor elétrico. Este trabalho apresenta uma metodologia para priorização de investimentos em redes primárias de distribuição de energia elétrica, associando duas consolidadas metodologias de auxílio à tomada de decisões de elevada complexidade (AHP e PROMETHEE) e métodos de pesquisa operacional para otimização no planejamento de obras de melhoria a serem realizadas no horizonte de curto prazo, com reflexo direto nas questões regulatórias, buscando ainda contemplar características regionais da empresa e a capacidade de execução de obras de cada região.

Made available in DSpace on 2014-06-11T19:26:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2004-07-30Bitstream added on 2014-06-13T20:55:45Z : No. of bitstreams: 1 cavali_r_me_sjrp.pdf: 560996 bytes, checksum: 6792ea8d0dd5f26eb5250b68217a4443 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Diariamente, em indústrias de móveis, painéis retângulares de madeira são cortados em retângulos menores para a manufatura de seus produtos. Por causa da possível perda de material envolvida neste processo e de sua influência no custo dos produtos, existe a necessidade de um planejamento prþevio para a realização dos cortes. Na maioria das empresas de móveis situadas na região Noroeste do estado de São Paulo, este planejamento é feito manualmente e não é uma tarefa simples. O enfoque deste trabalho þe analisar a utilização de um sistema computacional no planejamento do corte de painéis de madeira. Esta ferramenta é capaz de resolver o problema do corte bidimensional segundo o algoritmo de dois estþagios de Gilmory e Gomore. Aspectos práticos encontrados no corte dos painéis e estratégias adotadas pelas empresas no planejamento da produção são abordados. Além disso, apresentamos os resultados de um estudo computacional com base em dados reais de uma das empresas visitadas. / In the furniture industries, the cut of rectangular plates to produce smaller rectangular pieces is an every day task. To reduce the waste of material involved in this process and its influence in the cost of the products, a previous planning for the cuts is necessary. In the majority of the furniture companies situated at Northwest region of the state of São Paulo, the generation of cutting patterns is made manually and it is not a simple task. The goal of this work is to analyze the use of a computational system in the cutting patterns generation. This computational system is able to solve the two-dimensional cutting stock problem by the 2-stage Gilmory and Gomore method. Practical aspects found in the cutting patterns generation and strategies adopted for the companies in the production planning are discussed. We also report some results of the application of the computacional system to the cutting patterns generation based on real data of one company.

Made available in DSpace on 2014-06-11T19:27:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-05-05Bitstream added on 2014-06-13T19:34:54Z : No. of bitstreams: 1 figueiredo_ag_me_sjrp.pdf: 1360576 bytes, checksum: 72fa7984af3edfd1d741b5f6773cc5d8 (MD5) / Neste trabalho, analisamos os padrões de corte adotados por uma Indústria de Móveis, e identificamos suas características básicas. Definimos, a partir dessas características, os padrões tabuleiros compostos, que pertencem a classe dos padrões de corte n-grupos, apresentada por Gilmore e Gomory (1965). Os padrões tabuleiros compostos preservam as facilidades de corte dos padrões tabuleiros, apresentando melhores índices de sobra de matéria-prima. Propomos uma heurística para a geração de um pool de padrões tabuleiros compostos, usados para resolver o problema de corte de estoque na indústria de móveis. / In this work, we analyze the cutting patterns used by a furniture Industry, and we determine some of its basic characteristics. We defined a composed checkerboard pattern, that belongs to the class of n-groups cutting patterns, presented by Gilmore and Gomory (1965). The composed checkerboard patterns preserve the easiness of the cutting process and have better indexes of waste. We propose a heuristic to generate a pool of composed checkerboard patterns to solve the cutting stock problem in the furniture Industry.

Le développement de structures de réseau efficaces pour le transport de marchandises est fondamental sur le marché mondial actuel. Les demandes doivent être traitées rapidement, répondre aux besoins des clients dans les meilleurs délais, les congestions et les retards doivent être minimisés, les émissions de CO2 doivent être contrôlés et des coûts de transport moins élevés doivent être proposés aux clients. La structure hub-and-spoke est un modèle de réseau courant utilisé à la fois dans le transport régional comme dans le transport intercontinental, permettant une économie d'échelle grâce aux consolidations opérées au niveau des noeuds hub. Mais, les retards, les congestions et les longs délais de livraison sont des inconvénients de ce type de réseau. Dans cette thèse, un nouveau concept, "sub-hub", est ajouté à la structure du réseau classique hub-and-spoke. Dans les modèles de réseau proposés, une économie d'échelle et des chemins alternatifs plus courts sont mis en oeuvre, en minimisant ainsi le coût de transport et le délai de livraison. Le sub-hub est vu comme un point de connexion entre deux routes distinctes de régions voisines. Des transbordements sans passer par les noeuds hub sont possibles au niveau des sub-hubs. Des congestions peuvent ainsi être évitées et, par conséquent, les retards associés sont ainsi minimisés. Quatre modèles de programmation linéaire en nombres entiers binaires du problème de la localisation de hubs et de routage sont développés dans cette thèse. Des réseaux avec sub-hub et des réseaux sans sub-hub prenant en compte des routes circulaires entre hubs ou des connexions directes entre hubs sont ainsi comparées. Ces modèles sont composés de quatre sous-problèmes (localisation, allocation, conception de service et routage) qui rendent complexe la recherche de solutions. Une approche cutting plane est testée pour résoudre de petites instances de problème tandis qu'une recherche à voisinage variable avec décomposition (VNDS) composée de méthodes exactes (matheuristic) a été développée pour résoudre de grandes instances. Le VNDS mis en oeuvre, explore chaque sous-problème avec différents opérateurs. Des gains importants dans la fonction objective sont observés par les modèles avec sub-hub confirmant ainsi le développement de réseaux plus compétitifs. / The development of efficient network structures for freight transport is a major concern for the current global market. Demands need to be quickly transported and should also meet the customer needs in a short period of time. Traffic congestions and delays must be minimized, since CO2 emissions must be controlled and affordable transport costs have to be offered to customers. Hub-and-spoke structure is a current network model used by both regional and intercontinental transportation, which offers an economy of scale for aggregated demands inside hub nodes. However, delays, traffic congestions and long delivery time are drawbacks from this kind of network. In this thesis, a new concept, which is called "sub-hub", is proposed to the classic hub-and-spoke network structure. In the proposed network models, economy of scale and shorter alternative paths are implemented, thus minimizing the transport cost and delivery time. The sub-hub proposal can be viewed as a connection point between two routes from distinct and close regions. Transshipments without the need to pass through hub nodes are possible inside sub-hubs. This way, congestions can be avoided and, consequently, delays are minimized. Four binary integer linear programming models for hub location and routing problem were developed in this thesis. Networks with sub-hub and networks without sub-hub taking into account circular hub routes or direct connections between hubs are compared. These models are composed of four sub-problems (location, allocation, service design and routing), which hinders the solution. A cutting plane approach was used to solve small instances of problem, while a Variable Neighborhood Decomposition Search (VNDS) composed of exact methods (matheuristic) was developed to solve large instances. The VNDS was used to explore each sub-problem by different operators. Major benefits are provided by models with sub-hub, thus promoting the development of more competitive networks.

Afin d’accélérer les flux de produits, de réduire les niveaux de stocks et de faire des économies de transport, les entreprises de presque toutes les industries ont mis en place des centres de crossdock. Ces centres sont un point intermédiaire de consolidation dans une chaîne logistique. Les constructeurs automobiles Renault et Nissan s’appuient sur un réseau international de plateformes crossdock pour lier des fournisseurs de pièces de première monte avec des usines de production lointaines, généralement en outre-mer. Dans un cadre d’un partenariat académique-industriel entre le laboratoire LIMOS et Renault, cette thèse est focalisée sur la planification et l’ordonnancement des activités dans ces centres de crossdock. Des études de terrain menées chez Renault et Nissan nous ont permis d’identifier les caractéristiques, les contraintes et les inducteurs de coûts des plateformes de crossdock, ainsi que de cibler notre revue de la littérature. Sur ces bases, nous proposons une approche d’optimisation séquentielle, comprenant deux modèles en programmation linéaire en nombres entiers, implémentés dans CPLEX et testés sur des données industrielles de deux plateformes Renault. Les résultats des expérimentations obtenus sur le premier modèle (planification) ont montré une nette amélioration en termes de coûts, par rapport à la méthode Renault. Fort de ce constat, une implémentation industrielle a été faite, avec des résultats aussi probants. Le deuxième modèle (ordonnancement) s’avère pertinent pour des instances de moyenne taille. L’approche proposée permet de répondre à la configuration actuelle des AILN Renault et nous considérons qu’elle est adaptable à d’autres industries. / In order to accelerate product flow, reduce inventory levels and make economies in transportation, companies in almost all industries have set up cross-dock centres. These centres are an intermediate point of consolidation in a supply chain. Car manufacturers Renault and Nissan rely on an international network of crossdock platforms to link suppliers of OEM parts with overseas production plants. In a framework of an academic-industrial partnership between the LIMOS laboratory and Renault, this thesis focuses on the activity planning and scheduling at these crossdock centres.Field studies conducted at Renault and Nissan allowed us to identify the characteristics, constraints and cost drivers of crossdock platforms, as well as to target our review of the literature. Based on this, we propose a sequential optimization approach, comprising two integer linear programming models, implemented in CPLEX and tested on industrial data of two Renault platforms. Numerical experiments’ results obtained on the first model (planning) showed a significant improvement in cost, compared to the Renault method. In light of this results, an industrial implementation was made, with such convincing results. The second model (scheduling) proved to be relevant for medium-sized instances. The proposed approach fits to the current configuration of AILN Renault and we consider that it is adaptable to other industries.

Pour les voitures autonomes, la perception est une fonction principale où la sécurité est de la plus haute importance. Un système de perception construit un modèle de l'environnement de conduite en fusionnant plusieurs capteurs de perception incluant les LIDARs, les radars, les capteurs de vision, etc. La fusion basée sur les grilles d'occupation construit un modèle probabiliste de l'environnement en prenant en compte l'incertitude des capteurs. Cette thèse vise à intégrer le calcul des grilles d'occupation dans des systèmes embarqués à bas-coût et à basse-consommation. Cependant, les grilles d'occupation effectuent des calculs de probabilité intenses et difficilement calculables en temps-réel par les plateformes matérielles embarquées.Comme solution, cette thèse introduit une nouvelle méthode de fusion probabiliste appelée Grille d'Occupation Entière. Les Grilles d'Occupation Entières se reposent sur des principes mathématiques qui permettent de calculer la fusion de capteurs grâce à des simple addition de nombre entiers. L'intégration matérielle et logicielle des Grilles d'Occupation Entière est sûre et fiable. Les erreurs numériques engendrées par les calculs sont connues, majorées et paramétrées par l'utilisateur. Les Grilles d'Occupation Entière permettent de calculer en temps-réel la fusion de multiple capteurs sur un système embarqué bas-coût et à faible consommation dédié pour les applications pour l'automobile. / Perception is a primary task for an autonomous car where safety is of utmost importance. A perception system builds a model of the driving environment by fusing measurements from multiple perceptual sensors including LIDARs, radars, vision sensors, etc. The fusion based on occupancy grids builds a probabilistic environment model by taking into account sensor uncertainties. This thesis aims to integrate the computation of occupancy grids into embedded low-cost and low-power platforms. Occupancy Grids perform though intensive probability calculus that can be hardly processed in real-time on embedded hardware.As a solution, this thesis introduces the Integer Occupancy Grid framework. Integer Occupancy Grids rely on a proven mathematical foundation that enables to process probabilistic fusion through simple addition of integers. The hardware/software integration of integer occupancy grids is safe and reliable. The involved numerical errors are bounded and is parametrized by the user. Integer Occupancy Grids enable a real-time computation of multi-sensor fusion on embedded low-cost and low-power processing platforms dedicated for automotive applications.