2023
Autores
Peçaibes, V; Cardoso, P; Giesteira, B; Castro, L;
Publicação
?III SEVEN INTERNATIONAL CONGRESS OF HEALTH
Abstract
2023
Autores
Soulain, A; Perraut, K; Bouvier, J; Pantolmos, G; Caratti O Garatti, A; Caselli, P; Garcia, P; Lopez, R; Aimar, N; Amorin, A; Benisty, M; Berger, J; Bourdarot, G; Brandner, W; Clénet, Y; De Zeeuw, T; Davies, R; Drescher, A; Eckart, A; Eisenhauer, F; Schreiber, NM; Gendron, E; Genzuel, R; Gillessen, S; Heißel, G; Henning, T; Hippler, S; Horrobin, M; Jocou, L; Kervella, P; Labadie, L; Lacour, S; Lapeyrere, V; Le Bouquin, J; Léna, P; Lutz, D; Mang, F; Ott, T; Paumard, T; Perrin, G; Sanchez, J; Scheithauer, S; Shangguan, J; Shimizu, T; Straub, O; Straubmeier, C; Sturm, E; Tacconi, LJ; Vincent, F; Van Dishoeck, E; Widmann, F; Wieprecht, E; Wiezorrek, E; Yazici, S;
Publicação
ASTRONOMY & ASTROPHYSICS
Abstract
Context. T Tauri stars are known to be the cradle of planet formation. Most exoplanets discovered to date lie at the very inner part of the circumstellar disk (<1 au). The innermost scale of young stellar objects is therefore a compelling region to be addressed, and long-baseline interferometry is a key technique to unveil their mysteries. Aims. We aim to spatially and spectrally resolve the innermost scale (<= 1 au) of the young stellar system CI Tau to constrain the inner disk properties and better understand the magnetospheric accretion phenomenon. Methods. The high sensitivity offered by the combination of the four 8-m class telescopes of the Very Large Telescope Interferometer (VLTI) allied with the high spectral resolution (R similar to 4000) of the K-band beam combiner GRAVITY offers a unique capability to probe the sub-au scale of the CI Tau system, tracing both dust (continuum) and gas (Br gamma line) emission regions. We developed a physically motivated geometrical model to fit the interferometric observables - visibilities and closure phases (CP) - and constrained the physical properties of the inner dusty disk. The continuum-corrected pure line visibilities have been used to estimate the size of the Hydrogen Br gamma emitting region. Results. From the K-band continuum study, we report a highly inclined (i similar to 70 degrees) resolved inner dusty disk, with an inner edge located at a distance of 21 +/- 2 R-star from the central star, which is significantly larger than the dust sublimation radius (R-sub = 4.3 to 8.6 R-star). The inner disk appears misaligned compared to the outer disk observed by ALMA and the non-zero closure phase indicates the presence of an asymmetry that could be reproduced with an azimuthally modulated ring with a brighter south-west side. From the differential visibilities across the Br gamma line, we resolved the line-emitting region, and measured a size of 4.8(-1.0)(+0.8) R-star. Conclusions. The extended inner disk edge compared to the dust sublimation radius is consistent with the claim of an inner planet, CI Tau b, orbiting close in. The inner-outer disk misalignment may be induced by gravitational torques or magnetic warping. The size of the Br gamma emitting region is consistent with the magnetospheric accretion process. Assuming it corresponds to the magnetospheric radius, it is significantly smaller than the co-rotation radius (R-cor = 8.8 +/- 1.3 R-star), which suggests an unstable accretion regime that is consistent with CI Tau being a burster.
2023
Autores
Morujao, N; Correia, C; Andrade, P; Woillez, J; Garcia, P;
Publicação
ASTRONOMY & ASTROPHYSICS
Abstract
Context. Monitoring turbulence parameters is crucial in high-angular resolution astronomy for various purposes, such as optimising adaptive optics systems or fringe trackers. The former systems are present at most modern observatories and will remain significant in the future. This makes them a valuable complementary tool for the estimation of turbulence parameters. Aims. The feasibility of estimating turbulence parameters from low-resolution sensors remains untested. We performed seeing estimates for both simulated and on-sky telemetry data sourced from the new adaptive optics module installed on the four Auxiliary Telescopes of the Very Large Telescope Interferometer. Methods. The seeing estimates were obtained from a modified and optimised algorithm that employs a chi-squared modal fitting approach to the theoretical von Karman model variances. The algorithm was built to retrieve turbulence parameters while simultaneously estimating and accounting for the remaining and measurement error. A Monte Carlo method was proposed for the estimation of the statistical uncertainty of the algorithm. Results. The algorithm is shown to be able to achieve per-cent accuracy in the estimation of the seeing with a temporal horizon of 20 s on simulated data. A (0.76 '' +/- 1.2%vertical bar(stat) +/- 1.2%vertical bar(sys)) median seeing was estimated from on-sky data collected from 2018 to 2020. The spatial distribution of the Auxiliary Telescopes across the Paranal Observatory was found to not play a role in the value of the seeing.
2023
Autores
Pimentel L.; Bernardo M.D.R.M.; Rocha T.;
Publicação
Iberian Conference on Information Systems and Technologies, CISTI
Abstract
The intensive use of electronic equipment and the growing offer of services over the Internet has increased the incidence of computer crime. Although there are public measures in Portugal aimed at promoting the digital skills of citizens in matters of security and privacy of electronic equipment, they need to address the more complex aspects of this type of crime. Due to this specificity, preventive measures of the phenomenon may benefit from the know-how and experience of entities with legal powers in the area, especially the National Center for Cybersecurity (CNCS), the Public Prosecutor's Office (MP), and the Judicial Police (PJ). In the public administration in Portugal, emerging technologies based on artificial intelligence (AI) are being adopted to enhance communication between the State and citizens. Awareness-raising extensive actions should make use of these technological tools. Thus, this article describes the research leading to the identification of an efficient electronic device (artifact) in an e-government context aimed at informing and raising awareness among citizens about the growing phenomenon of cybercrime.
2023
Autores
Oliveira M.M.A.D.; Lima R.C.S.; Costa M.V.L.D.; Trindade C.S.; Queiroz P.G.G.;
Publicação
ACM International Conference Proceeding Series
Abstract
Designing systems to serve a large number of people, who have similar demands, but also have varied needs and generate a huge volume of data, requires a software architecture that allows constant evolution, is easy to maintain, and has the ability to scale smartly. The SPL technique with microservices architecture seems promising to meet these requirements, but this integration is not trivial. Thus, we conduct a SLR that identified 3 architectures that proposed the combination of these techniques. However, the architectures found were complex and reduced time-to-market, as they proposed the implementation of all resources through microservices. Thus, in order to reduce the complexity of development and, consequently, reduce the time to market, this work presents a proposal for the design of a hybrid SPL architecture, through the combination of large backend APIs and microservices. In addition, this research paper presents a case study that consisted of defining the architecture of a medical clinics SPL as a Multi-tenant Software as a Service. Finally, we compare the complexity of the architecture generated using our approach, with a microservice architecture constructed using other approach found in literature.
2023
Autores
Oliveira, LT; Carravilla, MA; Oliveira, JF; Toledo, FMB;
Publicação
Pesquisa Operacional
Abstract
Irregular strip packing problems are present in a wide variety of industrial sectors, such as the garment, footwear, furniture and metal industry. The goal is to find a layout in which an object will be cut into small pieces with minimum raw-material waste. Once a layout is obtained, it is necessary to determine the path that the cutting tool has to follow to cut the pieces from the layout. In the latter, the goal is to minimize the cutting distance (or time). Although industries frequently use this solution sequence, the trade-off between the packing and the cutting path problems can significantly impact the production cost and productivity. A layout with minimum raw-material waste, obtained through the packing problem resolution, can imply a longer cutting path compared to another layout with more material waste but a shorter cutting path, obtained through an integrated strategy. Layouts with shorter cutting path are worthy of consideration because they may improve the cutting process productivity. In this paper, both problems are solved together using a biobjective matheuristic based on the Biased Random-Key Genetic Algorithm. Our approach uses this algorithm to select a subset of the no-fit polygons edges to feed the mathematical model, which will compute the layout waste and cutting path length. Solving both strip packing and cutting path problems simultaneously allows the decision-maker to analyze the compromise between the material waste and the cutting path distance. As expected, the computational results showed the trade-off’s relevance between these problems and presented a set of solutions for each instance solved. © 2023, Sociedade Brasileira de Pesquisa Operacional. All rights reserved.
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