Options for land use management in Lingayen Gulf, Philippines

Includes bibliography

Estatégias para incorporação das deçisões de sequenciamento em um problema integrado de produção de bebidas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Propostas de solução para o problema de corte de estoque bidimensional de uma fábrica de móveis de pequeno porte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Modelagem do problema integrado de dimensionamento de lotes e corte de estoque em indústria moveleira

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O método de pontos interiores no planejamento da radioterapia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Redespacho de reativos como ação corretiva para alívio de sobrecargas em Redes de transmissão

Pós-graduação em Engenharia Elétrica - FEIS

Otimização combinatória para alocação de fontes renováveis em microrredes de corrente contínua

Pós-graduação em Engenharia Elétrica - FEIS

Uma investigação do minos e sua aplicação ao problema de fluxo de potência ótimo

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Transmission Expansion Planning Via a Constructive Heuristic Algorithm in Restructured Electricity Industry

The transmission expansion planning problem in modern power systems is a large-scale, mixed-integer, nonlinear and non-convex problem. this paper presents a new mathematical model and a constructive heuristic algorithm (CHA) for solving transmission expansion planning problem under new environment of electricity restructuring. CHA finds an acceptable solution in an iterative process, where in each step a circuit is chosen using a sensitivity index and added to the system. The proposed model consider multiple generation scenarios therefore the methodology finds high quality solution in which it allows the power system operate adequacy in an environment with multiple generators scenarios. Case studies and simulation results using test systems show possibility of using Constructive heuristic algorithm in an open access system.

Metodologia para otimização em subcontratação de serviço de usinagem

Operational Research (OR) is an eminent science to business competitiveness and the capacity of algorithms and spreadsheets that exist today allows people to apply them for a lower cost and with less complexity. However, spreadsheets linked to OR techniques, when directed to real problems, are still little explored in their full potential. In order to use them better, this article utilizes the Microsoft Office Excel to solve an optimization practical problem and decision-making of machining subcontracting. In general, although considered a frequent problem, is not of easy solution, optimize the mix of production versus outsourcing, because of the restrictions and resources available, it requests investments in specific software. In this way, this research aims to develop software to be called SOSU (Optimization Software for Machining Subcontracting). SOSU should introduce the best mix of internal and subcontracted machining for n types of parts that, over a certain period of time t, maximize capacity and meet all the demand at the lowest cost possible. The methodology adopted follows the bibliographic reference and it is assumed that the necessary data to prove from mathematical modeling of production areas and from a system of costs already structured. The nature of the problem justifies the application of Linear Programming (LP), Visual Basic for Applications (VBA) is used for computational implementation and interface with the user and the supplement Solver to find the solution. The analysis of the experiments show that the SOSU optimizes resources and improves the decision-making process, besides an easy operation, it can be implemented or quickly adapted and without the need of large investments.

Modelo matemático para determinação do custo e produção de energia na cultura da cana-de-açúcar

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise econômica da eficiência da produção de cana-de-açúcar de fornecedores do Estado do Paraná

The sugarcane industry has been important in the Brazilian economy since the colonial period. The search for alternative energy sources has gained more prominence, by offering a product generating clean energy. With the opening of the Brazilian economy, the sector has undergone transformations operating in a free market environment requiring greater efficiency and competitiveness of those involved in order to stay in business. This scenario is producer/supplier independent, and social aspects related to their stay in the market. Although its share in sugarcane production is smaller than the plant itself, it is still considerable having reached around 20% to 25% in 2008 by employing labor, also production factors had an important economic impact in the regions where they operate. Therefore, this study aimed to estimate the economic efficiency and production of independent sugarcane producers in the state of Paraná through the DEA model. The Data envelopment analysis (DEA) is a nonparametric technique that, using linear programming constructs production borders from production units that employ similar technological processes to transform inputs into outputs.The results showed that of the total surveyed, 13.56% had maximum efficiency (an efficiency score equal to 1). The average efficiency under variable returns to scale (BCC-DEA) was 0.71024. One can thus conclude that for the majority of the samples collected, it might be better use of available resources to the in order to obtain the economic efficiency of the production process.

Funções penalidade para o tratamento das variáveis discretas do problema de fluxo de potência ótimo reativo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Routing and Wavelength Assignment (RWA) with Power Considerations In All- Optical Wavelength-Routed Networks

Routing and wavelength assignment (RWA) is an important problem that arises in wavelength division multiplexed (WDM) optical networks. Previous studies have solved many variations of this problem under the assumption of perfect conditions regarding the power of a signal. In this paper, we investigate this problem while allowing for degradation of routed signals by components such as taps, multiplexers, and fiber links. We assume that optical amplifiers are preplaced. We investigate the problem of routing the maximum number of connections while maintaining proper power levels. The problem is formulated as a mixed-integer nonlinear program and two-phase hybrid solution approaches employing two different heuristics are developed

Three time-based scale formulations for the two-stage lot sizing and scheduling in process industries

In this paper, we propose three novel mathematical models for the two-stage lot-sizing and scheduling problems present in many process industries. The problem shares a continuous or quasi-continuous production feature upstream and a discrete manufacturing feature downstream, which must be synchronized. Different time-based scale representations are discussed. The first formulation encompasses a discrete-time representation. The second one is a hybrid continuous-discrete model. The last formulation is based on a continuous-time model representation. Computational tests with state-of-the-art MIP solver show that the discrete-time representation provides better feasible solutions in short running time. On the other hand, the hybrid model achieves better solutions for longer computational times and was able to prove optimality more often. The continuous-type model is the most flexible of the three for incorporating additional operational requirements, at a cost of having the worst computational performance. Journal of the Operational Research Society (2012) 63, 1613-1630. doi:10.1057/jors.2011.159 published online 7 March 2012