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Publicações

2019

Industry 4.0 implications in machine vision metrology: An overview

Autores
Alonso, V; Dacal Nieto, A; Barreto, L; Amaral, A; Rivero, E;

Publicação
Procedia Manufacturing

Abstract
Industry 4.0 is changing disruptively all the industrial processes from their base, and metrology is being challenged by this new 'wave' of rethinking industry. Therefore, new quality control systems are being conceived for measurement purposes, as well as being installed in factories, which represents a huge management challenge, towards handling and processing a large amount of data, as well as developing the required theory for metrology assessment. In this paper, three examples of machine vision systems are presented, which are used to highlight some of the main issues that metrology must deal within this new paradigm. As a main conclusion, every company needs to design its own roadmap towards implementing the adequate methods and processes to be properly adapted and aligned with this new generation of metrology-related systems. © 2019 The Authors. Published by Elsevier B.V.

2019

Reconstruction of Optical Vector-Fields With Applications in Endoscopic Imaging

Autores
Gataric, M; Gordon, GSD; Renna, F; Ramos, AGCP; Alcolea, MP; Bohndiek, SE;

Publicação
IEEE TRANSACTIONS ON MEDICAL IMAGING

Abstract
We introduce a framework for the reconstruction of the amplitude, phase, and polarization of an optical vector-field using measurements acquired by an imaging device characterized by an integral transform with an unknown spatially variant kernel. By incorporating effective regularization terms, this new approach is able to recover an optical vector-field with respect to an arbitrary representation system, which may be different from the one used for device calibration. In particular, it enables the recovery of an optical vector-field with respect to a Fourier basis, which is shown to yield indicative features of increased scattering associated with tissue abnormalities. We demonstrate the effectiveness of our approach using synthetic holographic images and biological tissue samples in an experimental setting, where the measurements of an optical vector-field are acquired by a multicore fiber endoscope, and observe that indeed the recovered Fourier coefficients are useful in distinguishing healthy tissues from tumors in early stages of oesophageal cancer.

2019

Typical Optical Clearing Agents

Autores
Oliveira, LMC; Tuchin, VV;

Publicação
SpringerBriefs in Physics

Abstract
With the growing research in the field of optical clearing and the various applications of this technique that have been recently developed, more than 1000 agents have been tested in various tissues in the past two decades to evaluate their clearing potential. To optimize the clearing treatments, knowledge on the dispersions and absorption spectra of the agents is necessary. We have gathered experimental and literature data to show that the absorption bands of typical clearing agents are located in the deep ultraviolet range, where the refractive index is significantly high. The desired characteristics for the clearing agents are presented, and their classification in three major groups is indicated. Solutions containing mixtures of optical clearing agents (OCAs) and diluted solutions are also important for certain applications, such as the enhancement of agent delivery or the evaluation of agent diffusion properties. Such applications are referred, and some examples are presented. A simple method to prepare diluted solutions of clearing agents is also described. © 2019, The Author(s), under exclusive license to Springer Nature Switzerland AG.

2019

Intelligent sensing and ubiquitous systems (ISUS) for smarter and safer home healthcare

Autores
Moreira, RS; Torres, J; Sobral, P; Soares, C;

Publicação
Intelligent Pervasive Computing Systems for Smarter Healthcare

Abstract
Abstract The world population is facing several difficulties related to an aging society. In particular, the widespread increase of chronic and incapacitating diseases is overwhelming for traditional healthcare services. Ambient assisted living (AAL) systems can greatly improve healthcare scalability and scope while keeping people in the comfort of their home environments. This chapter focuses precisely on presenting the fundamental key aspects (cf. processing and sensing, integration and management, communication and coordination, intelligence and reasoning) to promote safety and support for outpatients living autonomously in AAL settings. Furthermore, for each key issue, a set of practical technological solutions are reported and detailed, showing real applicability of ubicomp technology to the integration and management of AAL systems specially designed for supporting daily living activities of people with progressive loss of capacities. © 2019 John Wiley & Sons, Ltd.

2019

The GRAVITY Young Stellar Object survey I. Probing the disks of Herbig Ae/Be stars in terrestrial orbits

Autores
Perraut, K; Labadie, L; Lazareff, B; Klarmann, L; Segura Cox, D; Benisty, M; Bouvier, J; Brandner, W; Garatti, ACO; Caselli, P; Dougados, C; Garcia, P; Garcia Lopez, R; Kendrew, S; Koutoulaki, M; Kervella, P; Lin, CC; Pineda, J; Sanchez Bermudez, J; van Dishoeck, E; Abuter, R; Amorim, A; Berger, JP; Bonnet, H; Buron, A; Cantalloube, F; Clenet, Y; du Foresto, VC; Dexter, J; de Zeeuw, PT; Duvert, G; Eckart, A; Eisenhauer, F; Eupen, F; Gao, F; Gendron, E; Genzel, R; Gillessen, S; Gordo, P; Grellmann, R; Haubois, X; Haussmann, F; Henning, T; Hippler, S; Horrobin, M; Hubert, Z; Jocou, L; Lacour, S; Le Bouquin, JB; Lena, P; Merand, A; Ott, T; Paumard, T; Perrin, G; Pfuhl, O; Rabien, S; Ray, T; Rau, C; Rousset, G; Scheithauer, S; Straub, O; Straubmeier, C; Sturm, E; Vincent, F; Waisberg, I; Wank, I; Widmann, F; Wieprecht, E; Wiest, M; Wiezorrek, E; Woillez, J; Yazici, S;

Publicação
ASTRONOMY & ASTROPHYSICS

Abstract
Context. The formation and the evolution of protoplanetary disks are important stages in the lifetime of stars. Terrestrial planets form or migrate within the innermost regions of these protoplanetary disks and so, the processes of disk evolution and planet formation are intrinsically linked. Studies of the dust distribution, composition, and evolution of these regions are crucial to understanding planet formation. Aims. We built a homogeneous observational dataset of Herbig Ae/Be disks with the aim of spatially resolving the sub au-scale region to gain a statistical understanding of their morphological and compositional properties, in addition to looking for correlations with stellar parameters, such as luminosity, mass, and age. Methods. We observed 27 Herbig Ae/Be stars with the GRAVITY instrument installed at the combined focus of the Very Large Telescope Interferometer (VLTI) and operating in the near-infrared K-band, focused on the K-band thermal continuum, which corresponds to stellar flux reprocessed by the dust grains. Our sample covers a large range of effective temperatures, luminosities, masses, and ages for the intermediate-mass star population. The circumstellar disks in our sample also cover a range of various properties in terms of reprocessed flux, flared or flat morphology, and gaps. We developed semi-physical geometrical models to fit our interferometric data. Results. Our best-fit models correspond to smooth and wide rings that support previous findings in the H-band, implying that wedgeshaped rims at the dust sublimation edge are favored. The measured closure phases are generally non-null with a median value of similar to 10 degrees, indicating spatial asymmetries of the intensity distributions. Multi-size grain populations could explain the closure phase ranges below 20-25 degrees but other scenarios should be invoked to explain the largest ones. Our measurements extend the Radius-Luminosity relation to similar to 10(4) L-circle dot luminosity values and confirm the significant spread around the mean relation observed by PIONIER in the H-band. Gapped sources exhibit a large N-to-K band size ratio and large values of this ratio are only observed for the members of our sample that would be older than 1 Ma, less massive, and with lower luminosity. In the mass range of 2 M-circle dot, we do observe a correlation in the increase of the relative age with the transition from group II to group I, and an increase of the N-to-K size ratio. However, the size of the current sample does not yet permit us to invoke a clear, universal evolution mechanism across the Herbig Ae/Be mass range. The measured locations of the K-band emission in our sample suggest that these disks might be structured by forming young planets, rather than by depletion due to EUV, FUV, and X-ray photo-evaporation.

2019

Multi-Objective Optimisation of an Active Distribution System using Normalised Normal Constraint Method

Autores
Saffari, M; Misaghian, MS; Flynn, D; Kia, M; Vahidinasab, V; Lotfi, M; Catalao, JPS; Shafie Khah, M;

Publicação
2019 IEEE MILAN POWERTECH

Abstract
An increasing implementation of renewable sources and electric vehicles can be of help in reducing the total operational cost of a power system, affecting power system technical operation. To this end, a multi-objective optimisation method using Normalised Normal Constraint (NNC) is applied in this paper by which two competitive objectives are considered: Minimisation of Active Distribution System (ADS) operational cost and minimisation of ADS power losses. Meanwhile, the uncertain behaviour of wind, photovoltaic units, and arrival and departure time of electric vehicles are considered. The proposed model is a multi-objective problem which comprises two stochastic stages and is simulated under GAMS environment on a modified IEEE 18-bus test system. The results clearly represent the trade-off between economic and technical benefits of the considered ADS. Furthermore, the effect of electric vehicles charging and discharging tariffs on the operational cost of the system are shown.

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