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Publications

2020

Layout optimization of an airborne wind energy farm for maximum power generation

Authors
Roque, LAC; Paiva, LT; Fernandes, MCRM; Fontes, DBMM; Fontes, FACC;

Publication
ENERGY REPORTS

Abstract
We consider a farm of Kite Power Systems (KPS) in the field of Airborne Wind Energy (AWE), in which each kite is connected to an electric ground generator by a tether. In particular, we address the problem of selecting the best layout of such farm in a given land area such that the total electrical power generated is maximized. The kites, typically, fly at high altitudes, sweep a greater area than that of traditional wind turbines, and move within a conic shaped volume with vertex on the ground station. Therefore, constraints concerning kite collision avoidance and terrain boundaries must be considered. The efficient use of a given land area by a set of KPS depends on the location of each unit, on its tether length and on the elevation angle. In this work, we formulate the KPS farm layout optimization problem. Considering a specific KPS and wind characteristics of the given location, we study the power curve as a function of the tether length and elevation angle. Combining these results with an area with specified length and width, we develop and implement a heuristic optimization procedure to devise the layout of a KPS farm that maximizes wind power generation. (C) 2019 Published by Elsevier Ltd.

2020

Models for the two-dimensional level strip packing problem - a review and a computational evaluation

Authors
Bezerra, VMR; Leao, AAS; Oliveira, JF; Santos, MO;

Publication
JOURNAL OF THE OPERATIONAL RESEARCH SOCIETY

Abstract
The two-dimensional level strip packing problem has received little attention from the scientific community. To the best of our knowledge, the most competitive model is the one proposed in 2004 by Lodi et al., where the items are packed by levels. In 2015, an arc flow model addressing the two-dimensional level strip cutting problem was proposed by Mrad. The literature presents some mathematical models, despite not addressing specifically the two-dimensional level strip packing problem, they are efficient and can be adapted to the problem. In this paper, we adapt two mixed integer linear programming models from the literature, rewrite the Mrad's model for the strip packing problem and add well-known valid inequalities to the model proposed by Lodi et al. Computational results were performed on instances from the literature and show that the model put forward by Lodi et al. with valid inequalities outperforms the remaining models with respect to the number of optimal solutions found.

2020

User-Experience with Haptic Feedback Technologies and Text Input in Interactive Multimedia Devices

Authors
Silva, B; Costelha, H; Bento, LC; Barata, M; Assuncao, P;

Publication
SENSORS

Abstract
Remote control devices are commonly used for interaction with multimedia equipment and applications (e.g., smart TVs, gaming, etc.). To improve conventional keypad-based technologies, haptic feedback and user input capabilities are being developed for enhancing the UX and providing advanced functionalities in remote control devices. Although the sensation provided by haptic feedback is similar to mechanical push buttons, the former offers much greater flexibility, due to the possibility of dynamically choosing different mechanical effects and associating different functions to each of them. However, selecting the best haptic feedback effects among the wide variety that is currently enabled by recent technologies, remains a challenge for design engineers aiming to optimise the UX. Rich interaction further requires text input capability, which greatly influences the UX. This work is a contribution towards UX evaluation of remote control devices with haptic feedback and text input. A user evaluation study of a wide variety of haptic feedback effects and text input methods is presented, considering different technologies and different number of actuators on a device. The user preferences, given by subjective evaluation scores, demonstrate that haptic feedback has undoubtedly a positive impact on the UX. Moreover, it is also shown that different levels of UX are obtained, according to the technological characteristics of the haptic actuators and how many of them are used on the device.

2020

Gamifying the Museological Experience

Authors
Coelho, A; Zeller, Mv; Cardoso, P; Santos, L; Vaz, R; Raimundo, J;

Publication
XCR

Abstract
Museums continue to exert fascination in their visitors. However, the new generation of visitors expects museological experiences that promote their active participation. It is in this context that games and the gamification of such experiences capitalize on experiential learning by experimenting and enacting with in-game embedded artefact surrogates and know-how. In this article, we present four distinct projects that aim to enhance the visitors' experience in museums and green spaces, and also their effectiveness in informal learning. In the first project, gamification is used in combination with Augmented Reality to provide a more engaging experience in a boat museum. The drive of this experience is the metaphor of the stickers album collection to unleash the relevant information of the key-artefacts of the museum collection. The second and third projects focus on the use of pervasive games, more specifically location-based games, to enhance the visitors' experience and informal learning in a natural park and a botanical garden, respectively. The second project presents the concept of a mobile app for outdoor nature experiences. The drive for the experience in the third project is the narrative that intertwines specific locations in the botanic garden and a story inspired by the same place. Finally, in the fourth project, we focus on the potential of technology to provide accessibility in museums for people with special needs or disability, focusing more specifically on blind visitors. Copyright © 2020 for this paper by its authors.

2020

The Effect of Virtual Reality on Knowledge Transfer and Retention in Collaborative Group-Based Learning for Neuroanatomy Students

Authors
Souza, V; Maciel, A; Nedel, L; Kopper, R; Loges, K; Schlemmer, E;

Publication
2020 22nd Symposium on Virtual and Augmented Reality (SVR)

Abstract

2020

GNAO: An MCAO facility for Gemini North

Authors
Sivo G.; Palmer D.; Scahrwächter J.; Andersen M.; Provost N.; Marin E.; Van Dam M.; Chinn B.; Chirre E.; Cavedoni C.; Schneider T.; Kang S.; Hirst P.; Rambold W.; Ebbers A.; Gigoux P.; Catala L.; Hayward T.; Blakeslee J.; Roe H.; Lotz J.; Kleinman S.; Sivanandam S.; Krause A.; Ammons M.; Trujillo C.; Packham C.; Marchis F.; Christou J.; Jee J.; Bally J.; Pierce M.; Puzia T.; Turri P.; Kim H.; Schwamb M.; Dupuy T.; Diaz R.; Carrasco R.; Neichel B.; Correia C.; Steinbring E.; Rigaut F.; Véran J.P.; Chun M.; Lamb M.; Chapman S.; Esposito S.; Fusco T.;

Publication
Proceedings of SPIE - The International Society for Optical Engineering

Abstract
Gemini Observatory has been awarded a major funding from the National Science Foundation to build a complete new state of the art multi-conjugate adaptive optics system for Gemini North. The system will be designed to provide an MCAO facility delivering close to diffraction limit correction in the near-infrared over a 2 arcminutes field of view and feed imaging and spectroscopic instruments. We present in this paper the results of the conceptual design phase with details on the new proposed laser guide star facilities and adaptive optics bench. We will present results on the performance simulation assessments as well as the developed selected science cases.

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