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Publications

Publications by CTM

2022

Joint Energy and Performance Aware Relay Positioning in Flying Networks

Authors
Rodrigues, H; Coelho, A; Ricardo, M; Campos, R;

Publication

Abstract
<div>Unmanned Aerial Vehicles (UAVs) have emerged as suitable platforms for transporting and positioning communications nodes on demand, including Wi-Fi Access Points and cellular Base Stations. This paved the way for the deployment of flying networks capable of temporarily providing wireless connectivity and reinforcing coverage and capacity of existing networks. Several solutions have been proposed for the positioning of UAVs acting as Flying Access Points (FAPs). Yet, the positioning of Flying Communications Relays (FCRs) in charge of forwarding the traffic to/from the Internet has not received equal attention. In addition, state of the art works are focused on optimizing both the flying network performance and the energy-efficiency from the communications point of view, leaving aside a relevant component: the energy spent for the UAV propulsion.</div><div>We propose the Energy and Performance Aware relay Positioning (EPAP) algorithm. EPAP defines target performance-aware Signal-to-Noise Ratio (SNR) values for the wireless links established between the FCR UAV and the FAPs and, based on that, computes the trajectory to be completed by the FCR UAV so that the energy spent for the UAV propulsion is minimized. EPAP was evaluated in terms of both the flying network performance and the FCR UAV endurance, considering multiple networking scenarios. Simulation results show gains up to 25% in the FCR UAV endurance, while not compromising the Quality of Service offered by the flying network.</div>

2022

Symbolic Music Generation Conditioned on Continuous-Valued Emotions

Authors
Sulun, S; Davies, MEP; Viana, P;

Publication
IEEE ACCESS

Abstract
In this paper we present a new approach for the generation of multi-instrument symbolic music driven by musical emotion. The principal novelty of our approach centres on conditioning a state-of-the-art transformer based on continuous-valued valence and arousal labels. In addition, we provide a new large-scale dataset of symbolic music paired with emotion labels in terms of valence and arousal. We evaluate our approach in a quantitative manner in two ways, first by measuring its note prediction accuracy, and second via a regression task in the valence-arousal plane. Our results demonstrate that our proposed approaches outperform conditioning using control tokens which is representative of the current state of the art.

2022

Enhancing Photography Management Through Automatically Extracted Metadata

Authors
Carvalho, P; Freitas, D; Machado, T; Viana, P;

Publication
INTELLIGENT SYSTEMS DESIGN AND APPLICATIONS, ISDA 2021

Abstract
The tremendous increase in photographs that are captured each day by common users has been favoured by the availability of high quality devices at accessible costs, such as smartphones and digital cameras. However, the quantity of captured photos raises new challenges regarding the access and management of image repositories. This paper describes a lightweight distributed framework intended to help overcome these problems. It uses image metadata in EXIF format, already widely added to images by digital acquisition devices, and automatic facial recognition to provide management and search functionalities. Moreover, a visualization functionality using a graph-based strategy was integrated, enabling an enhanced and more interactive navigation through search results and the corresponding relations.

2022

Automated Adequacy Assessment of Cervical Cytology Samples Using Deep Learning

Authors
Mosiichuk, V; Viana, P; Oliveira, T; Rosado, L;

Publication
PATTERN RECOGNITION AND IMAGE ANALYSIS (IBPRIA 2022)

Abstract
Cervical cancer has been among the most common causes of cancer death in women. Screening tests such as liquid-based cytology (LBC) were responsible for a substantial decrease in mortality rates. Still, visual examination of cervical cells on microscopic slides is a time-consuming, ambiguous and challenging task, aggravated by inadequate sample quality (e.g. low cellularity or the presence of obscuring factors like blood or inflammation). While most works in the literature are focused on the automated detection of cervical lesions to support diagnosis, to the best of our knowledge, none of them address the automated assessment of sample adequacy, as established by The Bethesda System (TBS) guidelines. This work proposes a new methodology for automated adequacy assessment of cervical cytology samples. Since the most common reason for rejecting samples is the low count of the squamous nucleus, our approach relies on a deep learning object detection model for the detection and counting of different types of nuclei present in LBC samples. A dataset of 41 samples with a total of 42387 nuclei manually annotated by experienced specialists was used, and the best solution proposed achieved promising results for the automated detection of squamous nuclei (AP of 82.4%, Accuracy of 79.8%, Recall of 73.8% and Fl score of 81.5%). Additionally, by merging the developed automated cell counting approach with the adequacy criteria stated by the TBS guidelines, we validated our approach by correctly classifying an entire subset of 12 samples as adequate or inadequate.

2022

Classification of Table Tennis Strokes in Wearable Device using Deep Learning

Authors
Ferreira, NM; Torres, JM; Sobral, P; Moreira, R; Soares, C;

Publication
ICAART: PROCEEDINGS OF THE 14TH INTERNATIONAL CONFERENCE ON AGENTS AND ARTIFICIAL INTELLIGENCE - VOL 3

Abstract
Analysis of sports performance using mobile and wearable devices is becoming increasingly popular, helping users improve their sports practice. In this context, the goal of this work has been the development of an Apple Watch application, capable of detecting important strokes in the table tennis sport, using a deep learning (DL) model. A dataset of table tennis strokes has been created based on the watch's accelerometer and gyroscope sensors. The dataset collection was done in the Portuguese table tennis federation training sites, from several athletes, supervised by their coaches. To obtain the best DL model, three different architecture models where trained, compared and evaluated, using the complete dataset: a LSTM based on Create ML/Core ML frameworks (62.70% F1 score) and two Tensorflow based architectures, a CNN-LSTM (96.02% F1 score) and a ConvLSTM (97.33% F1 score).

2022

An IoT Sensing System for Managing Industrial FOG-Separators

Authors
Moreira, RS; Soares, C; Torres, J; Sobral, P; Carvalho, C; Gomes, B; Karmali, K; Karmali, S; Rodrigues, R;

Publication
2022 International Conference on Smart Applications, Communications and Networking, SmartNets 2022

Abstract
There is a widespread social awareness for the need of environment protection and sustainable systems in different areas of human activity. In particular, the catering industry is responsible for a significant share of sewage systems pollution, due to daily leaks of food remnants containing Fat, Oil and Grease (FOG). This work focuses on building a combined IoT monitoring solution to automate the remote management of industrial FOG-Separators, aiming to prevent or reduce leakage of FOG and food debris into sewer systems. The proposed solution adopted the use of custom-made in-premises sensor motes integrating two particular sensors: an in-the-house developed conductivity sensor, built specifically to distinguish levels of water and FOG in industrial FOG-Separators; an off-the-shelf turbidity sensor integrated to assess the amount of water debris. Briefly, this work has four major fold contributions: i) design and implementation of a combined IoT sensing solution; ii) most significant was the development, test, and integration of the capacity-based sensor coupled to local sensor motes, for assessing Water/FOG levels; iii) assessing and profiling edge motes energy autonomy; iv) finally, deploying the combined IoT architecture to validate the entire process of monitoring and scheduling the maintenance of industrial FOG-Separators. © 2022 IEEE.

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