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Publications

2022

Daytime calibration and testing of the Keck All sky Precision Adaptive Optics Tomography System

Authors
Surendran, A; Delorme, JR; Correia, CM; Doyle, S; Ragland, S; Richards, P; Wizinowich, P; Hinz, PM; Dillon, D; Laguna, C; Cetre, S; Lilley, S; Wetherell, E; Chin, JCY; Marin, E;

Publication
ADAPTIVE OPTICS SYSTEMS VIII

Abstract
The development of the Keck All sky Precision Adaptive optics (KAPA) project was initiated in September 2018 to upgrade the Keck I adaptive optics (AO) system to enable laser tomography adaptive optics (LTAO) with a four laser guide star (LGS) asterism. The project includes the replacement of the existing LMCT laser with a Toptica laser, the implementation of a new real-time controller (RTC) and wavefront sensor optics and camera, and a new daytime calibration and test platform to provide the required infrastructure for laser tomography. The work presented here describes the new daytime calibration infrastructure to test the performance for the KAPA tomographic algorithms. This paper outlines the hardware infrastructure for daytime calibration and performance assessment of tomographic algorithms. This includes the implementation of an asterism simulator having fiber-coupled light sources simulating four Laser Guide Stars (LGS) and two Natural Guide Stars (NGS) at the AO bench focus, as well as the upgrade of the existing TelSim on the AO bench to simulate focal anisoplanatism and wind driven atmospheric turbulence. A phase screen, that can be adjusted in effective altitude, is used to simulate wind speeds up to 10 m/s for a duration of upto 3 s.

2022

Do Multisensory Stimuli Benefit the Virtual Reality Experience? A Systematic Review

Authors
Melo, M; Gonçalves, G; Monteiro, P; Coelho, H; Vasconcelos Raposo, J; Bessa, M;

Publication
IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS

Abstract
The majority of virtual reality (VR) applications rely on audiovisual stimuli and do not exploit the addition of other sensory cues that could increase the potential of VR. This systematic review surveys the existing literature on multisensory VR and the impact of haptic, olfactory, and taste cues over audiovisual VR. The goal is to identify the extent to which multisensory stimuli affect the VR experience, which stimuli are used in multisensory VR, the type of VR setups used, and the application fields covered. An analysis of the 105 studies that met the eligibility criteria revealed that 84.8 percent of the studies show a positive impact of multisensory VR experiences. Haptics is the most commonly used stimulus in multisensory VR systems (86.6 percent). Non-immersive and immersive VR setups are preferred over semi-immersive setups. Regarding the application fields, a considerable part was adopted by health professionals and science and engineering professionals. We further conclude that smell and taste are still underexplored, and they can bring significant value to VR applications. More research is recommended on how to synthesize and deliver these stimuli, which still require complex and costly apparatus be integrated into the VR experience in a controlled and straightforward manner.

2022

A Brief Review on 4D Weather Visualization

Authors
Rudenko, R; Pires, IM; Liberato, M; Barroso, J; Reis, A;

Publication
SUSTAINABILITY

Abstract
The accelerated changes on our planet have led to a growing interest in climate change and its consequences: natural hazards and adverse socio-economic impacts. However, the development of climate research and the proliferation of datasets require an integrated and efficient approach to the analysis, investigation, and visualization of atmospheric meteorological data. Thus, we propose a literature review of existing systems viewing meteorological phenomena in four and three dimensions. Moreover, we evaluate meteorological occurrences to better understand the dynamics associated with a meteorological phenomenon and visualize different weather data. Based on the investigation of tools and methods, we consider the existence of different ways of representing meteorological data and methodologies. However, it was imperative to obtain knowledge and create our way of visualizing weather data. This article found eleven existing solutions for 4D meteorological visualization and meteorological phenomena.

2022

Classifying papers into subfields using Abstracts, Titles, Keywords and KeyWords Plus through pattern detection and optimization procedures: An application in Physics

Authors
Pech, G; Delgado, C; Sorella, SP;

Publication
JOURNAL OF THE ASSOCIATION FOR INFORMATION SCIENCE AND TECHNOLOGY

Abstract
Classifying papers according to the fields of knowledge is critical to clearly understand the dynamics of scientific (sub)fields, their leading questions, and trends. Most studies rely on journal categories defined by popular databases such as WoS or Scopus, but some experts find that those categories may not correctly map the existing subfields nor identify the subfield of a specific article. This study addresses the classification problem using data from each paper (Abstract, Title, Keywords, and the KeyWords Plus) and the help of experts to identify the existing subfields and journals exclusive of each subfield. These exclusive journals are critical to obtain, through a pattern detection procedure that uses machine learning techniques (from software NVivo), a list of the frequent terms that are specific to each subfield. With that list of terms and with the help of optimization procedures, we can identify to which subfield each paper most likely belongs. This study can contribute to support scientific policy-makers, funding, and research institutions-via more accurate academic performance evaluations-, to support editors in their tasks to redefine the scopes of journals, and to support popular databases in their processes of refining categories.

2022

An exploratory study on the barriers to innovative behavior: the spiteful effect of envy

Authors
Walter, CE; Au-Yong-Oliveira, M;

Publication
JOURNAL OF ORGANIZATIONAL CHANGE MANAGEMENT

Abstract
Purpose The present investigation aimed to evaluate the influence of envy on the predisposition to innovative behavior, starting from a conceptual model that considers not only the direct influence of envy but its indirect influence through ostracism and alignment with the negative behaviors of superiors. Design/methodology/approach Using a survey applied to 168 individuals, a conceptual model was developed based on the relationship ignored in the literature between envy and innovative behavior. The model was validated using the multivariate statistical technique of structural equation modeling with partial least squares estimation (Partial least squares structural equation modeling [PLS-SEM]). Findings The results of the study suggest that envy not only has a direct positive influence on alignment with negative boss behaviors and ostracism, but also an indirect influence on ostracism mediated by alignment with negative boss behaviors. Another important result of the present investigation refers to the negative effect of envy on the predisposition to innovative behavior. The results suggest that the greater the envy, the lower the innovative behavior. Practical implications This research provides evidence that envy can act as a barrier to innovation by triggering counterproductive behaviors such as ostracism and a decrease in predisposition to innovative behaviors, either due to innovative individuals prematurely exiting the organization or due to them lessening/dampening their innovativeness to avoid the negative consequences. Given this scenario, it becomes necessary to increase managerial awareness on the subject to manage negative emotions to promote the conditions for organizational innovation. Originality/value The present research contributes in both practical and theoretical ways to understanding the effects of envy on the predisposition to innovative behavior. Adding to this, this research represents a conceptual advance by linking envy to innovative behavior, providing a promising avenue for extending the psychological relevance of the envy construct to organizational and management studies, which are generally positive, normative and outcome-oriented.

2022

Classification of Table Tennis Strokes in Wearable Device using Deep Learning

Authors
Ferreira, NM; Torres, JM; Sobral, P; Moreira, R; Soares, C;

Publication
ICAART: PROCEEDINGS OF THE 14TH INTERNATIONAL CONFERENCE ON AGENTS AND ARTIFICIAL INTELLIGENCE - VOL 3

Abstract
Analysis of sports performance using mobile and wearable devices is becoming increasingly popular, helping users improve their sports practice. In this context, the goal of this work has been the development of an Apple Watch application, capable of detecting important strokes in the table tennis sport, using a deep learning (DL) model. A dataset of table tennis strokes has been created based on the watch's accelerometer and gyroscope sensors. The dataset collection was done in the Portuguese table tennis federation training sites, from several athletes, supervised by their coaches. To obtain the best DL model, three different architecture models where trained, compared and evaluated, using the complete dataset: a LSTM based on Create ML/Core ML frameworks (62.70% F1 score) and two Tensorflow based architectures, a CNN-LSTM (96.02% F1 score) and a ConvLSTM (97.33% F1 score).

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