Percorrer por autor "Antunes, Carlos Henggeler"
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- A comparative study of different approaches using an outranking relation in a multi-objective evolutionary algorithmPublication . Oliveira, Eunice; Antunes, Carlos Henggeler; Gomes, ÁlvaroThis paper presents a comparative analysis of three versions of an evolutionary algorithm in which the decision maker’s preferences are incorporated using an outranking relation and preference parameters associated with the ELECTRE TRI method. The aim is using the preference information supplied by the decision maker to guide the search process to the regions where solutions more in accordance with his/ her preferences are located, thus narrowing the scope of the search and reducing the computational effort. An example dealing with a pertinent problem in electrical distribution network is used to compare the different versions of the algorithm and illustrate how meaningful information can be elicited from a decision maker and used in the operational framework of an evolutionary algorithm to provide decision support in real-world problems.
- Direct Load Control in the Perspective of an Electricity Retailer – A Multi-Objective Evolutionary ApproachPublication . Gomes, Álvaro; Antunes, Carlos Henggeler; Oliveira, EuniceThe judicious use of end-use electric loads in the framework of demand-side management programs as valuable resources to increase the global efficiency of power systems as far as economical, technical and quality of service aspects are concerned, is a relevant issue in face of the changes underway in the power systems industry. This paper presents the results of a multi-objective optimization model, in the perspective of an electricity retailer, which is aimed at designing load control actions to be applied to groups of electric loads. An evolutionary algorithm is used to compute solutions to this problem.
- An Evolutionary Algorithm based on an outranking relation for sorting problemsPublication . Oliveira, Eunice; Antunes, Carlos HenggelerA new approach for using the preferences elicited from a Decision Maker (DM) into the operational framework of an Evolutionary Algorithm (EA) is presented. The preference representation is achieved using the parameters and principles of the ELECTRE TRI method devoted to the sorting problem. The outranking relation is used to replace the non-dominance relation in the usual operators in the EA (crossover, mutation and selection operator). The aim of this approach is to focus the search on the region of interest defined by the DM's preferences and consequently restrict the number of solutions in the Pareto-optimal front to be subject to further screening. This aspect is particularly important when dealing with problems that lead to a large number of non-dominated solutions.
- Gamification as a way to involve young adults in energy efficiency and sufficiency – a case studyPublication . Sousa, João Miguel C.; Neves, Luís Miguel P.; Lopes, Marta Alexandra; Reis, Inês F.; Coelho, Dulce Helena C.; Antunes, Carlos Henggeler; Dionissa, Rodrigo; Silva, Alexandre Gomes da; Sousa, José Luís; Costa, Dulce Helena P.; Henriques, Carla Oliveira; Silva, Catarina; Marcelino, Luis; Correia, Diogo; Gonçalves, Válter; Pereira, Rúben F.; Cabral Júnior, Jorge; Vieira, André Filipe; Moreira, LicinioSocial, economic and environmental concerns regarding en ergy use have fostered energy efficiency programs as effective tools to improve the rational use of energy in all activity sectors, i.e. for residential, industry and services consumers. Behav ioural change interventions play a key role to achieve energy efficiency. This paper discusses gamification as a tool to foster energy behaviour changes in young adults (higher education students) towards energy efficiency. The work was carried out as part of a research project (with the name Learn2Behave) aim ing to characterize residential energy consumption behaviours, seeking to contribute to improve energy efficiency and reduce energy bills. The project uses a mobile application (app), called “Minha Energia” (My energy, in Portuguese), as an inquiry tool to characterize consumers’ behaviours, giving suggestions and advices to participants as a reward. The development stage in volves students and researchers from three higher education institutions in Portugal, a research institute and three energy agencies. The application was made available not only to the target participants, but also to the general population, aiming to help the development of energy efficiency programs devoted to promoting more energy efficient behaviours while consider ing energy sufficiency. The data gathering has just started and is foreseen to last long enough to contribute to a more detailed knowledge of energy use in the residential sector. The use of mobile apps as an inquiry and dissemination tool of best prac tices, through gamification, allied to the involvement of circa 200 students, has the potential to change younger generations’ behaviours in the use of energy
- A hybrid evolutionary simulated annealing algorithm with incorporation of preferencesPublication . Oliveira, Eunice; Antunes, Carlos Henggeler; Gomes, ÁlvaroThis paper presents a hybrid evolutionary simulated annealing approach devoted to multi-objective models, in which preferences are elicited and exploited using the principles of the outranking-based ELECTRE TRI method. Preferences are used to guide the search process including deciding about the exploitation of new neighbor solutions. The overall approach has been used in a case study to provide decision support in identifying suitable load control actions in electrical networks.
- A hybrid multi-objective GRASP+SA algorithm with incorporation of preferencesPublication . Oliveira, Eunice; Antunes, Carlos Henggeler; Gomes, ÁlvaroA hybrid multi-objective approach based on GRASP (Greedy Randomized Adaptive Search Procedure) and SA (Simulated Annealing) meta-heuristics is proposed to provide decision support in a direct load control problem in electricity distribution networks. The main contributions of this paper are new techniques for the incorporation of preferences in these meta-heuristics and their hybridization. Preferences are included in the construction phase of multi-objective GRASP, in SA, as well as in the selection of solutions that go to the next generation, with the aim to obtain solutions more in accordance with the preferences elicited from a decision maker. The incorporation of preferences is made operational using the principles of the ELECTRE TRI method, which is based on the exploitation of an outranking relation in the framework of the sorting problem.
- A multi-objective simulated annealing approach to reactive power compensationPublication . Antunes, Carlos Henggeler; Lima, Paulo; Oliveira, Eunice; Pires, Dulce F.Reactive power compensation is an important problem in electrical distribution systems, involving the sizing and location of capacitors (sources of reactive power). The installation of capacitors also contributes to releasing system capacity and improving voltage level. A multi-objective simulated annealing approach to provide decision support in this problem is presented. This approach is able to compute a set of well-distributed and diversified solutions underlying distinct trade-offs, even for a challenging network. The characterization of the non-dominated front is relevant information for aiding planning engineers to select satisfactory compromise solutions (compensation schemes) to improve the network operation conditions.