5 research outputs found
Annotated Reconstruction of 3D Spaces Using Drones
As the fields of robotics and drone technologies are continually advancing, the challenge of teaching these agents to learn and maneuver in the real world becomes increasingly important. A critical component of this is the ability for a robot to map and understand its surrounding unknown environment, both in terms of physical structure and object classification. In this project we tackle the challenge of mapping a 3D space with annotations using only 2D images acquired from a Parrot Drone. In order to make such a system operate efficiently in close to real time, we address a number challenges including (1) creating a optimized version of Faster RCNN that can operate on drone hardware while still being accurate, (2) developing a method to reconstruct 3D spaces from 2D images annotated with bounding boxes, and (3) using generated 3D annotations to complete drone motion planning for unknown space exploration
Reliable Real-time Seismic Signal/Noise Discrimination with Machine Learning
In Earthquake Early Warning (EEW), every sufficiently impulsive signal is
potentially the first evidence for an unfolding large earthquake. More often
than not, however, impulsive signals are mere nuisance signals. One of the most
fundamental - and difficult - tasks in EEW is to rapidly and reliably
discriminate real local earthquake signals from all other signals. This
discrimination is necessarily based on very little information, typically a few
seconds worth of seismic waveforms from a small number of stations. As a
result, current EEW systems struggle to avoid discrimination errors, and suffer
from false and missed alerts. In this study we show how modern machine learning
classifiers can strongly improve real-time signal/noise discrimination. We
develop and compare a series of non-linear classifiers with variable
architecture depths, including fully connected, convolutional (CNN) and
recurrent neural networks, and a model that combines a generative adversarial
network with a random forest (GAN+RF). We train all classifiers on the same
data set, which includes 374k local earthquake records (M3.0-9.1) and 946k
impulsive noise signals. We find that all classifiers outperform existing
simple linear classifiers, and that complex models trained directly on the raw
signals yield the greatest degree of improvement. Using 3s long waveform
snippets, the CNN and the GAN+RF classifiers both reach 99.5% precision and
99.3% recall on an independent validation data set. Most misclassifications
stem from impulsive teleseismic records, and from incorrectly labeled records
in the data set. Our results suggest that machine learning classifiers can
strongly improve the reliability and speed of EEW alerts
Reliable Real-time Seismic Signal/Noise Discrimination with Machine Learning
In earthquake early warning (EEW), every sufficiently impulsive signal is potentially the first evidence for an unfolding large earthquake. More often than not, however, impulsive signals are mere nuisance signals. One of the most fundamentalâand difficultâtasks in EEW is to rapidly and reliably discriminate real local earthquake signals from all other signals. This discrimination is necessarily based on very little information, typically a few seconds worth of seismic waveforms from a small number of stations. As a result, current EEW systems struggle to avoid discrimination errors and suffer from false and missed alerts. In this study we show how modern machine learning classifiers can strongly improve realâtime signal/noise discrimination. We develop and compare a series of nonlinear classifiers with variable architecture depths, including fully connected, convolutional and recurrent neural networks, and a model that combines a generative adversarial network with a random forest. We train all classifiers on the same data set, which includes 374 k local earthquake records (M3.0â9.1) and 946 k impulsive noise signals. We find that all classifiers outperform existing simple linear classifiers and that complex models trained directly on the raw signals yield the greatest degree of improvement. Using 3âsâlong waveform snippets, the convolutional neural network and the generative adversarial network with a random forest classifiers both reach 99.5% precision and 99.3% recall on an independent validation data set. Most misclassifications stem from impulsive teleseismic records, and from incorrectly labeled records in the data set. Our results suggest that machine learning classifiers can strongly improve the reliability and speed of EEW alerts