Collaborating Authors


A technique to estimate emotional valence and arousal by analyzing images of human faces


In recent years, countless computer scientists worldwide have been developing deep neural network-based models that can predict people's emotions based on their facial expressions. Most of the models developed so far, however, merely detect primary emotional states such as anger, happiness and sadness, rather than more subtle aspects of human emotion. Past psychology research, on the other hand, has delineated numerous dimensions of emotion, for instance, introducing measures such as valence (i.e., how positive an emotional display is) and arousal (i.e., how calm or excited someone is while expressing an emotion). While estimating valence and arousal simply by looking at people's faces is easy for most humans, it can be challenging for machines. Researchers at Samsung AI and Imperial College London have recently developed a deep-neural-network-based system that can estimate emotional valence and arousal with high levels of accuracy simply by analyzing images of human faces taken in everyday settings.

The Ultimate Guide to Machine Learning Frameworks - The New Stack


We have seen an explosion in developer tools and platforms related to machine learning and artificial intelligence during the last few years. From cloud-based cognitive APIs to libraries to frameworks to pre-trained models, developers make many choices to infuse AI into their applications. AI engineers and researchers choose a framework to train machine learning models. These frameworks abstract the underlying hardware and software stack to expose a simple API in languages such as Python and R. For example, an ML developer can leverage the parallelism offered by GPUs to accelerate a training job without changing much of the code written for the CPU. These frameworks expose simpler APIs that translate to complex mathematical computations and numerical analysis often needed for training the machine learning models. Apart from training, the machine learning frameworks simplify inference -- the process of utilizing a trained model for performing prediction or classification of live data.

3 ways to get into reinforcement learning


When I was in graduate school in the 1990s, one of my favorite classes was neural networks. Back then, we didn't have access to TensorFlow, PyTorch, or Keras; we programmed neurons, neural networks, and learning algorithms by hand with the formulas from textbooks. We didn't have access to cloud computing, and we coded sequential experiments that often ran overnight. There weren't platforms like Alteryx, Dataiku, SageMaker, or SAS to enable a machine learning proof of concept or manage the end-to-end MLops lifecycles. I was most interested in reinforcement learning algorithms, and I recall writing hundreds of reward functions to stabilize an inverted pendulum.

Backpropagation in Neural Networks: How it Helps?


Neural networks have shown significant advancements in recent years. From facial recognition tools in smartphone Face ID, to self driving cars, the applications of neural networks have influenced every industry. This subset of machine learning is comprised of node layers, containing an input layer, one or more hidden layers, and an output layer. Each node is interconnected like human brain and has an associated weight and threshold. Suppose the output value of a node is higher than the specified threshold value, it implies that the node is activated and ready to relay data to the next layer of the neural network. There are various activation functions like Threshold function, Piecewise linear function or Sigmoid function.

Deep learning - Wikipedia


The word "deep" in "deep learning" refers to the number of layers through which the data is transformed. More precisely, deep learning systems have a substantial credit assignment path (CAP) depth. The CAP is the chain of transformations from input to output. CAPs describe potentially causal connections between input and output. For a feedforward neural network, the depth of the CAPs is that of the network and is the number of hidden layers plus one (as the output layer is also parameterized).

Technical Perspective: Why Don't Today's Deep Nets Overfit to Their Training Data?

Communications of the ACM

The following article by Zhang et al. is well-known for having highlighted that widespread success of deep learning in artificial intelligence brings with it a fundamental new theoretical challenge, specifically: Why don't today's deep nets overfit to training data? This question has come to animate the theory of deep learning. Let's understand this question in context of supervised learning, where the machine's goal is to learn to provide labels to inputs (for example, learn to label cat pictures with "1" and dog pictures with "0"). Deep learning solves this task by training a net on a suitably large training set of images that have been labeled correctly by humans. The parameters of the net are randomly initialized and thereafter adjusted in many stages via the simplest algorithm imaginable: gradient descent on the current difference between desired output and actual output.

Understanding Deep Learning (Still) Requires Rethinking Generalization

Communications of the ACM

Despite their massive size, successful deep artificial neural networks can exhibit a remarkably small gap between training and test performance. Conventional wisdom attributes small generalization error either to properties of the model family or to the regularization techniques used during training. Through extensive systematic experiments, we show how these traditional approaches fail to explain why large neural networks generalize well in practice. Specifically, our experiments establish that state-of-the-art convolutional networks for image classification trained with stochastic gradient methods easily fit a random labeling of the training data. This phenomenon is qualitatively unaffected by explicit regularization and occurs even if we replace the true images by completely unstructured random noise. We corroborate these experimental findings with a theoretical construction showing that simple depth two neural networks already have perfect finite sample expressivity as soon as the number of parameters exceeds the number of data points as it usually does in practice. We interpret our experimental findings by comparison with traditional models. We supplement this republication with a new section at the end summarizing recent progresses in the field since the original version of this paper. For centuries, scientists, policy makers, actuaries, and salesmen alike have exploited the empirical fact that unknown outcomes, be they future or unobserved, often trace regularities found in past observations. We call this idea generalization: finding rules consistent with available data that apply to instances we have yet to encounter. Supervised machine learning builds on statistical tradition in how it formalizes the idea of generalization. We assume observations come from a fixed data generating process, such as samples drawn from a fixed distribution. In a first optimization step, called training, we fit a model to a set of data.

Supervised Learning with Azure


Several steps need to be performed during the preparation phase to transform images/sounds into numerical vectors accepted by the algorithms. Regression on text data: Training data consists of texts whose numerical scores are already known. Several steps need to be performed during the preparation phase to transform the text into numerical vectors accepted by the algorithms. Examples: Housing prices, Customer churn, Customer Lifetime Value, Forecasting (time series), and Anomaly Detection.

Learn how to code in 2021 with training on the 12 most popular programming languages


The more dependent we become on apps, the more demand there'll be for skilled programmers. It just so happens that learning how to code is easier than ever in 2021. In fact, we've rounded up 12 amazing deals on courses and training programs that will teach you the skills you need to start creating your own software, and they're on sale for a limited time! Go, or GoLang, is Google's open-source programming language that's designed to simplify many programming tasks. This course is perfect for beginners, as Go is one of the fastest-growing languages in the industry thanks to its ease of use and familiar syntax.

Recent and forthcoming machine learning and AI seminars: February 2021 edition


Title to be confirmed Speaker: Fabio Petroni Organised by: Stanford MLSys Join the email list to find out how to register for each seminar. Title to be confirmed Speaker: Chad Jenkins (University of Michigan) Organised by: Robotics Today Watch the seminar here. Title to be confirmed Speaker: Samory K. Kpotufe Organised by: London School of Economics and Political Science Register here.