Deep Learning
Learning from Incomplete Ratings using Nonlinear Multi-layer Semi-Nonnegative Matrix Factorization
Krishna, Vaibhav, Antulov-Fantulin, Nino
Recommender systems problems witness a growing interest for finding better learning algorithms for personalized information. Matrix factorization that estimates the user liking for an item by taking an inner product on the latent features of users and item have been widely studied owing to its better accuracy and scalability. However, it is possible that the mapping between the latent features learned from these and the original features contains rather complex nonlinear hierarchical information, that classical linear matrix factorization can not capture. In this paper, we aim to propose a novel multilayer non-linear approach to a variant of nonnegative matrix factorization (NMF) to learn such factors from the incomplete ratings matrix. Firstly, we construct a user-item matrix with explicit ratings, secondly we learn latent factors for representations of users and items from the designed nonlinear multi-layer approach. Further, the architecture is built with different nonlinearities using adaptive gradient optimizer to better learn the latent factors in this space. We show that by doing so, our model is able to learn low-dimensional representations that are better suited for recommender systems on several benchmark datasets.
Towards Deep Learning Models Resistant to Adversarial Attacks
Madry, Aleksander, Makelov, Aleksandar, Schmidt, Ludwig, Tsipras, Dimitris, Vladu, Adrian
Recent work has demonstrated that neural networks are vulnerable to adversarial examples, i.e., inputs that are almost indistinguishable from natural data and yet classified incorrectly by the network. In fact, some of the latest findings suggest that the existence of adversarial attacks may be an inherent weakness of deep learning models. To address this problem, we study the adversarial robustness of neural networks through the lens of robust optimization. This approach provides us with a broad and unifying view on much of the prior work on this topic. Its principled nature also enables us to identify methods for both training and attacking neural networks that are reliable and, in a certain sense, universal. In particular, they specify a concrete security guarantee that would protect against any adversary. These methods let us train networks with significantly improved resistance to a wide range of adversarial attacks. They also suggest the notion of security against a first-order adversary as a natural and broad security guarantee. We believe that robustness against such well-defined classes of adversaries is an important stepping stone towards fully resistant deep learning models.
SVCCA: Singular Vector Canonical Correlation Analysis for Deep Learning Dynamics and Interpretability
Raghu, Maithra, Gilmer, Justin, Yosinski, Jason, Sohl-Dickstein, Jascha
We propose a new technique, Singular Vector Canonical Correlation Analysis (SVCCA), a tool for quickly comparing two representations in a way that is both invariant to affine transform (allowing comparison between different layers and networks) and fast to compute (allowing more comparisons to be calculated than with previous methods). We deploy this tool to measure the intrinsic dimensionality of layers, showing in some cases needless over-parameterization; to probe learning dynamics throughout training, finding that networks converge to final representations from the bottom up; to show where class-specific information in networks is formed; and to suggest new training regimes that simultaneously save computation and overfit less.
Bayesian GAN
Saatchi, Yunus, Wilson, Andrew Gordon
Generative adversarial networks (GANs) can implicitly learn rich distributions over images, audio, and data which are hard to model with an explicit likelihood. We present a practical Bayesian formulation for unsupervised and semi-supervised learning with GANs. Within this framework, we use stochastic gradient Hamiltonian Monte Carlo to marginalize the weights of the generator and discriminator networks. The resulting approach is straightforward and obtains good performance without any standard interventions such as feature matching, or mini-batch discrimination. By exploring an expressive posterior over the parameters of the generator, the Bayesian GAN avoids mode-collapse, produces interpretable and diverse candidate samples, and provides state-of-the-art quantitative results for semi-supervised learning on benchmarks including SVHN, CelebA, and CIFAR-10, outperforming DCGAN, Wasserstein GANs, and DCGAN ensembles.
What does an LSTM look for in classifying heartbeats?
van der Westhuizen, Jos, Lasenby, Joan
Long short-term memory (LSTM) recurrent neural networks are renowned for being uninterpretable "black boxes". In the medical domain where LSTMs have shown promise, this is specifically concerning because it is imperative to understand the decisions made by machine learning models in such acute situations. This study employs techniques used in the convolutional neural network domain to elucidate the inputs that are important when LSTMs classify electrocardiogram signals. Of the various techniques available to determine input feature saliency, it was found that learning an occlusion mask is the most effective.
Revealing structure components of the retina by deep learning networks
Yan, Qi, Yu, Zhaofei, Chen, Feng, Liu, Jian K.
Deep convolutional neural networks (CNNs) have demonstrated impressive performance on visual object classification tasks. In addition, it is a useful model for predication of neuronal responses recorded in visual system. However, there is still no clear understanding of what CNNs learn in terms of visual neuronal circuits. Visualizing CNN's features to obtain possible connections to neuronscience underpinnings is not easy due to highly complex circuits from the retina to higher visual cortex. Here we address this issue by focusing on single retinal ganglion cells with a simple model and electrophysiological recordings from salamanders. By training CNNs with white noise images to predicate neural responses, we found that convolutional filters learned in the end are resembling to biological components of the retinal circuit. Features represented by these filters tile the space of conventional receptive field of retinal ganglion cells. These results suggest that CNN could be used to reveal structure components of neuronal circuits.
Deep learning architecture diagrams - FastML
As a wild stream after a wet season in African savanna diverges into many smaller streams forming lakes and puddles, so deep learning has diverged into a myriad of specialized architectures. Each architecture has a diagram. Here are some of them. Neural networks are conceptually simple, and that's their beauty. A bunch of homogenous, uniform units, arranged in layers, weighted connections between them, and that's all.
Andrew Ng Wants a New "New Deal" to Combat Job Automation
Andrew Ng, formerly the head of AI for Chinese search giant Baidu and, before that, creator of Google's deep-learning Brain project, knows as well as anyone that artificial intelligence is coming for plenty of jobs. And many of us don't even know it. Speaking at MIT Technology Review's annual EmTech MIT conference in Cambridge, MA, on Tuesday, Ng said he's visited call centers and spoken to workers, knowing that his teams of software engineers will then write software that will automate aspects of their work. "There are many professions in the crosshairs of AI teams across the world," he said. Ng, who's currently working on a startup called Deeplearning.ai
[P] New Stanford Course: Theories of Deep Learning (STATS 385) • r/MachineLearning
Any plans on sharing the video lectures? By the way, my credits to the pace that Stanford starts courses on new topics. My faculty (EE) has yet to pick up on machine learning and deep learning. All the while, Stanford started CS231n on the Convnet wave and now it launches this course on the theory-of-deep-learning wave.
12 Artificial Intelligence Terms You Need to Know - InformationWeek
Suddenly, artificial intelligence (AI) is everywhere. For decades, the dream of creating machines that can think and learn like humans seemed like it would be perpetually out of reach, but now artificial intelligence is embedded in the phones we carry everywhere, the websites we use every day and, in some cases, even in the appliances we use around our homes. The market researchers at IDC have predicted that companies will spend $12.5 billion on cognitive and AI systems in 2017, 59.3% more than they spent last year. And by 2020, total AI revenues could top $46 billion. In many cases, AI has crept into our lives and our work without us realizing it.