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Publications

2024

A Multimodal Perception System for Precise Landing of UAVs in Offshore Environments

Authors
Claro, RM; Neves, FSP; Pinto, AMG;

Publication

Abstract
The integration of precise landing capabilities into UAVs is crucial for enabling autonomous operations, particularly in challenging environments such as the offshore scenarios. This work proposes a heterogeneous perception system that incorporates a multimodal fiducial marker, designed to improve the accuracy and robustness of autonomous landing of UAVs in both daytime and nighttime operations. This work presents ViTAL-TAPE, a visual transformer-based model, that enhance the detection reliability of the landing target and overcomes the changes in the illumination conditions and viewpoint positions, where traditional methods fail. VITAL-TAPE is an end-to-end model that combines multimodal perceptual information, including photometric and radiometric data, to detect landing targets defined by a fiducial marker with 6 degrees-of-freedom. Extensive experiments have proved the ability of VITAL-TAPE to detect fiducial markers with an error of 0.01 m. Moreover, experiments using the RAVEN UAV, designed to endure the challenging weather conditions of offshore scenarios, demonstrated that the autonomous landing technology proposed in this work achieved an accuracy up to 0.1 m. This research also presents the first successful autonomous operation of a UAV in a commercial offshore wind farm with floating foundations installed in the Atlantic Ocean. These experiments showcased the system’s accuracy, resilience and robustness, resulting in a precise landing technology that extends mission capabilities of UAVs, enabling autonomous and Beyond Visual Line of Sight offshore operations.

2024

Augmented Reality in Omnichannel Marketing: A Systematic Review in the Retail Sector

Authors
Gomes, F; Pereira, I; Nicola, S; Silva, R; Pereira, A; Madureira, A;

Publication
Smart Innovation, Systems and Technologies

Abstract
Remaining current with emerging trends and technologies is crucial for businesses to stay at the forefront, satisfy consumer demands, and maintain competitiveness. As marketing strategies such as phygital and omnichannel tactics continue to evolve, technologies like augmented reality are becoming increasingly relevant and disruptive. Augmented reality is an innovative technology that is currently revolutionizing omnichannel marketing strategies. It offers numerous opportunities in both the metaverse and phygital marketing, greatly improving the overall customer experience, increasing sale success rate, and improving brand image. A systematic review using PRISMA methodology incorporating a total of six studies explores augmented reality (AR) technology’s influence on omnichannel marketing strategies in the retail industry. The findings analyze AR, omnichannel marketing, and the metaverse in-depth, their interplay, and how they influence the customer journey, experience, and behavior. This study explores how to effectively integrate AR into omnichannel marketing for retail, emphasizing on harnessing synergies between channels and devising targeted strategies. Research gaps in the literature are identified and future steps to seamlessly integrate channels through AR technology in retail. © The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2024.

2024

Effect of Weather Conditions and Transactions Records on Work Accidents in the Retail Sector - A Case Study

Authors
Borges, LD; Sena, I; Marcelino, V; Silva, FG; Fernandes, FP; Pacheco, MF; Vaz, CB; Lima, J; Pereira, AI;

Publication
OPTIMIZATION, LEARNING ALGORITHMS AND APPLICATIONS, PT I, OL2A 2023

Abstract
Weather change plays an important role in work-related accidents, it impairs people's cognitive abilities, increasing the risk of injuries and accidents. Furthermore, weather conditions can cause an increase or decrease in daily sales in the retail sector by influencing individual behaviors. The increase in transactions, in turn, leads employees to fatigue and overload, which can also increase the risk of injuries and accidents. This work aims to conduct a case study in a company in the retail sector to verify whether the transactions records in stores and the weather conditions of each district in mainland Portugal impact the occurrence of work accidents, as well as to perform predictive analysis of the occurrence or non-occurrence of work accidents in each district using these data and comparing different machine learning techniques. The correlation analysis of the occurrence or non-occurrence of work accidents with weather conditions and some transactions pointed out the nonexistence of correlation between the data. Evaluating the precision and the confusion matrix of the predictive models, the study indicates a predisposition of the models to predict the non-occurrence of work accidents to the detriment of the ability to predict the occurrence of work accidents.

2024

Reusing Past Machine Learning Models Based on Data Similarity Metrics

Authors
Peixoto, E; Carneiro, D; Torres, D; Silva, B; Novais, P;

Publication
Ambient Intelligence - Software and Applications - 15th International Symposium on Ambient Intelligence, ISAmI 2024, Salamanca, Spain, 26-28 June 2024.

Abstract
Many of today’s domains of application of Machine Learning (ML) are dynamic in the sense that data and their patterns change over time. This has a significant impact in the ML lifecycle and operations, requiring frequent model (re-)training, or other strategies to deal with outdated models and data. This need for dynamic and responsive solutions also has an impact on the use of computational resources and, consequently, on sustainability indicators. This paper proposes an approach in line with the concept of Frugal AI, whose main aim is to minimize the resources and time spent on training models by re-using models from a pool of past models, when appropriate. Specifically, we present and validate a methodology for similarity-based model selection in data streaming environments with concept drift. Rather than training a new model for each new block of data, this methodology considers a pool with only a subset of the models and, for each new block of data, will select the best model from the pool. The best model is determined based on the distance between its training data and the current block of data. Distance is calculated based on a set of meta-features that characterizes the data, and on the Bray-Curtis distance. We show that it is possible to reuse previous models using this methodology, leading to potentially significant saving of resources and time, while maintaining predictive quality. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2025.

2024

The City Makes Its Mark in a Review on Digital Communication and Citizenship

Authors
Andrade, JG; Sampaio, A; Garcia, JE; Fonseca, MJ;

Publication
INFORMATION SYSTEMS AND TECHNOLOGIES, VOL 4, WORLDCIST 2023

Abstract
This article delves into the intersections of place branding, digital strategic communication, citizenship, and tourism. It explores the dynamic relationship between these concepts, particularly within the context of Brazilian city governments. With an emphasis on reflexivity, the study investigates how governments manage their public image and engage citizens through digital channels. Simultaneously, it examines how these governments strategically position their cities as attractive tourist destinations. By analyzing these tensions and synergies, the article provides insights into the complex landscape of communication strategies employed by Brazilian city governments, which aim to balance citizen engagement and tourism promotion.

2024

Dynamic pricing in EV charging stations with renewable energy and battery storage

Authors
Silva, CAM; Andrade, JR; Bessa, RJ; Lobo, F;

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

Abstract
The integration of electric vehicles is paramount to the electrification of the transport sector, supporting the energy transition. The charging process of electric vehicles can be perceived as a controllable load and targeted with price or incentive-based programs. Demand-side management can optimize charging station performance and integrate renewable energy generation through electrical energy storage. Data flowing through charging stations can be used in computational approaches to solve open challenges and create new services, such as a dynamic pricing strategy, where the charging tariff depends on operating conditions. This work presents a data-driven service that optimizes day-ahead charging tariffs with a bilevel optimization problem and develops a case study around a large-scale pilot. The impact of photovoltaics and battery storage on the dynamic pricing scheme was assessed. A dynamic pricing strategy was found to benefit self-consumption and self-sufficiency of the charging station, increasing over 4 percentage points in some cases.

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