RCIPL
Repositório Institucional do Politécnico de Lisboa
Entradas recentes
Decomposition-driven Mamba state space models with expert routing for wind curtailment forecasting
Publication . Seman, Laio Oriel; Stefenon, Stefano Frizzo; Matos-Carvalho, João Pedro; Stefenon, Stefano Frizzo; Elsevier
Wind power curtailment, known in Brazil as constrained-off, has intensified with the rapid expansion of renew able generation, driven by transmission operational constraints. Accurate forecasting of curtailment is essential for grid planning, compensation mechanisms, and infrastructure optimization. However, constrained-off time series exhibit strong non-stationarity, multi-scale behavior, and long-range dependencies that challenge conventional forecasting models. This paper proposes a decomposition-driven Mamba state space framework with Mixture-of-Experts (MoE) routing for wind curtailment forecasting. The approach integrates Entropy-Guided Variational Mode Decomposition (EG-VMD) for adaptive trend and noise separation, Reversible Instance Normalization to mitigate distribution shift, multi-scale seasonal-trend modeling, and a sparse expert-based Mamba backbone with linear-time complexity. In benchmark comparisons against state-of-the-art forecasting models, the proposed MoE-Mamba reduces Mean Squared Error (MSE) by up to 27%, Root Mean Squared Error by 14.6%, and Mean Absolute Error by 16.1% relative to the strongest baselines, while improving upon a single-expert Mamba by 15.6% in MSE. The results highlight the effectiveness of decomposition-enhanced State Space Models with expert routing for scalable, long-horizon forecasting in renewable power systems.
O conceito de corpo-mundo e do corpo fantasmagórico: um manifesto sensorial para desacelerar o tempo
Publication . De Lima, Cecília
A depredação do planeta inscrita no sistema capitalista mundial continua a passos largos. Diante de uma realidade deveras desanimadora, pergunto-me: como pode a prática e conhecimento artístico contribuir para a tentativa de abraçar um mundo mais sustentável? A prática artística da dança trabalha uma intensificação da consciência corporal em que a perceção de corpo é experienciada como um constante fluxo relacional – um corpo-mundo. Partindo deste conceito, no pensamento de Bruno Latour (2005) e de Ailton Krenak (2019), e com base nos estudos das ciências de Embodied Cognition e na noção de “cronopolítica” dePaul Virilio (2007), proponho um manifesto para a perceção de corpo enquanto um processo relacional ecológico, resistente á embriagues da tirania da velocidade
Gold nanoparticles functionalized with antibodies: a colorimetric analysis for implementation in PoC devices
Publication . Serafinelli, Caterina; Fantoni, Alessandro; Alegria, Elisabete C.B.A.; Pacheco, Rita; Vieira, Manuela; Fantoni, Alessandro; Alegria, Elisabete; Pacheco, Rita; Vieira, Manuela
The growing interest in the fast and easy identification of many biomarkers for several diseases, supporting a future precision medicine, results in the development of miniaturized, user-friendly, automated, and portable sensing systems able to provide a real-time and reliable response. Herein we evaluate the sensing capability of gold nanoflowers (AuNFs) for their integration in the setup of the Color Picker System, a Point-of-Care (PoC) sensing device developed by our group for a user-friendly colorimetric detection of molecules. A simulation study measures the color changes arising from the variations in the dielectric environment around the AuNFs surface. The process starts with the synthesis of AuNFs and their functionalization with 3-Mercaptopropionic acid. The measured transmittance spectra of the AuNFs before and after the functionalization, have been combined with the spectra of two different light sources to simulate the spectral response of the light transmitted through the colloidal dispersion. The calculated spectra have been converted into vectors in different color spaces producing the color chart. The sensitivity of the AuNFs has been evaluated as Euclidian distance between two consecutive points in the color chart, but also as differences in the RGB channels, that are the one returned from the Color Picker System. The AuNFs showed the greatest distances in the color chart and the greatest differences in the RGB when using the Cold LED as light source. The chromatic changes arising from their use make the AuNFs a potential sensing platform to be inserted into the Color Picker System for antibodies sensing. © 2025 SPIE.
Gold nanoflowers for colorimetric detection of NGAL antibodies
Publication . Serafinelli, Caterina; Fantoni, Alessandro; Alegria, Elisabete C. B. A.; Pacheco, Rita; Vieira, Manuela; Vieira, Manuela; Pacheco, Rita; Alegria, Elisabete; Fantoni, Alessandro
Colorimetric sensors are a type of sensing platform enabling visual measurements that offers an instant report. Due to their intrinsic advantages, such as low cost, simplicity, low acquisition time and no need for expensive instrumentation, colorimetric transducers are attracting a growing attention for the PoC devices. In light of their brilliant colors arising from their Localized Surface Plasmon Resonance (LSPR), gold nanoparticles have revealed a great potential to develop new analytical techniques and advanced assays. Stimulated by the need of PoC devices for an affordable and real-time detection of biomarkers outside clinical environment, in this work we explore the potential of gold nanoflowers (AuNFs) as sensing system to integrate in a PoC device. Firstly, gold AuNFs functionalized with NGAL antibodies along with antibodies conjugated onto AuNFs surface binding their complementary antigens will be synthesized and their transmittance spectra measured. In a successive step, the measured spectra have been converted into vectors in the L*a*b*, xyY and RGB Color spaces by means of simulation study. Transferring the study into real world application, the AuNFs will be integrated into the fiber network of paper to create the plasmonic paper that will be the transducer of a colorimetric device.
Macro-scale finite element simulation of wire-arc additive manufacturing
Publication . Pragana, J. P. M.; Sampaio, R. F. V.; Bragança, I. M. F.; Silva, C. M. A.; Nielsen, C. V.; Martins, P. A. F.; Bragança, Ivo; SAGE Publications Ltd.
This paper focuses on the development of a finite element computer software to perform macro-scale thermo-mechan ical simulations of wire-arc additive manufacturing (WAAM). The emphasis is placed on various aspects of computer implementation, such as modeling the heat source, incorporating an element birth approach to replicate material depos ition, and ensuring compatibility of solution time increments with the wire feed rate, travel speed of the heat source and melt pool volume. Thermal strains are also included due to their impact on residual stresses and distortions of the built parts after finishing material deposition. Experiments consisting of single bead, multi-layer deposition of AISI 316L stain less steel along linear paths are utilized to validate the predicted temperature distribution over time and evaluate the computed geometry and distortions of the deposited vertical walls after unclamping. Microstructure observations of samples extracted from the walls combined with finite element estimates of the temperature gradient help understand the
influence of temperature history on the morphology and orientation of columnar grain growth.