2024
Autores
Jesus, SM; Saleiro, P; Silva, IOe; Jorge, BM; Ribeiro, RP; Gama, J; Bizarro, P; Ghani, R;
Publicação
J. Mach. Learn. Res.
Abstract
Aequitas Flow is an open-source framework and toolkit for end-to-end Fair Machine Learning (ML) experimentation, and benchmarking in Python. This package fills integration gaps that exist in other fair ML packages. In addition to the existing audit capabilities in Aequitas, the Aequitas Flow module provides a pipeline for fairness-aware model training, hyperparameter optimization, and evaluation, enabling easy-to-use and rapid experiments and analysis of results. Aimed at ML practitioners and researchers, the framework offers implementations of methods, datasets, metrics, and standard interfaces for these components to improve extensibility. By facilitating the development of fair ML practices, Aequitas Flow hopes to enhance the incorporation of fairness concepts in AI systems making AI systems more robust and fair. © 2025 Elsevier B.V., All rights reserved.
2024
Autores
Pinheiro, CR; Guerreiro, SLPD; Mamede, HS;
Publicação
IEEE ACCESS
Abstract
Enterprise Architecture (EA) is defined as a set of principles, methods, and models that support the design of organizational structures, expressing the different concerns of a company and its IT landscape, including processes, services, applications, and data. One role of EA management is to automate modeling tasks and maintain up-to-date EA models while reality changes. However, EA modeling still relies primarily on manual methods. Contributing to EA modeling automation, EA Mining is an approach that uses data mining techniques for EA modeling and management. It automatically captures existing information in operational databases to generate architectural models and views. This paper presents an ontology for EA Mining that focuses on generating architectural models from API gateway log files. An ontology defines the concepts and relationships among them to uniquely describe a domain of interest and specify the meaning of the terms. API Gateways are information technology components that serve as a facade between information systems and enterprise business partners. The ontology development methodology followed the SABiO process, whereas the Unified Foundational Ontology provided the foundations of the ontology and OntoUML, the ontology modeling language. An experiment in an e-commerce application scenario was conducted to evaluate the theoretical feasibility and applicability of the ontology. Automatic semantic and syntactic validation tools and semi-structured expert interviews were used to confirm the desired ontology properties. This study aims to contribute to the evolution of the knowledge base of EA Management.
2024
Autores
Assaf, R; Mendes, D; Rodrigues, R;
Publicação
COMPUTER GRAPHICS FORUM
Abstract
Collaboration in extended reality (XR) environments presents complex challenges that revolve around how users perceive the presence, intentions, and actions of their collaborators. This paper delves into the intricate realm of group awareness, focusing specifically on workspace awareness and the innovative visual cues designed to enhance user comprehension. The research begins by identifying a spectrum of collaborative situations drawn from an analysis of XR prototypes in the existing literature. Then, we describe and introduce a novel classification for workspace awareness, along with an exploration of visual cues recently employed in research endeavors. Lastly, we present the key findings and shine a spotlight on promising yet unexplored topics. This work not only serves as a reference for experienced researchers seeking to inform the design of their own collaborative XR applications but also extends a welcoming hand to newcomers in this dynamic field.
2024
Autores
Guimaraes, JD; Vasilevskiy, MI; Barbosa, LS;
Publicação
QUANTUM
Abstract
Classical non-perturbative simulations of open quantum systems' dynamics face several scalability problems, namely, exponential scaling of the computational effort as a function of either the time length of the simulation or the size of the open system. In this work, we propose the use of the Time Evolving Density operator with Orthogonal Polynomials Algorithm (TEDOPA) on a quantum computer, which we term as Quantum TEDOPA (Q-TEDOPA), to simulate nonperturbative dynamics of open quantum systems linearly coupled to a bosonic environment (continuous phonon bath). By performing a change of basis of the Hamiltonian, the TEDOPA yields a chain of harmonic oscillators with only local nearestneighbour interactions, making this algorithm suitable for implementation on quantum devices with limited qubit connectivity such as superconducting quantum processors. We analyse in detail the implementation of the TEDOPA on a quantum device and show that exponential scalings of computational resources can potentially be avoided for time-evolution simulations of the systems considered in this work. We applied the proposed method to the simulation of the exciton transport between two light-harvesting molecules in the regime of moderate coupling strength to a non-Markovian harmonic oscillator environment on an IBMQ device. Applications of the Q-TEDOPA span problems which can not be solved by perturbation techniques belonging to different areas, such as the dynamics of quantum biological systems and strongly correlated condensed matter systems.
2024
Autores
Amorim, P; Dehoratius, N; Eng Larsson, F; Martins, S;
Publicação
MANAGEMENT SCIENCE
Abstract
Retailers face increasing competitive pressure to determine how best to deliver products purchased online to the end customer. Grocery retailers often require attended home delivery where the customer must be present to receive the delivery. For attended home delivery to function, the retailer and customer must agree on a delivery time slot that works for both parties. Using online data from a grocery retailer, we observe customer preferences for three delivery service attributes associated with each time slot: speed, precision, and timing. We define speed as the expected time between the placement of an order and its delivery, precision as the duration of the offered time slot, and timing as the availability of choices across times of the day and days of the week. We show that customers not only value speed as an attribute of delivery service but that precision and timing are also key drivers of the customer's time slot selection process. We also observe substantial customer heterogeneity in the willingness of customers to pay for time slots. Customers that differ in their loyalty to the retailer, basket value, basket size, and basket composition exhibit distinct differences in their willingness to pay. We show that retailers with the capability to tailor their time slot offerings to specific customer segments have the potential to generate approximately 9% more shipping revenue than those who cannot. Our findings inform practitioners seeking to design competitive fulfillment strategies and academics customer behavior in the attended home context.
2024
Autores
Balmer, WO; Pueyo, L; Lacour, S; Wang, JJ; Stolker, T; Kammerer, J; Pourré, N; Nowak, M; Rickman, E; Blunt, S; Sivaramakrishnan, A; Sing, D; Wagner, K; Marleau, GD; Lagrange, AM; Abuter, R; Amorim, A; Asensio-Torres, R; Berger, JP; Beust, H; Boccaletti, A; Bohn, A; Bonnefoy, M; Bonnet, H; Bordoni, MS; Bourdarot, G; Brandner, W; Cantalloube, F; Caselli, P; Charnay, B; Chauvin, G; Chavez, A; Choquet, E; Christiaens,; Clénet, Y; du Foresto, VC; Cridland, A; Davies, R; Dembet, R; Drescher, A; Duvert, G; Eckart, A; Eisenhauer, F; Schreiber, NMF; Garcia, P; Lopez, RG; Gendron, E; Genzel, R; Gillessen, S; Girard, JH; Grant, S; Haubois, X; Heissel, G; Henning, T; Hinkley, S; Hippler, S; Houllé, M; Hubert, Z; Jocou, L; Keppler, M; Kervella, P; Kreidberg, L; Kurtovic, NT; Lapeyrère,; Le Bouquin, JB; Léna, P; Lutz, D; Maire, AL; Mang, F; Mérand, A; Mollière, P; Mordasini, C; Mouillet, D; Nasedkin, E; Ott, T; Otten, GPPL; Paladini, C; Paumard, T; Perraut, K; Perrin, G; Pfuhl, O; Ribeiro, DC; Rodet, L; Rustamkulov, Z; Shangguan, J; Shimizu, T; Straubmeier, C; Sturm, E; Tacconi, LJ; Vigan, A; Vincent, F; Ward-Duong, K; Widmann, F; Winterhalder, T; Woillez, J; Yazici, S;
Publicação
ASTRONOMICAL JOURNAL
Abstract
Young, low-mass brown dwarfs orbiting early-type stars, with low mass ratios (q less than or similar to 0.01), appear to be intrinsically rare and present a formation dilemma: could a handful of these objects be the highest-mass outcomes of planetary formation channels (bottom up within a protoplanetary disk), or are they more representative of the lowest-mass failed binaries (formed via disk fragmentation or core fragmentation)? Additionally, their orbits can yield model-independent dynamical masses, and when paired with wide wavelength coverage and accurate system age estimates, can constrain evolutionary models in a regime where the models have a wide dispersion depending on the initial conditions. We present new interferometric observations of the 16 Myr substellar companion HD 136164 Ab (HIP 75056 Ab) made with the Very Large Telescope Interferometer (VLTI)/GRAVITY and an updated orbit fit including proper motion measurements from the Hipparcos-Gaia Catalog of Accelerations. We estimate a dynamical mass of 35 +/- 10 M-J (q similar to 0.02), making HD 136164 Ab the youngest substellar companion with a dynamical mass estimate. The new mass and newly constrained orbital eccentricity (e = 0.44 +/- 0.03) and separation (22.5 +/- 1 au) could indicate that the companion formed via the low-mass tail of the initial mass function. Our atmospheric fit to a SPHINX M-dwarf model grid suggests a subsolar C/O ratio of 0.45 and 3 x solar metallicity, which could indicate formation in a circumstellar disk via disk fragmentation. Either way, the revised mass estimate likely excludes bottom-up formation via core accretion in a circumstellar disk. HD 136164 Ab joins a select group of young substellar objects with dynamical mass estimates; epoch astrometry from future Gaia data releases will constrain the dynamical mass of this crucial object further.
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