Roberto Ribeiro

Prof. Roberto Ribeiro

School of Technology and Management, Computer Science and Communication Research Centre, Polytechnic Institute of Leiria
orcid

Research Focus & Metrics

Academic Career Length

7Years (2020-Present)

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

Representative Publications

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28 May 2024 in Sensors
Verified
Journal Article
Open access
PDF file
RPRafael Pereira
Rafael Pereira
CMCarla Mendes
Carla Mendes
José Carlos Bregieiro RibeiroJosé Carlos Bregieiro Ribeiro
José Carlos Bregieiro Ribeiro
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
Rolando MiragaiaRolando Miragaia
Rolando Miragaia
APAntónio Pereira
António Pereira
Emotion recognition has become increasingly important in the field of Deep Learning (DL) and computer vision due to its broad applicability by using human–computer interaction (HCI) in areas such as psychology, healthcare, and entertainment. In this paper, we conduct a systematic review of facial and pose emotion recognition using DL and computer vision, analyzing and evaluating 77 papers from different sources under Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Our review covers several topics, including the scope and purpose of the studies, the methods employed, and the used datasets. The scope of this work is to conduct a systematic review of facial and pose emotion recognition using DL methods and computer vision. The studies were categorized based on a proposed taxonomy that describes the type of expressions used for emotion detection, the testing environment, the currently relevant DL methods, and the datasets used. The taxonomy of methods in our review includes Convolutional Neural Network (CNN), Faster Region-based Convolutional Neural Network (R-CNN), Vision Transformer (ViT), and “Other NNs”, which are the most commonly used models in the analyzed studies, indicating their trendiness in the field. Hybrid and augmented models are not explicitly categorized within this taxonomy, but they are still important to the field. This review offers an understanding of state-of-the-art computer vision algorithms and datasets for emotion recognition through facial expressions and body poses, allowing researchers to understand its fundamental components and trends.

22 January 2020 in Sensors
Verified
Journal Article
Open access
PDF file
David SafadinhoDavid Safadinho
David Safadinho
JRJoão Ramos
João Ramos
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
Vítor Jesus FilipeVítor Jesus Filipe
Vítor Jesus Filipe
JBJoão Barroso
João Barroso
APAntónio Pereira
António Pereira
The capability of drones to perform autonomous missions has led retail companies to use them for deliveries, saving time and human resources. In these services, the delivery depends on the Global Positioning System (GPS) to define an approximate landing point. However, the landscape can interfere with the satellite signal (e.g., tall buildings), reducing the accuracy of this approach. Changes in the environment can also invalidate the security of a previously defined landing site (e.g., irregular terrain, swimming pool). Therefore, the main goal of this work is to improve the process of goods delivery using drones, focusing on the detection of the potential receiver. We developed a solution that has been improved along its iterative assessment composed of five test scenarios. The built prototype complements the GPS through Computer Vision (CV) algorithms, based on Convolutional Neural Networks (CNN), running in a Raspberry Pi 3 with a Pi NoIR Camera (i.e., No InfraRed—without infrared filter). The experiments were performed with the models Single Shot Detector (SSD) MobileNet-V2, and SSDLite-MobileNet-V2. The best results were obtained in the afternoon, with the SSDLite architecture, for distances and heights between 2.5–10 m, with recalls from 59%–76%. The results confirm that a low computing power and cost-effective system can perform aerial human detection, estimating the landing position without an additional visual marker.
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19 February 2021 in Sensors
Verified
Journal Article
Open access
PDF file
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
JRJoão Ramos
João Ramos
David SafadinhoDavid Safadinho
David Safadinho
ARArsénio Reis
Arsénio Reis
Carlos RabadãoCarlos Rabadão
Carlos Rabadão
APAntónio Pereira
António Pereira
Data and services are available anywhere at any time thanks to the Internet and mobile devices. Nowadays, there are new ways of representing data through trendy technologies such as augmented reality (AR), which extends our perception of reality through the addition of a virtual layer on top of real-time images. The great potential of unmanned aerial vehicles (UAVs) for carrying out routine and professional tasks has encouraged their use in the creation of several services, such as package delivery or industrial maintenance. Unfortunately, drone piloting is difficult to learn and requires specific training. Since regular training is performed with virtual simulations, we decided to propose a multiplatform cloud-hosted solution based in Web AR for drone training and usability testing. This solution defines a configurable trajectory through virtual elements represented over barcode markers placed on a real environment. The main goal is to provide an inclusive and accessible training solution which could be used by anyone who wants to learn how to pilot or test research related to UAV control. For this paper, we reviewed drones, AR, and human–drone interaction (HDI) to propose an architecture and implement a prototype, which was built using a Raspberry Pi 3, a camera, and barcode markers. The validation was conducted using several test scenarios. The results show that a real-time AR experience for drone pilot training and usability testing is achievable through web technologies. Some of the advantages of this approach, compared to traditional methods, are its high availability by using the web and other ubiquitous devices; the minimization of technophobia related to crashes; and the development of cost-effective alternatives to train pilots and make the testing phase easier for drone researchers and developers through trendy technologies.

12 February 2025 in Future Internet
Verified
Journal Article
Open access
PDF file
CPCarolina Pereira
Carolina Pereira
AMAnabela Marto
Anabela Marto
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
AGAlexandrino José Gonçalves
Alexandrino José Gonçalves
Nuno RodriguesNuno Rodrigues
Nuno Rodrigues
LSLeonel Filipe Simões Santos
Leonel Filipe Simões Santos
Over recent decades, internet-based communication has grown exponentially, accompanied by a surge in cyber threats from malicious actors targeting users and organizations, heightening the demand for robust security and privacy measures. With the emergence of physical–digital environments based on Mixed Reality (MR) and the Metaverse, new cybersecurity, privacy, and confidentiality challenges have surfaced, requiring innovative approaches. This work examines the current landscape of cybersecurity concerns in MR and Metaverse environments, focusing on their unique vulnerabilities and the risks posed to users and their data. Key challenges include authentication issues, data breaches, and risks to user anonymity. The work also explores advancements in secure design frameworks, encryption techniques, and regulatory approaches to safeguard these technologies. Additionally, it identifies opportunities for further research and innovation to strengthen data protection and ensure a safe, trustworthy experience in these environments.

24 April 2025 in Virtual Reality
Verified
Journal Article
Open access
PDF file
CCCarlos Costa
Carlos Costa
EGEnrico Gomes
Enrico Gomes
Nuno RodriguesNuno Rodrigues
Nuno Rodrigues
AGAlexandrino José Gonçalves
Alexandrino José Gonçalves
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
APAntónio Pereira
António Pereira
Wildfires have become increasingly critical, affecting forests, air and water quality, soil health, and contributing to climate change. Unmanned aerial vehicle (UAV) have emerged as an effective solution for monitoring and managing wildfires, due to their rapid deployment, low cost, and reduced environmental impact. This study presents a digital twin (DT) system for UAVs that enables users to interact with virtual simulations and real UAVs for wildfire prevention and detection through a smartphone or a tablet. The proposed DT-based system leverages virtual reality and augmented reality (AR) and includes four key services: UAV flight data generator (UAV-FDG), visualization, control, and retrieval. Also, these services allow users to test and train UAV control with a virtual one before moving to real scenarios, reducing risks and costs. The integration of mobile devices increases accessibility and flexibility, enabling real-time monitoring and control of UAVs for wildfire management and facilitating deployment in diverse environments. The main contributions of this research include the proposal, implementation, and validation of a DT-based mobile system for visualization, control, and retrieval using AR, autonomous flight data attribution and movement, and the deployment of DTs of UAVs in real environments. The assessment results showcase the successful implementation of the proposed system, with positive participant feedback, supported by a positive system usability scale score of 79.75.

20 February 2021 in Sensors
Verified
Journal Article
Open access
PDF file
JRJoão Ramos
João Ramos
Roberto RibeiroRoberto Ribeiro
Roberto Ribeiro
David SafadinhoDavid Safadinho
David Safadinho
JBJoão Barroso
João Barroso
Carlos RabadãoCarlos Rabadão
Carlos Rabadão
APAntónio Pereira
António Pereira
The demand for online services is increasing. Services that would require a long time to understand, use and master are becoming as transparent as possible to the users, that tend to focus only on the final goals. Combined with the advantages of the unmanned vehicles (UV), from the unmanned factor to the reduced size and costs, we found an opportunity to bring to users a wide variety of services supported by UV, through the Internet of Unmanned Vehicles (IoUV). Current solutions were analyzed and we discussed scalability and genericity as the principal concerns. Then, we proposed a solution that combines several services and UVs, available from anywhere at any time, from a cloud platform. The solution considers a cloud distributed architecture, composed by users, services, vehicles and a platform, interconnected through the Internet. Each vehicle provides to the platform an abstract and generic interface for the essential commands. Therefore, this modular design makes easier the creation of new services and the reuse of the different vehicles. To confirm the feasibility of the solution we implemented a prototype considering a cloud-hosted platform and the integration of custom-built small-sized cars, a custom-built quadcopter, and a commercial Vertical Take-Off and Landing (VTOL) aircraft. To validate the prototype and the vehicles’ remote control, we created several services accessible via a web browser and controlled through a computer keyboard. We tested the solution in a local network, remote networks and mobile networks (i.e., 3G and Long-Term Evolution (LTE)) and proved the benefits of decentralizing the communications into multiple point-to-point links for the remote control. Consequently, the solution can provide scalable UV-based services, with low technical effort, for anyone at anytime and anywhere.