2022
Authors
Bifet, A; Ferreira, C; Gama, J; Gomes, HM;
Publication
Proceedings of the ACM Symposium on Applied Computing
Abstract
[No abstract available]
2022
Authors
Andrade, T; Gama, J;
Publication
PROGRESS IN ARTIFICIAL INTELLIGENCE, EPIA 2022
Abstract
Analyzing the way individuals move is fundamental to understand the dynamics of humanity. Transportation mode plays a significant role in human behavior as it changes how individuals travel, how far, and how often they can move. The identification of transportation modes can be used in many applications and it is a key component of the internet of things (IoT) and the Smart Cities concept as it helps to organize traffic control and transport management. In this paper, we propose the use of ensemble methods to infer the transportation modes using raw GPS data. From latitude, longitude, and timestamp we perform feature engineering in order to obtain more discriminative fields for the classification. We test our features in several machine learning algorithms and among those with the best results we perform feature selection using the Boruta method in order to boost our accuracy results and decrease the amount of data, processing time, and noise in the model. We assess the validity of our approach on a real-world dataset with several different transportation modes and the results show the efficacy of our approach.
2022
Authors
Leal, JP; Primo, M;
Publication
ADVANCED RESEARCH IN TECHNOLOGIES, INFORMATION, INNOVATION AND SUSTAINABILITY, ARTIIS 2022, PT I, VOL. 1675
Abstract
The work presented in this article is part of ongoing research on the automated assessment of simple web applications. The proposed algorithm compares two interfaces by mapping their elements, using properties to identify those with the same role in both interfaces. The algorithm proceeds in three stages: firstly, it selects the relevant elements from both interfaces; secondly, it refines elements' attributes, excluding some and computing new ones; finally, it matches elements based on attribute similitude. The article includes an experiment to validate the algorithm as an assessment tool. As part of this experiment, a set of experts classified multiple web interfaces. Statistical analysis found a significant correlation between classifications made by the algorithm and those made by experts. The article also discusses the exploitation of the algorithm's output to access both the layout and functionality of a web interface and produce feedback messages in an automated assessment environment, which is planned as future research.
2022
Authors
Paulino, N; Pessoa, LM; Branquinho, A; Gonçalves, E;
Publication
CSNDSP
Abstract
One the of the applications in the realm of the Internet-of-Things (IoT) is real-time localization of assets in specific application environments where satellite based global positioning is unviable. Numerous approaches for localization relying on wireless sensor mesh systems have been evaluated, but the recent Bluetooth Low Energy (BLE) 5.1 direction finding features based on Angle-of-Arrival (AoA) promise a low-cost solution for this application. In this paper, we present an implementation of a BLE 5.1 based circular antenna array, and perform two experimental evaluations over the quality of the retrieved data sampled from the array. Specifically, we retrieve samples of the phase value of the Constant Tone Extension which enables the direction finding functionalities through calculation of phase differences between antenna pairs. We evaluate the quality of the sampled phase data in an anechoic chamber, and in a real-world environment using a setup composed of four BLE beacons.
2022
Authors
Sarkar, S; Malta, MC; Dutta, A;
Publication
CONCURRENCY AND COMPUTATION-PRACTICE & EXPERIENCE
Abstract
The objective of coalition formation is to partition the agent set that gives the highest utility to the system. Over the past three decades, the process of coalition formation has been applied to various real-life applications where agents need to form efficient groups to accomplish a task. This article presents a study of the state-of-the-art approaches on the applications of coalition formation. In particular, it surveys the algorithmic approaches for optimizing the system's welfare. The algorithms are then analyzed based on a framework that consists of two dimensions: (i) the features of the problem environment, which gives an overview of the complexity level of the environment, and (ii) the features of the problem solver, which gives an overview of the solution quality. Our study analyses the approaches in terms of the framework mentioned above, justifies the use of the approaches in a particular problem setting, presents guidance to choose the right algorithmic approach for a problem at hand, and classifies the state-of-the-art approaches according to their basic working principles. This article also presents possible future directions of work to the research community. This study shows that theoretical models need more research before they can be deployed in the real world.
2022
Authors
Tapia Tarifa, SL; Proença, J;
Publication
FACS
Abstract
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