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Publicações

2024

AUTOMATED VISCERAL AND SUBCUTANEOUS FAT SEGMENTATION IN COMPUTED TOMOGRAPHY

Autores
Castro, R; Sousa, I; Nunes, F; Mancio, J; Fontes-Carvalho, R; Ferreira, C; Pedrosa, J;

Publicação
IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING, ISBI 2024

Abstract
Cardiovascular diseases are the leading causes of death worldwide. While there are a number of cardiovascular risk indicators, recent studies have found a connection between cardiovascular risk and the accumulation and characteristics of visceral adipose tissue in the ventral cavity. The quantification of visceral adipose tissue can be easily performed in computed tomography scans but the manual delineation of these structures is a time consuming process subject to variability. This has motivated the development of automatic tools to achieve a faster and more precise solution. This paper explores the use of a U-Net architecture to perform ventral cavity segmentation followed by the use of threshold-based approaches for visceral and subcutaneous adipose tissue segmentation. Experiments with different learning rates, input image sizes and types of loss functions were employed to assess the hyperparameters most suited to this problem. In an external test set, the ventral cavity segmentation model with the best performance achieved a 0.967 Dice Score Coefficient, while the visceral and subcutaneous adipose tissue achieve Dice Score Coefficients of 0.986 and 0.995. Not only are these competitive results when compared to state of the art, the interobserver variability measured in this external dataset was similar to these results confirming the robustness and reliability of the proposed segmentation.

2024

CINDERELLA Clinical trial (NCT05196269): using artificial intelligence-driven healthcare to enhance breast cancer locoregional treatment decisions

Autores
Bonel, EA; Kaidar-Person, O; Antunes, M; Ciani, O; Cruz, H; Di Micco, R; Gentilini, O; Heil, J; Kabata, P; Romariz, M; Gonçalves, T; Martins, H; Borsoi, L; Mika, M; Pfob, A; Romem, N; Schinköthe, T; Silva, G; Senkus, E; Cardoso, MJ;

Publicação
ANNALS OF SURGICAL ONCOLOGY

Abstract

2024

Review of Platforms and Frameworks for Building Virtual Assistants

Autores
Pereira, R; Lima, C; Reis, A; Pinto, T; Barroso, J;

Publicação
INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 3, WORLDCIST 2023

Abstract
Virtual assistants offer a new type of solution to handle interaction between human and machine and can be applied in various business contexts such as Industry or Education. When designing and building a virtual assistant the developers must ensure a set of parameters to achieve a good solution. Various platforms and frameworks emerged to allow developers to create virtual assistant solutions easier and faster. This paper provides a review of available platforms and frameworks used by authors to create their own solutions in different areas. Big tech companies like Google with Dialogflow, IBM with Watson Assistant and Microsoft with Bot Framework, present mature solutions to build virtual assistants that provide to the developer all components of the basic architecture to build a fast and solid solution. Open-Source solutions focus on providing to the developer the main components to build a virtual assistant, namely language understanding and response generation.

2024

Analyzing Sao Paulo's Place Branding Positioning in Promotional Videos (2017-2019)

Autores
Andrade, JG; Sampaio, A; Garcia, JE; Cairrao, A; da Fonseca, MJS;

Publicação
GOOD PRACTICES AND NEW PERSPECTIVES IN INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 6, WORLDCIST 2024

Abstract
This research aims to analyze the positioning theory and discourse within Sao Paulo's Place Branding from 2014 to 2019, investigating the symbolic representations employed by the Sao Paulo Tourism Bureau to emphasize its branding endeavors. The methodology employed a framework based on Semprini's [10] Project/Manifestation approach and Discourse Analysis. The impetus behind this study arises from the substantial investments made by cities to craft comprehensive disclosure strategies and establish place branding for their respective regions. We observed aspects of Communication and DigitalMarketing in the three promotional videos produced by SPTuris in 2014, 2017, and 2019, which underwent meticulous analysis. Our findings unveiled a consistent thematic discourse despite shifts in political administration. The 2014 video accentuated multiculturalism and cosmopolitanism, while the 2017 edition highlighted experiential marketing, business, consumption, and cosmopolitan elements. Remarkably, the 2019 presentation featured images emphasizing receptivity. Themes such as Culture, Arts, and Gastronomy were recurrent across all videos. The scrutinized discourse reaffirms Sao Paulo's capital as a trendsetter within Brazil.

2024

From fault detection to anomaly explanation: A case study on predictive maintenance

Autores
Gama, J; Ribeiro, RP; Mastelini, S; Davari, N; Veloso, B;

Publicação
JOURNAL OF WEB SEMANTICS

Abstract
Predictive Maintenance applications are increasingly complex, with interactions between many components. Black -box models are popular approaches based on deep -learning techniques due to their predictive accuracy. This paper proposes a neural -symbolic architecture that uses an online rule -learning algorithm to explain when the black -box model predicts failures. The proposed system solves two problems in parallel: (i) anomaly detection and (ii) explanation of the anomaly. For the first problem, we use an unsupervised state-of-the-art autoencoder. For the second problem, we train a rule learning system that learns a mapping from the input features to the autoencoder's reconstruction error. Both systems run online and in parallel. The autoencoder signals an alarm for the examples with a reconstruction error that exceeds a threshold. The causes of the signal alarm are hard for humans to understand because they result from a non-linear combination of sensor data. The rule that triggers that example describes the relationship between the input features and the autoencoder's reconstruction error. The rule explains the failure signal by indicating which sensors contribute to the alarm and allowing the identification of the component involved in the failure. The system can present global explanations for the black box model and local explanations for why the black box model predicts a failure. We evaluate the proposed system in a real -world case study of Metro do Porto and provide explanations that illustrate its benefits.

2024

Risk Adverse Optimization on Transmission Expansion Planning Considering Climate Change and Extreme Weather Events - The Texas Case

Autores
de Oliveira, LE; Saraiva, JT; Gomes, PV;

Publicação
2024 20TH INTERNATIONAL CONFERENCE ON THE EUROPEAN ENERGY MARKET, EEM 2024

Abstract
The global push for environmental sustainability is driving substantial changes in power systems, prompting extensive grid upgrades. Policies and initiatives worldwide aim to reduce CO2 emissions, with a focus on increasing reliance on Renewable Energy Sources (RESs) and electrifying transportation. However, the geographical variability and uncertainties of RESs directly impact power generation and distribution, necessitating adjustments in transmission system planning and operation. This paper presents a Transmission Expansion Planning (TEP) model using the 2021 Texas snowstorm as a benchmark scenario, incorporating wind and solar energy penetration while addressing associated uncertainties. Climate Change (CC) and Extreme Weather Events (EWE) are integrated into the set of scenarios aiming at evaluating the proposed method's effectiveness. Comparisons in extreme operative conditions highlight the importance of network reliability and security, emphasizing the significance of merged grids. All simulations are conducted using the ACTIVSg2000 synthetic test system, which emulates the ERCOT grid, with comparisons made between TEP scenarios considering and disregarding CC and EWEs, supporting the concept of umbrella protection.

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