2013
Authors
Pereira, I; Madureira, A; Moura Oliveira, PBd; Abraham, A;
Publication
Transactions on Computational Science XXI - Special Issue on Innovations in Nature-Inspired Computing and Applications
Abstract
In complexity theory, scheduling problem is considered as a NP-complete combinatorial optimization problem. Since Multi-Agent Systems manage complex, dynamic and unpredictable environments, in this work they are used to model a scheduling system subject to perturbations. Meta-heuristics proved to be very useful in the resolution of NP-complete problems. However, these techniques require extensive parameter tuning, which is a very hard and time-consuming task to perform. Based on Multi-Agent Learning concepts, this article propose a Case-based Reasoning module in order to solve the parameter-tuning problem in a Multi-Agent Scheduling System. A computational study is performed in order to evaluate the proposed CBR module performance. © 2013 Springer-Verlag Berlin Heidelberg.
2013
Authors
de Moura Oliveira, PBD; Boaventura Cunha, JB;
Publication
2013 2ND EXPERIMENT@ INTERNATIONAL CONFERENCE (EXP.AT'13)
Abstract
A simulation teaching experiment to control a gantry crane system is proposed. The control is performed both in open-loop and closed-loop. The open-loop control is based on the Posicast feedforward technique and the closed-loop control uses a two-degrees of freedom configuration. Posicast control is used as a pre-filter outside the feedback loop to enhance the set-point tracking response and a PID controller is used in the feedback loop to deal with disturbance rejection. Students are required to use a gantry crane animation, to visualize its movement promoting a better perception and control techniques understanding. The experiment was performed by undergraduate feedback control students which provided learning results through a survey questionnaire.
2017
Authors
Oliveira, J; Boaventura Cunha, J; Oliveira, PM;
Publication
Lecture Notes in Electrical Engineering
Abstract
This paper proposes the recently introduced Gravitational Search Algorithm (GSA) to tune a Sliding Mode Controller (SMC) applied on the temperature control of a grains drying system. The problem of maintaining the temperature precisely adjusted inside a silo is relevant to avoid thermal damage and spoilage losses, and thus guarantee the right conditions for storage. The objectives of setpoint tracking and disturbance rejection are incorporated into the minimization of the integral of the time-weighted absolute error. Simulation results are presented and compared with PID and with SMC tuned by Particle SwarmOptimization (PSO) and by earlier proposed tuning equations. © Springer International Publishing Switzerland 2017.
2018
Authors
de Moura Oliveira, PBD; Oliveira, J; Cunha, JB;
Publication
DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE
Abstract
The gravitational search algorithm (GSA) is reviewed, by presenting a tutorial analysis of its key issues. As any other metaheuristic, GSA requires the selection of some heuristic parameters. One parameter which is crucial in regulating the exploratory capabilities of this algorithm is the gravitational constant. An analysis regarding this parameter selection is presented and a heuristic rule proposed for this purpose. The GSA performance is compared both with a hybridization with particle swarm optimization (PSO) and standard PSO. Preliminary simulation results are presented considering simple continuous functions optimization examples.
2017
Authors
Santos, F; Almeida, A; Martins, C; de Oliveira, PM; Goncalves, R;
Publication
RECENT ADVANCES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 1
Abstract
This paper describes a set of models and algorithms used under a Tourism Recommendation System based in Users and Points-of-Interest (POI) profiles. This work aims to propose a recommendation system that considers user's functionality levels regarding physical and psychological issues. This proposal considers also in a different way to classify (POI) including their accessibility levels mapped with similar physical and psychological issues.
2017
Authors
de Moura Oliveira, PBD; Cunha, JB;
Publication
2017 25TH MEDITERRANEAN CONFERENCE ON CONTROL AND AUTOMATION (MED)
Abstract
New times demand new teaching and learning methodologies. A partial flipped classroom methodology was tested in a modelling and feedback control course for undergraduate biomedical engineering. A semester course was divided in two parts: the first half using a flipped approach and the second one using a classical approach. The experience results are reported, presenting the methodology ups and downs. The use of videos as student's primer study supporting element to prepare classes in advance was explored. Using part of the class time to perform quiz group activities proved to be a major enabler to actively involve students in the learning process. The results achieved in the flipped part strongly confirm a much higher engagement and participation level from students in theoretical classes. Moreover, the flipping approach promotes students to continuously study along the semester.
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