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Publications

2022

Simulation, modelling and classification of wiki contributors: Spotting the good, the bad, and the ugly

Authors
Garcia-Mendez, S; Leal, F; Malheiro, B; Burguillo-Rial, JC; Veloso, B; Chis, AE; Gonzalez-Velez, H;

Publication
SIMULATION MODELLING PRACTICE AND THEORY

Abstract

2022

Experimentally Validated Extended Kalman Filter Approach for Geomagnetically Induced Currents Measurement

Authors
Behdani, B; Tajdinian, M; Allahbakhshi, M; Popov, M; Shafie khah, M; Catalao, JPS;

Publication
IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS

Abstract
Geomagnetically induced currents (GICs) are referred to the quasi-DC current flows in power networks, driven by complex space weather-related phenomena. Such currents are a potential threat to the power delivery capability of electrical grids. To mitigate the detrimental impacts of GICs on critical infrastructures, the GICs should be monitored in power systems. Being inherently DC from the power frequency point of view, the components of GICs are, however, challenging and costly to monitor in AC power grids. This paper puts forward a novel methodology for the real-time estimation of GICs in power transformers. Such aim is attained by means of an extended Kalman filter (EKF)-based approach, mounted on the nonlinear state-space model of the transformer, whose parameters can be derived from standard tests. The proposed EKF-based algorithm employs the available measurements for the transformer differential protection. The proposed approach, relying on the differential current, can properly deal with the external sources of interference like harmonic excitation and loading. The EKF-based estimator presented is validated by simulation and experimental data. The results verify the ability of the proposed approach to robustly estimate the GIC level during various operating conditions.

2022

Websites Usability Evaluation of the Terras De Tras-Os-Montes Hotels

Authors
Morais, EP; Cunha, CR; Santos, A;

Publication
MARKETING AND SMART TECHNOLOGIES, VOL 1

Abstract
Website is a bridge between users and online information. It is extremely important in terms of marketing and must be designed according to the rules of usability, especially in hotel industry. Websites with high usability value will be accessed by more users. Therefore, building a useful website is important. This study aims to evaluate, from the point of view of usability, the websites of hotel establishments in Terras de Tras-os-Montes, a region located in the north of Portugal.

2022

The Game Pentade

Authors
Raposo, L; Guerra, H; Morais, C; Coelho, A;

Publication
Advances in Game-Based Learning

Abstract
The use of digital games as support tools for education has proven to be effective. To explore their potential, it is crucial to design them carefully. This chapter considers the design of games for education, where players cultivate their knowledge and practice their skills by multiplying numerous hindrances during gaming. Educational elements are integrated into the gameplay, which players acquire while playing. The game's effectiveness depends on the players' ability to form a cheerful and encouraging environment to continue playing while increasing their interest in gameplay and improving academic performance. Following a design-first development approach, an innovative proposal for this design is presented, adding a new dimension to the game's tetrad: learning dynamics. Benefiting from years of professional practice, this game pentad design framework fulfills the learning and user experience requirements while overcoming the design limitations of more conventional approaches not based on an educational purpose.

2022

Virtual Reality e-Commerce: Contextualization and Gender Impact on User Memory and User Perception of Functionalities and Size of Products

Authors
Goncalves, G; Meirinhos, G; Filipe, V; Melo, M; Bessa, M;

Publication
IEEE ACCESS

Abstract

2022

A Novel Discrete Particle Swarm Optimization Algorithm for the Travelling Salesman Problems

Authors
Sequeiros, JA; Silva, R; Santos, AS; Bastos, J; Varela, MLR; Madureira, AM;

Publication
INNOVATIONS IN INDUSTRIAL ENGINEERING

Abstract
There are Optimization Problems that are too complex to be solved efficiently by deterministic methods. For these problems, where deterministic methods have proven to be inefficient, if not completely unusable, it is common to use approximate methods, that is, optimization methods that solve the problems quickly, regardless of their size or complexity, even if they do not guarantee optimal solutions. In other words, methods that find “acceptable” solutions, efficiently. One particular type of approximate method, which is particularly effective in complex problems, are metaheuristics. Particle Swarm Optimization is a population-based metaheuristic, which has been particularly successful. In order to broaden the application and overcome the limitation of Particle Swarm Optimization, a discrete version of the metaheuristics is proposed. The Discrete Particle Swarm Optimization, DPSO, will change the PSO algorithm so it can be applied to discrete optimization problems. This alteration will focus on the velocity update equation. The DPSO was tested in an instance of the Traveling Salesman Problem, att48, 48 points problems proposed by Padberg and Rinaldi, which showed some promising results. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

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