Nuno Marques

Prof. Dr. Nuno Marques

DI-FCT & NOVA LINCS, Universidade NOVA, Lisboa, Portugal

Research Focus & Metrics

Academic Career Length

32Years (1995-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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23 March 2020 in Journal of Digital Imaging
Verified
Journal Article
Closed access
PDF file
FZFelipe André Zeiser
Felipe André Zeiser
Cristiano da CostaCristiano da Costa
Cristiano da Costa
TZTiago Zonta
Tiago Zonta
Nuno MarquesNuno Marques
Nuno Marques
ARAdriana Vial Roehe
Adriana Vial Roehe
Rodrigo RighiRodrigo Righi
Rodrigo Righi

1 December 2021 in Applied Soft Computing
Verified
Journal Article
Closed access
FZFelipe André Zeiser
Felipe André Zeiser
Cristiano da CostaCristiano da Costa
Cristiano da Costa
ARAdriana Vial Roehe
Adriana Vial Roehe
RRRodrigo da Rosa Righi
Rodrigo da Rosa Righi
Nuno MarquesNuno Marques
Nuno Marques

14 March 2023 in Journal of Imaging
Verified
Journal Article
Open access
PDF file
André AntunesAndré Antunes
André Antunes
Bruno FerreiraBruno Ferreira
Bruno Ferreira
Nuno MarquesNuno Marques
Nuno Marques
Nelson CarriçoNelson Carriço
Nelson Carriço
The current paper presents a hyper parameterization optimization process for a convolutional neural network (CNN) applied to pipe burst locations in water distribution networks (WDN). The hyper parameterization process of the CNN includes the early stopping termination criteria, dataset size, dataset normalization, training set batch size, optimizer learning rate regularization, and model structure. The study was applied using a case study of a real WDN. Obtained results indicate that the ideal model parameters consist of a CNN with a convolutional 1D layer (using 32 filters, a kernel size of 3 and strides equal to 1) for a maximum of 5000 epochs using a total of 250 datasets (using data normalization between 0 and 1 and tolerance equal to max noise) and a batch size of 500 samples per epoch step, optimized with Adam using learning rate regularization. This model was evaluated for distinct measurement noise levels and pipe burst locations. Results indicate that the parameterized model can provide a pipe burst search area with more or less dispersion depending on both the proximity of pressure sensors to the burst or the noise measurement level.

3 September 2001
Verified
Book Chapter
Closed access
PDF file
Nuno MarquesNuno Marques
Nuno Marques
GLGabriel Pereira Lopes
Gabriel Pereira Lopes

1 January 2005
Verified
Book Chapter
Open access
PDF file
NCNing Chen
Ning Chen
Nuno MarquesNuno Marques
Nuno Marques
Self-organizing maps (SOM) have been recognized as a powerful tool in data exploratoration, especially for the tasks of clustering on high dimensional data. However, clustering on categorical data is still a challenge for SOM. This paper aims to extend standard SOM to handle feature values of categorical type. A batch SOM algorithm (NCSOM) is presented concerning the dissimilarity measure and update method of map evolution for both numeric and categorical features simultaneously.

14 December 2015 in Journal of Big Data
Verified
Journal Article
Open access
PDF file
BSBruno Silva
Bruno Silva
Nuno MarquesNuno Marques
Nuno Marques
The Internet of things promises a continuous flow of data where traditional database and data-mining methods cannot be applied. This paper presents improvements on the Ubiquitous Self-Organized Map (UbiSOM), a novel variant of the well-known Self-Organized Map (SOM), tailored for streaming environments. This approach allows ambient intelligence solutions using multidimensional clustering over a continuous data stream to provide continuous exploratory data analysis. The average quantization error and average neuron utility over time are proposed and used to estimating the learning parameters, allowing the model to retain an indefinite plasticity and to cope with changes within a multidimensional data stream. We perform parameter sensitivity analysis and our experiments show that UbiSOM outperforms existing proposals in continuously modeling possibly non-stationary data streams, converging faster to stable models when the underlying distribution is stationary and reacting accordingly to the nature of the change in continuous real world data streams.