Deep Learning
Measuring the tendency of CNNs to Learn Surface Statistical Regularities
Deep CNNs are known to exhibit the following peculiarity: on the one hand they generalize extremely well to a test set, while on the other hand they are extremely sensitive to so-called adversarial perturbations. The extreme sensitivity of high performance CNNs to adversarial examples casts serious doubt that these networks are learning high level abstractions in the dataset. We are concerned with the following question: How can a deep CNN that does not learn any high level semantics of the dataset manage to generalize so well? The goal of this article is to measure the tendency of CNNs to learn surface statistical regularities of the dataset. To this end, we use Fourier filtering to construct datasets which share the exact same high level abstractions but exhibit qualitatively different surface statistical regularities. For the SVHN and CIFAR-10 datasets, we present two Fourier filtered variants: a low frequency variant and a randomly filtered variant. Each of the Fourier filtering schemes is tuned to preserve the recognizability of the objects. Our main finding is that CNNs exhibit a tendency to latch onto the Fourier image statistics of the training dataset, sometimes exhibiting up to a 28% generalization gap across the various test sets. Moreover, we observe that significantly increasing the depth of a network has a very marginal impact on closing the aforementioned generalization gap. Thus we provide quantitative evidence supporting the hypothesis that deep CNNs tend to learn surface statistical regularities in the dataset rather than higher-level abstract concepts.
ConvNets and ImageNet Beyond Accuracy: Explanations, Bias Detection, Adversarial Examples and Model Criticism
Stock, Pierre, Cisse, Moustapha
ConvNets and Imagenet have driven the recent success of deep learning for image classification. However, the marked slowdown in performance improvement, the recent studies on the lack of robustness of neural networks to adversarial examples and their tendency to exhibit undesirable biases (e.g racial biases) questioned the reliability and the sustained development of these methods. This work investigates these questions from the perspective of the end-user by using human subject studies and explanations. We experimentally demonstrate that the accuracy and robustness of ConvNets measured on Imagenet are underestimated. We show that explanations can mitigate the impact of misclassified adversarial examples from the perspective of the end-user and we introduce a novel tool for uncovering the undesirable biases learned by a model. These contributions also show that explanations are a promising tool for improving our understanding of ConvNets' predictions and for designing more reliable models
Towards Accurate Binary Convolutional Neural Network
Lin, Xiaofan, Zhao, Cong, Pan, Wei
We introduce a novel scheme to train binary convolutional neural networks (CNNs) -- CNNs with weights and activations constrained to {-1,+1} at run-time. It has been known that using binary weights and activations drastically reduce memory size and accesses, and can replace arithmetic operations with more efficient bitwise operations, leading to much faster test-time inference and lower power consumption. However, previous works on binarizing CNNs usually result in severe prediction accuracy degradation. In this paper, we address this issue with two major innovations: (1) approximating full-precision weights with the linear combination of multiple binary weight bases; (2) employing multiple binary activations to alleviate information loss. The implementation of the resulting binary CNN, denoted as ABC-Net, is shown to achieve much closer performance to its full-precision counterpart, and even reach the comparable prediction accuracy on ImageNet and forest trail datasets, given adequate binary weight bases and activations.
Deep Image Prior
Ulyanov, Dmitry, Vedaldi, Andrea, Lempitsky, Victor
Deep convolutional networks have become a popular tool for image generation and restoration. Generally, their excellent performance is imputed to their ability to learn realistic image priors from a large number of example images. In this paper, we show that, on the contrary, the structure of a generator network is sufficient to capture a great deal of low-level image statistics prior to any learning. In order to do so, we show that a randomly-initialized neural network can be used as a handcrafted prior with excellent results in standard inverse problems such as denoising, super-resolution, and inpainting. Furthermore, the same prior can be used to invert deep neural representations to diagnose them, and to restore images based on flash-no flash input pairs. Apart from its diverse applications, our approach highlights the inductive bias captured by standard generator network architectures. It also bridges the gap between two very popular families of image restoration methods: learning-based methods using deep convolutional networks and learning-free methods based on handcrafted image priors such as self-similarity. Code and supplementary material are available at https://dmitryulyanov.github.io/deep_image_prior .
MorphNet: Fast & Simple Resource-Constrained Structure Learning of Deep Networks
Gordon, Ariel, Eban, Elad, Nachum, Ofir, Chen, Bo, Yang, Tien-Ju, Choi, Edward
We present MorphNet, an approach to automate the design of neural network structures. MorphNet iteratively shrinks and expands a network, shrinking via a resource-weighted sparsifying regularizer on activations and expanding via a uniform multiplicative factor on all layers. In contrast to previous approaches, our method is scalable to large networks, adaptable to specific resource constraints (e.g. the number of floating-point operations per inference), and capable of increasing the network's performance. When applied to standard network architectures on a wide variety of datasets, our approach discovers novel structures in each domain, obtaining higher performance while respecting the resource constraint.
Differentially Private Dropout
Ermis, Beyza, Cemgil, Ali Taylan
Large data collections required for the training of neural networks often contain sensitive information such as the medical histories of patients, and the privacy of the training data must be preserved. In this paper, we introduce a dropout technique that provides an elegant Bayesian interpretation to dropout, and show that the intrinsic noise added, with the primary goal of regularization, can be exploited to obtain a degree of differential privacy. The iterative nature of training neural networks presents a challenge for privacy-preserving estimation since multiple iterations increase the amount of noise added. We overcome this by using a relaxed notion of differential privacy, called concentrated differential privacy, which provides tighter estimates on the overall privacy loss. We demonstrate the accuracy of our privacy-preserving dropout algorithm on benchmark datasets.
Amazon's AI camera helps developers harness image recognition
Far from the stuff of science fiction, artificial intelligence is becoming just another tool for developers to build the next big thing. It's built in to Photoshop to help you knock out backgrounds, Google is using AI to figure out if you have a person peeping on your phone and Microsoft uses the technology to teach you Chinese. As Amazon's Jeff Barr says, "I think it is safe to say, with the number of practical applications for machine learning, including computer vision and deep learning, that we've turned the corner" towards practical applications for AI. To that end, Amazon has announced AWS DeepLens, a new video camera that runs deep learning models right on the device. The DeepLens has a 4 megapixel camera that can capture 1080P video, along with a 2D microphone array.
Amazon unveils DeepLens, a $249 camera for deep learning
Amazon Web Services today unveiled DeepLens, a wireless video camera made for the quick deployment of deep learning. The camera will cost $249 and is scheduled to ship for customers in the United States in April 2018. DeepLens comes pre-loaded with AWS Greengrass for local computation and can operate with SageMaker, a new service to simplify the deployment of AI models, as well as popular open source AI services such as TensorFlow from Google and Caffe2 from Facebook, according to an AWS blog. "DeepLens runs the model directly onto the device. The video doesn't have to go anywhere. It can be trained with SageMaker and deployed to the model," said AWS general manager of AI services Matt Wood during the keynote address today at AWS re:Invent conference being held this week in Las Vegas.
The Possibility of a Deep Learning Intelligence Explosion
François Chollet argues about the Impossibility of an Intelligence Explosion. It is a strong article with the exception of the conclusion. Chollet is accurate in describing the many of the obstacles that we expect to encounter in creating an advanced artificial general intelligence (AGI). These obstacles are as follows ( I use my own categorization, but its mapping with Chollet's should be straightforward): The flaw in Collet's article is that he believes the pace to be linear. There is little evidence that this is true.
Demystifying "Matrix Capsules with EM Routing." Part 1: Overview
Recently, Geoffrey Hinton, one of the fathers of deep learning, made waves in the machine learning community by publishing a revolutionary computer vision architecture: capsule networks. Hinton has been pushing for using capsule networks since 2012, after he first revolutionized the use of Convolutional Neural Networks (CNNs) for image detection, but only now has he made them feasible. The initial successful approach, published two weeks ago, is titled "Dynamic Routing Between Capsules." Dynamic routing -- which we'll be exploring in depth throughout this post -- allows networks to more intuitively understand part-whole relationships. In the three days following the release of this paper, another paper on dynamic routing in capsule networks was submitted for review to ICLR 2018. This paper, titled "Matrix Capsules for EM Routing," is widely speculated to have been authored by Hinton, and discusses a revolutionary new method for dynamic routing -- even compared to his first paper.