Pedro Machado

Dr. Pedro Machado

Computer Science, Nottingham Trent University, Nottingham, UK
orcid
Senior Lecturer in Computer Science, BSc, MSc, PhD | IEEE Ce...

Research Focus & Metrics

Academic Career Length

13Years (2014-Present)

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

Representative Publications

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15 January 2025 in J
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MKManjunatha Shettigere Krishna
Manjunatha Shettigere Krishna
Pedro MachadoPedro Machado
Pedro Machado
RORichard Ikechukwu Otuka
Richard Ikechukwu Otuka
SYSalisu W Yahaya
Salisu W Yahaya
Filipe Neves dos SantosFilipe Neves dos Santos
Filipe Neves dos Santos
IIIsibor Kennedy IHIANLE
Isibor Kennedy IHIANLE
Agricultural productivity is increasingly threatened by plant diseases, which can spread rapidly and lead to significant crop losses if not identified early. Detecting plant diseases accurately in diverse and uncontrolled environments remains challenging, as most current detection methods rely heavily on lab-captured images that may not generalise well to real-world settings. This paper aims to develop models capable of accurately identifying plant diseases across diverse conditions, overcoming the limitations of existing methods. A combined dataset was utilised, incorporating the PlantDoc dataset with web-sourced images of plants from online platforms. State-of-the-art convolutional neural network (CNN) architectures, including EfficientNet-B0, EfficientNet-B3, ResNet50, and DenseNet201, were employed and fine-tuned for plant leaf disease classification. A key contribution of this work is the application of enhanced data augmentation techniques, such as adding Gaussian noise, to improve model generalisation. The results demonstrated varied performance across the datasets. When trained and tested on the PlantDoc dataset, EfficientNet-B3 achieved an accuracy of 73.31%. In cross-dataset evaluation, where the model was trained on PlantDoc and tested on a web-sourced dataset, EfficientNet-B3 reached 76.77% accuracy. The best performance was achieved with the combination of the PlanDoc and web-sourced datasets resulting in an accuracy of 80.19% indicating very good generalisation in diverse conditions. Class-wise F1-scores consistently exceeded 90% for diseases such as apple rust leaf and grape leaf across all models, demonstrating the effectiveness of this approach for plant disease detection.

5 October 2023 in Robotics
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João Filipe FerreiraJoão Filipe Ferreira
João Filipe Ferreira
David PortugalDavid Portugal
David Portugal
MAMaria Eduarda Andrada
Maria Eduarda Andrada
Pedro MachadoPedro Machado
Pedro Machado
Rui RochaRui Rocha
Rui Rocha
PPPaulo Peixoto
Paulo Peixoto
Artificial perception for robots operating in outdoor natural environments, including forest scenarios, has been the object of a substantial amount of research for decades. Regardless, this has proven to be one of the most difficult research areas in robotics and has yet to be robustly solved. This happens namely due to difficulties in dealing with environmental conditions (trees and relief, weather conditions, dust, smoke, etc.), the visual homogeneity of natural landscapes as opposed to the diversity of natural obstacles to be avoided, and the effect of vibrations or external forces such as wind, among other technical challenges. Consequently, we propose a new survey, describing the current state of the art in artificial perception and sensing for robots in precision forestry. Our goal is to provide a detailed literature review of the past few decades of active research in this field. With this review, we attempted to provide valuable insights into the current scientific outlook and identify necessary advancements in the area. We have found that the introduction of robotics in precision forestry imposes very significant scientific and technological problems in artificial sensing and perception, making this a particularly challenging field with an impact on economics, society, technology, and standards. Based on this analysis, we put forward a roadmap to address the outstanding challenges in its respective scientific and technological landscape, namely the lack of training data for perception models, open software frameworks, robust solutions for multi-robot teams, end-user involvement, use case scenarios, computational resource planning, management solutions to satisfy real-time operation constraints, and systematic field testing. We argue that following this roadmap will allow for robotics in precision forestry to fulfil its considerable potential.

7 February 2024 in Sensors
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LFLaura Maria De Jesus Fontes
Laura Maria De Jesus Fontes
Pedro MachadoPedro Machado
Pedro Machado
DVDoratha Vinkemeier
Doratha Vinkemeier
SYSalisu W Yahaya
Salisu W Yahaya
Jordan BirdJordan Bird
Jordan Bird
IIIsibor Kennedy IHIANLE
Isibor Kennedy IHIANLE
Stress has emerged as a major concern in modern society, significantly impacting human health and well-being. Statistical evidence underscores the extensive social influence of stress, especially in terms of work-related stress and associated healthcare costs. This paper addresses the critical need for accurate stress detection, emphasising its far-reaching effects on health and social dynamics. Focusing on remote stress monitoring, it proposes an efficient deep learning approach for stress detection from facial videos. In contrast to the research on wearable devices, this paper proposes novel Hybrid Deep Learning (DL) networks for stress detection based on remote photoplethysmography (rPPG), employing (Long Short-Term Memory (LSTM), Gated Recurrent Units (GRU), 1D Convolutional Neural Network (1D-CNN)) models with hyperparameter optimisation and augmentation techniques to enhance performance. The proposed approach yields a substantial improvement in accuracy and efficiency in stress detection, achieving up to 95.83% accuracy with the UBFC-Phys dataset while maintaining excellent computational efficiency. The experimental results demonstrate the effectiveness of the proposed Hybrid DL models for rPPG-based-stress detection.

19 November 2022 in Engineering Applications of Artificial Intelligence
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Journal Article
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Sandro MagalhãesSandro Magalhães
Sandro Magalhães
Filipe Neves dos SantosFilipe Neves dos Santos
Filipe Neves dos Santos
Pedro MachadoPedro Machado
Pedro Machado
Antonio Paulo MoreiraAntonio Paulo Moreira
Antonio Paulo Moreira
JDJorge Dias
Jorge Dias

10 November 2023 in Expert Systems with Applications
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Journal Article
Open access
IIIsibor Kennedy IHIANLE
Isibor Kennedy IHIANLE
Pedro MachadoPedro Machado
Pedro Machado
KOKayode Owa
Kayode Owa
DADavid Ada Adama
David Ada Adama
RORichard Ikechukwu Otuka
Richard Ikechukwu Otuka
Ahmad LotfiAhmad Lotfi
Ahmad Lotfi

2 November 2020 in Electronics
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ZYZheqi Yu
Zheqi Yu
Pedro MachadoPedro Machado
Pedro Machado
AZadnan zahid
adnan zahid
AAAmir M. Abdulghani
Amir M. Abdulghani
KDKia Dashtipour
Kia Dashtipour
Qammer AbbasiQammer Abbasi
Qammer Abbasi
This paper suggests an optimisation approach in heterogeneous computing systems to balance energy power consumption and efficiency. The work proposes a power measurement utility for a reinforcement learning (PMU-RL) algorithm to dynamically adjust the resource utilisation of heterogeneous platforms in order to minimise power consumption. A reinforcement learning (RL) technique is applied to analyse and optimise the resource utilisation of field programmable gate array (FPGA) control state capabilities, which is built for a simulation environment with a Xilinx ZYNQ multi-processor systems-on-chip (MPSoC) board. In this study, the balance operation mode for improving power consumption and performance is established to dynamically change the programmable logic (PL) end work state. It is based on an RL algorithm that can quickly discover the optimization effect of PL on different workloads to improve energy efficiency. The results demonstrate a substantial reduction of 18% in energy consumption without affecting the application’s performance. Thus, the proposed PMU-RL technique has the potential to be considered for other heterogeneous computing platforms.