966 resultados para Capacity expansion planning
Resumo:
O problema de Planejamento da Expansão de Sistemas de Distribuição (PESD) visa determinar diretrizes para a expansão da rede considerando a crescente demanda dos consumidores. Nesse contexto, as empresas distribuidoras de energia elétrica têm o papel de propor ações no sistema de distribuição com o intuito de adequar o fornecimento da energia aos padrões exigidos pelos órgãos reguladores. Tradicionalmente considera-se apenas a minimização do custo global de investimento de planos de expansão, negligenciando-se questões de confiabilidade e robustez do sistema. Como consequência, os planos de expansão obtidos levam o sistema de distribuição a configurações que são vulneráveis a elevados cortes de carga na ocorrência de contingências na rede. Este trabalho busca a elaboração de uma metodologia para inserir questões de confiabilidade e risco ao problema PESD tradicional, com o intuito de escolher planos de expansão que maximizem a robustez da rede e, consequentemente, atenuar os danos causados pelas contingências no sistema. Formulou-se um modelo multiobjetivo do problema PESD em que se minimizam dois objetivos: o custo global (que incorpora custo de investimento, custo de manutenção, custo de operação e custo de produção de energia) e o risco de implantação de planos de expansão. Para ambos os objetivos, são formulados modelos lineares inteiros mistos que são resolvidos utilizando o solver CPLEX através do software GAMS. Para administrar a busca por soluções ótimas, optou-se por programar em linguagem C++ dois Algoritmos Evolutivos: Non-dominated Sorting Genetic Algorithm-2 (NSGA2) e Strength Pareto Evolutionary Algorithm-2 (SPEA2). Esses algoritmos mostraram-se eficazes nessa busca, o que foi constatado através de simulações do planejamento da expansão de dois sistemas testes adaptados da literatura. O conjunto de soluções encontradas nas simulações contém planos de expansão com diferentes níveis de custo global e de risco de implantação, destacando a diversidade das soluções propostas. Algumas dessas topologias são ilustradas para se evidenciar suas diferenças.
Resumo:
Uma compreensão aprofundada da dinâmica de competição portuária é particularmente importante dado o contexto atual do setor, que orienta à outorga de novos portos e terminais no Brasil, à luz da Nova Lei dos Portos, Lei Nº 12.815 de 2013. A avaliação dos reais impactos decorrentes do aumento de capacidade portuária em cada região será atividade fundamental para que, por um lado, o poder público oriente a alocação efetiva de recursos, sem prejudicar a operação dos complexos existentes; e para que a iniciativa privada, por sua vez, possa compreender os impactos dos possíveis novos empreendimentos sobre as suas operações e delinear estratégias comerciais compatíveis com o novo cenário competitivo. A partir de extensa revisão bibliográfica e da aplicação de técnicas a casos específicos, o presente trabalho detalha a dinâmica competitiva entre terminais de contêineres e avalia criticamente seis métodos utilizados para identificar a existência de competição: correlação de market share, comparação de taxas de ocupação, sobreposição de escalas marítimas, comparação de custos logísticos terrestres, representatividade da região de influência contestável e existência de poder de mercado sobre a região de influência. Dos seis métodos analisados, dois apresentam conclusões fulminantes para a questão, embora sua aplicação demande grande volume de informações; um é assertivo em condições normais de distribuição geográfica de cargas; dois apresentam condições necessárias, porém não suficientes para a identificação de competição; e um deve ser aplicado com ressalvas, uma vez que pode levar a conclusões equivocadas.
Resumo:
Overcommitment of development capacity or development resource deficiencies are important problems in new product development (NPD). Existing approaches to development resource planning have largely neglected the issue of resource magnitude required for NPD. This research aims to fill the void by developing a simple higher-level aggregate model based on an intuitive idea: The number of new product families that a firm can effectively undertake is bound by the complexity of its products or systems and the total amount of resources allocated to NPD. This study examines three manufacturing companies to verify the proposed model. The empirical results confirm the study`s initial hypothesis: The more complex the product family, the smaller the number of product families that are launched per unit of revenue. Several suggestions and implications for managing NPD resources are discussed, such as how this study`s model can establish an upper limit for the capacity to develop and launch new product families.
Resumo:
This paper examines an attempt to build capacity and empower local institutions in war-torn Jaffna,, on the northern tip of Sri Lanka. A participatory approach that is aimed at social empowerment is seen to be possible even under the most restrictive of political environments. However, whether or not the development intervention provides a foundation for longer-term improvement depends on the extent to which institutional capacity is built. Through an examination of the Jaffna Reconstruction Project, it is argued that if any of the ingredients of this institutional capacity are missing, not only will the 'islands of participation and empowerment' that are built by the development initiative be short-lived, but there may also be a negligible contribution to building a foundation for longer-term improvement in quality of life. (C) 2001 Elsevier Science Ltd. All rights reserved.
Resumo:
Thesis to obtain the Master Degree in Electronics and Telecommunications Engineering
Resumo:
Amman the primate capital city of the Hashemite Kingdom of Jordan currently has a population in excess of 2 million, but in 1924 it consisted of little more than a collection of dwellings and some 2000-3000 inhabitants. The present paper sets out to document and explain the phenomenal expansion of "ever-growing Amman". The physical geography of the urban region and the early growth of the city are considered at the outset and this leads directly to consideration of the highly polarised social structuring that characterises contemporary Amman. In doing this, original data derived from the recent Greater Amman Municipality's Geographical Information System are presented. In this respect, the essential modernity of the city is exemplified. The employment and industrial bases of the city and a range of pressing contemporary issues are then considered, including transport and congestion, the provision of urban water under conditions of water stress and privatisation, and urban and regional development planning for the city. The paper concludes by emphasizing the growing regional and international geopolitical salience of the city of Amman at the start of the 21st century. (C) 2008 Elsevier Ltd. All rights reserved.
A decision framework for considering climate change adaptation in biodiversity conservation planning
Resumo:
General principles of climate change adaptation for biodiversity have been formulated, but do not help prioritize actions. This is inhibiting their integration into conservation planning. We address this need with a decision framework that identifies and prioritizes actions to increase the adaptive capacity of species. The framework classifies species according to their current distribution and projected future climate space, as a basis for selecting appropriate decision trees. Decisions rely primarily on expert opinion, with additional information from quantitative models, where data are available. The framework considers in-situ management, followed by interventions at the landscape scale and finally translocation or ex-situ conservation. Synthesis and applications: From eight case studies, the key interventions identified for integrating climate change adaptation into conservation planning were local management and expansion of sites. We anticipate that, in combination with consideration of socio-economic and local factors, the decision framework will be a useful tool for conservation and natural resource managers to integrate adaptation measures into conservation plans.
Resumo:
The usefulness of the application of heuristic algorithms in the transportation model, first proposed by Garver, is analysed in relation to planning for the expansion of transmission systems. The formulation of the mathematical model and the solution techniques proposed in the specialised literature are analysed in detail. Starting with the constructive heuristic algorithm proposed by Garver, an extension is made to the problem of multistage planning for transmission systems. The quality of the solutions found by heuristic algorithms for the transportation model is analysed, as are applications in problems of planning transmission systems.
Resumo:
Cage aquaculture in hydroelectric reservoirs has great potential for expansion in Brazil, but there are concerns of negative environmental impacts. The environmental sustainability of cage culture depends on hamornization between farming practices and the hydrological peculiarities of the site. Mass balance modeling can estimate the amounts of nutrients that can be loaded without triggering eutrophication and resulting maximum allowable production volume. Careful climate zoning can also assist proper siting.
Resumo:
In this study, we investigated if monolayer expansion of adult human articular chondrocytes (AHAC) on specific substrates regulates cell phenotype and post-expansion multilineage differentiation ability. AHAC isolated from cartilage biopsies of five donors were expanded on plastic dishes (PL), on dishes coated with collagen type II (COL), or on slides coated with a ceramic material (Osteologic, OS). The phenotype of expanded chondrocytes was assessed by flow cytometry and real-time RT-PCR. Cells were then cultured in previously established conditions promoting differentiation toward the chondrogenic or osteogenic lineage. AHAC differentiation was assessed histologically, biochemically, and by real-time RT-PCR. As compared to PL-expanded AHAC, those expanded on COL did not exhibit major phenotypic changes, whereas OS-expanded cells expressed (i) higher bone sialoprotein (BSP) (22.6-fold) and lower collagen type II (9.3-fold) mRNA levels, and (ii) lower CD26, CD90 and CD140 surface protein levels (1.4-11.1-fold). Following chondrogenic differentiation, COL-expanded AHAC expressed higher mRNA levels of collagen type II (2.3-fold) and formed tissues with higher glycosaminoglycan (GAG) contents (1.7-fold), whereas OS-expanded cells expressed 16.5-fold lower collagen type II and generated pellets with 2.0-fold lower GAG contents. Following osteogenic differentiation, OS-expanded cells expressed higher levels of BSP (3.9-fold) and collagen type I (2.8-fold) mRNA. In summary, AHAC expansion on COL or OS modulated the de-differentiated cell phenotype and improved the cell differentiation capacity respectively toward the chondrogenic or osteogenic lineage. Phenotypic changes induced by AHAC expansion on specific substrates may mimic pathophysiological events occurring at different stages of osteoarthritis and may be relevant for the engineering of osteochondral tissues.
Resumo:
Healthcare professionals and the public have increasing concerns about the ability of emergency departments to meet current demands. Increased demand for emergency services, mainly caused by a growing number of minor and moderate injuries has reached crisis proportions, especially in the United Kingdom. Numerous efforts have been made to explore the complex causes because it is becoming more and more important to provide adequate healthcare within tight budgets. Optimisation of patient pathways in the emergency department is therefore an important factor. This paper explores the possibilities offered by dynamic simulation tools to improve patient pathways using the emergency department of a busy university teaching hospital in Switzerland as an example.