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Publications

2021

Deformation Fringes Detection in SAR interferograms Using Deep Learning

Authors
Silva, B; Sousa, JJ; Lazecky, M; Cunha, A;

Publication
Procedia Computer Science

Abstract
The success achieved by using SAR data in the study of the Earth led to a firm commitment from space agencies to develop more and better space-borne SAR sensors. This involvement of the space agencies makes us believe that it is possible to increase the potential of SAR interferometry (InSAR) to near real-time monitoring. Among this ever-increasing number of sensors, the ESA's Sentinel-1 (C-band) mission stands out and appears to be disruptive. This mission is acquiring vast volumes of data making current analyzing approaches inviable. This amount of data can no longer be analyzed and studied using classic methods raising the need to use and create new techniques. We believe that Machine Learning techniques can be the solution to overcome this issue since they allow to train Deep Learning models to automate human processes for a vast volume of data. In this paper, we use deep learning models to automatically find and locate deformation areas in InSAR interferograms without atmospheric correction. We train three state-of-the-art classification models for detection deformation areas, achieving an AUC of 0.864 for the best model (VGG19 for wrapped interferograms). Additionally, we use the same models as encoders to train U-net models, achieving a Dice score of 0.54 for InceptionV3. It is necessary more data to achieve better results in segmentation.

2021

Machine Learning Methods for Signal, Image and Speech Processing

Authors
Jabbar M.A.; Prasad K.M.V.V.; Peng S.L.; Reaz M.B.I.; Madureira A.;

Publication
Machine Learning Methods for Signal Image and Speech Processing

Abstract
The signal processing (SP) landscape has been enriched by recent advances in artificial intelligence (AI) and machine learning (ML), yielding new tools for signal estimation, classification, prediction, and manipulation. Layered signal representations, nonlinear function approximation and nonlinear signal prediction are now feasible at very large scale in both dimensionality and data size. These are leading to significant performance gains in a variety of long-standing problem domains like speech and Image analysis. As well as providing the ability to construct new classes of nonlinear functions (e.g., fusion, nonlinear filtering). This book will help academics, researchers, developers, graduate and undergraduate students to comprehend complex SP data across a wide range of topical application areas such as social multimedia data collected from social media networks, medical imaging data, data from Covid tests etc. This book focuses on AI utilization in the speech, image, communications and yirtual reality domains.

2021

Femtosecond laser micromachining of an optofluidics-based monolithic whispering-gallery mode resonator coupled to a suspended waveguide

Authors
Maia, JM; Amorim, VA; Viveiros, D; Marques, PVS;

Publication
SCIENTIFIC REPORTS

Abstract
A monolithic lab-on-a-chip fabricated by femtosecond laser micromachining capable of label-free biosensing is reported. The device is entirely made of fused silica, and consists of a microdisk resonator integrated inside a microfluidic channel. Whispering gallery modes are excited by the evanescent field of a circular suspended waveguide, also incorporated within the channel. Thermal annealing is performed to decrease the surface roughness of the microstructures to a nanometric scale, thereby reducing intrinsic losses and maximizing the Q-factor. Further, thermally-induced morphing is used to position, with submicrometric precision, the suspended waveguide tangent to the microresonator to enhance the spatial overlap between the evanescent field of both optical modes. With this fabrication method and geometry, the alignment between the waveguide and the resonator is robust and guaranteed at all instances. A maximum sensitivity of 121.5 nm/RIU was obtained at a refractive index of 1.363, whereas near the refractive index range of water-based solutions the sensitivity is 40 nm/RIU. A high Q-factor of 10(5) is kept throughout the entire measurement range.

2021

A Survey on Data-Driven Predictive Maintenance for the Railway Industry

Authors
Davari, N; Veloso, B; Costa, GD; Pereira, PM; Ribeiro, RP; Gama, J;

Publication
SENSORS

Abstract
In the last few years, many works have addressed Predictive Maintenance (PdM) by the use of Machine Learning (ML) and Deep Learning (DL) solutions, especially the latter. The monitoring and logging of industrial equipment events, like temporal behavior and fault events-anomaly detection in time-series-can be obtained from records generated by sensors installed in different parts of an industrial plant. However, such progress is incipient because we still have many challenges, and the performance of applications depends on the appropriate choice of the method. This article presents a survey of existing ML and DL techniques for handling PdM in the railway industry. This survey discusses the main approaches for this specific application within a taxonomy defined by the type of task, employed methods, metrics of evaluation, the specific equipment or process, and datasets. Lastly, we conclude and outline some suggestions for future research.

2021

Smart4RES: Next generation solutions for renewable energy forecasting and applications with focus on distribution grids

Authors
Camal, S; Kariniotakis, G; Sossan, F; Libois, Q; Legrand, R; Raynaud, L; Lange, M; Mehrens, A; Pinson, P; Pierrot, A; Giebel, G; Göcmen, T; Bessa, R; Gouveia, J; Teixeira, L; Neto, A; Santos, RM; Mendes, G; Nouri, B; Lezaca, J; Verziljbergh, R; Deen, G; Sideratos, G; Vitellas, C; Sauba, G; Eijgelaar, M; Petit, S;

Publication
CIRED 2021 - The 26th International Conference and Exhibition on Electricity Distribution

Abstract

2021

Preface

Authors
Jabbar, MA; Prasad, KMVV; Peng, SL; Reaz, MBI; Madureira, A;

Publication
Machine Learning Methods for Signal, Image and Speech Processing

Abstract
[No abstract available]

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