364 research outputs found
Best Practices in Convolutional Networks for Forward-Looking Sonar Image Recognition
Convolutional Neural Networks (CNN) have revolutionized perception for color
images, and their application to sonar images has also obtained good results.
But in general CNNs are difficult to train without a large dataset, need manual
tuning of a considerable number of hyperparameters, and require many careful
decisions by a designer. In this work, we evaluate three common decisions that
need to be made by a CNN designer, namely the performance of transfer learning,
the effect of object/image size and the relation between training set size. We
evaluate three CNN models, namely one based on LeNet, and two based on the Fire
module from SqueezeNet. Our findings are: Transfer learning with an SVM works
very well, even when the train and transfer sets have no classes in common, and
high classification performance can be obtained even when the target dataset is
small. The ADAM optimizer combined with Batch Normalization can make a high
accuracy CNN classifier, even with small image sizes (16 pixels). At least 50
samples per class are required to obtain test accuracy, and using
Dropout with a small dataset helps improve performance, but Batch Normalization
is better when a large dataset is available.Comment: Author version; IEEE/MTS Oceans 2017 Aberdee
Improving Sonar Image Patch Matching via Deep Learning
Matching sonar images with high accuracy has been a problem for a long time,
as sonar images are inherently hard to model due to reflections, noise and
viewpoint dependence. Autonomous Underwater Vehicles require good sonar image
matching capabilities for tasks such as tracking, simultaneous localization and
mapping (SLAM) and some cases of object detection/recognition. We propose the
use of Convolutional Neural Networks (CNN) to learn a matching function that
can be trained from labeled sonar data, after pre-processing to generate
matching and non-matching pairs. In a dataset of 39K training pairs, we obtain
0.91 Area under the ROC Curve (AUC) for a CNN that outputs a binary
classification matching decision, and 0.89 AUC for another CNN that outputs a
matching score. In comparison, classical keypoint matching methods like SIFT,
SURF, ORB and AKAZE obtain AUC 0.61 to 0.68. Alternative learning methods
obtain similar results, with a Random Forest Classifier obtaining AUC 0.79, and
a Support Vector Machine resulting in AUC 0.66.Comment: Author versio
Real-time Convolutional Neural Networks for Emotion and Gender Classification
In this paper we propose an implement a general convolutional neural network
(CNN) building framework for designing real-time CNNs. We validate our models
by creating a real-time vision system which accomplishes the tasks of face
detection, gender classification and emotion classification simultaneously in
one blended step using our proposed CNN architecture. After presenting the
details of the training procedure setup we proceed to evaluate on standard
benchmark sets. We report accuracies of 96% in the IMDB gender dataset and 66%
in the FER-2013 emotion dataset. Along with this we also introduced the very
recent real-time enabled guided back-propagation visualization technique.
Guided back-propagation uncovers the dynamics of the weight changes and
evaluates the learned features. We argue that the careful implementation of
modern CNN architectures, the use of the current regularization methods and the
visualization of previously hidden features are necessary in order to reduce
the gap between slow performances and real-time architectures. Our system has
been validated by its deployment on a Care-O-bot 3 robot used during
RoboCup@Home competitions. All our code, demos and pre-trained architectures
have been released under an open-source license in our public repository.Comment: Submitted to ICRA 201
Image Captioning and Classification of Dangerous Situations
Current robot platforms are being employed to collaborate with humans in a
wide range of domestic and industrial tasks. These environments require
autonomous systems that are able to classify and communicate anomalous
situations such as fires, injured persons, car accidents; or generally, any
potentially dangerous situation for humans. In this paper we introduce an
anomaly detection dataset for the purpose of robot applications as well as the
design and implementation of a deep learning architecture that classifies and
describes dangerous situations using only a single image as input. We report a
classification accuracy of 97 % and METEOR score of 16.2. We will make the
dataset publicly available after this paper is accepted
Mass and Reliability Source (MaRS) Database
The Mass and Reliability Source (MaRS) Database consolidates components mass and reliability data for all Oribital Replacement Units (ORU) on the International Space Station (ISS) into a single database. It was created to help engineers develop a parametric model that relates hardware mass and reliability. MaRS supplies relevant failure data at the lowest possible component level while providing support for risk, reliability, and logistics analysis. Random-failure data is usually linked to the ORU assembly. MaRS uses this data to identify and display the lowest possible component failure level. As seen in Figure 1, the failure point is identified to the lowest level: Component 2.1. This is useful for efficient planning of spare supplies, supporting long duration crewed missions, allowing quicker trade studies, and streamlining diagnostic processes. MaRS is composed of information from various databases: MADS (operating hours), VMDB (indentured part lists), and ISS PART (failure data). This information is organized in Microsoft Excel and accessed through a program made in Microsoft Access (Figure 2). The focus of the Fall 2017 internship tour was to identify the components that were the root cause of failure from the given random-failure data, develop a taxonomy for the database, and attach material headings to the component list. Secondary objectives included verifying the integrity of the data in MaRS, eliminating any part discrepancies, and generating documentation for future reference. Due to the nature of the random-failure data, data mining had to be done manually without the assistance of an automated program to ensure positive identification
Sub-Ensembles for Fast Uncertainty Estimation in Neural Networks
Fast estimates of model uncertainty are required for many robust robotics applications. Deep Ensembles provides state of the art uncertainty without requiring Bayesian methods, but still it is computationally expensive due to the use of large ensembles. In this paper we propose deep sub-ensembles, an approximation to deep ensembles where the core idea is to ensemble only a selection of layers close to the output, and not the whole model. This is motivated by feature hierarchy learned by convolutional networks that should allow for feature reuse across ensembles. With ResNet-20 on the CIFAR10 dataset, we obtain 1.5-2.5 speedup over a deep ensemble, with a small increase in error and loss, and similarly up to 5-15 speedup with a VGG-like network on the SVHN dataset. Our results show that this idea enables a trade-off between error and uncertainty quality versus computational performance as a sub-ensemble effectively works as an approximation of a deep ensemble
- …