Aproveitamento hidroelétrico da bacia do Douro: um olhar crítico

No presente artigo, faz-se uma breve resenha histórica da evolução do aproveitamento dos recursos hídricos nacionais em termos hidroelétricos, bem como uma análise da situação atual. Dá-se particular destaque à vertente hidroelétrica, mas não se limita a ela. Mostra-se a insuficiência das obras hidráulicas até agora realizadas a nível das nossas principais bacias, em particular no caso da bacia portuguesa do Douro, e alerta-se para as nefastas consequências que poderiam advir caso a situação não se alterasse. O PNBEPH aprovado em 2007 veio contribuir para relançar esta importante temática, a qual pareceu inexplicavelmente esquecida durante quase duas décadas, por parte das entidades às quais competia zelar pelo interesse público e pela salvaguarda dos legítimos direitos e expectativas das populações nacionais

Spreading Algorithm for Single-Objective Problems

This paper addresses the problem of finding several different solutions with the same optimum performance in single objective real-world engineering problems. In this paper a parallel robot design was proposed. Thereby, this paper presents a genetic algorithm to optimize uni-objective problems with an infinite number of optimal solutions. The algorithm uses the maximin concept and -dominance to promote diversity over the admissible space. The performance of the proposed algorithm is analyzed with three well-known test functions and one function obtained from practical realworld engineering optimization problems. A spreading analysis is performed showing that the solutions drawn by the algorithm are well dispersed.info:eu-repo/semantics/publishedVersio

Survey on the Advancements of Dielectric Fluids and Experiment Studies for Distribution Power Transformers

-The main objective of this work is to summarize the most commonly used dielectric fluids in the power distribution transformers, as well as to discuss what are the latest and the rationale behind those trends. The favorable and unfavorable reasons for any choice behind each of those dielectric fluids will be discussed. Additionally, this work also advances the power distribution transformers health index most commonly used to assess the condition of the transformer. (c) 2021, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ). All rights reserved

Cálculo de sobretensões em linhas aéreas multiterno de transporte de energia eléctrica

Dissertação apresentada para obtenção do grau de Doutor na Faculdade de Engenharia da Universidade do Porto, sob a orientação do Prof. Doutor Almeida do Val

Pára-raios de óxido de zinco

Trabalho complementar das provas de doutoramento na Faculdade de Engenharia da Universidade do Port

Configuração do turismo cultural nas cidades de média dimensão em Portugal : o caso de Braga

A presente dissertação pretende estudar o Turismo Cultural enquanto produto turístico aplicável a cidades de média dimensão, abordando o caso específico da cidade de Braga. Numa primeira parte detemo-nos sobre os processos de globalização, os conceitos de turismo e as relações existentes. Igualmente se aborda a problemática do Turismo Cultural. Numa segunda parte, analisa-se a realidade do Turismo Cultural em Braga, com apresentação dos resultados de questionários à procura e análise de programas de Operadores Turísticos, terminando com a apresentação de propostas e recomendações. ABSTRACT: The present research intends to study the Cultural Tourism as a tourism product in medium size cities, concerning the specific case of Braga – Portugal. The first part deals with de globalization process, tourism concepts and the relationship between them. We also presented some considerations about Cultural Tourism. In a second part we analyse the cultural tourism in Braga, including the results of a questionnaire to the tourism supply and also a review of tour operators catalogues and brochures, finishing with the presentation of some global recommendations

Optimal location of the workpiece in a PKM-based machining robotic cell

Most machining tasks require high accuracy and are carried out by dedicated machine-tools. On the other hand, traditional robots are flexible and easy to program, but they are rather inaccurate for certain tasks. Parallel kinematic robots could combine the accuracy and flexibility that are usually needed in machining operations. Achieving this goal requires proper design of the parallel robot. In this chapter, a multi-objective particle swarm optimization algorithm is used to optimize the structure of a parallel robot according to specific criteria. Afterwards, for a chosen optimal structure, the best location of the workpiece with respect to the robot, in a machining robotic cell, is analyzed based on the power consumed by the manipulator during the machining process

Single-objective spreading algorithm

This paper addresses the problem of finding several different solutions with the same optimum performance in single objective real-world engineering problems. In this paper a parallel robot design is proposed. Thereby, this paper presents a genetic algorithm to optimize uni-objective problems with an infinite number of optimal solutions. The algorithm uses the maximin concept and ε-dominance to promote diversity over the admissible space. The performance of the proposed algorithm is analyzed with three well-known test functions and a function obtained from practical real-world engineering optimization problems. A spreading analysis is performed showing that the solutions drawn by the algorithm are well dispersed

Maximin Spreading Algorithm

This paper presents a genetic algorithm to optimize uni-objective problems with an infinite number of optimal solutions. The algorithm uses the maximin concept and -dominance to promote diversity over the admissible space. The proposed algorithm is tested with two well-known functions. The practical results of the algorithm are in good agreement with the optimal solutions of these functions. Moreover, the proposed optimization method is also applied in two practical real-world engineering optimization problems, namely, in radio frequency circuit design and in kinematic optimization of a parallel robot. In all the cases, the algorithm draws a set of optimal solutions. This means that each problem can be solved in several different ways, all with the same maximum performance.N/