Este texto trata de um dos temas fundamentais no planejamento de produção, o problema de dimensionamento de lotes de um único item. Uma descrição sucinta e informal do problema segue abaixo. Considere um intervalo de tempo dividido em períodos e que a cada período de tempo está associada a demanda de um item. Dados os custos e as eventuais restrições na produção e no armazenamento, determine os períodos em que se produzirá e em que quantidade para que as demandas sejam atendidas com o menor custo possível, respeitando as restrições impostas. Apresentamos aqui resultados sobre a estrutura ótima do problema, sobre complexidade e algoritmos para os casos básicos do problema / This text studies one of the core subjects in production planning, the single-item lot-sizing problem. A brief and informal description of this problem follows below. Considering a time interval split into time periods and that there is a demand of an item associated with each time period. Given production and holding costs and possibly production and holding restrictions, determine in which periods the production must occur and in which quantity, in order to attend the demands with a minimum cost, without violate any restriction. Here, it will be shown some results about the optimal structure of the problem, about the complexity and algorithms for the simpler cases

The goal of my thesis is to analyze physical and moral survival in three novels from King's oeuvre. Scholars have attributed survival in King's universe to factors such as innocence, imaginative capacity, and career choice. Although their arguments are convincing, I believe that physical and moral survival ultimately depends on a character's knowledge of the dark side of human nature and an understanding of moral agency. I have chosen three novels that span several decades of Kings work-'Salem's Lot, Needful Things, and Desperation-to illustrate the relationship between knowledge and survival. In 'Salem's Lot, King uses the main character's interest in the horror genre to emphasize the importance of an exposure to the dark side of human nature. In Needful Things, King vividly shows the dire consequences of naiveté, or in other words, uneducated innocence. Desperation represents a culmination of King's ideas. The final novel in my analysis shows the power of youth tempered by knowledge of human nature and informed by religious conviction. King links religion and horror to show the power of both in religious survival and to show the ultimate morality of horror.

Nesta dissertação abordamos o problema de dimensionamento e sequenciamento de lotes com aceitação de pedidos. As demandas dos clientes são agregadas em pedidos, os quais podem ou não ser aceitos e devem ser entregues dentro de uma janela de tempo. Os itens são perecíveis e podem permanecer no estoque somente por um tempo determinado (shelf-life). O objetivo do problema é maximizar a receita gerada pelo atendimento dos pedidos, descontando os custos de estoque e das preparações da máquina. Para tratar o problema são propostas formulações matemáticas e abordagens heurísticas contendo uma etapa construtiva seguida por uma heurística de melhoramento. Testes computacionais foram realizados e os resultados obtidos foram analisados. As heurísticas obtiveram desempenho superior ao branch-and-cut do solver de otimização na obtenção de soluções de boa qualidade, no limite de tempo estabelecido. / In this dissertation, we approach the lot sizing and scheduling problem with order acceptance. Customers demands are aggregated into orders, which may or may not be accepted and must be delivered within a time window. The items are perishable and can remain in inventory only for a limited time (shelf-life). The aim of the problem is profit maximizing generated by orders acceptance, discounting inventory and machine setups costs. To deal with this problem math formulations, constructive and improvement heuristics were proposed. Computational tests were performed and the results obtained were analyzed. The heuristics obtained superior performance then branch-and-cut of the optimization solver obtaining good quality solutions within the established time limit.

Orientador: Adriana Cristina Cherri Nicola / Banca: Silvio Alexandre de Araujo / Banca: Sonia Cristina Poltroniere Silva / Resumo: Este trabalho aborda o Problema de Redimensionamento de Lotes (PRL) capacitado, com múltiplos produtos e máquinas paralelas. O redimensionamento de lotes é uma variação do problema de dimensionamento de lotes que pode ser identificado em sistemas produtivos com elevada taxa de interrupções, como quebras, refugos, entre outros, fazendo com que o plano de produção seja prejudicado, necessitando de atualizações a medida que ocorrem as interrupções. São considerados três parâmetros de interrupção: manutenção corretiva, mão de obra insuficiente e indisponibilidade de matéria-prima. É permitido o atendimento da demanda nos períodos com atrasos e utilização de hora extra. O problema tem por objetivo minimizar os custos de preparação, estoque, atraso e hora extra. Baseado em um modelo matemático proposto na literatura para resolver problemas de dimensionamento de lotes, um modelo matemático para representar o PRL foi proposto. O PRL foi formulado como um problema de programação linear inteira mista (PLIM) e resolvido através do método exato branch and bound. Testes computacionais foram realizados com exemplares adaptados da literatura e abrangem os três parâmetros de interrupção / Abstract: This work approaches the capacitated Lot Resizing Problem (LRP) with multi-products and parallel machines. The lot resizing problem is a lot sizing problem variation which can be identified in productive systems with high rate of interruptions, as breaks, refuse, and others, impairing the planning production and making update needed as soon as interruptions happens. Three parameters for interruption were considered: corrective maintenance, insufficient man power and unavailability of raw material. Demand can be performed with back-orders and overtime requests. This work has the objective of minimize inventory holding costs, back-orders, setup and overtime costs. Based on a mathematical model proposed in the literature to solve the lot sizing problem, a mathematical model to represent the LRP was proposed. The LRP was formulated as a mixed integer problem and solved by branch and bound exact method. Computational experiments were performed with adapted literature instances embracing the three parameters of interruption / Mestre

Dans cette thèse, nous traitons des problèmes d'intégration des décisions prises aux niveaux planification (tactique) et ordonnancement (opérationnel). Que ce soit en théorie ou en pratique, ces deux niveaux sont habituellement traités indépendamment l'un de l'autre. Ainsi, les objectifs de production à réaliser sont souvent incohérents avec la capacité réelle de l'atelier. Cette thèse propose des méthodes de résolution pour des problèmes intégrés de planification et d'ordonnancement. Nous développons un nouveau modèle mathématique qui prend en compte de manière originale les contraintes de séquencement des opérations sur les machines, garantissant ainsi la faisabilité du plan de production. Ce modèle est résolu à l'aide d'une heuristique Lagrangienne pour une séquence des opérations axée. Notre approche est originale à double titre : dans la mise à jour des multiplicateurs Lagrangiens (puisque il existe un nombre exponentiel de contraintes de capacité dans notre modèle), et par la proposition d'une nouvelle procédure de lissage pour la construction d'une solution réalisable. Nous développons ensuite deux approches, basées sur le recuit simulé et la recherche taboue, qui permettent d'améliorer la séquence des opérations sur les ressources et ainsi de chercher un plan de production optimal associé à une séquence réalisable. De nombreux résultats expérimentaux ont été effectués et valident l'efficacité de nos approches.

Thomas Pynchon’s novel, The Crying of Lot 49, details Oedipa Maas’ quest to unearth a possibly centuries-old clandestine mail system, the Trystero. Oedipa is immersed in notions of sociality and she must navigate the social landscape, searching for clues as to the existence of the social system. In her quest she assumes the role of a detective who searches for meaning, as she looks for clues and questions others who might potentially be privy to the secrets of the Trystero. She necessarily performs the process of symbolic exchange with those she encounters in an attempt at ascertaining some greater meaning within the world that she thinks might lie behind the Trystero. In this, the nature of the circulation of meaning is revealed as a cultural construct.

LVT (Land Value Tax), unlike other taxes, causes no distortions in economic decision-making and therefore does not compromise the efficiency of a market economy. While there have been various challenges to this conclusion, it seems that the neutrality of LVT has been proven in the literature. Although it has been established conceptually that LVT is non-distortive, it is important to empirically test the effects of LVT reform in diverse aspects. Unlike other studies, this dissertation examines the economic, spatial, and welfare effects of LVT reform in a second-best situation employing an urban (and spatial) CGE (Computable General Equilibrium) model. In addition, it examines the distributional effects among different income groups and the short-term aspects of LVT as well. The feature that the present dissertation incorporates as the second-best situation includes LLZ (Large Lot Zoning). The computation and the assumptions about parameters for the current CGE model are made based on demographic, physical, and economic features of the Atlanta urban area in Georgia. The results suggest the following: (1) LVT reform is economically feasible, (2) the tax on land rent stabilizes prices and contracts the CBD (Central Business District) and urban boundary in the economy where the CBD and urban area are endogenously determined, while the tax on land rent is purely neutral in the economy where the CBD and urban area are fixed, (3) LVT reform increases the money-metric welfare of residents by about 20% of the tax revenue in the economy where residents are landowners, while LVT reform increases the money-metric welfare of residents by about 45% of the tax revenue in the economy where the lands are owned by absentee, (4) LVT reform more increases the money-metric welfare of the less-income groups that own the smaller land area, which is contrary to the case of LLZ, (5) LLZ and property tax can cause the sprawl of an urban area, but at a very low elasticity of substitution between land and the other factors (0.1), even switching from the land tax to the property tax (or graded property tax) can contract the urban area, (6) LLZ, in the long-term during which housing capital and urban boundary are not fixed and in the economy where residents are landowners, can improve the welfare of households, while LLZ worsens the welfare of households both in the economy where the lands are owned by absentee and in the short-term during which housing capital is immobile in any economy, (7) When we consider that housing capital is immobile, the increase in the money-metric welfare due to LVT reform becomes weak, compared to the case with perfectly mobile housing capital.

University of Macau / Faculty of Social Sciences and Humanities / Department of English

L'évolution de l'environnement des entreprises a transformé la nature des relations entre elles, qui de simple relations d'achat entre clients et fournisseurs se sont transformées en des rapports plus contractualisés et plus durables. Ces derniers imposent à ces entreprises de revoir leurs méthodes de gestion et de production pour une meilleure synchronisation de leurs flux. Nous nous intéressons dans ce mémoire à une relation particulière entre clients et fournisseurs, celle fondée sur le principe de livraisons cycliques, selon lequel le fournisseur s 'engage à livrer des quantités de produits à des intervalles de temps fixes et de façon répétitive. L'intérêt de ce mode de livraison et qu'il permet, aux donneurs d'ordres, une gestion extrêmement simple des approvisionnements et facilite l'organisation des activités. Comme réponse à ce type de livraisons et afin de synchroniser leurs flux de production à ceux de livraisons, les entreprises adoptent la production cyclique. L'avantage de cette dernière est qu ;elle permet entre autres de réduire les coûts engendrés par la fabrication, et de simplifier l'organisation du travail. Notre travail consiste alors en l'évaluation et la mise en oeuvre d'un plan de production cyclique, pour un atelier de type Flow Shop pur fabricant plusieurs produits, lorsque les appels de livraisons sont cycliques. Nous proposons une nouvelle méthode déterminant un plan de production cyclique minimisant des coûts de lancements, coûts de stockage et des coûts de fabrication. Nous introduisons dans un premier temps le contexte -de notre travail en précisant les différentes hypothèses que 1 'on pose. Nous proposons par la suite une revue de la littérature sur les différents travaux réalisés, et proposons une classification des problèmes traitant de la production cyclique étudiés par la communauté scientifique. Nous exposons également la méthode que l'on propose pour la détermination d'un plan de production cyclique minimisant les différents coûts que l'on considère. Nous présentons une analyse des résultats issus de l'application de notre approche ainsi que ses variantes sur un ensemble de benchmarks générés aléatoirement et respectant les traits caractéristiques des problèmes réels. Nous réalisons une étude comparative d?s approches que l'on propose à 1 'une de celles proposées dans la littérature. Nous terminons ce mémoire par une conclusion et un ensemble de voies de recherches futures.

When single-family lots are valued for development of new residential areas,the valuation is influenced by several factors. The valuation is a matter ofdefinition that varies according to its interpreter. Previous research conductedin other countries, has identified a number of value-influencing factors. Thesefactors are the basis for this study.The study's purpose is to highlight the value-influencing factors thatcustomers value and are looking for in the choice of single-family lots. Thestudy also seeks to determine if there is an unknown difference between howprofessionals and clients value single-family lots.The study showed that the value factors considered important for customersand also professionals are consistent and applicable with the factors reportedfrom previous research. These value factors are the location, adjacentneighboring areas, public transportation service, house plot size and proximityto the community, bodies of water and schools. For the Swedish market fourvalue-influencing factors not mentioned in the previous research wereidentified. The additional factors are; the selling price of the single-family lot, acorner placement lot, connecting bicycle path and walkway and lot withorientation south and west. The previous research mentioned also three valueinfluencingfactors that were not identified in the Swedish study. These factorswere; distance to the highway, municipal tax rate and access to the singlefamilylot.The study showed that the parties generally have good knowledge of oneanother´s valuation of single-family lots. This study focused mainly on theprofessional’s knowledge of the customer’s value-influencing factors. Theprofessionals base their valuation on incurred development costs, local priceassessments and a consideration of customer’s value-influencing factors. Thisknowledge is important for real estate appraisers and developers when settinga value on single-family lots, to be able to determine the most accurate value.The study is limited to Swedish medium-sized cities and was performed inKarlstad and Hammaro, which together have a population of approximately100,000 inhabitants. The data was collected through both a qualitative and aquantitative method approach, intended to reflect both professionals andcustomers perspectives. The qualitative method approach consisted of openand individual interviews with experienced professionals. The quantitative7method approach consisted of an online questionnaire, which was answeredby existing and potential customers. The empirical data for the qualitativemethod approach is presented in text and the quantitative method approachby the empirical data presented in tabular form.