Using Long-Short-Term-Memory Recurrent Neural Networks To Predict Aviation Engine Vibrations

This thesis examines building viable Recurrent Neural Networks (RNN) using Long Short Term Memory (LSTM) neurons to predict aircraft engine vibrations. The different networks are trained on a large database of flight data records obtained from an airline containing flights that suffered from excessive vibration. RNNs can provide a more generalizable and robust method for prediction over analytical calculations of engine vibration, as analytical calculations must be solved iteratively based on specific empirical engine parameters, and this database contains multiple types of engines. Further, LSTM RNNs provide a “memory” of the contribution of previous time series data which can further improve predictions of future vibration values. LSTM RNNs were used over traditional RNNs, as those suffer from vanishing/exploding gradients when trained with back propagation. The study managed to predict vibration values for 1, 5, 10, and 20 seconds in the future, with 2.84% 3.3%, 5.51% and 10.19% mean absolute error, respectively. These neural networks provide a promising means for the future development of warning systems so that suitable actions can be taken before the occurrence of excess vibration to avoid unfavorable situations during flight

Efeito da carga de memória de trabalho sobre o reconhecimento de expressões faciais de raiva e nojo em aeroportuários

Dissertação (mestrado)—Universidade de Brasília, Instituto de Psicologia, Departamento de Processos Psicológicos Básicos, Programa de Pós-Graduação em Ciências do Comportamento, 2019.A memória de trabalho é um construto relacionado à habilidade humana de processar informações. Nesse sentido, a investigação de sua relação com o reconhecimento de expressões faciais emocionais se mostra informativa para a compreensão de como o processamento emocional ocorre. O objetivo do presente estudo foi investigar a capacidade de reconhecer as expressões faciais de raiva e nojo conforme a memória de trabalho era sujeita a diferentes cargas de processamento. Optou-se por realizar o experimento no ambiente da aviação civil, onde dois grupos de participantes foram convidados: trabalhadores da área administrativa e fiscais de pátio, todos exercendo suas atividades laborais no Aeroporto Internacional de Brasília. No total, foram coletados os dados de 51 participantes, 44 homens, na faixa etária entre 18 e 54 anos. O experimento consistiu na tarefa de apresentação de estímulos expressando duas emoções de ameaça, raiva e nojo, sempre intercalada com uma tarefa secundária que utilizava a memória de trabalho dos participantes. As expressões faciais também foram apresentadas em duas intensidades diferentes. Obteve-se, como resultado, um efeito significativo da carga e da intensidade sobre a discriminabilidade dos estímulos, assim como da interação entre carga e condição experimental sobre a discriminabilidade. A interação entre carga, intensidade e condição também influenciou de forma significativa a proporção de acertos entre expressões faciais de raiva e de nojo. Desse estudo, concluiu-se que a memória de trabalho pode ser um importante pilar para o reconhecimento de expressões emocionais, sendo que variações em sua carga impactaram o reconhecimento das expressões emocionas faciais de raiva e nojo.Working memory is a construct related to the human ability to process information. In this sense, the investigation of its relationship with the recognition of emotional facial expressions is informative for the understanding of how emotional processing occurs. The aim of the present study was to investigate the ability to recognize facial expressions of anger and disgust as working memory was subjected to different processing loads. It was decided to conduct the experiment in the civil aviation environment, where two groups of participants were invited: workers from the administrative area and patio inspectors, all working at Brasília International Airport. In total, data were collected from 51 participants, 44 men, aged between 18 and 54 years. The experiment consisted of a stimulus presentation task expressing two threatening emotions, anger and disgust, always interspersed with a secondary task that used the participants' working memory. Facial expressions were also presented at two different intensities. The result was a significant effect of load and intensity on the discriminability of the stimuli, as well as the interaction between load and experimental condition on the discriminability. The interaction between load, intensity and condition also significantly influenced the proportion of correct answers between facial expressions of anger and disgust. From this study, it was concluded that working memory can be an important pillar for the recognition of emotional expressions, and variations in its load impacted the recognition of facial expressions of anger and disgust