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Publications

2024

Combining UAV-Based Multispectral and Thermal Infrared Data with Regression Modeling and SHAP Analysis for Predicting Stomatal Conductance in Almond Orchards

Authors
Guimaraes, N; Sousa, JJ; Couto, P; Bento, A; Padua, L;

Publication
REMOTE SENSING

Abstract
Understanding and accurately predicting stomatal conductance in almond orchards is critical for effective water-management strategies, especially under challenging climatic conditions. In this study, machine-learning (ML) regression models trained on multispectral (MSP) and thermal infrared (TIR) data acquired from unmanned aerial vehicles (UAVs) are used to address this challenge. Through an analysis of spectral indices calculated from UAV-based data and feature-selection methods, this study investigates the predictive performance of three ML models (extra trees, ET; stochastic gradient descent, SGD; and extreme gradient boosting, XGBoost) in predicting stomatal conductance. The results show that the XGBoost model trained with both MSP and TIR data had the best performance (R2 = 0.87) and highlight the importance of integrating surface-temperature information in addition to other spectral indices to improve prediction accuracy, up to 11% more when compared to the use of only MSP data. Key features, such as the green-red vegetation index, chlorophyll red-edge index, and the ratio between canopy temperature and air temperature (Tc-Ta), prove to be relevant features for model performance and highlight their importance for the assessment of water stress dynamics. Furthermore, the implementation of Shapley additive explanations (SHAP) values facilitates the interpretation of model decisions and provides valuable insights into the contributions of the features. This study contributes to the advancement of precision agriculture by providing a novel approach for stomatal conductance prediction in almond orchards, supporting efforts towards sustainable water management in changing environmental conditions.

2024

Applying the LOT Methodology to Enhance the Cinematic Heritage Archives

Authors
Cosentino, A; Araújo, WJ; Koch, I;

Publication
International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management, IC3K - Proceedings

Abstract
The Locarno Film Festival (LFF) archives represent a valuable collection of cinematic history, providing essential resources for research, education, and the promotion of international film culture. To ensure these resources are easily accessible, it is crucial to develop advanced methods for managing and linking the information they contain. This work focuses on creating a shared way for organizing information, transforming the LFF archives into dynamic, interconnected resources. This transformation is essential for preserving cinematic heritage, improving discoverability, promoting digital transformation, and efficiently managing archives. Using an interdisciplinary approach, we developed the OntoFest following the Linked Open Terms (LOT) Methodology. Significant outcomes of this project include the successful reuse of existing ontologies to manage heterogeneous information, which has improved our ability to understand and retrieve relevant data. This work demonstrates the potential of digital archives in the cinematic field and provides a foundation for future initiatives in digitizing cinematic heritage archives. OntoFest not only contributes to preserving the cinematic cultural heritage of the LFF but also lays the groundwork for new research and creative applications in the digital transformation of film festival archives. © 2024 by SCITEPRESS – Science and Technology Publications, Lda.

2024

Static and Dynamic Comparison of Mutation Testing Tools for Python

Authors
Guerino, LR; Kuroishi, PH; Paiva, ACR; Vincenzi, AMR;

Publication
23TH BRAZILIAN SYMPOSIUM ON SOFTWARE QUALITY, SBQS 2024

Abstract
Context: Mutation testing is a rigorous approach for assessing the quality of test suites by injecting faults (i.e., mutants) into software under test. Tools, such as CosmicRay and Mutpy, are examples of Mutation Testing tools for Python software programs. Problem: With different Python mutation testing tools, comparative analysis is lacking to evaluate their effectiveness in different usage scenarios. Furthermore, the evolution of these tools makes continuous evaluation of their functionalities and characteristics necessary. Method: In this work, we evaluate (statically and dynamically) four Python mutation testing tools, namely CosmicRay, MutPy, MutMut, and Mutatest. In static evaluation, we introduce a comparison framework, adapted from one previously applied to Java tools, and collected information from tool documentation and developer surveys. For dynamic evaluation, we use tests built based on those produced by Pynguin, which are improved through the application of Large Language Models (LLMs) and manual analyses. Then, the adequate test suites were cross-tested among different tools to evaluate their effectiveness in killing mutants each other. Results: Our findings reveal that CosmicRay offers superior functionalities and customization options for mutant generation compared to its counterparts. Although CosmicRay's performance was slightly lower than MutPy in the dynamic tests, its recent updates and active community support highlight its potential for future enhancements. Cross-examination of the test suites further shows that mutation scores varied narrowly among tools, with a slight emphasis on MutPy as the most effective mutant fault model.

2024

Online detection and infographic explanation of spam reviews with data drift adaptation

Authors
Arriba Pérez, Fd; Méndez, SG; Leal, F; Malheiro, B; Burguillo, JC;

Publication
CoRR

Abstract

2024

High contrast at short separation with VLTI/GRAVITY: Bringing Gaia companions to light

Authors
Pourré, N; Winterhalder, TO; Le Bouquin, J; Lacour, S; Bidot, A; Nowak, M; Maire, A; Mouillet, D; Babusiaux, C; Woillez, J; Abuter, R; Amorim, A; Asensio Torres, R; Balmer, WO; Benisty, M; Berger, J; Beust, H; Blunt, S; Boccaletti, A; Bonnefoy, M; Bonnet, H; Bordoni, MS; Bourdarot, G; Brandner, W; Cantalloube, F; Caselli, P; Charnay, B; Chauvin, G; Chavez, A; Choquet, E; Christiaens, V; Clénet, Y; Du Foresto, V; Cridland, A; Davies, R; Defrère, D; Dembet, R; Dexter, J; Drescher, A; Duvert, G; Eckart, A; Eisenhauer, F; Schreiber, NM; Garcia, P; Lopez, R; Gendron, E; Genzel, R; Gillessen, S; Girard, JH; Gonte, F; Grant, S; Haubois, X; Heiãà  El, G; Henning, T; Hinkley, S; Hippler, S; Hönig, SF; Houllé, M; Hubert, Z; Jocou, L; Kammerer, J; Kenworthy, M; Keppler, M; Kervella, P; Kreidberg, L; Kurtovic, NT; Lagrange, A; Lapeyrère, V; Lutz, D; Mang, F; Marleau, G; Mérand, A; Millour, F; Mollière, P; Monnier, JD; Mordasini, C; Nasedkin, E; Oberti, S; Ott, T; Otten, GPPL; Paladini, C; Paumard, T; Perraut, K; Perrin, G; Pfuhl, O; Pueyo, L; Ribeiro, DC; Rickman, E; Rustamkulov, Z; Shangguan, J; Shimizu, T; Sing, D; Soulez, F; Stadler, J; Stolker, T; Straub, O; Straubmeier, C; Sturm, E; Sykes, C; Tacconi, LJ; Van Dishoeck, EF; Vigan, A; Vincent, F; Von Fellenberg, SD; Wang, JJ; Widmann, F; Yazici, S; Abad, JA; Aller Carpentie, E; Alonso, J; Andolfato, L; Barriga, P; Beuzit, J; Bourget, P; Brast, R; Caniguante, L; Cottalorda, E; Darré, P; Delabre, B; Delboulbé, A; Delplancke Ströbele, F; Donaldson, R; Dorn, R; Dupuy, C; Egner, S; Fischer, G; Frank, C; Fuenteseca, E; Gitton, P; Guerlet, T; Guieu, S; Gutierrez, P; Haguenauer, P; Haimerl, A; Heritier, CT; Huber, S; Hubin, N; Jolley, P; Kirchbauer, J; Kolb, J; Kosmalski, J; Krempl, P; Le Louarn, M; Lilley, P; Lopez, B; Magnard, Y; McLay, S; Meilland, A; Meister, A; Moulin, T; Pasquini, L; Paufique, J; Percheron, I; Pettazzi, L; Phan, D; Pirani, W; Quentin, J; Rakich, A; Ridings, R; Reyes, J; Rochat, S; Schmid, C; Schuhler, N; Shchekaturov, P; Seidel, M; Soenke, C; Stadler, E; Stephan, C; Suárez, M; Todorovic, M; Valdes, G; Verinaud, C; Zins, G; Zúñiga Fernández, S;

Publication
ASTRONOMY & ASTROPHYSICS

Abstract
Context. Since 2019, GRAVITY has provided direct observations of giant planets and brown dwarfs at separations of down to 95 mas from the host star. Some of these observations have provided the first direct confirmation of companions previously detected by indirect techniques (astrometry and radial velocities). Aims. We want to improve the observing strategy and data reduction in order to lower the inner working angle of GRAVITY in dual-field on-axis mode. We also want to determine the current limitations of the instrument when observing faint companions with separations in the 30-150 mas range. Methods. To improve the inner working angle, we propose a fiber off-pointing strategy during the observations to maximize the ratio of companion-light-to-star-light coupling in the science fiber. We also tested a lower-order model for speckles to decouple the companion light from the star light. We then evaluated the detection limits of GRAVITY using planet injection and retrieval in representative archival data. We compare our results to theoretical expectations. Results. We validate our observing and data-reduction strategy with on-sky observations; first in the context of brown dwarf follow-up on the auxiliary telescopes with HD 984 B, and second with the first confirmation of a substellar candidate around the star Gaia DR3 2728129004119806464. With synthetic companion injection, we demonstrate that the instrument can detect companions down to a contrast of 8 x 10(-4) (Delta K = 7.7 mag) at a separation of 35 mas, and a contrast of 3 x 10(-5) (Delta K = 11 mag) at 100 mas from a bright primary (K < 6.5), for 30 min exposure time. Conclusions. With its inner working angle and astrometric precision, GRAVITY has a unique reach in direct observation parameter space. This study demonstrates the promising synergies between GRAVITY and Gaia for the confirmation and characterization of substellar companions.

2024

Perceived greenwashing and its impact on eco-friendly product purchase

Authors
Shojaei, AS; Barbosa, B; Oliveira, Z; Coelho, AMR;

Publication
TOURISM & MANAGEMENT STUDIES

Abstract
The main aim of this article is to investigate the effect of perceived greenwashing on consumers' purchasing behavior of eco-friendly products. Twelve research hypotheses were defined based on contributions from the literature. To test these hypotheses, a quantitative methodology was employed, collecting data through an online survey (N = 270) and using SmartPLS for analysis. The results confirm that perceived both perceived greenwashing and perceived risk have a negative influence on consumer attitudes. While their direct effects on purchase intention were found to be insignificant, both perceived greenwashing and perceived risk had a significant negative indirect effect on purchase intention through attitude. Additionally, it was confirmed that purchase behavior is positively affected by attitude and by willingness to pay more. These results contribute to addressing the limited knowledge regarding the impact of consumers' perceived greenwashing on their behavior, especially concerning different product types. Furthermore, they provide valuable insights for managers, highlighting the importance of mitigating greenwashing and risk perceptions associated with eco-friendly products due to their indirect negative impacts on purchase intention and behavior.

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