36 documents found, page 1 of 4
Optimized European Portuguese Speech-To-Text using Deep Learning
Medeiros, Eduardo; Corado, Leonel; Rato, Luis; Quaresma, Paulo; Salgueiro, PedroWe have developed an ASR system for European Portuguese implement ing the QuartzNet [3] architecture with the NeMo [4] framework. Two approaches were used in this work: from scratch and using transfer learning. The experiments were data-driven focused instead of algorithm finetuning. Experiments confirm that models developed using transfer learning have shown better results (WER=0.0513) than developing models f...
Abbreviating labelling cost for sentinel-2 image scene classification through a...
Raiyani, Kashyap; Gonçalves, Teresa; Rato, LuisOver the years, due to the enrichment of paired-label datasets, supervised machine learning has become an important part of any problem-solving process. Active Learning gains importance when, given a large amount of freely available data, there’s a lack of expert’s manual labels. This paper proposes an active learning algorithm for selective choice of training samples in remote sensing image scene classificatio...
Sentinel 2 Image Scene Classifica- tion: A Comparison Between Bands and Spectra...
Raiyani, Kashyap; Gonçalves, Teresa; Rato, LuisGiven the continuous increase in the global population, the food manufacturers are advocated to either intensify the use of cropland or expand the farmland, making land cover and land usage dynamics mapping vital in the area of remote sensing. In this regard, identifying and classifying a high-resolution satellite imagery scene is a prime challenge. Several approaches have been proposed either by using static r...
Predicting soil electro-conductivity using Sentinel-1 images
Medeiros, Eduardo; Gonçalves, Teresa; Rato, Luis; Ahmed, SajibThe quality and yield of a soil can be measured by using a wide range of soil indicators. One such indicator is soil’s electro-conductivity which is an excellent indicator of the presence of soil nutrients. This work aims to create a machine learning model to predict the soil’s electro-conductivity (EC) using radar images from the satellite Sentinel-1. Using EC readings from 14 corn field parcels and Sentinel-1...
Classifying Soil Type Using Radar Satellite Images
Ahmed, Md Sajib; Gonçalves, Teresa; Rato, Luis; Marques da Silva, José Rafael; Vieira, Filipe; Paixão, Luís; Salgueiro, PedroThe growth of the crop is dependent on soil type, apart from atmospheric and geo-location characteristics. As of now, there is no direct and cost free method to measure soil property or to classify soil type. In this work, we proposed a machine learning model to classify soil type using Sentinel-1 satellite radar images. Further, the developed classifier achieved 72.17% F1-score classifying sandy, free and clay...
Identifying Risky Dropout Student Profiles using Machine Learning Models
Prite, Shramin; Gonçalves, Teresa; Rato, LuisStudent dropout prediction is essential to measure the success of an educa- tion institute system. This paper focuses on identifying the dropout risk at the University of Évora based on student’s academic performance. Educa- tional data was collected from four different programs, from the academic years of 2006/2007 until 2018/2019. After gathering the raw data, some data pre-processing was done aiming to build...
RADON‐WAVELET BASED NOVEL IMAGE DESCRIPTOR FOR MAMMOGRAM MASS CLASSIFICATION
Obaidullah, Sk Md; Ahmed, Sajib; Gonçalves, Teresa; Rato, LuisMammography based breast cancer screening is very popular because of its lower costing and readily availability. For automated classification of mammogram images as benign or malignant machine learning techniques are involved. In this paper, a novel image descriptor which is based on the idea of Radon and Wavelet transform is proposed. This method is quite efficient as it performs well without any clinical info...
Feature extraction from MRI ADC images for brain tumor classification using mac...
Vijithananda, Sahan; Jayatilake, Mohan; Hewavithana, Badra; Gonçalves, Teresa; Rato, Luis; Weerakoon, Bimali; Kalupahana, Tharindu; Silva, AnilDiffusion-weighted (DW) imaging is a well-recognized magnetic resonance imaging (MRI) technique that is being routinely used in brain examinations in modern clinical radiology practices. This study focuses on extracting demographic and texture features from MRI Apparent Diffusion Coefficient (ADC) images of human brain tumors, identifying the distribution patterns of each feature and applying Machine Learning (...
Automatic classification of ornamental stones using Machine Learning techniques...
Tereso, Marco; Rato, Luis; Gonçalves, TeresaThe industry of extraction and transformation of rock minerals has an enormous importance in the Portuguese trade balance. The export volume increases every year, and to maintain these results it is necessary to invest in the modernization and optimization of production processes, as well as, in the classification of raw materials. This study aims to implement a classification model of ornamental rocks through ...
The Impact of Endocrine-Disrupting Chemicals in Male Fertility: Focus on the Ac...
Rato, Luis; Sousa, Ana CatarinaThe current scenario of male infertility is not yet fully elucidated; however, there is increasing evidence that it is associated with the widespread exposure to endocrine-disrupting chemicals (EDCs), and in particular to obesogens. These compounds interfere with hormones involved in the regulation of metabolism and are associated with weight gain, being also able to change the functioning of the male reproduct...