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Publicações

Publicações por Ana Pereira

2015

An ordered heuristic for the allocation of resources in unrelated parallel-machines

Autores
E Santos, AS; Madureira, AM; Varela, MLR;

Publicação
International Journal of Industrial Engineering Computations

Abstract
Global competition pressures have forced manufactures to adapt their productive capabilities. In order to satisfy the ever-changing market demands many organizations adopted flexible resources capable of executing several products with different performance criteria. The unrelated parallel-machines makespan minimization problem (Rm||Cmax) is known to be NP-hard or too complex to be solved exactly. In the heuristics used for this problem, the MCT (Minimum Completion Time), which is the base for several others, allocates tasks in a random like order to the minimum completion time machine. This paper proposes an ordered approach to the MCT heuristic. MOMCT (Modified Ordered Minimum Completion Time) will order tasks in accordance to the MS index, which represents the mean difference of the completion time on each machine and the one on the minimum completion time machine. The computational study demonstrates the improved performance of MOMCT over the MCT heuristic.

2016

Study on the Impact of the NS in the Performance of Meta-Heuristics in the TSP

Autores
Santos, AS; Madureira, AM; Varela, MLR;

Publicação
2016 IEEE INTERNATIONAL CONFERENCE ON SYSTEMS, MAN, AND CYBERNETICS (SMC)

Abstract
Meta-heuristics have been applied for a long time to the Travelling Salesman Problem (TSP) but information is still lacking in the determination of the parameters with the best performance. This paper examines the impact of the Simulated Annealing (SA) and Discrete Artificial Bee Colony (DABC) parameters in the TSP. One special consideration of this paper is how the Neighborhood Structure (NS) interact with the other parameters and impacts the performance of the meta-heuristics. NS performance has been the topic of much research, with NS proposed for the best-known problems, which seem to imply that the NS influences the performance of meta-heuristics, more that other parameters. Moreover, a comparative analysis of distinct meta-heuristics is carried out to demonstrate a non-proportional increase in the performance of the NS.

2017

Intelligent Systems Design and Applications

Autores
Madureira, AM; Abraham, A; Gamboa, D; Novais, P;

Publicação
Advances in Intelligent Systems and Computing

Abstract

2018

Characterizing Parkinson's Disease from Speech Samples Using Deep Structured Learning

Autores
Sousa, L; Braga, D; Madureira, A; Coelho, LP; Renna, F;

Publicação
Proceedings of the Tenth International Conference on Soft Computing and Pattern Recognition, SoCPaR 2018, Porto, Portugal, December 13-15, 2018

Abstract
An early detection of neurodegenerative diseases, such as Parkinson’s disease, can improve therapy effectiveness and, by consequence, the patient’s quality of life. This paper proposes a new methodology for automatic classification of voice samples regarding the presence of acoustic patterns of Parkinson’s disease, using a deep structured neural network. This is a low cost non-invasive approach that can raise alerts in a pre-clinical stage. Aiming to a higher diagnostic detail, it is also an objective to accurately estimate the stage of evolution of the disease allowing to understand in what extent the symptoms have developed. Therefore, two types of classification problems are explored: binary classification and multiclass classification. For binary classification, a deep structured neural network was developed, capable of correctly diagnosing 93.4% of cases. For the multiclass classification scenario, in addition to the deep neural network, a K-nearest neighbour algorithm was also used to establish a reference for comparison purposes, while using a common database. In both cases the original feature set was optimized using principal component analysis and the results showed that the proposed deep structure neural network was able to provide more accurate estimations about the disease’s stage, reaching a score of 84.7%. The obtained results are promising and create the motivation to further explore the model’s flexibility and to pursue better results. © 2020, Springer Nature Switzerland AG.

2020

A Production Scheduling Support Framework

Autores
Reis, P; Santos, AS; Bastos, JA; Madureira, AM; Varela, LR;

Publicação
Intelligent Systems Design and Applications - 20th International Conference on Intelligent Systems Design and Applications (ISDA 2020) held December 12-15, 2020

Abstract

2025

Leveraging Feature Extraction to Perform Time-Efficient Selection for Machine Learning Applications

Autores
Coelho, D; Madureira, A; Pereira, I; Gonçalves, R; Nicola, S; César, I; de Oliveira, DA;

Publicação
APPLIED SCIENCES-BASEL

Abstract
In the age of rapidly advancing machine learning capabilities, the pursuit of maximum performance encounters the practical limitations imposed by limited resources in several fields. This work presents a cost-effective proposal for feature selection, which is a crucial part of machine learning processes, and intends to partly solve this problem through computational time reduction. The proposed methodology aims to strike a careful balance between feature exploration and strict computational time concerns, by enhancing the quality and relevance of data. This approach focuses on the use of interim representations of feature combinations to significantly speed up a potentially slow and computationally expensive process. This strategy is evaluated in several datasets against other feature selection methods, and the results indicate a significant reduction in the temporal costs associated with this process, achieving a mean percentage decrease of 85%. Furthermore, this reduction is achieved while maintaining competitive model performance, demonstrating that the selected features remain effective for the learning task. These results emphasize the method's feasibility, confirming its ability to transform machine learning applications in environments with limited resources.

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