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Publications

2023

Electrical sensing of the plant Mimosa pudica under environmental temperatures

Authors
Lobo, MA; Cardoso, JMP; Rocha, PRF;

Publication
2023 IEEE 7TH PORTUGUESE MEETING ON BIOENGINEERING, ENBENG

Abstract
Plants gather and process information about their surroundings to make decisions that prioritize their well-being while considering the environment. These decisions are conveyed through electrical signals within and between cells, mainly in the form of action and variation potentials, in response to stimuli, including mechanical vibrations, changes in temperature, light intensity, and humidity. Although the ability of some plants, such as the Mimosa pudica, to react to sudden environmental stimuli (e.g., touch) is well known, their long-term electrical response under slow environmental changes remains not fully understood. Here, a multi-source monitoring system has been developed to collect and store electrical signals from the plant Mimosa pudica, and surrounding environmental temperature and humidity, over a period of approximately 5 days. A realtime dashboard shows the environmental temperature and variation potential (VP) from Mimosa pudica. The VP mimics the environmental temperature changes, with an associated delay. Our long-term physiological observations suggest that environmental temperature sensing in the plant Mimosa pudica can be monitored and is likely driven by bioelectricity.

2023

Bi-level stochastic energy trading model for technical virtual power plants considering various renewable energy sources, energy storage systems and electric vehicles

Authors
Gough, M; Santos, SF; Javadi, MS; Home-Ortiz, JM; Castro, R; Catalao, JPS;

Publication
JOURNAL OF ENERGY STORAGE

Abstract
The ongoing transition of the energy system towards being low-carbon, digitized and distributed is accelerating. Distributed Energy Resources (DERs) are playing a major role in this transition. These DERs can be aggregated and controlled by Virtual Power Plants (VPPs) to participate in energy markets and make full use of the potential of DERs. Many existing VPP models solely focus on the financial impact of aggregating DERs and do not consider the technical limitations of the distribution system. This may result in technically unfeasible solutions to DERs operations. This paper presents an expanded VPP model, termed the Technical Virtual Power Plant (TVPP), which explicitly considers the technical constraints of the network to provide operating schedules that are both economically beneficial to the DERs and technically feasible. The TVPP model is formulated as a bi-level sto-chastic mixed-integer linear programming (MILP) optimization model. Two objective functions are used, the upper level focuses on minimizing the amount of power imported into the TVPP from the external grid, while the lower level is concerned with optimally scheduling a mixture of DERs to increase the profit of the TVPP operator. The model considers three TVPPs and allows for energy trading among the TVPPs. The model is applied to several case studies based on the IEEE 119-node test system. Results show improved DERs operating schedules, improved system reliability and an increase in demand response engagement. Finally, energy trading among the TVPP is shown to further reduce the costs of the TVPP and power imported from the upstream electrical network.

2023

Deep Convolutional Neural Networks applied to Hand Keypoints Estimation

Authors
Santos, BM; Pais, P; Ribeiro, FM; Lima, J; Gonçalves, G; Pinto, VH;

Publication
2023 IEEE INTERNATIONAL CONFERENCE ON AUTONOMOUS ROBOT SYSTEMS AND COMPETITIONS, ICARSC

Abstract
Accurate estimation of hand shape and position is an important task in various applications, such as human-computer interaction, human-robot interaction, and virtual and augmented reality. In this paper, it is proposed a method to estimate the hand keypoints from single and colored images utilizing the pre-trained deep convolutional neural networks VGG-16 and VGG-19. The method is evaluated on the FreiHAND dataset, and the performance of the two neural networks is compared. The best results were achieved by the VGG-19, with average estimation errors of 7.40 pixels and 11.36 millimeters for the best cases of two-dimensional and three-dimensional hand keypoints estimation, respectively.

2023

Hybrid optimisation and machine learning models for wind and solar data prediction

Authors
Amoura, Y; Torres, S; Lima, J; Pereira, I;

Publication
International Journal of Hybrid Intelligent Systems

Abstract
The exponential growth in energy demand is leading to massive energy consumption from fossil resources causing a negative effects for the environment. It is essential to promote sustainable solutions based on renewable energies infrastructures such as microgrids integrated to the existing network or as stand alone solution. Moreover, the major focus of today is being able to integrate a higher percentages of renewable electricity into the energy mix. The variability of wind and solar energy requires knowing the relevant long-term patterns for developing better procedures and capabilities to facilitate integration to the network. Precise prediction is essential for an adequate use of these renewable sources. This article proposes machine learning approaches compared to an hybrid method, based on the combination of machine learning with optimisation approaches. The results show the improvement in the accuracy of the machine learning models results once the optimisation approach is used. © 2023 - IOS Press. All rights reserved.

2023

Evaluation of Vectra® XT 3D Surface Imaging Technology in Measuring Breast Symmetry and Breast Volume

Authors
Pham, M; Alzul, R; Elder, E; French, J; Cardoso, J; Kaviani, A; Meybodi, F;

Publication
AESTHETIC PLASTIC SURGERY

Abstract
Background Breast symmetry is an essential component of breast cosmesis. The Harvard Cosmesis scale is the most widely adopted method of breast symmetry assessment. However, this scale lacks reproducibility and reliability, limiting its application in clinical practice. The VECTRA (R) XT 3D (VECTRA (R)) is a novel breast surface imaging system that, when combined with breast contour measuring software (Mirror (R)), aims to produce a more accurate and reproducible measurement of breast contour to aid operative planning in breast surgery. Objectives This study aims to compare the reliability and reproducibility of subjective (Harvard Cosmesis scale) with objective (VECTRA (R)) symmetry assessment on the same cohort of patients. Methods Patients at a tertiary institution had 2D and 3D photographs of their breasts. Seven assessors scored the 2D photographs using the Harvard Cosmesis scale. Two independent assessors used Mirror (R) software to objectively calculate breast symmetry by analysing 3D images of the breasts. Results Intra-observer agreement ranged from none to moderate (kappa - 0.005-0.7) amongst the assessors using the Harvard Cosmesis scale. Inter-observer agreement was weak (kappa 0.078-0.454) amongst Harvard scores compared to VECTRA (R) measurements. Kappa values ranged 0.537-0.674 for intra-observer agreement (p < 0.001) with Root Mean Square (RMS) scores. RMS had a moderate correlation with the Harvard Cosmesis scale (r(s) = 0.613). Furthermore, absolute volume difference between breasts had poor correlation with RMS (R-2 = 0.133). Conclusion VECTRA (R) and Mirror (R) software have potential in clinical practice as objectifying breast symmetry, but in the current form, it is not an ideal test.

2023

Perceptions of Forest Experts on the Impact of Wildfires on Ecosystem Services in Portugal

Authors
Pacheco, R; Claro, J;

Publication
Environmental Science and Engineering

Abstract
In Mediterranean Europe, one of the expected consequences of climate change is the intensification of wildfire events. Given the importance of forests in helping regulate climate and the many ecosystem services they provide, it is crucial to identify how wildfires might impact them. In this context, the present work aims to identify the wildfire impacts caused to the ecosystem services in Portugal. This is done through a survey directed to Portuguese fire experts. Using The Economics of Ecosystems and Biodiversity (TEEB) definitions, experts were asked to share their perceptions on the fire impacts to forest ecosystem services in the short and long-term and indicate which services they feel require more policies to mitigate the impacts. The results showed that all ecosystem services are impacted to various degrees and different lengths of time. Regulating services were overall the most affected group and the most in need of specific policies. This study helped identify fire impacts, policy needs, and priorities in the perception of the experts in Portugal, which is valuable for guiding future research in various knowledge fields, especially related to raising awareness about behavioral adaptation to prevent and mitigate wildfire impacts in a changing climate. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2023.

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