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Publications

2019

Gait classification of patients with Fabry's disease based on normalized gait features obtained using multiple regression models

Authors
Fernandes, C; Ferreira, F; Gago, MF; Azevedo, O; Sousa, N; Erlhagen, W; Bicho, E;

Publication
2019 IEEE International Conference on Bioinformatics and Biomedicine, BIBM 2019, San Diego, CA, USA, November 18-21, 2019

Abstract
Diagnosis of Fabry disease (FD) remains a challenge mostly due to its rare occurrence and phenotipical variability, with considerable delay between onset and clinical diagnosis. It is then of extreme importance to explore biomarkers capable of assisting the earlier diagnosis of FD. There is growing evidence supporting the use of gait assessment in the diagnosis and management of several neurological diseases. In fact, gait abnormalities have previously been observed in FD, justifying further investigation. The aim of this study is to evaluate the effectiveness of different machine learning strategies when distinguishing patients with FD from healthy controls based on normalized gait features. Gait features of an individual are affected by physical characteristics including age, height, weight, and gender, as well as walking speed or stride length. Therefore, in order to reduce bias due to inter-subject variations a multiple regression (MR) normalization approach for gait data was performed. Four different machine learning strategies - Support Vector Machines (SVM), Random Forest (RF), Multiple Layer Perceptrons (MLPs), and Deep Belief Networks (DBNs) - were employed on raw and normalized gait data. Wearable sensors positioned on both feet were used to acquire the gait data from 36 patients with FD and 34 healthy subjects. Gait normalization using MR revealed significant differences in percentage of stance phase spent in foot flat and pushing (p < 0.05), with FD presenting lower percentages in foot flat and higher in pushing. No significant differences were observed before gait normalization. Support Vector Machine was the superior classifier achieving an FD classification accuracy of 78.21% after gait normalization, compared to 71.96% using raw gait data. Gait normalization improved the performance of all classifiers. To the best of our knowledge, this is the first study on gait classification that includes patients with FD, and our results support the use of gait assessment on the clinical assessment of FD. © 2019 IEEE.

2019

Towards a Realistic Simulation Framework for Vehicular Platooning Applications

Authors
Vieira, B; Severino, R; Koubaa, A; Tovar, E;

Publication
2019 IEEE 22ND INTERNATIONAL SYMPOSIUM ON REAL-TIME DISTRIBUTED COMPUTING (ISORC 2019)

Abstract
Cooperative vehicle platooning applications increasingly demand realistic simulation tools to ease their validation, and to bridge the gap between development and real-word deployment. However, their complexity and cost, often hinders its validation in the real-world. In this paper we propose a realistic simulation framework for vehicular platoons that integrates Gazebo with OMNeT++ over Robot Operating System (ROS) to support the simulation of realistic scenarios of autonomous vehicular platoons and their cooperative control.

2019

A construção de um Eldorado? O projeto socialista do Orinoco como estratégia de desenvolvimento regional na Venezuela

Authors
Da Silva, RD; De Matos, MVM;

Publication
Revista Brasileira de Desenvolvimento Regional

Abstract
O principal objetivo do artigo é apresentar as linhas gerais da importância da indústria petrolífera para a Venezuela a partir do estudo da tentativa de expansão produtiva e urbana em direção à faixa centro-oriental do território nacional sob os objetivos do Projeto Socialista do Orinoco (PSO). Baseado em revisão da literatura e análise de dados secundários, o trabalho discute a proposta de adensamento urbano e diversificação produtiva comandada pela grande indústria de petróleo, assinalando seus objetivos, suas características e os desafios enfrentados. O texto conclui que a proposta de crescimento econômico e diversificação, baseada na indústria de petróleo, mostrou-se frágil pela alta dependência inicial à conjuntura internacional favorável e por não conseguir superar problemas estruturais crônicos de longa data que afetam o país, tal como a valorização cambial, que atua no desestímulo à substituição de importações.

2019

Analyzing the Footprint of Classifiers in Adversarial Denial of Service Contexts

Authors
Martins, N; Cruz, JM; Cruz, T; Abreu, PH;

Publication
Progress in Artificial Intelligence, 19th EPIA Conference on Artificial Intelligence, EPIA 2019, Vila Real, Portugal, September 3-6, 2019, Proceedings, Part II.

Abstract

2019

A Comprehensive Study on Enterprise Wi-Fi Access Points Power Consumption

Authors
Silva, P; Almeida, NT; Campos, R;

Publication
IEEE ACCESS

Abstract
Wi-Fi networks are becoming more and more ubiquitous and represent a substantial source of energy consumption around the globe, mainly when it comes to Access Points (APs). There has been some work done on the characterization of the power consumption of Wi-Fi APs and network interface cards (NICs), and the power usage of these devices under different configurations and standards but mostly using legacy standards. A detailed AP power consumption analysis, exploring the whole set of degrees of freedom and capabilities of these devices is lacking in the state of the art. In this paper, we present a thorough power consumption analysis, covering the configuration options available in enterprise Wi-Fi APs from the three major vendors on the market. The goal is to understand how the power consumption of an AP varies with the different configurations, and provide insights on the parameters that significantly affect the AP power consumption. The obtained experimental results confirm previous state-of-the-art conclusions but contradict some of the studies and results found in the literature, while updating results and conclusions taken in the past to the most recent standards, configurations, and data rates available today. The analysis provided herein is a valuable source of information for deriving new AP power consumption models and designing energy-efficient Wi-Fi networks.

2019

Development of an image-based system to assess agricultural fertilizer spreader pattern

Authors
Marcal, ARS; Cunha, M;

Publication
COMPUTERS AND ELECTRONICS IN AGRICULTURE

Abstract
An Automatic Calibration of Fertilizers (ACFert) system was developed, for use with centrifugal, pendulum or other types of broadcast spreaders which distribute dry granular agricultural materials on the top of the soil. The ACfert is based on image processing techniques and includes a specially designed mat, which should be placed in the ground for spreaders calibration. A set of images acquired outdoor by a standard device (simple camera) is used to extract information about the spreader distribution pattern. Each image is processed independently, providing as output two numerical values for each grid element present in the image - the number of fertilizers/seeds counted, and its numerical label. The performance of ACFert was evaluated for automatic granules detection using a set of manual counting measurements of nitrate fertilizer and wheat seeds. A total of 185 images acquired with two mobiles devices were used with a total of 498 quadrilateral elements observed and analysed. The overall mean absolute relative error between counting and computed by the ACFert system, were 0.75 +/- 0.75% for fertilizer and 2.12 +/- 1.68% for wheat. This near real-time calibration tool is a very low cost system that can be easily used on field, providing results to support accurate spreader calibration in near real time for different types of fertilizers or seeds.

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